Poster Session: Abstracts & Awards
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.
1999 Best Overall Poster
Lonhart, Steve I.
Dept. of Biology, University of California, Santa Cruz, CA
1999 Best Regional, Inter-Disciplinary Poster
R. P. Michisaki, F. P. Chavez, G. E. Friederich, J. T. Pennington, B. Schlining, C. Fayos, P. Walz, C. Sakamoto, R. Hopcroft, R. Kudela, C. Castro, E. Mauri
Monterey Bay Aquarium Research Institute
1999 Best Student Poster ($100 Award)
Los Huertos, Marc W.
Environmental Studies, University of California, Santa Cruz, CA
DO VEGETATIVE BUFFERS STRIPS CAPTURE NITROGEN LEAVING ROW CROPS ALONG THE CENTRAL COAST OF CALIFORNIA
Poster Session Abstracts
Asanuma, H. (1), F. Chavez, C. Collins (1), R. Michisaki (2), T. Rago (1)
1. Department of Oceanography Naval Postgraduate School, Monterey, CA
2. Monterey Bay Aquarium Research Institute
Hydrography Of The California Current System Off Central California, 1997-1998
A hydrographic section (CALCOFI Line 67) to the west-southwest of Monterey Bay was occupied bimonthly during 1997-1998. The section extended from the coast to a distance of 200 n.miles offshore and observations extended from the surface to a depth of 1000 m when bottom depth permitted. Stations were typically 10 n.miles apart. Results are used to describe the temporal evolution of hydrographic conditions. Next to the coast, warm and saline waters were observed to flow poleward from summer 1997 through early winter, 1998. In early 1998, these were replaced by equatorward flowing waters, which were fresh and low in nutrients. Results are compared with observations made during 1997-1998 and with time series from moored coastal buoys.
Benson, Scott (1), Andrew DeVogelaere (2), and James T. Harvey (1)
1. Moss Landing Marine Laboratories, P.O. Box 450, Moss Landing, CA 95039
2. Monterey Bay National Marine Sanctuary, 299 Foam Street, Suite D, Monterey, CA 93940
Monitoring Beachcast Marine Birds And Mammals In Monterey Bay
In May 1997, a monitoring study of beachcast birds and mammals was established in the Monterey Bay region. During monthly surveys, 44 trained volunteers systematically searched 47 km of sandy beaches within Monterey Bay. The purpose of the program is to assess trends in the distribution and abundance of beachcast marine birds and mammals, and assist the Monterey Bay Sanctuary program with early detection of mortality events caused by natural and anthropogenic perturbations. Counts of beachcast seabirds were variable during 1998. The greatest seabird deposition occurred during April through July, and few were encountered during February and December. Common Murre (Uria aalge) was the most frequently encountered seabird during 1998, accounting for over 29 percent of all beachcast seabirds. Counts of beachcast seabirds were greater during May - December 1998 than during the same period in 1997. A four-fold increase in the presence of marine mammal carcasses occurred between May and June 1998. California sea lion (Zalophus californianus) was the most frequently encountered marine mammal. It is suspected that the increased deposition of marine mammals resulted from the unusual presence of female California sea lions in Monterey Bay and a toxigenic bloom of the diatom, Pseudo-nitzchia, along the central California coast during May.
Dept. Ocean Sciences, University of California Santa Cruz
The Mussel Mytilus : Recruitment And Predation On A Monterey Bay Exposed Intertidal Bench
The sea mussel, Mytilus californianus, is the dominant space occupier on an intertidal bench at Terrace Point located at the northern end of Monterey Bay, California. In contrast, adults of the bay mussel, Mytilus trossulus/galloprovincialis, are consistently absent from this site even though newly settled individuals are occasionally observed. The mussel bed was sampled monthly for species composition and mussel recruitment from May 1997 to August 1998. While newly recruited bay mussels were observed during this period, individuals greater than 10 mm total length were extremely rare. Field and laboratory experiments indicated that a major predator at this site, the whelk Nucella spp. exhibits a strong preference for bay mussels of all sizes. These results indicate that the dominance of sea mussels at this location may be due to a combination of differential recruitment and post-settlement survivorship driven by predation.
Forde, Samantha E.
