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.
Poster Session Abstracts
Friends of the Sea Otter
THE SOUTHERN SEA OTTER: A KEYSTONE SPECIES
The southern sea otter is considered by many to be an ecological "keystone" species in the coastal nearshore environment. They are powerful shapers of both the kelp forest ecosystem and nearby softbottom habitats. They are top-level predators, feeding on many shellfish species that are also consumed by humans, and spend virtually all their time in waters also used for human recreation and business. Threats to the sea otter population and its habitat also have powerful ramifications for human use of associated resources. This poster will briefly describe several nearshore coastal issues, ecosystem-level conservation policies, and the difficulties and opportunities posed when constructing sound conservation policies that bridge protection needs at both single-species and ecosystem levels. An example using the recently-released southern Sea Otter Recovery Plan will be used to illustrate how species-specific research and habitat protection can also be effectively used to leverage understanding and protection of ecosystem-level biological diversity.
Environmental Studies Department, University of California, Santa Cruz.
CULTURES OF CONSERVATION IN THE MONTEREY BAY
The designation of the Monterey Bay National Marine Sanctuary heralded a long history of conservation efforts within the region. It marked the creation of the country's largest marine protected area, with blanket restrictions against offshore oil drilling and exploration as well as establishing innovative practices within the institutional framework of sanctuary management. The social and political history of sanctuary designation reveals the important role that citizen action played in ensuring that this designation became a reality. This research traces the roots of environmental action within the Monterey Bay region and seeks to demonstrate the development of a political culture of conservation based on the past actions of local communities to protect local marine resources. This regional political culture explains the continuing high level of citizen action within the region regarding the protection of marine resources.
King, JoAnn J.
MARITIME STUDIES: A NEW MODEL OF STUDY & RESEARCH FOR COAST COMMUNITIES
Maritime studies, an interdisciplinary innovative field, is a vehicle for studying historic and current aspects of any coast or littoral community. The main components of this model include: maritime art, maritime literature, maritime folklore, maritime historians, underwater archeology/exploration, maritime sanctuary preservation, maritime ecology, and maritime industry. This model may include oral history studies of local people and events, a biographical approach, and provides an opportunity for the blending of the humanities and sciences in this Monterey Bay area.
Andrews, Allen H., Gregor M. Cailliet, and Kenneth H. Coale
Moss Landing Marine Laboratories
RADIOMETRIC AGE DETERMINATION OF THE PACIFIC GRENADIER (CORYPHAENOIDES ACROLEPIS), A RAPIDLY DEVELOPING FISHERY IN MONTEREY BAY
Current longevity estimates for the Pacific grenadier range from 6 to 60 years. Age estimates in this study, using the quantification of growth increments in thin otolith (ear-bone) sections, indicate that the Pacific grenadier is a long-lived fish that may approach 75 years. To validate this trend, age was determined using the radioactive disequilibria of 210Pb and 226Ra in otolith cores from adult Pacific grenadier. Radiometric ages closely agree with age estimates from the quantification of growth increments. This confirms the annual periodicity of these increments. Radiometric results indicate that the Pacific grenadier can live at least 50 years. Because the Pacific grenadier is long-lived, it may be vulnerable to heavy fishing pressure. Therefore, conservative measures need to be taken in this rapidly developing and unregulated fishery.
Anima, Roberto J. (1), Yvonne W. Rodriguez (2), and Gary B. Griggs (2)
1. U.S. Geological Survey, 345 Middlefield Road Menlo Park, CA
SEAFLOOR MORPHOLOGY MAP BETWEEN AÑO NUEVO AND RIO DEL MAR REVEAL OFFSHORE EXTENSIONS OF ONSHORE GEOLOGY
The extent of submarine rock exposures along the Northern Monterey Bay Sanctuary are displayed in map view based on side-scanning sonar and underwater video. The mapping defines the nearshore morphology of the Central California Coast between Año Nuevo and Pt. Santa Cruz. The extensive rock outcrops pose questions concerning longshore sediment transport pathways, and sediment storage sites along the nearshore. The side scan sonar record interpretations are supported with underwater video imaging of the various bedrock types. The mapping shows variations in sediment texture associated with proximity to bedrock and sediment transport pathways. The results of this study can be applied to understanding the dynamics of longshore sediment transport in the nearshore environment of and active-margin coastline.
