The MBNMS presents awards for outstanding research posters presented at the MBNMS Sanctuary Currents Symposium. The judges determine the specific kinds of awards to present each year based on the posters presented at the Symposium.
2000 Best Overall Poster
Pennington, J. Timothy (1), Reiko P. Michisaki (1), Carmen G. Castro (2), and Francisco P. Chavez (1)
1. Monterey Bay Aquarium Research Institute
2000 Best Thematic Poster
Benson, Scott R. (1), Andrew DeVogelaere (2), and James T. Harvey (1)
1. Moss Landing Marine Laboratories
2000 Best Student Poster
Brown, Jennifer A.
Department of Biology, University of California Santa Cruz.
Poster Session Abstracts
Ammann, Arnold J.
University of California at Santa Cruz.
Developing A Better Method For Quantifying Reef Fish Recruitment: The Smurf
Population dynamics of reef fishes have been examined using a variety of methods. Censuses of number and size of adults can be done using visual observations (i.e. transects) or some type of fishing method. Determining timing and magnitude of recruitment of juveniles into the adult population is more difficult but essential for understanding population dynamics and predicting future cohort strength. Researchers have used many methods in an attempt to measure recruitment success. These include visual observations, active capture methods (i.e. net tows), and passive capture methods (i.e. light traps). Although these methods can be quite successful they each have drawbacks associated with sampling error and effort (cost). I propose a novel method for estimating settlement of fishes by using discrete units of artificial structure that competent (i.e., ready-to-settle) pelagic juvenile fishes will choose to associate with. These standard monitoring units for the recruitment of fishes (SMURFs) have many advantages over other methods. Results of a pilot study done during the summer 1999, which evaluate many aspects of SMURFs, are presented. Ultimately, SMURFs could be used for estimating year to year variation in recruitment and cohort strength, this is important information for managing fisheries. Moreover, SMURFs could be used to estimate daily settlement which when compared to oceanographic conditions could determine if settlement is passive or active, and if active which parameters are important.
Anderson, Brian (1), John Hunt (1), Bryn Phillips (1), Ronald Tjeerdema (1), and Russell Fairey (2)
1) Department of Environmental Toxicology, UC Davis
Sediment Toxicity In Moss Landing Harbor
Moss Landing Harbor has been listed as a toxic hot spot by the California State Water Resources Control Board due to sediment contamination, toxicity, and bioaccumulation of pesticides in bivalve tissues. Repeated monitoring of harbor sediments as part of the California Bay Protection and Toxic Cleanup Program has indicated consistent extreme toxicity to the amphipod Eohaustorius estuarius in laboratory experiments. Harbor sediments are contaminated by moderate concentrations of a mixture of organochlorine pesticides (e.g., DDTs, chlordane), polynuclear aromatic hydrocarbons, and metals (e.g., copper, zinc). Laboratory manipulations of ML Harbor sediments have indicated that toxicity is caused by non-polar organic chemicals, and that survival of amphipods increases when these chemicals are bound with carbon. Results are confounded by the fact that detection of toxicity in ML Harbor sediments varies depending on the amphipod species used. For example, although these sediments are consistently toxic to Eohaustorius estuarius, experiments with a second amphipod, Ampelisca abdita, showed minimal toxicity using the same samples. This study explores the relationship between sediment contamination and amphipod survival, and presents results of experiments designed to identify chemicals of concern in Moss Landing Harbor sediments.
Andrews, Allen H. (1), Erica J. Burton (1), Donald E. Pearson (2), Gregor M. Cailliet (1), Kenneth H. Coale (1)
1) Moss Landing Marine Laboratories
Radiometric Age Validation Of The Bocaccio Rockfish, Sebastes Paucispinis.
Recent and historic longevity estimates for the bocaccio rockfish, Sebastes paucispinis, range from less than 20 yr to greater than 50 yr based on a variety of traditional ageing techniques (scales, otolith surface ageing, break and burn and transverse sectioning). Otoliths of bocaccio are difficult to read using these techniques and attempts to validate the periodicity of annulus formation have been unsuccessful using marginal increment analysis and oxytetracycline. Because the growth structure of otoliths suggest the bocaccio is long-lived, age was determined using the radioactive disequilibria of lead-210 and radium-226 in otolith cores of adult bocaccio. A combination of age estimates from break-and-burn and otolith weight as a proxy for age were used to place fish into age groups. In some cases radiometric age agreed with the estimates and others did not. Based on radiometric results bocaccio can live at least 24 years and may approach 37 years.
Andrews, Allen H. (1), Erik Cordes (1), Jonathan Heifetz (2), Melissa M. Mahoney (1), David Somerton (2), Gregor M. Cailliet (1), Kenneth H. Coale (1), and Kristen Munk (3)
1) Moss Landing Marine Laboratories
Age And Growth Of A Deep-Sea, Habitat-Forming Octocorallian (Primnoa Sp.) From The Gulf Of Alaska, With Radiometric Age Validation
Two nearly complete colonies of red tree coral (Primnoa sp.) collected from off southeast Alaska were provided for an analysis of age and growth characteristics. Growth zones were identified throughout the wood-like skeletal structure (gorgonin) and in the heavily calcified (marble-like) accretion found near the base of large colonies. Growth zones in the calcified region were made visible by thin sectioning and viewed through a dissecting microscope with transmitted light. The calcified base of the complete colonies terminated in a very large knob-shaped accretion. To view the growth pattern within the knob-shaped base without cutting, a CT scan was performed on the two colonies. The views created by these scans were spectacular and revealed that colonies consisted of multiple settlement events, where older basal structures provide for settlement of new colonies. A full limb from one colony was analyzed by taking several sections over the full length of the limb. At each sampling point, thin sections were cut to estimate age from growth zone counts. Contiguous to each section, a 3 to 6 cm piece was cut for radiometric age determination. Cores that appeared to be the first year's growth were extracted from these sections. Because exogenous 210Pb was present, the decay of 210Pb over the length of the colony was used to validate age estimates from growth zone counts. Preliminary results indicated the growth zones identified in sections were formed annually. Age estimates were as high as 89 yr for sections just above the heavily calcified base. Based on validated growth zone counts, growth of red tree coral ranged from 1.8 to 2.1 cm per year in height and was approximately 0.4 mm in radius per year.
1) Moss Landing Marine Laboratories
Can We Distinguish Between Natural And Anthropogenic Beach Deposition Events?
Marine birds and mammals are excellent indicators of ecosystem health because they are large, easily counted consumers of important prey species such as krill, anchovies, and squid. In May 1997, a beach monitoring study, designated Beach COMBERS (Coastal Ocean Mammal / Bird Education and Research Surveys), was established within the Monterey Bay National Marine Sanctuary (MBNMS) to obtain information on stranding rates for all species of seabirds and marine mammals. Between May 1997 and December 1999, Beach COMBERS volunteers recorded beachcast birds and mammals monthly along >50 km of sandy beaches within and around Monterey Bay. During that time, deposition of marine birds and mammals was variable, and two distinct peaks in deposition were evident. The first peak occurred in August 1997, and based on temporal and geographic patterns of deposition, species composition, the distribution of seabirds in the Bay, and patterns of fishing effort in the halibut set gillnet fishery, we conclude that fishery bycatch was the most likely cause. By contrast, the deposition event of 1998 was broader in time and space and affected a wide assemblage of marine bird and mammal species. These patterns, combined with oceanographic data, suggest that environmental conditions related to El Niño were likely the culprit. No major depositional peaks were observed during 1999, indicating that the ecosystem was less stressed by natural and anthropogenic factors in that year. By combining Beach COMBERS data with information from other sources, including at-sea surveys, fishing records, pathological examinations, and oceanographic data, this program has become a valuable tool for detecting and differentiating human-caused and natural mortality events within the MBNMS.
Benson, Scott R. (1), Donald A. Croll (2), Baldo Marinovic (2), Francisco P. Chavez (3), and James T. Harvey (1)
1) Moss Landing Marine Laboratories
Temporal Variability In The Cetacean Community Of A Coastal Upwelling System Spanning An El Niño Event
The world's most productive fisheries and marine mammal foraging areas are located in coastal upwelling centers. Temporal variability in strength of upwelling can affect primary production, zooplankton productivity, and the distribution and abundance of fish and marine mammals. In this study, we report on ecosystem studies in Monterey Bay, California during the summer upwelling periods of 1996-98, including impacts of the 1997/98 El Niño. We combine monthly line-transect surveys for marine mammals along random-systematic lines, hydrographic stations, zooplankton net tows, and hydroacoustic surveys of zooplankton backscatter with data from the Monterey Bay Aquarium Research Institute biological oceanographic monitoring program to examine the impacts of the 1997/98 El Niño event on higher trophic levels in Monterey Bay. The abundance of several of the California Current's most common cetaceans varied among years. As temperatures warmed throughout the period, the temperate Dall's porpoise, Phocoenoides dalli, decreased in abundance and the sub-tropical common dolphins, Delphinus spp., increased in abundance, mirroring oceanographic patterns. Rorquals responded strongly to El Niño conditions. A sharp drop in abundance occurred between 1996 and 1997 as zooplankton productivity decreased. In 1998, while zooplankton volume slowly increased, rorqual abundance sharply increased to the highest observed abundance. We hypothesize that a dramatic reduction in productivity offshore concentrated rorquals in the remaining productive coastal upwelling areas, including Monterey Bay. These patterns exemplify short-term responses of cetaceans to large-scale changes in oceanic conditions and demonstrate the importance of coastal upwelling systems to higher trophic level predators.
Department of Biology, University of California Santa Cruz.