Biology Department, University of California Santa Cruz
Spatial Variation In Nearshore Oceanographic Processes: Correlations With Intertidal Community Structure
Past theoretical work in marine ecology proposed that dramatic variation in barnacle recruitment common to the central California coast could be explained by the dynamics of upwelling patterns (Roughgarden, et al. 1988). Further, while it has been demonstrated in many systems that recruitment variability is correlated with adult numbers, the implications of this variation on local community interactions is less clear (Keough and Downes 1982, Gaines and Roughgarden 1985, Keough 1986, Raimondi 1991). The work presented here is part of research investigating the link between small-scale oceanographic processes, variation in input of a dominant member of the intertidal community (the barnacle, Balanus glandula), and community structure along the central California coast.
Experiments were established along the Monterey peninsula at sites I had a priori reason to believe would differ in the nearshore upwelling patterns. I used the Bray-Curtis similarity index to compare community structure between sites, which could be a function of differences in local oceanographic processes at each site. The results of this research lend insight into whether chronic differences in nearshore oceanography result in differences in community structure. Future experiments will test for the mechanisms (e.g. spatial variation in barnacle recruitment or upwelling of nutrients) that may result in differences in the structure of intertidal communities along the central California coast.
Jaffe, Bruce (1), Curt Storlazzi (2), Roberto Anima (2), Deirdre Scholar (2), and Don Canestro (3)
1. Coastal and Marine Geology, US Geological Survey, Menlo Park
2. Coastal Geology and Imaging Lab, UC Santa Cruz
3. Dive Safety Program, UC Santa Cruz.
Investigations Of Hydrodynamics And Sediment Transport In The Monterey Bay National Marine Sanctuary
The Monterey Bay Sediment Exchange Experiment (MOBSEE) is studying hydrodynamics, sediment movement, and water properties at a site on the inner shelf near Davenport to improve our knowledge of the pathways and processes of sediment transport in Sanctuary. A shallow-water environmental monitoring station roughly 400 m offshore in 12 m water depth measures currents, water levels, waves, bed level changes, temperature, salinity, water clarity, and material suspended in the water column every hour. This study has been collecting data for more than a year; the data set is not continuous, however, because of instrument failures and servicing time between deployments. The environment in which the instrument has been deployed is extremely energetic. Wave orbital flows near the bottom during storms are nearly 100 cm/s in the spring and summer; in the fall and winter these flows have greatly exceeded 100 cm/s. Combined with mean currents that can attain velocities greater than 20 cm/s, these flows transport large quantities of sediment and result in a very unstable seafloor. Individual storms can cause the seafloor to erode or accrete more than 10 cm. Additional results on water properties, hydrodynamics, and sediment transport magnitudes and directions are presented.
Janousek, Christopher N.
Department of Biology, University of California Santa Cruz
Symmetry Variation And Deformity In Ephyrae Of Aurelia (Scyphozoa)
Variation in radial symmetry (i.e. number of marginal lobes) of Aurelia sp. ephyrae is common in the laboratory and parallels field observations made by other researchers. The extent of variation differs by genotype. Other non-symmetry-related morphological abnormalities also occur and rise in frequency as the proportion of non-octuple ephyrae produced by a given clone of strobilae increases. Ephyrae with more than eight marginal lobes are more common than those with less than eight marginal lobes, regardless of genotype. Ephyrae of various symmetries, raised over nearly ten weeks under identical conditions showed slightly different (but not statistically significant) growth rates. Ephyra success in food capture and swimming ability is probably not significantly affected by symmetry variation but may be by more egregious abnormalities.
Few studies have rigorously considered aspects of the morphological plasticity of the Cnidaria. This work helps elucidate the extent of variation in the Aurelia body design and lays groundwork for further investigation of natural or anthropogenic causes of developmental variation.
Kilbourne, Kelly Halimeda (1), Michael E. Field (1), James V. Gardner (1), and Chris Jenkins (2)
1. U.S. Geological Survey, Menlo Park, CA 94025
2. Ocean Science Institute, University of Sydney, NSW, Australia
A New Method For Variable Scale Description Of Benthic Habitats
Increased concern about the sustainability of commercial and sports fisheries has intensified efforts to map benthic habitats on the US continental shelves. To address this problem, we are developing a method of seafloor data management to be used for mapping seafloor habitats at various scales. This project is a version of the AUSEABED project developed in Australia to map the entire Australian seafloor. The system uses fuzzy logic algorithms to convert verbal descriptions of the sediment into estimated numbers. The approximations can then be compared with other quantitative data in the database using GIS software.