Arimitsu, Mayumi L., Lucy H. Marcus, and Steve I. Lonhart
University of California Santa Cruz
GASTROPOD DIVERSITY IN THE KELP FORESTS OF MONTEREY BAY
Gastropod diversity in the Hopkins Marine Life Refuge (HMLR) were first documented by kelp forest ecology students from 1971-73. Students at UC Santa Cruz repeated these surveys in 1995 and 1996. The two sets of surveys were compared to detect changes in species richness and qualitative measures of abundance. Gastropods observed in kelp forests outside the Refuge but within Monterey Bay were compared to a comprehensive list of all Monterey Bay gastropods compiled during the 1950's. Three southern Californian gastropods were present in 1995-96 that had not been observed in the 1950's or 1970's: Maxwellia gemma, Maxwellia santarosana, and Kelletia kelletii. Other southern species, like Serpulorbis squamigerus, have increased in number. Species previously known in Monterey Bay but added to the HMLR list include: Calliostoma gloriosum, Opalia borealis, Cancellaria cooperi, Megasurcula carpenteriana and Bursa californica. Potential explanations for these observed changes in species composition and abundances include ENSO events, global warming, and the slow, natural expansion of ranges.
1. Oceanic Society and Monterey Peninsula College
MONTEREY BAY NATIONAL MARINE SANCTUARY BIODIVERSITY AND MONITORING PROJECT: SUBTIDAL SURVEYS IN BIG SUR
One goal of the MBNMS Biodiversity and Monitoring Project is to establish permanent subtidal sites within the Sanctuary. These sites will act as focal points for (1) long-term studies of species diversity and abundance and (2) short-term ecological projects. The objectives of the 1996 R/V Ballena research cruise were to: (1) survey subtidal sites at Pt. Sur, Slate Rock (Esalen), and Dolan Rock; (2) establish permanent 50 m transects at each site for a long-term monitoring program; and (3) collect qualitative and quantitative data on algae and invertebrates. Substrate types varied from steep pinnacles to large boulder fields, and sand channels were common. Sites were chosen in low relief areas with similar substrate type. At each site the algal assemblage and structure were very similar: Macrocystis pyrifera and Nereocystis luetkeana formed dense canopies, Pterygophora californica formed a thick understory, and the turf consisted primarily of Calliarthron sp. and crustose red algae. Didemnum carnulentum and several unidentified colonial tunicates were the dominant sessile invertebrates covering the rocky outcrops. Strawberry anemones (Corynactis californica) and several bryozoan species were conspicuously sparse. The bat star (Asterina miniata) was very common, but other sea stars were scarce and there was a general paucity of motile invertebrates. Because the Big Sur coastline is unlike Monterey Bay and largely unexplored scientifically, qualitative observations and species lists are necessary first steps for subsequent quantitative characterization of the Big Sur subtidal communities.
Diaz, Maria Cristina
Institute of Marine Sciences, University of California, Santa Cruz
MULTIMEDIA SOFTWARE FOR SPECIES DATA STORAGE AND IDENTIFICATION: A PROPOSAL FOR THE MONTEREY BAY SPONGE FAUNA
The applicability of the ETI (Expert Center for Taxonomic Identification) multimedia software for biodiversity studies of the sponge fauna in the Monterrey Bay area is discussed. Various regional projects underway (Western Eureopean sponges, Central West Atlantic sponges, Papua New Guinea sponges, etc.) have demonstrated the usefulness of such a system for sponge species identification and data storage. Sponges constitute a common and rather diverse group in marine benthic environments. In the Monterey Bay area, kelp forest bottoms, rocky outcrops, and lower intertidal zones harbor the highest sponge diversity. The development of such an identification system will facilitate the access to Porifean species information for the Monterey Bay fauna (names, descriptions, records, literature). In addition it will facilitate the exchange of this data between various disciplines (education, ecology, environmental studies, taxonomy, etc.).
U.S. Geological Survey, Menlo Park, CA
RIPPLED SCOUR DEPRESSIONS OF THE SOUTHERN MONTEREY BAY SHELF
Similar to many other continental shelves of the world, the southeast Monterey Bay inner shelf contains distinct depressions floored with rippled sand in which the dominantly coarse material of the depressed floor moves as bedload. These 1-m-deep features occur in the offshore former Fort Ord region, the site of impingement of very large storm waves from the northwest, and have been ascribed to rip-current and alongshore flow associated with these large waves. Recently-acquired EM-1000 multibeam bathymetric data now show that two types of these features exist on the southeast Monterey Bay shelf: the dominantly shore-parallel type in 10-30m water-depth and the shore-normal type at greater water depths, to 60m. Both types tend to have thin pinch-outs that point offshore. The shore-normal, deep-water type is concentrated in one area that has been called a nodal zone for alongshore sediment transport separating the consistently southerly flow off northern Fort Ord from the variable and northerly flow off southern Fort Ord. The inter-trough areas of the shore-normal troughs are flat featureless plains with small ripples populated with abundant short seapens. No large crecentic dunes exist in the inter-trough areas as is the case on the shelf off north-central California. Repeated measurements show that, whereas the shallow shore parallel troughs are extremely dynamic, with major changes in shape over periods of months, the deep shore-normal trough system shows no change whatsoever, within the accuracies of differential GPS navigation.