Can Elemental Composition Of Otoliths Be Used To Determine Nursery Habitat Use By Juvenile Flatfish?
The chemical composition of otoliths may act as a permanent record of the environmental conditions experienced by fish. I examined the utility of otolith chemical composition as a natural tag of the nursery grounds inhabited by young-of-the-year English sole Pleuronectes vetulus and speckled sanddab Citharichthys stigmaeus. Juveniles were collected from multiple estuarine and coastal sites along the central California coast during July - September 1998. Discriminant functions, based on the trace element composition of the otoliths, correctly classified fish to habitat type (estuarine or coastal) and to specific estuaries with greater than 80% accuracy for both species. The temporal and spatial consistency of these findings will be tested with juveniles collected from a larger number of sites during the summers of 1999 and 2000. Based on these preliminary findings, this method could be used to determine the nursery habitats of adult flatfish and, thus, the relative importance of estuarine and coastal nursery habitats to adult populations.
Burton, Robert K. (1), J. Josh Snodgrass (2), Diane Gifford-Gonzalez (3) and Paul L. Koch (3)
1) Moss Landing Marine Laboratories
Variations In The Ecology Of Pinnipeds From Central California: From The Middle Holocene To The Present Day
The site of the new Moss Landing Marine Laboratory was occupied by humans more than 7000 years ago, and they left behind the remains of the animals they preyed on. The most abundant marine mammal at this site were northern fur seals (Callorhinus ursinus), which are now very rare on the central California coast. At present, this species breeds exclusively on offshore islands, primarily at high latitudes; the only known exceptions are 2 small colonies formed recently on islands off California. Females and juveniles from the Alaskan rookeries do migrate south to forage along the shelf slope break, but typically occur at low densities ~100 km from the coast. We use stable isotope analysis to demonstrate that northern fur seals from the middle Holocene of California, foraged offshore as they do today, yet unlike their modern conspecifics remained at middle latitudes throughout the year. We use archaeofaunal analysis to demonstrate these animals bred on the mainland, and that middle latitude mainland rookeries were numerous. In deposits younger than ~1000 BP however, northern fur seal remains are less abundant, and sea otter and harbor seal remains dominate archaeofaunas. This kind of historical information is needed to model the ecological dynamics of top marine consumers, and of marine ecosystems as a whole, in relation to long-term climatic cycles. Likewise such data are necessary to unravel the complexities of how marine ecosystems have been altered by humans over longer time spans, and how human actions have affected the current distribution of other species such as the northern elephant seal, which is virtually nonexistent in ancient sites north of the Channel Islands.
Caffrey, J.M. (1), S. Shaw (2), M. Silberstein (2), and K. Thomasberg (3)
1) Institute of Marine Science, UCSC, Santa Cruz
Effects Of Changing In Agricultural Practices On Dissolved Nutrient Concentrations In Elkhorn Slough, California
Agriculture represents about 22% of the land-use within the Elkhorn Slough watershed. The dominant crops include strawberries, artichokes and cut flowers, which are all intensively fertilized. Many farms extend to the edge of the marsh so there is a relatively narrow buffer between farm and Slough. Long term monitoring data from two regions (Bennett Slough and Azevedo Ponds) which receive farm runoff and have similar land-use are compared. Nitrate concentrations in both regions were usually less than 32 µM, although peak concentrations during winter runoff often exceeded 100 µM. Ammonium and dissolved phosphate concentrations were comparable in the two regions averaging 6 µM and 10 µM, respectively.
Carr, Mark H. and Arnold Ammann
Department of Ecology and Evolutionary Biology, University of California, Santa Cruz
Contrasting Effects Of La Niña And El Niño On Recruitment Of Juvenile Rockfishes
Understanding how and why populations and communities change over time is one of the greatest challenges to marine ecologists and fisheries biologists alike. Such knowledge is crucial to distinguishing anthropogenic from natural causes of change in populations or communities. Critical to this goal is recognizing how life history traits influence how populations respond to environmental variation. This was made very clear by the observed responses of rockfish recruitment to recent environmental changes experienced between the El Niño of 1998 and the La Niña of 1999. We surveyed rockfish recruitment visually by counting young (< 8 cm long) rockfish in kelp beds along the coast of Monterey during the summers of 1998 and 1999. We also created plots of giant kelp plants and monitored year-to-year recruitment to these controlled habitats. During El Niño conditions, shallow dwelling rockfishes such as gopher, kelp, and black and yellow rockfish recruited in great numbers. At the same time, recruitment of juvenile blue, black, olive, yellowtail and boccacio rockfish was poor. However, the pattern was completely reversed the following year under La Niña conditions. The marked change in recruitment of the kelp-associated species to kelp plots indicates that such changes are not based on changes in the amount of kelp. These observations indicate not only how such climatic events contribute to year-to-year changes in replenishment of reef fish populations, but also how species respond very differently to such events. Such changes in the relative strength of recruitment among species can influence the structure of reef fish assemblages.
Castleton, Michael R.
California State University Monterey Bay
Depth And Substrate Preferences Of Sexually Immature Preadult Cabezon(Scorpaenichthys Marmoratus) In Point Lobos Marine Reserve
With the recent boom in the live-fish industry, nearshore ecosystems that were once relatively unfished are now experiencing heavy fishing pressure. From 1994 to 1997, live-fishery landings for the state of California went from estimated values of 408 metric tons (MT) to 617 MT, an increase of 51%. The cabezon (Scorpaenichthys marmoratus) was first targeted by live-fishermen in 1994. Since then fishing pressure has been on the rise. From 1996 to 1997 there was a 115% increase in cabezon landings. A major problem with the cabezon fishery is the size of the fish being taken. Preliminary data from the California Department of Fish and Game shows that along the Big Sur coast, from Pfeiffer Point to Salmon Cove, the average size of fish caught during the period of October 1997 to October 1998 was 379 mm total length. This size meets the state's minimum requirement of 356 mm, but it's on the lower end of the range at which cabezon mature, and in general it will only be males that have reached maturity by that length. This puts cabezon populations at an unnecessary risk due to fishing pressure. The lack of effective regulations on the live-fishery and cabezon in particular is due in part to insufficient knowledge of species habitat associations and how they change with age. Extensive searching of the literature reveals only unsupported assumptions about habitat associations. The purpose of this is to quantify the depth and substrate preferences of sexually immature, pre-adult cabezon. If discreet areas of habitat can be linked to these non-reproductive fish then these results will have clear policy implications for regulating local fisheries and maintaining a healthy population of cabezon.
Castro, C.G. (1,2), F.P. Chavez (2) and C.A. Collins (1)
1) Naval Postgraduate School, Monterey, CA
Hydrographic And Chemical Conditions During The 1997-98 El Niño Off Central California
From March-97 to November-98, during the strong El Niño event, six oceanographic cruises were made off Monterey Bay to study the structure and temporal variability of the hydrographic and chemical properties of the water column from the coast to a distance of 300km offshore and to 1000m. Comparison of the average fields from these cruises with mean fields, during Non-Niño conditions, shows that the largest anomalies are found in the first 200m. Warmer temperatures during El Niño cruises are associated with lower salinities (S <-0.05) and decreasing nutrient levels (NO3 <-2 µmol-l-1 and SiO2 < -2 µmol-l-1). The lowest salinities are found close to the coast, probably due to intense continental runoff and stronger advection of Subartic waters, and the highest temperature anomalies (> 1.5° C) are found offshore (~200km). At deeper levels (~ 600m), a core of relatively low temperature (T < 0.1°C) and high silicate (SiO2 >1 µmol-l-1), probably of northern origin, is the most striking feature. Temporal variability was also studied based on the anomalies from each cruise, obtained by subtracting the monthly Non-Niño average. In the upper 200m, the variability is strongly determined by the warm, fresh anomalies, which extend further offshore from September-97 to August-98. At deeper waters, the core of low temperature and high silicate water, confined to the slope, is a recurrent structure from September-97 to August-98. However, it shifted offshore in November-98, just after the end of the El Niño event.
Clark, Kit C., Amy Little, Baldo Marinovic, and Francisco Chavez
Onshore/Offshore Distribution Of Larval Euphausiids Off Central California During A Period Of Intense Upwelling
Ecosystems along the California current system largely revolve around seasonal winds, hydrography, and current patterns. Monterey Bay populations of two predominant krill species, Euphausia pacifica and Thysanoessa spinifera, shed larvae in conjunction with periods of strong spring upwelling and pulses of dense phytoplankton blooms. Environmental conditions affecting larval growth (temperature, food availability, advection, etc.) may reflect spawning strategies of gravid females both spatially and temporally. Nearshore spawning directly following upwelling bursts ("relaxed states"), as well as the convergent flow of oceanographic fronts, may minimize the advective loss of eggs and larvae offshore. Such spawning strategies could also insure that planktotrophic larvae emerge during periods of increased phytoplankton abundance--an indicator of recently upwelled water. Daytime surface swarms of reproductively active krill are thought to signify spawning events. Here we present preliminary data on the onshore/offshore distribution and abundance of euphausiid larvae in relation to oceanographic parameters during a period of intensive coastal upwelling. Additionally, we explore the ramifications of nearshore spawning and swarming of reproductively active krill during times of intense upwelling and relaxed states. Daytime surface swarms of E. pacifica and T. spinifera were observed throughout the months of April and May, coinciding with periods of intense upwelling in Monterey Bay. Surface dip-net samples on May 23rd and 24th reflect reproductively mature adults of both species. In addition to a hydrographic survey of CalCOFI line 67 (nearshore Monterey Bay to 250 km's offshore) during May 24th-27th, zooplankton was collected from the upper 200 meters of the surface. Offshore stations reflected large cohorts of larval euphausiids as a result of strong wind forcing and ekman pumping of newly upwelled water. All larvae followed direct developmental pathways, indicating optimal growth conditions. Accumulations of larvae were further associated with distinct oceanographic fronts and peaks in chlorophyll a. Nearshore samples revealed signs of reproductively active individuals, while offshore samples were relatively absent of reproductively active adult krill.