Because different research questions require information about different sediment attributes, we are attempting to build a database that can be manipulated to suit individual needs. The database can be queried to select attributes that may be useful for resolving questions about specific seafloor characteristics or benthic processes. The scale and projection of the maps are also changeable. Thus both regional and small scale maps can be produced for any number of uses.
Linthicum, Janet, Brian Walton, Brian Latta, Craig Himmelwright, and Glenn Stewart
Santa Cruz Predatory Bird Research Group, UCSC
Status of Peregrine Falcons (Falco Peregrinus) In The MBNMS Region
Eggshell thinning effects of the now restricted pesticide DDT caused near extirpation of peregrine falcons in California. In 1970, searches revealed no breeders in the region now encompassing the Monterey Bay National Marine Sanctuary (MBNMS), and the state's breeding population did not exceed 15 pairs. Since 1975, we have conducted hands-on management of the species throughout the state, with particular interest in what is now the MBNMS region. We removed thin-shelled wild eggs from coastal nests in the MBNMS area for artificial incubation, and fostered 84 young from wild- and captive-laid eggs into them. The Central Coast population increased from one nest at Morro Rock to the current known 13 pairs nesting within the area of influence of the MBNMS ecosystem. Hands-on management in the region ended in 1990. Subsequently, despite continued eggshell thinning near or exceeding levels associated with population declines, banding data has shown that the local population has maintained itself and is expanding through local reproduction and immigration. While DDE levels have declined in lower-trophic level animals in the region, peregrines, continue to accumulate enough DDE to result in recent eggshell thinning levels averaging 18.8 percent (n=18 clutches). We expect continued expansion because the main causes of decline, DDT and shooting, have been reduced.
Dept. of Biology, University of California, Santa Cruz, CA
Feeding Preferences Of Invasive And Native Turban Snail Predators
Novel function has been proposed as a potential mechanism Å contributing to the successful establishment of invasive species. The recent expansion of Kellet's whelk (Kelletia kelletii) north of Point Conception into central California added a novel functional feeding mode to the guild of invertebrate predators that consume turban snails. Whelks feed with a proboscis while sea stars, common predators of subtidal turban snails, feed with an eversible stomach. In a series of laboratory experiments, I compared consumption rates and feeding preferences of whelks and sea stars for several allopatric Tegula species from southern and central California. Predators included the giant-spined sea star (Pisaster giganteus) from southern and central California, the Fragile Rainbow star (Astrometis sertulifera), a southern California native, and Kellet's whelk (Kelletia kelletii) from southern and central California. I also tested for local adaptation among predators and prey by comparing whelks and Pisaster from both southern and central California. The novel feeding mode of the whelk did not contribute significantly to higher feeding rates. Sea star and whelk preferences among turban snails were identical irrespective of the geographic origin of prey. There was no evidence of local adaptation. Despite its novelty for central California turban snails, the whelk's functional feeding mode apparently has not contributed significantly to successful establishment of the whelk.
Lonhart, Steve I.
Dept. of Biology, University of California, Santa Cruz, CA
Comparing Size-Frequency Distributions Of A Subtidal Whelk In Native And Invaded Habitats
Invasive species often experience an ecological release in non-native habitats due to the absence of coevolved natural enemies. This release can lead to invader population explosions and significant changes in life history characteristics. The recent expansion of Kellet's whelk (Kelletia kelletii) into central California is an opportunity to study differences in population structure in native and invaded habitats. I compared size-frequency distributions for whelks in southern and central California over a 4 yr period. In the native habitats, whelk size ranges were greatest, densities were highest, and distribution was nearly continuous. In central California, whelks were primarily small adults, densities were low, and populations were patchy. Whelks in Monterey Bay consist of a few closely overlapping cohorts with some evidence of weak, episodic recruitment. This recruitment pattern may be the result of planktonic larvae carried northward during ENSO events, making central California populations larval sinks of southern California source populations.