Fernandez, Daniel M.
CSU Monterey Bay, Institute for Earth Systems Science and Policy, 100 Campus Center, Seaside, CA 93955
SATELLITE SYNTHETIC APERTURE RADAR, CODAR, AND IN SITU MEASUREMENTS OF OCEANIC FEATURES IN MONTEREY BAY
Comparisons of images collected by the ERS-1 SAR over Monterey Bay and adjacent coastal regions and comparison of these images to CODAR-derived ocean surface currents and other in-situ measurements in this vicinity yield some interesting correlations between the various data sets. During the spring of 1995 approximately 5 separate SAR images were collected and image distortion corrected (courtesy Atlantic Centre for Remote Sensing of the Oceans and Canada Centre for Remote Sensing). During this same period, regular, hourly CODAR ocean surface current measurements were collected and processed from three CODAR sites surrounding Monterey Bay as part of the UCSC REINAS project (with the Naval Postgraduate school and MBARI as participating institutions). In situ data from two buoys in Monterey Bay as well as 6 coastal meteorological stations complement the SAR images and CODAR data. The MET station data (as well as the CODAR data) was collected as part of the ONR funded UC Santa Cruz REINAS project.
Most notably, within some of the SAR images are highly reflective features that appear to be associated with regions of strong offshore flow in the CODAR ocean surface current data. These could indicate localized upwelling features. Furthermore, calmer regions and the appearance of slick features in Monterey Bay are correlated with more sheltered regions of Monterey Bay and regions of lower wind driven currents as determined by the CODAR data. A comparison of the features seen in each image we have from the ERS-1 SAR and the ocean surface current vectors and in situ data will be discussed.
UC Santa Cruz (In cooperation with Steve Addington, BLM and Ken Gray, CDPR)
THE CONSERVATION OF NATURAL SPECIES AND HABITATS AT FORT ORD: A COMPLEX PROCESS
Closure of the Fort Ord Army base and preparation of a Habitat Management Plan (HMP) has mandated certain protections for 9 federally listed plants and animals and the endemic Maritime Chaparral community. The HMP specifically designates lands to be placed in protected status and the implementation of a Coordinated Resource Management and Planning (CRMP) process. The Bureau of Land Management (BLM), the California Department of Parks and Recreation (CDPR), Monterey County (MC), and the University of California Natural Reserve System (NRS) at UCSC all have specific responsibilities to protect lands as Habitat Reserves and the listed species found on those lands. Other areas are designated with some protective status. The sustainability of the native communities and the listed species will depend on the individual management of each area by it's agency and on the cooperation of all the agencies, facilitated through the CRMP. The HMP is being finalized, monitoring protocols are being designed, funding is being secured and agencies are preparing for the long term protection of the listed elements. We describe the situation to date.
Gilman, Sarah E. (1), Raphael D. Sagarin (2), Charles H. Baxter (3,4), and James P. Barry (4)
1. UC Davis, CA
CHANGES IN THE COMPOSITION AND DISTRIBUTION OF A ROCKY INTERTIDAL COMMUNITY
In order to identify changes over the past 30 years in the floral and faunal composition of Monterey Bay, California, we resampled quadrats established by P. Glynn in an Endocladia - Balanus community at Hopkins Marine Station in 1965. Of the 30 characteristic species of the community, 16 decreased and none increased significantly in abundance between 1965 and 1995. In conjunction, the tidal distribution of Endocladia muricata dropped 1.3 feet. These changes were associated with significant increases in air and surface water temperatures, suggesting that local or regional climate change is driving the observed biological changes.
Hunt, John W. (1), Anderson, Brian S. (1), Phillips, Bryn M. (1), Piekarski, Witold J. (1), Tjeerdema, Ron S. (1) and, deVlaming, Victor (2)
1. University of California, Santa Cruz
INVESTIGATING SOURCES AND CAUSES OF TOXICITY IN A MONTEREY BAY WATERSHED: THE PAJARO RIVER AND LAGOON SYSTEM
The Pajaro River and adjacent sloughs and coastal lagoon form an estuarine system that receives runoff from upstream urban, industrial, residential and agricultural areas. Seven sites in the area were sampled eighteen times over a two-year period, and water samples were tested for toxicity to the mysid Neomysis mercedis, a crustacean that occurs in the estuary. Sampling sites were chosen to identify tributaries to the ponded lower river and lagoon that may serve as sources for toxic runoff. Mysid survival declined significantly in 72% of the samples from agricultural ditches. Samples from the sloughs were toxic 22% of the time. The lower river, lagoon, and upstream river site produced toxic samples 11% of the time. Limited chemical analyses identified three samples in which pesticide concentrations were higher than toxicity thresholds. Toxicity in the lower river and lagoon was significantly correlated with increased river flow. Analysis of temporal patterns indicated that drainage ditches and the upper river may provide toxic runoff to the lower river and lagoon. Distinct temporal patterns in Harkin and Watsonville Sloughs indicate that these may be less significant sources. Potential causes of observed toxicity in two agricultural drainage ditches were investigated by chemically manipulating four selected samples in toxicity identification evaluations (TIEs). Shifting and restoring pH resulted in the elimination of toxicity in all four samples, perhaps implicating major ion imbalances as a cause. Toxicity was not removed by carbon filtration, indicating that non-polar organic pesticides were not responsible for toxicity in these samples.