Cochran, Susan A.
Dept. of Ocean Sciences, University of California Santa Cruz
Hyperspectral Techniques For Ecosystem Monitoring In Elkhorn Slough
Studies in terrestrial systems have shown that reflectance spectra of higher plants are sensitive to a variety of stresses, and that such rapid and easily detectable spectral changes are powerful indicators of both acute and chronic environmental stress. Although hyperspectral imaging methods have been used in terrestrial systems for years, there have been few applications in coastal systems. Coastal zones contain some of the most biologically diverse and productive ecosystems on earth. However, these habitats are under risk from increased anthropogenic activity. It is necessary to establish baseline conditions, map development, and monitor its effects, so that efficient environmental management practices can be designed. This study evaluates the use of hyperspectral imaging spectroscopy techniques for identifying, mapping, assessing, and monitoring natural and anthropogenic effects on coastal and shallow marine ecosystems. Specifically, it involves the integration and analysis of AVIRIS (Airborne Visible/InfraRed Imaging Spectrometer) imagery, along with hand-held spectrometry, to investigate the terrestrial aquatic interface zone of Elkhorn Slough. AVIRIS imagery was analyzed to create basic ground cover distribution maps and search for patterns of stress in vegetation. New spectral information of estuarine and aquatic plants, and other ground coverages, was collected at a higher spatial resolution with a hand-held spectroradiometer.
Collins, C. (1), F. Chavez (2), S. Ramp (1), J. Paduan (1), R. Maffione (3), L. Rosenfeld (1), D. Fernandez (4), F. Bahr (1), C. Whelan (4), D. Barrick (5), C.-S. Chiu (1), C. Miller (1), J. Vesecky (6), N. Garfield (1), I. Shulman (7), J. Kindle (8), E. Rienecker (2), C.-R. Wu (7), R. Durazo (1), C. Teague (6), M. Cook (1), C. Fayos (1), and M. Stone (1)
1) Naval Postgraduate School
Monterey Bay's Innovative Coastal-Ocean Observing Network (Icon)
The Innovative Coastal-Ocean Observing Network, ICON, is a partnership of government, academic, and industrial entities funded by the National Ocean Partnership Program (NOPP). Its goal is to bring together modern measurement technologies, to develop new technologies, and to integrate them within a data assimilating coastal ocean circulation model. Data is currently being collected in near real-time from moorings, tomographic arrays, and land-based HF radars. Variables measured include temperature, salinity, water and wind velocity, and bio-optical properties. These measurements, together with other data acquired via ship and satellite, are being integrated into a cohesive picture of the coastal environment in Monterey Bay, California. The goal of this project is to demonstrate both the scientific and societal applications of such an integrated system, and to evaluate the minimum suite of instrumentation necessary to successfully constrain the numerical model. (see: www.oc.nps.navy.mil/~icon)
Downing, J. W. (1), Fairey, R. (1), Roberts, C.A. (1), Clark, R.P (2), Hunt, J. (3), Anderson, B. (3), Phillips, B. (3), and Tjeerdema, R. (3)
1) Moss Landing Marine Laboratories
Pilot Study For Synoptic Water Quality Monitoring In An Urban/Agricultural Watershed
Sediment and water were tested at seven stations in the lower reaches of the Tembladero watershed (Monterey County, California, USA) as a pilot study for monitoring many such urban/agricultural drainages in the region. Stations were selected at confluences to the Tembladero slough above its drainage into Moss Landing Harbor at the Sandholdt Bridge. Chemical and toxicological tests were done, including sediment organic chemistry and SEM/AVS analyses, water nitrate and TSS analyses. Water was tested for presence and relative concentrations of organochlorine pesticides using semipermiable membrane devices (SPMDs). Bulk phase sediment (Eohaustorius estuarius or Hyalella azteca) and water column (Ceriodaphnia sp. or Holmesimysis costata) toxicity tests were done at all stations. The most abundant metals were chromium and nickel, and the most abundant pesticides were Dieldrin, DDT, and Chlordane. The highest pesticide values (SPMD and Sediment) and strongest toxic responses were measured at the most upstream station. In general, water was toxic higher in the watershed, while sediment exhibited toxicity lower in the watershed. Results suggest that the watershed is acting as a sink as well as a source of pollutants for the Moss Landing Harbor. Recommendations for further investigation will be discussed.
DiGirolamo, Lisa A. and Laurel R. Fox.
Biology Deparment, University of California, Santa Cruz.
Invasion Rates And Consequences Of The Argentine Ant, Linepithema Humile
Invasions create perturbations that may modify interactions and composition of native communities. The invasive Argentine ant (Linepithema humile) causes agricultural losses and the extinction of native ants, which are extremely important in structuring communities. Our project documents the Argentine ant invasion at the UC Natural Reserve at Fort Ord and examines the indirect effects on plants of the displacement of native harvester ants. The Reserve is an urban/natural interface, with oak woodland, maritime chaparral and coastal grasslands, and is being invaded on the 3 sides abutting development. Within the past year, the front moved 270m on the eastern boundary, across all community types, while both the southern and western sides have stable fronts, ~50m inside the Reserve. We also documented seasonal variations in the invasion front. The Reserve has a unique ant fauna, but only one species co-exists with Argentine ants. We have documented local extinctions of native ants as the eastern front moves across the Reserve. We are also documenting the indirect changes in seed abundance as the Argentine ants cause local extinctions of the harvester ant guild.
Fernandez, D. (1), J. Paduan (2), J. Vesecky (3), C. Teague (4), C. Whelan (1), K. Laws (3), and P. Hansen (5)
1) California State University, Monterey Bay
Icon High-Frequency Radar Deployments In Monterey Bay Region
As a part of the Innovative Coastal Ocean Network (ICON), a total of seven high-frequency radar systems have been deployed and maintained within the Monterey Bay area. These systems are designed to measure the near-surface ocean current, but some can also be used to glean information on the near-surface vertical current shear and wind direction. Existing deployments include Santa Cruz, Moss Landing, Monterey, Carmel Highlands, and Big Sur. Measurements made from several of these deployments begin as early as 1994. This represents one of the largest deployments and data sets ever collected with this type of instrument. Goals of this network include analysis of long- and short-term variability in Monterey coastal waters and application of the data collected to improve regional numerical circulation models.
Eittreim, Stephen L., Roberto J. Anima, Andrew J. Stevenson, Brian D. Edwards, and Pat S. Chavez
USGS, Menlo Park, CA 94025
New Findings And Curiosities From Detailed Mapping of The Monterey Bay Continental Shelf
Side-scan sonar coverage of the Santa Cruz shelf has revealed details of bedrock outcrops, discrete deposits of coarse sands, and the ubiquitous cover of Holocene muds. Bedrock outcrops occur on the inner- and outer parts of the shelf, with a mid-shelf Holocene mudbelt in between. This outcrop pattern is a product of the continuing uplift of the Santa Cruz mountains, the recent 100-m rise of sealevel, and the prevailing supply of muds to the shelf. The time since the post-glacial rise in sealevel has apparently not been long enough for the volume of mud supplied to fill up the approximately 50-m of accomodation space on the shelf.
Forney, Karin A.
Southwest Fisheries Science Center, National Marine Fisheries Service
Interpreting Trends In Cetacean Abundance: Human-Caused Changes Vs. Natural Variability
Trends in population abundance are often used to monitor species affected by human activities. However, for highly mobile species in dynamic environments, such as cetaceans in the marine realm, natural variability can confound the ability to detect and interpret trends in abundance. Natural variability can cause dramatic shifts in the distribution of cetaceans, and thus, abundance estimates for a fixed region may be based on a different proportion of the population each time. This decreases statistical power to detect trends and introduces uncertainty whether apparent trends represent true changes in population size or merely reflect natural changes in the distribution of cetaceans. To minimize these problems, it may be possible to account for environmental variability analytically by including models of species-environment patterns in trend analyses, but this will only be successful if such models have interannual predictive power. In this study, generalized additive models (GAMs) of cetacean sighting rates in relation to environmental variables are developed and evaluated for two widely distributed odontocete species, Dall's porpoise, Phocoenoides dalli, and short-beaked common dolphins, Delphinus delphis, using data from shipboard surveys conducted in 1991, 1993 and 1996 off California. Results show that sighting rates for these two species are variable and can be partially accounted for by environmental models; however, additional surveys will be required to adequately model species-environment relationships. If patterns are consistent across years, GAMs may represent an effective tool for reducing uncertainty caused by environmental variability, and for improving our ability to detect and interpret trends in abundance.
Forney, Karin A. (1), Scott R. Benson (2,3), and Grant A. Cameron (1)
1) Southwest Fisheries Science Center, National Marine Fisheries Service
Central California Gillnet Effort And Bycatch Of Sensitive Species, 1990-98.