Environmental Studies, University of California, Santa Cruz, CA
Do Vegetative Buffers Strips Capture Nitrogen Leaving Row Crops Along The Central Coast Of California
Elevated nitrogen (N) concentrations in groundwater and surface water in many watersheds of the Monterey Bay, CA, are primarily derived from agricultural production. Vegetative buffer strips (VBSs) successfully remove N from agricultural runoff along the Atlantic Coastal Plain. Local policy makers have proposed the use of VBSs to improve runoff water quality leaving heavily fertilized row crops. I compared three buffer treatments (a perennial grass mix, barley, and a treatment composed of volunteers), that received N from an adjacent agricultural field. In the buffers, I measured several pools of N for three years: soil inorganic N, vadose water nitrate, plant and microbial N, and total soil N. Soil inorganic N concentrations varied seasonally with peak nitrate in soil and vadose water occurring prior to and during the onset of the first rains after the summer drought. Regardless of treatment, results suggest that plants and microbes assimilate inorganic nitrogen during the winter and spring, but then release inorganic N each summer and fall. The release of inorganic N is available for leaching and has the potential to contaminate surface waters. Therefore, VBSs may not prevent N loading from agricultural runoff along the central coast of California.
McCann, Mike (1), Jennifer Paduan (1), Don Brutzman (2)
1. Monterey Bay Aquarium Research Institute
2. Naval Postgraduate School
Interactive 3d Data Visualization In Monterey Bay
The Virtual Reality Modeling Language is used to create interesting visualizations of the variety of data collected by the Monterey Bay Aquarium Research Institute. With this technology we can distribute diverse data sets over the World Wide Web in a common, compelling, efficient, and easy-to-use system. This technology will enable scientists and submersible operators to view dive sites on a larger scale than possible through the camera's eye and merge this view with archived data and images. Our poster will describe this collaborative project between MBARI and the Naval Postgraduate School. We will demonstrate a prototype scene showing real data from deep-water sites in Monterey Bay. Attendees will be able to sit and interact with the scene, gaining insight into how visualization with 3D graphics can help research and education.
U.S. Geological Survey, Menlo Park, CA
Early 20th Century Record Of Microscopic Organisms (Foraminifers) In Monterey Bay, California
In 1930-31, E. Wayne Galliher of Stanford University collected bottom samples from Monterey Bay, California in order to describe the nature and geographic distribution of the sediments in the region. Recently, archived assemblage slides of the microscopic organisms (benthic and planktic foraminifers) obtained from these sediment samples were located and the benthic species analyzed for faunal composition. Although no information is available regarding the method by which the foraminifers were extracted from his samples, it appears that they were picked in relative proportion to their total occurrence in the samples. If true, their abundances can be compared to those of foraminifers from sediment samples recovered by the USGS from the shelf of Monterey Bay over 60 years later (1995 and 1997). The foraminifers of Galliher's 1930s samples fall into five groups, or biofacies: nearshore, mid-shelf, outer shelf, and two from the southern portion of the shelf from Fort Ord to Pt. Pinos. All of the assemblages are dominated by specimens with calcareous shells. In contrast, five out of seven of the foraminiferal assemblages from the late 1990s samples are dominated by arenaceous shells composed of sand and mineral grains. It is possible that these arenaceous specimens were not included in the 1930s data set simply because they were not picked or because they were not even recognized as foraminifers. Considering this omission, it is surprising that the geographic distribution of the seven biofacies defined by the 1990s data is in general agreement with that of the 1930s, although it is somewhat more complex.
Monterey Bay Aquarium Research Institute
Detecting The Effects Of Global Change In The Open Ocean Waters Of Monterey Bay, California
Atmospheric scientists and physical oceanographers have long realized the importance of defining climatological conditions in order to detect interannual and longer scale variations. Key to this is uncovering the processes that determine the climatological conditions because without this it becomes difficult to understand and predict the effects of climate and global change. Data presented here is from a ten-year time series of ship occupations of five major stations in Monterey Bay that began in 1989 and includes data from the 1992-93 and 1997-98 El Niño's. Our primary focus is phytoplankton, the organisms that form the base of the Monterey Bay ecosystem. We have concentrated on determining the mean and fluctuating components of phytoplankton biomass, production and species composition. We seek also to find the physical, chemical and biological processes responsible for the mean and fluctuating components. Here we report the climatological conditions, the biological consequences of El Niño, as well as long term trends. There is clear physical-biological coupling in the time series, starting with the seasonal cycle. There is a maximum in nutrients, centric diatoms, chlorophyll, and primary production associated with the upwelling season. The so-called oceanic and winter seasons and their characteristics will also be described. Chlorophyll levels dropped during the warmer El Niño years (-19% in 1992 and -21% in 1997), and during colder years levels have risen (+19% in 1991 and +11% in 1994). Phytoplankton biomass dropped by 15% in 1992 and 27% in 1997, and rose in 1995 by 29%, a year in which the average temperature is gradually rising over the course of the ten-year study, while chlorophyll, primary production and nitrate levels are decreasing.