Department of Ocean Sciences, University of California, Santa Cruz, CA 95064
EFFECTS OF SEA OTTER PREDATION ON BIVALVE SIZE AND BIOMASS IN ELKHORN SLOUGH
Over the last decade Elkhorn Slough, CA has been used seasonally by small numbers of sea otters (Enhydra lutris). In December 1994 it became a permanently-occupied foraging habitat supporting up to 50 otters at a time. Observations of foraging sea otters in Elkhorn Slough between July 1995 and June 1996 showed that the diet consisted largely of the deep-burrowing bivalves Saxidomus nuttalli (Washington clam) and Tresus nuttallii (gaper clam), supplemented by fat innkeeper worms, Cancer crabs, and cockles. There was a significant shift in the diet over the study period: the high- biomass clams (Tresus and Saxidomus) together comprised 72% of the sea otter diet early in the study year, and 72% of these clams were greater than 10 cm in length. Later in the year these species were reduced to 38% of the diet; 82% of the clams selected were less than 10 cm in length and 52% were 5 cm or less. The densities and size distributions of Elkhorn Slough bivalve populations were measured in June 1996. Since 1986 the densities of Tresus and Saxidomus have increased or remained the same. However, for both species the average clam size was smaller in 1996 than in 1986, resulting in a dramatic decrease in clam biomass since the arrival of sea otters in Elkhorn Slough. Within the first 18 months of occupation sea otters depleted the largest size classes of high-quality prey, and consequently switched to smaller sizes and different prey species.
Lonhart, Steve I.
Department of Biology, University of California Santa Cruz
PREDATOR-PREY INTERACTIONS BETWEEN AN INVADING WHELK (KELLETIA KELLETII) AND NATIVE PREY IN MONTEREY BAY
Kellet's whelk (Kelletia kelletii), a subtidal species common in southern California, was first reported in Monterey Bay in 1980. Kelletia brings a functionally different mode of feeding to the guild of invertebrate predators in Monterey Bay. In the field Kelletia feeds on a variety of benthic invertebrates, but primarily on turban snails. To study interactions between an invading predator and native prey, I used a non-choice feeding experiment with four prey treatments: Tegula brunnea, T. montereyi, T. pulligo, and Calliostoma ligatum. For each of 21 replicates, a single whelk was placed in a box with 5 individuals of one prey species. Dead prey were replaced every 2-3 days. Initially, Kelletia ate more T. brunnea than any other species (ANOVA, P <0.001). After 10 weeks, T. brunnea, T. pulligo, and C. ligatum treatments did not differ (SNK test, P <0.05) but T. montereyi was less preferred (ANOVA, P<0.001). Since cumulative feeding rates increased through time, it is possible that whelks began to consume what might normally be considered less preferred prey.
Lonhart, Steve I. (1), Julie A. Hymer (2), Michelle M. Staedler (2), and Hilary F. Waites (3)
1. University of California, Santa Cruz
ARE INVADING WHELKS (KELLETIA KELLETII) IN MONTEREY BAY REGULATED BY SEA OTTERS (ENHYDRA LUTRIS)?
Native predators of an invaded community may play an important role in regulating the establishment and success of an invading species. A subtidal whelk, Kelletia kelletii, from southern California was first reported in Monterey Bay in 1980. In 1996, 476 Kelletia shells were collected from plots within the Hopkins Marine Life Refuge and examined for damage. Most shell debris consisted of spires (20%), body whorls (24%), and whole shells with a large hole above the aperture (44%). To test the hypothesis that sea otters (Enhydra lutris) caused such damage to the thick shells, six sea otters at the Monterey Bay Aquarium were given 1-5 live Kelletia prior to a normally scheduled feeding. All otters pounded the whelks, but only one otter caused extensive shell damage (primarily to the outer lip and siphonal canal) and consumed some tissue. In an area of the HMLR kelp forest where otters were known to forage, 10 Kelletia each were tethered to an exposed reef and the adjacent sandy bottom. After 6 weeks only one Kelletia remained on the reef, while only one was missing from the sand. Although otters have not been observed feeding on Kelletia in the field, they are presumably the only predators capable of causing the extensive shell damage observed in the field and therefore likely to significantly impact the whelk population.