During the 1980s, extensive bycatch of seabirds and marine mammals in central California's set gillnet fisheries prompted a series of area and depth closures, which ultimately appeared successful at reducing mortality of the species of primary concern, Common Murre (Uria aalge), sea otter (Enhydra lutris) and harbor porpoise (Phocoena phocoena). The effects of the restrictions, however, were confounded with changes in the distribution and intensity of fishing effort during the early 1990s. This study documents 1990-98 patterns of fishing effort in the central California halibut (Paralichthys californicus) gillnet fishery and presents information on bycatch of the above three species. A National Marine Fisheries Service observer program obtained bycatch data from 1990 to 1994, but was discontinued after 1994. Since then, gillnet effort has increased and shifted into the southern areas of Monterey Bay, where bycatch was high during the 1980s. The recent increase in gillnet effort coincides with higher beach deposition rates for all three species. In this study, historical entanglement rate data are combined with estimates of fishing effort for 1995-98 to produce several sets of mortality estimates based on a variety of assumptions. Without further data, it is not possible to validate most of the assumptions. The range of total mortality estimates for the 4-year period 1995-98 is 5,918-13,060 Common Murres (s.e. 477-1,252), 144-662 harbor porpoises (s.e. 18-53) and 17-125 sea otters (s.e. 4-25), raising concern for all three species. The recent changes in fishing effort and distribution underscore the importance of monitoring variability in both fishing practices and the distribution of vulnerable species when evaluating longterm fishery impacts.
Green, Phaedra M., Franklin B. Schwing, and Tom Murphree
Pacific Fisheries Environmental Laboratory, National Marine Fisheries Service, Pacific Grove
The Extratropical Northern Oscillation Index (NOIx): A New Index Of Environmental Variability For The Northeast Pacific
Prior studies of annual cycles and warm and cold ENSO events have shown that the North Pacific High (NPH) pressure system is an important indicator of climate variability in the northeast Pacific Ocean (NEP). On a basin scale, this stems from the NPH's role in the north Pacific's Hadley-Walker atmospheric circulation, which links the NEP to the tropics. On a smaller scale, this stems from the NPH's role in surface wind stress over much of the NEP, which drives coastal upwelling in the Monterey Bay National Marine Sanctuary. A strong correlation between the Southern Oscillation Index (SOI) and NPH on interannual to decadal scales led us to develop a North Pacific equivalent of the SOI. The extratropical Northern Oscillation Index (NOIx) is the sea level pressure anomaly from climatology at the annual mean position of the NPH (35N, 135W) minus the pressure anomaly at Darwin, Australia. It relates variability in the teleconnections between equatorial and midlatitude Northern Hemisphere regions. The NOIx seems to be a better indicator of NEP variability then the SOI due to the proximity of the NPH, plus a connection to a tropical location (Darwin) that encompasses zonal and meridional processes, including variations in the north Pacific trade winds. We explore the connection between the NOIx and a number of atmosphere and ocean variables (e.g. SST, winds, and precipitation) for regional to global scales, and evaluate the utility of the NOIx as an index of ecosystem climate change in the Sanctuary and for the NEP.
Greig, Denise and Jim Harvey
Moss Landing Marine Laboratories
Pregnant Harbor Seals Captured In Elkhorn Slough, Ca
An increasing number of harbor seals have been resting on tidal mudflats in Elkhorn Slough, CA. To better understand their population growth and structure we used circulating hormone levels of progesterone and estrogen to detect pregnancy. From September 1998 through March 1999, thirteen adult female harbor seals were captured in the slough. Hormone levels were measured from blood samples taken at the time of capture, and visible hat tags with unique numbers were glued to the pelage of the animals. To monitor marked animals and record total numbers of seals ashore, boat surveys of the slough were conducted throughout the pupping season. The first pup was sighted 3/22/99 and a peak number of 36 pups was observed on 5/11/99. Total numbers of seals ranged from 34 to 194. Of the 13 tagged seals, 4 remained in the slough to give birth, and 2 remained in the slough throughout the pupping season, but were never spotted with a pup. Two were never relocated after capture, and 5 were observed in the slough leading up to, but not during, the pupping season. Mean progesterone concentration for 4 pregnant seals was 115.522 nmol/L (± 25.617 SE), and was significantly greater than the mean of 9.070 nmol/L (± 2.081 SE) for 4 seals that probably were not-pregnant (t-test df=3, p=0.025). One smaller animal with a relatively high progesterone concentration, who was often present in the slough, was never seen with a pup. Progesterone level may be a better predictor of pregnancy when combined with body mass. Seals who vacated the slough may have traveled to more traditional pupping beaches off Monterey and Point Reyes to give birth. As numbers increase, a greater percentage may remain in Elkhorn Slough with their pups.
Henkel, Laird A. and Josh Adams
Moss Landing Marine Laboratories
Distribution Of Marbled Murrelets In Monterey Bay, California
The Marbled Murrelet (Brachyramphus marmortatus) is a small seabird federally listed as threatened. Marbled Murrelets are regularly observed in northern Monterey Bay, California, yet few directed surveys have been conducted in the area. Information on winter distribution in Monterey Bay is particularly lacking. Knowledge of winter distribution of Marbled Murrelets is important for the conservation of the species. Monterey Bay is approximately 20-km south of the southernmost breeding area of murrelets. Birds from this southern sub-population probably move into the protected waters of Monterey Bay in winter months. We conducted 20 line-transect surveys in Monterey Bay between February 1999 and February 2000. Most murrelets moved into northern Monterey Bay in November, and departed in April. Direct counts of murrelets exceeded 100 birds on several winter surveys. The total number of birds using northern Monterey Bay in winter may exceed 300. Creek and river plumes and tidal and rip fronts may affect the distribution of murrelets. We also summarize historic and opportunistic sightings of murrelets in Monterey Bay, and discuss specific locations of importance to the species.
Hunt, J.W. (1), B.S. Anderson (1), B.M. Phillips (1), V. DeVlaming (2), and K. Worcester (3)
1) University of California, Davis, CA
Toxicity In Runoff From Two Monterey Bay Watersheds: Implicated Chemicals And Tributary Sources.
Of the three large river systems flowing to Monterey Bay, the Salinas and Pajaro Rivers each drain significant urban and agricultural areas capable of contributing toxic runoff. Studies are being conducted in both watersheds to identify causes of water quality impairment and to locate sources of toxic runoff. Stations located in the lower reaches and tributaries of both rivers were sampled repeatedly to measure ambient toxicity and concentrations of selected chemical contaminants. In the Pajaro River, 78% of agricultural drain samples, 25% of tributary slough samples, and 11% of river and estuary samples were toxic to resident mysid crustaceans in laboratory exposures. Organophosphate pesticides were detected in Pajaro River samples collected during low flow, and potentially toxic concentrations of persistent hydrophobic organochlorine pesticides were detected after high surface runoff. In the Salinas River watershed, a tributary draining agricultural surface runoff was consistently toxic, while tributaries fed by subsurface tile drains were toxic much less often. Toxicity identification evaluations (TIEs) indicated that the organophosphate pesticides chlorpyrifos and diazinon were responsible for recurrent toxicity in tributary streams, and these compounds were also present in elevated concentrations when toxicity was observed in the main Salinas River.
Jaffe, Bruce (1), Curt Storlazzi (2), and Don Canestro (3)
1) Coastal and Marine Geology, US Geological Survey, Menlo Park
Comparison Of Nearshore Environmental Conditions During The Spring And Fall Near Davenport, Ca
Nearshore oceanographic conditions directly affect biologically important processes such as spore and larval dispersal and settlement. Environmental conditions are primarily controlled by waves and winds, which vary seasonally. A shallow-water instrument package was deployed near Davenport in a sand-filled channel in 12-m water depth approximately 500-m offshore to document seasonal changes in environmental conditions and sediment transport. The package included sensors to measure water temperature and salinity, flow, waves, and water depth. Sensors were mounted near the seabed (within 1 m) on a pipe jetted into the bottom. Data from these instruments were recorded each hour. High-quality data were collected during month-long deployments in May and November 1998. Wind data measured at Long Marine Lab during the experiments were obtained from the REINAS project. The central California coast is a high-energy environment that may be subject to large waves during all times of year. In May, five wave events with deepwater significant wave heights greater than 3 m impacted the study site; the largest significant wave height was more than 4 m. Refraction and bottom dissipation reduced the height as waves traveled to shore. Significant wave height at the experiment site during events was still large, but less than 2 m. During events, oscillatory flows were moderate to strong (standard deviation of 0.5 m/s). In November, 7 wave events with deepwater significant wave heights greater than 3 m impacted the study site; the largest significant wave height was more than 7 m. Maximum significant wave height at the experiment site was greater than 4 m. During events, oscillatory flows were strong (standard deviation of 1 m/s). Maximum near bed (0.2 m above the bed) currents were weaker than expected (less than 0.15 m/s) during both spring and fall; although, spring currents tended to be stronger. Stronger currents in the spring were caused by more persistent, stronger winds exerting more drag on the water column. Spring winds also created upwelling and downwelling events measured by sensors at the site. These events resulted in greater variability in water temperature (9.5 to 14.1 deg. C in May vs. 10.5 to 13.5 deg. C in November). Salinity was also more variable during the spring deployment. Springtime is a period of greater water property variability and stronger mean flows; fall has larger waves, which result in greater oscillatory flows near the seabed. These differences have strong implications to seasonal variability of biological processes in the nearshore of the open coasts of the Monterey Bay Marine Sanctuary.
Kaplan, K. Brynie
Moss Landing Marine Laboratories, Chemical Oceanography and Invertebrate Zoology
The Invasive Asian Clam Potamocorbula Amurensis : Effects On Geochemical Flux In South San Francisco Bay, California.