Ryan, Holly, and Marlene Noble
U.S. Geological Survey, Menlo Park
El Niño-Forced Temperature And Sea Level Along The Central California Coast During 1997-98
Beginning in the spring of 1997, we observed increases in daily-averaged sea level at San Francisco and sea surface temperatures at the Farallon Islands located west of San Francisco. An array of 3 temperature sensors deployed offshore of Davenport (north of Santa Cruz) on the shelf in 120 m of water showed a rise in temperature throughout the water column and a deepening of the thermocline associated with the higher sea levels. The sea level and temperature increases are partially forced by coastally-trapped waves that formed near the equator and propagated northward along the coast of central California. In addition, unusually strong winds blowing to the north contributed to downwelling conditions that further increased sea level and temperatures at the coast in the fall and winter. By November, 1997, the sea temperatures to over 100 m depth on the shelf were above 15°C, with some of the highest sea level anomalies ever recorded at San Francisco occurring during major storms. Near the end of February 1998, both sea level at San Francisco and temperatures at depth on the shelf at Davenport abruptly dropped (over 30 cm and about 5°C) over a relatively short time period of several days.
Moss Landing Marine Laboratories
Monterey Bay Aquarium Research Institute
Seasonal Intrusions Of Equatorial Waters In Monterey Bay
Between January 30, 1991 and July 31,1995, the Monterey Bay Aquarium Research Institute's (MBARI) remotely-operated vehicle (ROV) Ventana made one-hundred-four dives to observe hydrography and abundances of mesopelagic animals. The locations of the dives were 36o 42' N, 122o 02' W, near the center of the mouth of Monterey Bay and over the axis of the Monterey Submarine Canyon. Analysis of hydrography between the surface and 1000 m showed annual intrusions of three water masses into Monterey Bay. Using characteristics of these intrusions along with information from acoustic Doppler current profiler (ADCP) data, the year was divided into four hydrographic periods, Upwelling (April-June, days 90-182), Oceanic-CUC (July-September, days 183-274), Early Davidson (October-November, days 275-334), and Late Davidson (December-March, days 335-89).
Stanbury, K.B. and R.M. Starr
University of California Sea Grant Extension Program, P.O. Box 440 Moss Landing, CA 95039
Applications Of Geographic Information Systems For Marine Resource Assessment And Management
Marine scientists often assess habitats to understand the distribution and relative abundance of marine resources. Due to the spatial nature of habitats and associated temporal changes, however, assimilating data using traditional analytical methods is often difficult. Geographic Information Systems (GIS) are proving to be effective tools to help address problems inherent in the analysis of spatial data. GIS can be used to effectively collate, archive, display, analyze, and model spatial and temporal data. Additionally, by combining dissimilar data types, such as socio-political boundaries, bottom types, and fish distributions, for example, resource managers can use GIS to make informed management decisions. In this way, GIS provides resource managers with a means to integrate scientific data with prevailing cultural values and traditions. We have developed a working GIS for the Monterey Bay National Marine Sanctuary that allows the interpretation of many terrestrial and marine datasets, including intertidal monitoring data, permit locations, seabird strandings, fisheries catch data, habitat types, marine political boundaries, as well as landcover classification from satellite imagery, watersheds, streams, roads, and political boundaries. We have linked terrestrial and marine data to create a broad spatial and temporal database that will be used in a variety of ways such as evaluating natural processes, permitting and monitoring coastal development and assessing environmental impacts (e.g. oil spills).