Lorenson,Thomas D. (1), Keith A. Kvenvolden (1), Jonathan B. Martin (2), Norman M. Maher (3), and Daniel L. Orange (3)
1. U.S. Geological Survey, Menlo Park, California 94025
COMPOSITION OF HYDROCARBON GASES IN SEDIMENT OF SMOOTH RIDGE NEAR MONTEREY CANYON
Chemosynthetic 'cold seep' communities occur at a 1,000 m site interpreted as the surface expression of a mud volcano on Smooth Ridge near Monterey Canyon. In order to examine the gas composition of these seeps, sediment samples were collected within and nearby the clam fields using push cores from the Remote Operated Vehicle (ROV) Ventana. Upon retrieval, the cores (maximum length, 30 cm) were subsampled for measurements of a variety of chemical parameters including compositions of hydrocarbon gases. In a collection of 20 samples, methane concentrations range from 1.4 to 7,000 micromol/L; carbon isotopic compositions of the methane range from -71.0 to -86.6 per mil with two exceptions of -53.8 and -30.6 per mil. These results suggest that most of the methane is microbial in origin; the isotopically heavier methane may represent a thermogenic source or oxidation of the microbial methane. Minor concentrations of other hydrocarbon gases (ethane through butanes) accompany the methane. Colonies of clams mark the locations on the seafloor where gas apparently vents through small conduits. The small amount of putative thermogenic methane which was found adjacent to the clam colonies implies that the expulsion of thermally generated hydrocarbons from depth is not the principal driving mechanism for flow in this region; however, microbial production of methane resulting in reduced fluid density could be a factor in facilitating fluid flow at these cold seeps.
Los Huertos, Marc and Steve Gliessman
University of California, Santa Cruz, California, 95064
PATTERNS AND PROCESSES OF NITROGEN DYNAMICS IN VEGETATIVE BUFFER STRIPS RECEIVING FERTILIZER RUNOFF
Studies show vegetative buffer strips can effectively remove fertilizer run-off before contaminating surface and ground waters. In this study, we monitor the ecological processes that determine the effectiveness for three buffer treatments, an annual non-native barley, a mix of perennial native grasses, and a managed treatment that includes mowing and herbicide. Strawberry and flower beds generate channeled water, together with subsurface flow, enter down gradient buffer treatments that are 40 meters long. We collect and analyze the soil water at the top, middle, and bottom of the buffers. The managed treatment had the highest nitrate concentrations, over 30 ppm NO3 N after the first winter rains. Barley has the lowest soil water nitrates and may be more effective as when the groundwater is near the surface. Soil microbial biomass and microbial nitrogen are not significantly different when the runoff was at its maximum. Soil denitrification rates are generally dominated by the slope. There seems to be a treatment effect in the middle of the slope (p<0.05) where denitrification rates are highest in the managed treatment. These results suggest that the management of buffer strips can determine their effectiveness. Furthermore, the Mediterranean determines the plant and microbial mediated processes and how effective buffer strips are at removing nitrates from agricultural runoff.
Lucas, Scot S., Steve I. Lonhart, Giacomo Bernardi, and Pete T. Raimondi
Department of Biology, University of California Santa Cruz
COMPARATIVE SPECIES SURVEY OF A COASTAL CALIFORNIA MARINE REFUGE
A species survey of algae, invertebrates and fishes within the Hopkins Marine Life Refuge (HMLR) was undertaken by students in the first two kelp forest ecology courses taught by John Pearse during Summer 1971 and Fall 1972 quarters. California's Department of Fish and Game conducted fish surveys at an adjacent site in 1969-70. During the Fall quarters of 1995 and 1996, students enrolled in the UC Santa Cruz Kelp Forest Ecology course repeated the surveys to determine major changes over the 25 yr interval. Our results indicate some notable changes. Of particular interest were several species previously known to inhabit southern California kelp forests that had been rare or absent in 1971-72, but were common in the 1995-96 surveys. Key species found included: the crabs Heterocrypta occidentalis and Paraxanthias taylori, the whelk Kelletia kelletii, the bryozoans Diaperoecia californica and Pherusella brevituba, and the anemones Anthopleura artemisia and Urticina piscivora. Furthermore, some species considered conspicuous and abundant in 1971-72 were rare or absent in 1995-96. These included the anemone Epiactis prolifera, the shrimp Heptacarpus palpator, and the fishes Hypsurus caryi and Sebastes mystinus. Although HMLR is a reserve protected from fishing, the number of rockfishes and surfperches were lower than the number observed in 1971-72. Further analysis must be undertaken to establish which factors, including climate change, might be responsible for the differences observed.