Estuaries are dynamic and unique habitats which act as transition regions between terrestrial and marine environments, and as receiving waters for many anthropogenic compounds. Chemical flux, as influenced by sediment geochemistry and biota, can dramatically effect overlying water concentrations of metals and nutrients within an estuarine system. Benthic filter feeders and their mediation of processes such as contamination transfer, biomagnification, and bioturbation have a major influence on the transport of materials across the sediment/seawater interface. Of particular concern in South San Francisco Bay, California is the invasive Asian clam Potamocorbula amurensis, and its role as an accelerator of contaminant transfer to higher trophic levels, including organisms consumed by humans. The purpose of this study was to evaluate the benthic community in South San Francisco Bay, with specific focus on P. amurensis and its effect on chemical and nutrient fluxes. Using benthic flux chambers, the effects of P. amurensis on phytoplankton standing stock, benthic respiration, and particulate carbon/nitrogen removal rates were measured. Other benthic macrofaunal species were also collected, counted, and weighed to compare total respiratory biomass to that of P. amurensis, and to estimate the effects of these organisms on geochemical flux. During a period of low food availability (2-3 µg chl a /L seawater) and low densities (700 individual clams/m2), P. amurensis did not significantly increase fluxes of POC, PON, or chlorophyll a. The clams did, however, contribute to higher benthic respiration rates and higher fluctuations of suspended POC and PON concentrations. It is estimated that low filtration rates are common for much of the year (non-bloom conditions when food availability is low), but should increase dramatically during spring phytoplankton bloom periods when high food availability and quality stimulate filtration. The role of P. amurensis in benthic flux is therefore episodic depending on the time of year and food availability in the water column. As such, removal rates by P. amurensis may be important for accelerating the transport of both carbon and associated anthropogenic contaminants to the sediments during bloom conditions in the South San Francisco Bay.
Keiper, Carol A. (1), David G. Ainley (2), Sarah G. Allen (3), and James T. Harvey (1)
1) Moss Landing Marine Laboratories
Marine Mammal Sightings In Association With Upwelling Off Central California 1986-1999
Relationships between marine mammals and hydrographic features off central California from Bodega Bay to Monterey Bay 1986 -1999 (except 1995-96) were investigated using a Geographical Information System (GIS) Arc/View Spatial Analyst. Data were collected using standard strip transect methodology. Marine mammal sightings and sea surface isotherms derived from shipboard data were mapped; AVHRR images for 1993 and 1994 were overlaid with isotherm data to validate the location of upwelling regions. Preliminary analysis indicates that the spatial and temporal distribution of marine mammals changed relative to surface hydrographic features associated with coastal upwelling. Regions of maximum upwelling and coincident cold-water plumes were identified near Point Reyes and Point Año Nuevo. GIS measurements document a persistent, relatively large upwelling plume (mean 2110 sq.km (1005 sq.km, n=12 ) near Pt. Reyes that varied from 4.7 to 23 percent of the survey area during late spring in all years. The Point Año Nuevo upwelling plume was only 0.06 to six percent of the survey area (mean 191 sq.km. (286 sq.km n=8 ) and occurred in 8 of the 12 years during the survey periods. Although sightings of marine mammals occurred more frequently within upwelling zones in eight of 12 years, these results were not statistically significant (Mann-Whitney, U 0.05(2),12,12=107, P=.45). Within these zones, cetacean sightings were greater than pinniped sightings in seven of 12 years, whereas pinniped sightings were greater than cetacean sightings in the 1992-93, and 1997-98 El Niño years. Sixty-three percent of the pinniped sightings within upwelling zones were California Sea Lions (Zalophus californianus), 41 percent of the cetacean sightings were Dall's Porpoise (Phocoenoides dalli) and 22 percent were Harbor Porpoise (Phocoena phocoena) during the survey period. These results document distinct temporal and spatial patterns in the distribution of marine mammals relative to ephemeral upwelling plumes off central California.
Kvenvolden, K.A., R.J. Rosenbauer, F.D. Hostettler, and T.D. Lorenson
U.S. Geological Survey, Menlo Park
Coastal Tar Residues On The Shoreline Of The Monterey Bay National Marine Sanctuary
Tar residues are common on the coastline of the Monterey Bay National Marine Sanctuary (MBNMS). These coastal tar residues washed ashore and usually are found on rocky headlands near high-tide lines. In this study, we determined stable carbon-isotope compositions and values of selected biomarker ratios in order to characterize the tar residues. All of the residues are 13C-enriched, spanning a narrow range (delta 13C = -22.2 to -23.4), and contain the specific biomarker 28,30-bisnorhopane. These same geochemical characteristics are diagnostic of crude oils from the Miocene Monterey Formation from which the coastal tar residues were likely originally derived. However, the specific history of these coastal tar residues is not yet understood. Potential sources such as local seeps, local tar-saturated sands, and in-situ tar residues in local rocks were examined, but the samples do not correlate geochemically with any of the coastal tar residues. Statistically, these residues can be organized into three groups, each of which may represent a different event such as an undiscovered natural seep or a past oil spill. Accounting for the origin of these coastal tars in MBNMS may aid in understanding the history of coastal tars elsewhere and may help in the identification of sources of future oil spills.
Ladizinsky, Nicolas and G. Jason Smith
Moss Landing Marine Laboratories
Domoic Acid And Metals: The Function Of Domoic Acid In Copper Homeostasis In Pseudo-Nitzschia Spp. From Monterey Bay, Ca.
Specific environmental cues responsible for stimulating the accumulation of domoic acid (DA in Pseudo-nitzschia spp. are poorly defined, although some evidence indicates that elevated metal concentrations can induce DA accumulation (Subba Rao et al. 1998 P.S.Z.N. Mar. Ecol. 19:31). Other algal species have been observed to produce proline (an amino acid structurally analogous to DA) in response to elevated copper concentrations, suggesting a possible complexation strategy since proline exhibits chemical characteristics found in many unidentate ligands. As part of our ongoing studies investigating the interrelationship of proline and DA metabolism, we are evaluating the response in DA pools during exposure of Pseudo-nitzschia spp. to varying total copper availability, ranging from limitation to toxicity. Copper enrichment experiments indicate that cultures of Pseudo-nitzschia multiseries strain MU5, when exposed to elevated total copper concentrations [Cu] in media (0.160 µM to 16.0 µM), exhibit cell yields two to three times greater than those grown in standard f/2 media; Pseudo-nitzschia australis strain AU43demonstrate no such covariance in growth with copper enrichment. The production of DA was not induced by elevated [Cu]. However, differences in growth response between the two strains was associated with MU5 having a 100 fold greater DA concentration, relative to total amino acids, compared to AU43. Domoic acid contains three carbonyl groups, a nitrogen substituted ring structure and an isoprenoid side chain. Theoretically, these chemical structures and functional groups provide DA with substantially greater chelation capacity than proline: however, stability constants with respect to copper have not yet been measured for DA. Flow injection analysis with chemiluminescent detection will be used to determine DA's affinity for binding copper. The potential role DA plays in maintaining intracellular copper homeostasis will be discussed.
Lander, Michelle E. (1) and James T. Harvey (2)
1) The Marine Mammal Center, Marin Headlands
Diving Behaviors Of Wild And Rehabilitated Harbor Seal (Phoca Vitulina Richardsi) Pups
A previous study we conducted during 1995 and 1996 indicated that mean duration of dives did not differ significantly between free-ranging and rehabilitated harbor seal (Phoca vitulina richardsi) pups that were tagged with radio transmitters. It was uncertain, however, whether dive durations of pups reflected anything other than apnea abilities. The objective of this study was to examine the diving behaviors of wild and rehabilitated pups in greater detail using time-depth recorders (TDRs), which have never been deployed on Pacific harbor seal pups. To measure depths and durations of dives, surface intervals, time at depth, and average rates of descent and ascent of dives, TDRs (Mk5 and Mk7 models) with a remote release mechanism (RRM) were attached to the dorsum of a control group of 11 newly weaned wild pups captured at Pebble Beach, California, and 9 rehabilitated pups released from The Marine Mammal Center, Sausalito, from 1997 to 1999. Radio transmitters also were glued to the heads of pups to locate them after release. Diving behaviors of wild pups and rehabilitated pups were similar. Most dives of all pups were shallow and data collected by instruments with a better resolution (Mk7s) probably were a more accurate representation of mean dive parameters. Mean depth and duration of dives generally increased over time for most pups and presumable foraging bouts became more prominent. Time depth recorders were difficult to recover because of the dispersal behavior of newly weaned pups. Furthermore, the battery life of the RRM was only two weeks. In the future, therefore, developmental diving behaviors of harbor seal pups should be examined using instruments such as satellite-linked time depth recorders.
Lonhart, Steve I. (1) and Jeff W. Tupen (2)
1) Department of Biology, University of California, Santa Cruz
Recent Range Extensions Of Marine Species Into Central California: Multiple Mechanisms Alter Geographic Range
We report recent range extensions for 12 species of intertidal or shallow subtidal marine invertebrates (11 mollusks, 1 ophiuroid) along the California coast. Ten range extensions were northward and two southward. We consider six potential reasons explaining these range extensions: 1) climate change; 2) El Niño Southern Oscillation (ENSO) events; 3) thermal refugia; 4) search artifacts; 5) anthropogenic effects; and 6) unpublished data. Ten extensions appear to be the result of search artifacts and two are due to thermal refugia. Additionally, unpublished museum material further extended the ranges of six species. The 1998 ENSO is a likely transport mechanism for only one species, but previous ENSO events may have contributed to the remaining nine northward extensions. While global warming is consistent with patterns of northward expansion, and 10 of 12 species did expand northward, we suggest that other mechanisms must be excluded before invoking climate change.