Starr, Richard M. (1), John N. Heine (2), Korie A. Johnson (1,2,3), Jason M. Felton (1) and Gregor M. Cailliet (2)
1. University of California Sea Grant Extension Program
2. Moss Landing Marine Laboratories
3. Currently with National Marine Fisheries Service
Signals From The Deep: Techniques For Assessing Movements Of Deepwater Rockfishes
In August and September of 1997 and 1998, we used SCUBA techniques to surgically implant Vemco V16 series acoustic transmitters in 17 bocaccio (Sebastes paucispinis) and 6 greenspotted rockfish (S. chlorostictus) on the flank of Soquel Canyon in Monterey Bay. This year we are reporting some of the results from the 1997 work, and describing preliminary information gained from 1998 tagging efforts.
In 1998, we worked with a commercial fisherman to capture and tag bocaccio. Rockfish were captured at a depth of about 100 m, then reeled up to a depth of approximately 20 m. This depth was chosen to reduce temperature and pressure stress caused by bringing fish to the surface. SCUBA divers descended to the depth of the captured fish, then anesthetized and surgically implanted acoustic transmitters in bocaccio. Tagged fish were released on the bottom at the location of catch. Several weeks after fish were tagged, we used the Delta submersible to place an array of recording receivers on the seafloor. The array of receivers enabled the tracking of horizontal and vertical fish movements for a three month period. In September 1998, scientists and pilots were able to re-locate three of the tagged fish by using a deepwater hydrophone on the submersible to navigate to the middle of schools that contained tagged fish. Tagged fish were tracked for a three month period and results indicate that the two species have different movement patterns.
Marine Ecology Lab, University of California Santa Cruz
A Subtidal Survey To Determine The Effects Of Macrocystis Pyrifera Stand Density On The Morphology Of Individual Plants
The subtidal Macrocystis pyrifera stands in Monterey and Carmel Bays were surveyed to determine the effects of stand density on plant morphology. It was hypothesized that as the density of kelp stands increased that there would be a decrease in the amount of overall blade biomass and an increase in the proportion of blades in the canopy. However, the data collected in this April-June 1998 sampling suggested otherwise. There were no significant correlations for either of these relationships. The data indicate a positive correlation between the plant density and the number of blades per stipe in the non-canopy portion of the plant, which was the opposite of what was initially hypothesized. It was also found that blade biomass for canopy blades decreased as a function of increasing blades per stipe. The mechanisms for these relationships are not entirely understood and thus further investigation to determine the validity of these findings is needed.
Storlazzi, Curt D. (1), Michael E. Field (2), and Gary B. Griggs (1)
1. Coastal Geology and Imaging Lab, Univ. of California, Santa Cruz
2. Coastal and Marine Geology, U.S. Geological Survey
The Influence Of Antecedent Topography, Oceanographic Forcing, And Local Tectonics On The Distribution And Transport Of Littoral Sediments Along The Monterey Peninsula And Carmel Bay, California
1Most of the United States' Pacific coastline is characterized by a cliffed, sediment-deficient erosional shoreline with bedrock commonly cropping out in the nearshore and on the adjacent shelf. These outcrops form bathymetric highs and barriers to alongshore sediment transport not commonly observed along depositional, coastal plain shorelines. By examining the sedimentary characteristics, mineralogy, and morphology of 21 beaches along the Monterey Peninsula and Carmel Bay, California, we were able to document the role of the dominant northwesterly incident wave direction, location of major sediment sources, and local tectonic structure on beach morphology and sediment character. Aerial imagery was utilized to map the distribution of sediment and outcropping rock in the nearshore and shallow offshore to a depth of at least 15 m. Two major features were identified by combing the imagery with high resolution bathymetry. Along sections of the peninsula and Carmel Bay facing into the dominant northwesterly wave direction, the littoral sediments collect in shore-normal channels that align with onshore ephemeral stream and/or paleo-stream channels. Beaches oriented roughly 90 degrees to the dominant wave direction also have shore-normal sediment-filled channels. In addition, these shore-normal features are observed to commonly be connected to one another by shore-parallel patches of sediment at a depth generally between 3 m and 6 m. This depth corresponds to the upper shoreface closure depth for active alongshore transport identified by others in northern Monterey Bay. These sediment-filled paleo-drainages appear to play a significant role in the storage and transport of littoral sediments along the rocky shoreline of central California.