U.S. Geological Survey, 345 Middlefield Rd., Menlo Park, CA 94025
CURRENT-WINNOWED COARSE-GRAINED SEDIMENTS AT THE POINT SUR PINNACLES OFF CENTRAL CALIFORNIA YIELD A DIVERSE MICROFAUNA
Coarse-grained sediments with a significant biogenic component were collected by SCUBA divers off Point Lopez (36=B001.2'N, 121=B034.9'W) and Slate Rock (36=B007.6'N, 121=B039.1'W) at water depths of 18 and 21 meters, respectively. These samples contain a diverse microfauna, including forty-five species of benthic and planktonic foraminifers. The benthic foraminiferal fauna is dominated by Cibicides fletcheri, Alveolophragmium columbiense, Rotorbinella turbinata, Trochammina pacifica, Cassidulina californica, C. tortuosa, and Rosalina globularis. Less abundant constituents include Planulina exorna, Cibicides lobatulus, Buccella frigida, Elphidiella crispum, Elphidium magellanicum and Trochammina kelletae. Many of these species exhibit an attached mode of life to either coarse-grained sediments or plants, a strategy which is well suited for the harsh conditions resulting from the swift currents in the area. The benthic foraminiferal fauna in these sediments is also quite distinct from any other found on the Monterey Bay shelf. Instead, it looks remarkably similar to the fauna collected from the turbulent waters of Cordell Bank to the north. As expected, only a few planktonic foraminifers were recovered from the Point Lopez and Slate Rock sediments due to the relatively shallow depth of these sites, as they prefer to live offshore in the open-ocean over the shelf break and slope. Planktonic foraminiferal species recovered include the upwelling-indicator species Globigerina bulloides and the warm-water indicating (right-coiling) form of Neogloboquadrina pachyderma.
Miller, Douglas K.
Naval Postgraduate School, Meteorology Department
ON THE IMPORTANCE OF VERTICAL RESOLUTION IN INITIAL MODEL TEMPERATURE AND VAPOR FIELDS FOR NUMERICAL SIMULATIONS OF A SEA BREEZE CIRCULATION
The availability of nonhydrostatic mesoscale models has made numerical simulations of weather events with very fine horizontal resolutions possible. It seems intuitive that accurate simulations of mesoscale weather phenomenon would also require fine model vertical resolution. An important issue that must be addressed is whether the cost of a fine vertical resolution is justified for accurate mesoscale simulations when only coarse vertical resolution data is available in model initialization. In other words, does coarse vertical resolution input data introduce error in model initialization that cannot be overcome once the model has passed its spin-up period? Naturally, this question applies primarily to simulations initialized with no clouds or precipitation (cold start) and with coarse vertical first guess model information.
This issue will be examined in the context of a Monterey Bay sea breeze circulation that developed on 7 June 1996 using the PSU/NCAR Mesoscale Model Version 5 (MM5) and soundings collected at the Naval Postgraduate School (NPS) for model temperature and vapor initialization. The onset of the sea breeze circulation will be compared for cases where the model has been initialized with fine and coarse vertical resolution temperature and vapor information.
Mullan, Anne T. and Cogan, Christopher
University of California, Santa Cruz
MANAGING HUMAN IMPACTS ON SALMONID HABITAT IN CENTRAL CALIFORNIA
Human interactions with salmonid habitat must be managed to maintain sustainable salmon populations. To manage habitat successfully, we should evaluate how various activities affect population levels, and how phenotypically or genotypically distinct stocks respond. Some of the main impacts which degrade habitat result from urbanization, agriculture, and logging. A necessary step in evaluating the extent of these impacts is to examine land use patterns in the watersheds of interest. This study focuses on steelhead (Oncorhynchus mykiss) habitat in the Central California Coast region. Spatial analysis of land use patterns shows the extent to which each activity impacts steelhead in the regions watersheds. Based on this analysis, we will recommend effective changes to maintain stable populations. The stocks in this area are currently proposed by the National Marine Fishery Service for listing as endangered, lending urgency to this work.
U. S. Geological Survey
INVESTIGATIONS OF TRANSPORT PATHWAYS FOR WATER AND SEDIMENT BETWEEN THE FARALLON SHELF AND MONTEREY BAY
It is generally thought that water and resuspended materials on the Farallon shelf move as a single unit. In late spring and early summer, the cold, nutrient-rich, upwelled water that makes this area productive joins fresher water from San Francisco Bay and flows generally southeastward towards Monterey Bay. It is not known if this water and suspended material directly enters Monterey Bay or is diverted offshore at Año Nuevo, a strong upwelling center. The cold, nutrient-rich surface waters can move offshore in a jet. A tongue of this cold surface water is sometimes observed fairly far offshore, extending across the rim of Monterey Canyon. In summer, the surface water inside Monterey Bay itself tends to flow in a counter-clockwise gyre. Hence at the northern end, there is a convergence of westward flowing surface water from the bay and southeastward flowing water from the Farallones shelf. Exactly what happens at this convergence zone is not known. Water from the shelf may be forced offshore or it could override the outflow from Monterey Bay and enter the bay directly. There are no observations that tell us the fate of mid-depth or near-bed waters and suspended materials. We deployed 5 moorings in August, 1996 across the shelf and within Monterey Bay for one year to investigate these processes.