Lorenson, Thomas D., Keith A. Kvenvolden, Frances D. Hostettler, and Robert J. Rosenbauer
U.S. Geological Survey, Menlo Park
Hydrocarbon Geochemistry Of Cold Seeps And The Background Hydrocarbon Signature In The Monterey Bay National Marine Sanctuary, Offshore Central California
Background hydrocarbon signatures are present in recent sediments, including those influenced by cold seeps in the Monterey Bay National Marine Sanctuary (MBNMS). Because the production and discharge of petroleum are prohibited activities in MBNMS it is important to define the current hydrocarbon background in sediments of this region in anticipation of any possible future violations of these prohibited activities. The continental shelf between San Francisco and Monterey contains aliphatic and aromatic hydrocarbons of biological origin from both marine and terrigenous sources. Terrigenous sources are more pronounced near Monterey. There is a low-level background of petrogenic (petroleum-related) compounds, including 28,30-bisnorhopane, which is characteristic of many crude oils from the Monterey Formation of California. Thus, the sediment is overprinted by a regional chemical signature which may be derived from eroded Monterey Formation rocks and from onshore and offshore petroleum seeps. Cold seeps vent fluids and dissolved gas through this sediment and add their own diverse and unique hydrocarbons to the system. We analyzed sediment samples from four geographically and tectonically discrete cold seeps named Clam Flat, Clamfield, Horseshoe-Scarp South, and Tubeworm City. The sediment contains dissolved gaseous hydrocarbons and CO2, as well as higher molecular weight aliphatic and aromatic hydrocarbons often with a composition similar to the background hydrocarbon signature. Of particular interest is the cold seep site at Clamfield which is characterized by the presence of thermogenic hydrocarbons including oil that may be correlated to oil-saturated strata at Majors Creek near Davenport, California. At Clam Flat, there is some evidence for thermogenic hydrocarbon. At Horseshoe-Scarp South and Tubeworm City, hydrocarbon gases, mainly methane, are likely microbial in origin. These varied sources of hydrocarbons highlight the diverse chemical systems that appear at cold seeps and in the associated sediment.
Los Huertos, Marc (1), Jess Brown (2), Kelly Huff (3) , Carol Shennan (1), Brian Largay (4), Traci Roberts (4), Lamaia Hoffman (5)
1) Center for Agroecology and Sustainable Food Systems, University of California, Santa Cruz
Partnership In Water Quality Monitoring In Six County Region
As part of the Coalition of Central Coast County Farm Bureaus Agricultural Water Quality Program, we have developed a partnership to work together on water quality monitoring and maintain the high water quality that drains into the Monterey Bay Sanctuary. The Santa Cruz (SC) County Farm Bureau and the SC Resource Conservation District are developing a program for growers to participate in pilot projects that explore and improve water quality. The University of California at SC will provide technical assistance and water quality data analysis for these projects. We are coordinating an anonymous reporting procedure and quality control and quality assurance methods that meet EPA standards. We would like to explore several aspects through the partnership. First, which on-farm practices are most effective in addressing water quality issues? What are the economic constraints for growers trying to manage water quality in the current market structure?
Maffione, R. 1, K. Flynn (1), A. Bullard (1), S. Baron (1), E. Palomino (1,2), F. Chavez (3), S. Ramp (4), and J. Paduan (4), L. Rosenfeld (4)
1) Hydro-Optics, Biology, and Instrumentation Laboratories
Optical Properties Of The Monterey Sanctuary Monitored By The Innovative Coastal-Ocean Observing Network (Icon)
The National Ocean Partnership Program (NOPP) is funding a team of government, academic, and private institutions to install and operate an Innovative Coastal-Ocean Observing Network (ICON) in and around Monterey Bay. The ICON project is described in a companion poster and detailed information about it, as well as the data we're collecting, can be found at <http://www.oc.nps.navy.mil/~icon>. In this poster, we describe the optical and ocean color aspect of this project and present examples of the types of optical measurements being made and the innovative instruments needed to perform these measurements. How sunlight interacts with the water is an important and fundamental process in oceanography. Directly measuring the various optical properties of the water provides the necessary information for understanding why the water appears a particular color, which in turn helps us to understand what primary biological processes are occurring in the water. With the emergence of satellite sensors that record global images of the color of the ocean's surface, measuring and understanding the ocean's optical properties are becoming increasing vital. In the ICON project, we are intensively measuring and analyzing the optical properties of the Sanctuary waters and relating them to ocean-color satellite imagery to better understand and monitor this vital and beautiful coastal environment.
Manouki, Talitha J., Rikk G. Kvitek, and Carolyn Bretz
California State University, Monterey Bay
Emerita analoga (Stimpson) As An Indicator Species For Paralytic Shellfish Poisoning Toxins Along The California Coast
M. californianus has long been used as an indicator for levels of Paralytic Shellfish Poisoning Toxicity (PSPT) in the environment, but because this species distribution is limited to rocky shores, large stretches of sandy beaches are essentially unmonitored. The inability to monitor PSPT toxicity along sandy shores results in a lack of information on harmful algal bloom development and movement along much of the California coast. Early studies on E. analoga, a common sandy shore invertebrate, have shown that this species can sequester saxitoxin (STX, the primary neurotoxin in PSPT blooms) in their tissues. The purpose of this study was to develop a PSPT extraction protocol for E. analoga, and to compare the utility of this species as a PSPT indicator with that of M. californianus. Samples of both species were spiked with known amounts of saxitoxin and processed (M. californianus with the standard acid extraction procedure and E. analoga with the new adapted acid extraction process). Spike and recovery results show that the percentage of STX recovery for E. analoga is 3-9% higher than for M. californianus. To compare the uptake and depuration rates of PSPT for the two species, samples of each were collected at paired rocky and sandy beaches, along the central coast of California in 1998 and 1999 from May through November, the season of historically high Paralytic Shellfish Poisoning Toxicity.
Moore, Christopher S. and Phaedra M. Green
Pacific Fisheries Environmental Laboratory, National Marine Fisheries Service, Pacific Grove
A Verification Of PFEL Wind Products With NODC Buoy Observations And NCEP/NCAR Assimilated Data
The Pacific Fisheries Environmental Laboratory (PFEL) derives a number of well-known environmental data and index products for the North Pacific Ocean (18°N - 60°N) from the U.S. Navy Fleet Numerical Meteorology and Oceanography Center's monthly mean surface pressure fields. These include: surface wind vectors, wind stress and Ekman transport; wind stress curl; wind mixing; vertical velocity into the Ekman layer; and integrated total transport. These products are routinely distributed to researchers at many state and federal laboratories, as well as to academic and international researchers. The coastal upwelling index, which is an index of the strength of the wind forcing on the ocean, has been used in more than 400 published studies of the effects of ocean variability on the reproductive and recruitment success of fish and invertebrates. PFEL also prepares products in response to special requests for environmental data for specific research and management projects. To insure the quality of these data products, the pressure-derived winds are compared to two different independent data sets at five different locations in the northeast Pacific between 17°N and 52°N over an 18-year period (1981-1998). The PFEL pressure-derived winds are compared to winds from U.S. National Oceanographic Data Center (NODC) buoys and NOAA's Climate Diagnostics Center NCEP/NCAR Reanalysis. Mean monthly climatologies, the annual biharmonic signal, and time series were compared for each data set at each location. The PFEL winds are highly correlated with the other wind data sets, indicating the PFEL wind products reasonably reproduce forcing factors in the Monterey Bay National Marine Sanctuary and over the north Pacific.
U.S. Geological Survey, Menlo Park, CA
Human Causes Of Ecosystem Change: Introduction Of A Non-Indigenous Microorganism From Japan.
Exotic nuisance species have invaded ports throughout the United States, disrupting many estuarine ecosystems. Although generally overlooked, invasive microorganisms are important because, as primary producers or consumers, they occupy positions at or near the base of the food chain and have the potential for disrupting the entire food web above them by outcompeting the indigenous organisms for nutrients. The Japanese pollution-indicating benthic foraminifer, Trochammina hadai Uchio, appears to have been introduced into San Francisco Bay between 1981 and 1983. This estuarine species most likely was transported to the Bay in ships' ballast tanks or in mud associated with anchors. In 1983, it constituted 3% of the foraminiferal fauna at one site in the Bay. By 1986-87, it was present at 46 stations, comprising up to 89% of the assemblage. Sampling from 1995-98 has shown that T. hadai is now a dominant foraminifer in all but the extreme ends of the Bay, constituting up to 93% of the foraminiferal fauna. This study is the first to document the introduction of an invasive foraminifer in any aquatic community worldwide and shows how rapidly an exotic microorganism may proliferate in its new environment. Trochammina hadai has also been found at 13 other sites along the west coast of North America, but has not yet been recovered in the harbors of Monterey, Moss Landing, or Santa Cruz. The species' absence at these sites may simply reflect a lack of opportunity for innoculation as no ballast release occurs here, or a failure to establish itself due to unfavorable environmental conditions.
Onofre, Jose Alberto, Chris Miller, Ching-Sang Chiu, and Curtis Collins
Naval Postgraduate School, Department of Oceanography
Analysis Of Acoustic Tomography Signal Transmission From Davidson Seamount To Sur Ridge: The Forward Problem.