Thayer, Julie A., T. Colleen Murray, Michelle M. Hester, William J. Sydeman
Point Reyes Bird Observatory, 4990 Shoreline Hwy., Stinson Beach, CA 94970
Effects Of The 1998 El Niño On Rhinoceros Auklets At Año Nuevo Island, California
Breeding population size, reproductive performance, and prey utilization of the recently colonized population of Rhinoceros Auklets (Cerorhinca monocerata) on Ano Nuevo Island (ANI), have been investigated since 1993. After increases from 1993 to 1997, breeding population size, productivity, chick growth rates, and fledgling weights all declined in 1998, likely due to poor oceanographic conditions brought on by this year's El Niño event. We suspect that the low population numbers probably reflect reduced attendance on the breeding colony, rather than adult mortality. Productivity, chick growth and fledging weights may be influenced by prey availability. Low nesting success was partially due to a high rate of abandonment during incubation, indicating that adult prey availability may have been poor. Our chick diet samples also indicate that prey utilization changed significantly during the nestling period in 1998, with parents foraging predominantly on Pacific saury (Cololabis saira) to rear their chicks. In past years, Northern anchovies (Engraulis mordax) made up a large part of chick diets. Documenting the changes in prey availability and selection among years has important implications for evaluating auklet reproductive performance, as well as the status of the forage fish stocks in central California.
VenTresca, David, James Downing, Marty Gingras, Mike Donnellan, Jennifer Fisher, Scott Clark, and Robert Hornady
California Department of Fish and Game
Very Near-Shore Bathymetry And Substrate Classification From The Big Creek Marine Resources Protection Act Ecological Reserve, Monterey County
California Department of Fish and Game (CDFG) contracted with ABA Consultants to use acoustic methods to describe substrate type and area within the Big Creek Ecological Reserve (BCER). Running transects parallel to shore at approximately 20 meter intervals, bathymetry and substrate information were collected with survey equipment mounted temporarily on CDFG's RV Melanops, a 25-foot Boston Whaler. Indices of substrate roughness and hardness from the RoxAnn Seabed Classification System and sidescan sonar data were collected simultaneously. Here we present a preliminary summary of substrate type across BCER and a sidescan sonogram mosaic. From polygons hand-drawn around RoxAnn point data, approximately 40% (1.17 square km) of areas shallower than 34 m within BCER appear to be rocky substrate suitable for fishes associated with this bottom type. The rest of the surveyed area is of little or unknown value to these fishes. The substrate classifications are tentative and will require groundtruthing via direct observation which we plan to complete in spring 1999.
Willis, Cope M., Curt D. Storlazzi, and Gary B. Griggs
Coastal Geology and Imaging Lab, University of California, Santa Cruz
Comparative Impacts Of The 1982-83 And The 1997-98 El Niño Winters On The Central California Coast
The 1982-83 El Niño-Southern Oscillation (ENSO) event caused over $100 million in damages to California's coastline. Although most indices suggest the 1997-98 winter was more intense than the 1982-83 ENSO event, there was significantly more damage to coastal development during the 1982-83 winter. These damages included undermining of structures, wave or debris impact, and seacliff erosion. Of the areas heavily damaged in 1982-83, only a small fraction experienced repeated damage during the 1997-98 winter. We attribute the difference in coastal response to a combination of oceanographic and anthropogenic factors. During 1982-83, the large wave events tended to coincide with more southerly and higher velocity winds, increasing set-up along the shoreline and beach erosion due to offshore-directed flow. These large wave events also occurred during very high tides, causing the waves to strike the coast with more energy and break closer to shore, increasing their impact on coastal structures and property. During the 1997-98 winter, however, the largest waves arrived during lower tides and coincided with lower wind velocities. These winds also came out of the northwest, reducing set-up along the shoreline and causing net onshore flow, decreasing wave impact. Another important factor contributing to the disproportionate damage between the winters was the higher percentage of shoreline that had been armored by 1997. Most areas significantly damaged in 1982-83 winter were protected by seawalls or revetments during the 1997-98 ENSO event. Improving the understanding of variations in coastal response to extreme storm seasons is essential to bolster the resiliency of our coastal communities.