Paduan, Jeffrey D., Leslie K. Rosenfeld, and Michael S. Cook
Dept. of Oceanography, Naval Postgraduate School, Monterey, CA 93943
DIURNAL SURFACE CURRENT FLUCTUATIONS IN MONTEREY BAY FROM CODAR-TYPE HF RADAR
Diurnal-period surface current fluctuations in the coastal waters of Monterey Bay are described based on measurements from a network of CODAR-type HF radar sites. Emphasis is placed on the summertime conditions when diurnal sea breeze forcing dominates the near surface (~1m) HF radar measurements. The amplitude of diurnal current variations (~20 cm/s) is comparable to the strongest portions of the background circulation within Monterey Bay. Peak currents are directed onshore in the early afternoon immediately following onset of sea breeze forcing. Closer to shore, surface currents rotate clockwise out from under the wind forcing, and the entire diurnal surface current response decays offshore out to ~50 km, similar to the observed off-shore limit of sea breeze forcing. Mooring data show that the depth extent of the wind-forced diurnal fluctuations is limited to the upper few meters of the water column. Tidal analyses of month-long time series reveal different spatial patterns for the diurnal surface currents, which are dominated wind forcing, versus the semidiurnal surface currents, which are dominated by internal tides and the complicated local bathymetry.
University of California, Santa Cruz
STABILITY AND FLUX IN THE ROCKY INTERTIDAL
Ten rocky intertidal platforms along the coast of central California were surveyed for invertebrate species richness in 1971-73 and again in 1996, after droughts, floods, and an earthquake had perturbed the area. Quantitative data on dominant species were also collected periodically over the intervening 24 years. Sites varied in topography, rock type, exposure to the open ocean, and use by people and pinnipeds. Over 500 species were recorded, with species richness, species similarity among sites, and dominant species abundance remaining similar between the two study periods, even for the sites heavily impacted by people. However, there was on average a 50% species turnover at each site between the two study periods, and the full species inventory method detected fluctuations that would have been missed within the constraints of quantitative data collection. The species flux mainly reflected appearance and disappearance of rare species; there was little evidence of southern species replacing northern species, as might be expected from suspected global warming, or of any other major shifts. Supported by California Sea Grant and the Monterey Bay National Marine Sanctuary.
Pincetich, Christopher and Kathleen Reaugh
University of California at Santa Cruz
SITE FIDELITY AND HOMING BEHAVIOR IN THE INTERTIDAL WOOLY SCULPIN, CLINOCOTUS ANALIS.
The locations of individual intertidal fish of the species Clinocotus analis were tracked among five pre-determined tidepools within a 200 m2 area of a Santa Cruz Mudstone shelf. From Feb 2, 1996 to May 20, 1996, 31 Clinnocotus analis were tagged and their locations within the study site recorded during periods of low tide when all five pools were isolated from incoming surf. In phase 1, from February 2 through April 4, the locations of the fish were determined through a thorough searching of the tidepools in the study site. For phase 2, April 4 through May 20, the tagged fish that we could find were all relocated to a foreign pool to determine if they would exhibit a philopatric homing behavior with respect to their pool of first capture. A significant difference from random Brownian movement was observed in the low-tide behavior of Clinocottus analis. The patterns revealed by this tag and release study suggest the fish are able to successfully return to their habitable "home" pool at successive low tides, ensuring the survival of this inter-tidal species.
Pomeroy, Caroline (1) and Julie Beck (2)
1. Institute of Marine Sciences, UC Santa Cruz
AN EXPERIMENT IN COOPERATIVE MANAGEMENT: PRELIMINARY FINDINGS ON THE BIG CREEK HOOK AND-LINE KELP BED SURVEY
Management of coastal fisheries along California's 1100 mile coastline is a daunting task, made more complicated by the scarcity of public funds for research and management. Cooperative management among fishermen, researchers and managers to provide much-needed data and other management services offers a potential alternative or complement to traditional resource management. Since 1991, Big Sur fishermen have systematically collected rockfish samples and other fishery data in connection with their small-scale commercial fishing adjacent to Big Creek Marine Ecological Reserve. In a pilot study sponsored by UC Santa Cruz' Monterey Bay Regional Studies program, we explored the arrangement as a local institution for common pool resource management. Our goals were to describe and explain the arrangement, and identify questions for further research. We provide an overview of that analysis and our preliminary results. We argue that the hook-and-line survey, and the cooperation between fishermen and the reserve manager, constitute an experiment in cooperative management that should be evaluated to determine how the arrangement and the information generated can be integrated into fishery and reserve management at Big Creek. The Big Creek approach should then be considered as it might be adapted for use in other coastal fisheries, to provide resource managers with timely information at very low cost to the state.