Repeated transmissions of a tomography signal from an autonomous sound source placed on Davidson Seamount was continuously monitored by a bottom-lying, cabled-to-shore receiver on Sur Ridge. To address the signal stability, resolvability and identifiability criteria that determine the applicability of ocean tomography along this path, the data recorded from July 1998 to January 1999 were first processed to obtain the multipath pulse arrival structure and its variability in time. The processed signals showed strong arrivals that were both stable and resolvable. Acoustic propagation modeling was performed using ray theory in conjunction with measured sound speed and high resolution bathymetric data. A comparison of the predicted and measured arrival structures show that the observed arrivals were identifiable and consisted of eigenray groups instead of individual eigenrays. Since the eigenrays within each group were found to have nearly identical trajectories through the ocean, the common passage along which the ray group integrates the ocean variability was unambiguous. Arrivals exhibited dominant oscillations with semidiurnal, diurnal, 8-day, 18-day and 26-day periods. Variances of ocean temperature for each of these periods was estimated. Semidurnal variability was unexpectedly large for the first 3 arrivals. The temperature variances provide important constraints for the validation of regional ocean models.
1) Monterey Bay Aquarium Research Institute
The 1997-98 El Niño, Chlorophyll And Primary Production: Spatial And Seasonal Effects Off Central California
Effects of the 1997-98 El Niño on chlorophyll and primary production levels across the central California upwelling zone were observed with quarterly cruises from 0-275 km of the coast over 1997-99, and with semi-monthly cruises from 0-55 km of the coast over the decade 1989-99. The 0-275 km cruises show (1) normal early upwelling season (February, March, April) phytoplankton biomass and growth in 1997, (2) progressive restriction of high chlorophyll and productivity waters inshore during the late upwelling (May, June, July) and oceanic (August, September, October) seasons of 1997, (3) depression of biomass and growth during the 1997-98 Davidson and 1998 early and late upwelling seasons, and (4) recovery to normal and above-normal values during and following the 1998 oceanic season.
Price, Holly and Susan Pufahl
Monterey Bay National Marine Sanctuary
Sanctuary Creates New Land And Sea Partnership
Protecting the resources of the Monterey Bay Sanctuary means not only focusing on the ocean itself, but on human activities in the 7000 square miles of watersheds which drain to it. Although the offshore waters of the Sanctuary are in relatively good condition compared to other parts of the country, a number of warning signs are present in coastal resources and the surrounding watersheds. Water quality issues in the region include high levels of nitrates in the region's rivers, bioaccumulation of persistent pesticides such as DDT which move down the watersheds via erosion, and sedimentation of the spawning grounds of salmon and steelhead populations.
Ralston, Stephen, Dale A. Roberts, Keith M. Sakuma, and David P. Woodbury
National Fisheries Service, Santa Cruz/Tiburon Laboratory
From El Nino to La Nina in the Gulf of the Farallones
Ocean conditions off the US west coast changed dramatically from 1997-99. During that time period the coastal ocean environment experienced one of the strongest "El Nino" events in recent history (1998), which was then followed by a major "La Nina" in 1999. We compare and contrast ocean in and around the Gulf of the Farallones during these years, based on a variety of shipboard observations collected aboard the NOAA R/V David Starr Jordan during annual May-June surveys conducted off the central California coast. In particular, we analyze spatial patterns in data from CTD casts, a temperuature-salinity surface profiler, and an Acoustic Doppler Current Profiler (ADCP). Results show marked differences in the hydrography of the Gulf of the Farallones between these two years.
University of California, Santa Cruz, Department of Biology
Can Succession Drive Vertical Shifts In Intertidal Zonation?
The distributions of many species on rocky shores are limited to distinct zones. A general paradigm in marine ecology is that the upper limits of these zones are set by physical factors and that the lower limits are set by biological factors. This idea suggests that species zonation patterns do not vary much unless the determining factors vary. As physical factors are relatively stable over long time periods, movement of species upper limits are expected to be uncommon. The Minerals Management Service of California has funded a long-term monitoring study in San Louis Obispo and Santa Barbara counties for the past nine years. At some sites the data reveal a temporal pattern in which the upper limits of two mid-intertidal algal species, Endocladia muricata and Pelvetia compressa, have shifted upwards on the shore in a predictable, successional sequence of events. Barnacles (the highest species) became colonized by Endocladia (the intermediate species) and Endocladia became colonized by Pelvetia (the lowest species). Surprisingly, at two sites Pelvetia has recruited into the plots originally set up in the barnacle zone. These data reveal that species zones, previously thought to be stable over time, can be vertically dynamic. With support from previous research that describes the facilitative capabilities of barnacles and Endocladia, I suggest that disturbance and succession may be able to drive long-term vertical changes in intertidal zonation.
Sakuma, Keith M. and Stephen Ralston
National Marine Fisheries Service, Santa Cruz/Tiburon Laboratory
Distributional patterns of late larval groundfish off central California in relation to hydrographic feature during 1992 and 1993.
Late larval groundfish were collected using Methot's frame trawl with a modified Isaacs-Kidd depressor during late winter of 1992 and 1993. CTD casts were conducted throughout the trawl survey area to obtain hydrographic data. Surface waters were relatively warm in both years in association with El Nino conditions.
Schwing, Frank, Phaedra Green, and Tom Murphree
Pacific Fisheries Environmental Laboratory, National Marine Fisheries Service, Pacific Grove
Climate Change In The Monterey Bay National Marine Sanctuary Based On The Extratropical Northern Oscillation Index (NOIx)
The extratropical Northern Oscillation Index (NOIx) is a new index of climate variability in the northeast Pacific. It is an analog to the well-known Southern Oscillation Index (SOI) and captures variability in atmospheric forcing over the north Pacific, and tropical-extratropical coupling. We analyze monthly time series of these indices since 1950, to identify a variety of local and remote climate signals of significance to the Monterey Bay National Marine Sanctuary (MBNMS). The SOI and NOIx have a similar overall appearance, but clearly reflect distinct climate patterns and a different set of individual climate events. Interannual variations indicating El Niño (EN) and La Niña (LN) events can be seen in both series, however the NOIx displays a number of positive and negative extrema not evident in the SOI. While the SOI is often associated with its negative extremes indicative of EN events, LNs occur about twice as frequently as ENs in both indices. Both types of event were twice as likely to be followed by another EN as a LN. The classic biennal oscillation between EN and LN states is not evident. The NOIx identifies climate shifts in 1970, 1977, 1983, and 1991 that may be ecologically important to the MBNMS. Large-scale anomaly fields during these climate regimes suggest likely mechanisms for the development and global propagation of climate change signals. Correlations with a variety of physical and biological time series from the Sanctuary and along the west coast indicate the NOIx may be a reliable index of the effects of climate variability in the MBNMS.
Schwing, Franklin B. and Christopher S. Moore
Pacific Fisheries Environmental Laboratory, National Marine Fisheries Service, Pacific Grove
Record Breaking Upwelling Anomalies In The MBNMS During 1999: Gidget Goes To Florida
Upwelling in the Monterey Bay National Marine Sanctuary during the peak of the upwelling season in April-July 1999 was the strongest in the 54-year record of the coastal upwelling index, 2.5-3.5 standard deviations above normal. Strong upwelling-favorable (northerly) coastal wind events and very low sea surface temperatures (7.5-8C) were measured at local buoys during this period. Coastal sea levels were anomalously low as well. Local CTD observations in the Sanctuary reflect high upwelling through very low temperatures and high salinity values throughout the water column that are 1-2 standard deviations outside the long-term (1987-1996) means for this area (1-2C cooler and S = .2-.4 higher). Monterey Bay waters are characterized by very high biological productivity due to enrichment from a unique combination of upwelling processes. Coastal upwelling through advection from outside the Bay, open ocean upwelling through positive wind stress curl and deep upwelling in Monterey Submarine Canyon may all contribute to the waters found in Monterey Bay. The 1999 upwelling season shows a strong relationship between the extreme local wind, sea level, and SST anomalies, indicating that local upwelling processes were responsible for the unusual state of the coastal ocean. Major shifts in ecosystem structure have been observed in 1999 elsewhere along the west coast in association with the unusually high rates of upwelling. The rapid shift in the physical and biological nature of the northeast Pacific from an El Niño to La Niña patterns is unprecedented. While it is too early to say, the extreme conditions of 1999 may signify the onset of a new climate regime that will alter the Sanctuary's ecosystems and affect its marine populations for the next several years.
Smith, G. Jason (1), Nicolas Ladizinsky (1), and Peter E. Miller (2)
1) Moss Landing Marine Laboratories 2) Monterey Bay Aquarium Research Institute
Amino Acid Profiles In Species And Strains Of Pseudo-Nitzschia From Monterey Bay, Ca: Insights Into The Metabolic Role(S) Of Domoic Acid
The phenomenology of domoic acid (DA) production by strains of the Pseudo-nitzschia species complex has received considerable attention, leading to general observations that DA accumulation is stimulated by growth limiting or stress conditions. Although DA is a structural analogue of proline, no direct evidence is available linking DA and proline metabolism in Pseudo-nitzschia. In order to ascertain whether DA behaves as a functional analogue of proline, the free amino acid (FAA) composition of 5 species and 20 strains of Pseudo-nitzschia spp. from Monterey Bay were obtained by HPLC-UV profiling of their phenylthiocarbamyl amino acid (PTC-AA) derivatives. DA accumulation varied by 2-orders of magnitude among independent isolates of P. multiseries and P. australis, with the isolates of the latter species exhibiting consistently higher cellular yields of DA. Proline content was lower in cells accumulating high levels of DA (>1 fmole/cell) indicating a regulatory switch occurs between the biosynthetic pathways for these amino acids. All Pseudo-nitzschia species accumulated large pools of taurine (greater than 50% of total FAAs) when grown in Monterey Bay seawater (34 ppt). This osmolyte was not detected in other diatom species when grown under equivalent conditions. These trends indicate that the genus Pseudo-nitzschia may be characterized by a hypersensitive phenotype with respect to oceanic salinity. As taurine content covaried with DA accumulation in Pseudo-nitzschia, it may provide a useful biomarker for potentially toxic bloom events. Interactions between DA, proline and taurine metabolism will be discussed.