Rein, Felicia A.
University of California at Santa Cruz
EFFECTS OF NATIVE PERENNIAL GRASSES ON NON POINT SOURCE POLLUTANTS IN ELKHORN SLOUGH
Previous research, mostly on the east coast, has shown that vegetative buffer strips are effective at protecting water quality. The goals of this research are to determine whether native perennial grasses serve to restore native biodiversity while simultaneously capturing both sediments and nutrients from adjacent conventional row-cropped agriculture. Buffer strips bordering Elkhorn Slough have received one of three treatments: annual non-native grasses, perennial native grasses, or no vegetation. I am measuring sediment movement and quantifying nitrogen and phosphorus pools in soil, surface water, groundwater and vegetation. Preliminary results indicate that the amount of erosion differs significantly between treatments.
Sagarin, Rafe David (1), Sarah Gilman (2), Jim Barry (3), Chuck Baxter (3)
1. U.C. Santa Barbara
THE LONG AND THE SHORT OF IT: CLIMATE AND COMMUNITY CHANGE AT HOPKINS MARINE STATION, MONTEREY, CALIFORNIA, USA
Changes in the intertidal community at Hopkins Marine Station (HMS) were investigated along a transect surveyed in 1930, 1993-1995, and again in 1996. In the first resurvey (1993-94) it was found that southern species generally increased in abundance, northern species generally decreased, and cosmopolitan species showed no trends. These changes occurred concomitant with an increase in annual shoreline temperature of 0.8 degrees C on average, and 1.9 degrees C in summer temperatures, suggesting a climate-related faunal shift. In an effort to more fully understand the role that short term variation may have played in these trends, I resampled 19 of the plots we first resampled in 1993. In the short-term comparison, the pattern of range-related changes does not hold. However, when 1996 data are compared to 1933, the pattern is restored, suggesting that such patterns may take several decades to appear. This study shows both the importance of long-term data sets, and the need for protected scientific refugia, such as HMS.
1. NOAA-NMFS, Pacific Fisheries Environmental Group
MAPPING BENTHIC FISH HABITATS AND OCEAN CURRENTS IN THE BIG CREEK ECOLOGICAL RESERVE
Characterizations of benthic fish habitat and coastal ocean circulation patterns are critical steps in evaluating the effectiveness of the Big Creek Ecological Reserve at protecting and enhancing coastal resources. With the coordinated efforts of geologists, biologists, and physical oceanographers, data were collected during a three-day (3-5 June 1996) research cruise onboard the NOAA ship McArthur . We used side scan sonar to survey the seafloor in deep water (30-250 m), and have created maps of predicted bottom types. We have identified and quantified eight types of potential habitat, ranging from sand ripple fields to extensive rock outcrops to isolated pinnacles. This information will help direct our next efforts to assess the fishes and their habitat associations within the Reserve.
We also characterized patterns of ocean circulation over the continental shelf and upper slope (to 30 km offshore). Upwelling and substantial offshore transport off Point Sur and Lopez Point are evident in temperature, salinity, and current data collected at sea and in satellite surface temperature (SST) imagery. Counter to the traditional view of a southward flowing California current, we found coherent 10-25 cm/s flow to the north out to ~20 km from shore. This northward flow contributes to the convergence of water and offshore transport at Point Sur. This information will help us define the physical processes that affect the distribution, transport, and survival of young fishes, and clarify our expectations for recruitment from the Reserve to nearby unprotected areas. Partial funding for this study was received from the Monterey Bay National Marine Sanctuary.
University of California at Santa Cruz
THE ESTABLISHMENT OF AN INTRODUCED BRYOZOAN, WATERSIPORA SUBTORQUATA, IN MONTEREY BAY HARBORS AND ESTUARIES
Recent surveys of local harbors and Elkhorn Slough have revealed the presence of an introduced bryozoan species, Watersipora subtorquata, on pilings, docks, boats and jetties. The origin of this bryozoan is not clear due to taxonomic difficulties, but Watersipora species have been reported from San Francisco Bay since the mid-'80s and from Southern California since 1967. Watersipora species have become important fouling pests in Australia and New Zealand, where they have been since the mid-'50s. In Auckland harbor, Watersipora has reportedly attained 100 percent cover in the lower intertidal, smothering and displacing other species. Although Watersipora subtorquata is quite abundant in local harbors, particularly on floating docks, it has not turned up in surveys of the rocky intertidal of the open coast, including areas immediately adjacent to the harbors, and may be restricted to low-energy waters. Current research is exploring possible reasons for its failure to colonize the open coast.