Marine Biology Teacher at The Branson School, Ross, CA
Sustainable Seas Intertidal Educational Kiosk At Agate Beach, Duxbury Reef
The Branson School in cooperation with Gulf of the Farallones National Marine Sanctuary (GFNMS) has developed a Sustainable Seas Student Intertidal Monitoring Project (SSSIMP) at Duxbury Reef in Marin County. The SSSIMP goals include: monitoring the health and diversity of rocky intertidal habitat; developing a database of species diversity, density, and abundance; contributing to the conservation of the rocky intertidal habitat and educating students and the general public about the requirements for maintaining a healthy, diverse intertidal ecosystem. To this end, Sustainable Seas student volunteers have completed an intensive training program on the natural history of intertidal invertebrates and algae, identification of key species, rocky intertidal ecology and monitoring techniques. Students have researched and are designing a rocky intertidal informational kiosk to greet visitors at the entrance of Agate Beach. The kiosk will include pictures and natural history information on key intertidal species as well as tidepooling etiquette and monitoring results. Monitoring results will be updated annually. In addition, students will organize an annual celebration at Duxbury Reef and lead intertidal walks for the public. This will be an ongoing project with goals to expand monitoring sites to different habitats within the GFNMS.
Moss Landing Marine Laboratories
Deepwater Algal Assemblages In Central California- How Low Can They Go?
Macroalgal assemblages below 30 m in central California are largely unexplored, despite their potential usefulness in understanding biodiversity, biogeography, and plant/animal interactions. The distribution and abundance of these assemblages were determined at 4 locations in central California using NITROX Scuba surveys at 30 m and video transects and algal collections with the ROV Ventana from 30 to 100 m. The lowest observed depth limits were 77-80 m for nongeniculate (encrusting) coralline algae, 58 m for non-calcified red algae (i.e. Maripelta rotata) and 40 m for large brown algae (i.e. Desmarestia tabacoides). Green algae, such as Derbesia and an undescribed deep water species of Codium, were observed at 30m, while large patches of an unknown green or blue-green algal film were found from 45 to 48 m. Twenty four species of algae (13 Rhodophyta, 11 Phaeophyta) were sampled during the percent cover analysis at 30 m. Nongeniculate corallines varied from 53 to 91% cover depending on location, while geniculate corallines ( i.e. Bossiella californica var. schmittii) averaged ~25% cover. Pleurophycus gardneri, a stipitate brown algae previously described as rare in central California, was particularly abundant, averaging from 2.68 to 4.8 individuals/m2. Data from the ROV and NITROX dives to date suggest that deep water kelps are very abundant in the region, forming previously undescribed kelp bed assemblages below the well known kelp forest communities in central California. The results suggest that while species composition differs, the overall depth zonation of subtidal macroalgae in central California is similar to that of southern California.
Starr, R.M. (1), J. Heine (2), J. M. Felton (1,2), and K. A. Johnson (3)
1) UC Sea Grant Extension Program
Movements Of Bocaccio And Greenspotted Rockfish: Implications For Design Of Marine Reserves
Rockfishes are an extremely important component of the commercial and recreational fisheries on the west coast of the United States. Recent stock assessments conducted by the Pacific Fishery Management Council (PFMC) have indicated large population declines for many commercially harvested rockfish species. These declines have led to discussions about the need for alternative fishery management strategies, such as the use of marine fishery reserves. Although fishery reserves are rapidly being established, their effectiveness in fisheries management is poorly understood. An understanding of fish movements is especially critical information needed to properly design reserve sizes, shapes, and locations. Currently, little information is available on the movement patterns of deepwater rockfishes. In this project we are studying the range and frequency of fish movements of some deep water rockfishes within Soquel Canyon, a branch of the Monterey submarine canyon.
Starr, R.M. (1), J. M. Felton (1,2), J. O'Sullivan (3), H. Dewar (4), G. M. Cailliet (2), N. Mayer (5), and J. Heine (2)
1) UC Sea Grant Extension Program
Movements Of The Prickly Shark (Echinorhinus Cookei) Associated With The Head Of The Monterey Submarine Canyon
Named for their sharp, thorny dermal denticles, the prickly shark (Echinorhinus cookei) is a rare deepwater shark that inhabits both tropical and temperate waters of the pacific. It is one of two species of sharks known as bramble sharks in the family Echinorhinidae. Few facts have been published about the basic biology of prickly sharks, as the majority of reports are based on descriptions of a small number of dead animals incidentally caught in fisheries.
Sydeman, William J. and Michelle M. Hester
Point Reyes Bird Observatory, Stinson Beach
Temporal Shifts In Fish And Zooplankton Species Composition In Seabird Chick Diets Off Central California Indicate Marine Climate Change.
We used time series data (10 to 25 years) to assess temporal variation in prey composition of chick diets for 4 seabird species that forage within the Gulf of the Farallones, central California. Prey data was collected from late May to early August on Southeast Farallon Island (37°N 123°W), 40 km offshore. We used conventional techniques of diet assessment including observations from a blind for Common Murres (Uria aalge) and Pigeon Guillemots (Cepphus columba), and collection of prey items from adult Rhinoceros Auklets (Cerorhinca monocerata) and Cassinís Auklets (Ptychoramphus aleuticus) returning to feed their chicks at night. Shifts in the major prey species used through time are described.
Weise, M.J. and J. T. Harvey
Moss Landing Marine Laboratories
Abundance And Food Habits Of California Sea Lion (Zalophus Californianus) And Their Impacts On Salmon Fisheries In Monterey Bay, California
California sea lions on haul-out sites were counted once a month during photographic aerial surveys and twice per month from the ground in the Monterey Bay region in 1997 and 1998. Seasonal trends in sea lion numbers were apparent corresponding to their annual migration, with greater numbers of animals in the region in summer and fall 1998. Prey hard parts identified in sea lion fecal samples (n=503) indicated that sea lions consumed mostly schooling species such as market squid (Loligo opalescens), northern anchovy (Engraulis mordax), and Pacific sardine (Sardinops caeruleus). Similar prey species, dominated by market squid and northern anchovy, were consumed in 1997 and spring 1998 (PSI > 70.0), with a significant shift toward Pacific sardine, and rockfish (Sebastes sp.) in summer and fall of 1998 (PSI < 43.0). Shifts in sea lion diet were most likely a result of shifts in prey distribution in response to the 1997-1998 El Niño Southern Oscillation event. Commercial fish catches and biomass consumed by sea lions were compared using a biomass consumption model. Predictions of daily energetic requirements of sea lions, relative seasonal number and age structure of the population, proportion of prey species seasonally present in the diet, and energetic value of prey were used to estimate consumption. In 1998, sea lions consumed 609,600 kg of salmon, the equivalent of 314.8% of the commercial catch, 5,336,200 kg of sardine, the equivalent of 53.2% of the commercial catch, and 607,600 kg of rockfish, the equivalent of 42.1% of the commercial catch. Effects of California sea lion on commercial and recreational ocean salmon fisheries were investigated by monitoring the percentage of hooked salmon consumed by sea lions during 1,041 hours of onboard and dockside surveys at three ports in Monterey Bay, California from April 1997 to October 1998. Sea lions took 11.9 % (1997) and 31.5% (1998) of the fish in the commercial fishery, 9.1 % (1997) and 15.5 % (1998) of the fish in the Commercial Passenger Fishing Vessel (CPFV) fishery, and 15.3 % (1997) and 12.1 % (1998) of the fish in the skiff fishery. Peak percentages of fish taken by sea lions were concurrent with peak abundance of sea lions in spring and late summer to early fall. Increased predation in 1998 was likely because of the large El Niño event in 1997-1998, during which, a greater number of sea lions were present in central California, many fish species changed distribution, and sea lion prey composition shifted. Food stressed sea lions were more likely to take hooked salmon when available.
Willis, Cope M. (1), and Gary B. Griggs (2)
1) Earth Science Department and
The impacts of climate variability and land use change on sediment supply to the central California coastal zone
The sustainability of central California's beaches depends on periodic nourishment of sediment from the watersheds that drain the steep coast range between San Francisco and Santa Cruz and the broad alluvial valley along Monterey Bay. The delivery of sediment is controlled by (1) regional climate that dictates the frequency and intensity of precipitation events and (2) watershed topography and land use that control the local hydrologic response. Between 1950 and 1996, California's population has grown from 10.6 to 32 million, generating extensive dam construction and changes in land use. While there are 52 dams currently operating along central California, 89% of the central coast's 8,000 river miles remain natural flowing. In addition, despite large shifts in vegetation species between 1945 and 1977, there has been only a 4% net loss of canopy and vegetation cover. Preliminary evidence from historical precipitation and streamflow records over this period suggests that land use change has not systematically altered rainfall-runoff patterns. Coastal streamflow and sediment discharge are effected by both seasonal and multi-annual variations in precipitation. Not only does California experience a typical monsoon seasonal rainfall pattern, but there are also climate variations that produce extreme flooding and sediment discharge to the coast on 5, 10, and 20 year cycles. Over the last 70 years on the San Lorenzo and Salinas rivers, which drain 75% of the study area, less than 90 high flow events over approximately 200 days (less than 2% of time) have provided 70% of the total suspended sediment supply to the coast. Therefore, we conclude that the scale of climate variability dominates over the incremental human impacts to the central coast's watersheds and that natural episodic floods control the flux of sediment to the coastal zone.