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.
Poster Session Abstracts
Anima, R.J., S. E. Eittreim, S.E., and A.J. Stevenson
U.S. Geological Survey, Coastal and Marine Geology Team, Menlo Park, Ca. 94025.
HIGH-RESOLUTION SEISMIC IMAGERY OF PALEO-STREAM VALLEYS THAT CROSS THE NEARSHORE CONTINENTAL SHELF OF NORTH-CENTRAL MONTEREY BAY NATIONAL MARINE SANCTUARY, CALIFORNIA
A series of shallow sediment filled channels that align with coastal streams are incised into submerged Miocene to Pliocene outcrop exposures in the nearshore continental shelf of northern Monterey Bay Sanctuary. High-resolution seismic reflection records collected along the north-central Monterey Bay Sanctuary have shed light on the nearshore shelf and its relationship to the onshore geology and topography. A map, produced using high-resolution seismic imagery, shows details of size and shape of paleo-stream valleys. The stream valleys cross the inner shelf, from onshore pocket beaches at the mouths of coastal streams and extend to 45 meters of water depth. These sediment filled, paleo-stream valleys follow nearly straight to sinuous courses out to a larger sediment-filled basin. These paleo-stream valleys are the remnants of streams that cut across the nearshore shelf-platform approximately 18,000 years ago when sea level was 80 to 100 meters lower (Nardin et al. 1981, Mullins et al. 1985). Other work in the area have mapped bedrock exposures of the paleo-stream valleys based on side-scan sonar image interpretations.
Benson, Scott R. (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, Monterey, CA 93940
MONITORING BEACHCAST SEABIRDS IN MONTEREY BAY
In May 1997, a monitoring study of beachcast birds and mammals was established in the Monterey Bay region. During weekly and monthly surveys, trained volunteers systematically searched 47km of sandy beaches along Monterey and Carmel Bays. The primary goal was to assess trends in the distribution and abundance of beachcast seabirds, and assist the Monterey Bay Sanctuary program with early detection of mortality events caused by natural and anthropogenic perturbations. Secondary objectives of the program were to determine the appropriate sampling frequency for beachcast monitoring, and assess the effects of time-of-day and tidal cycles on deposition rates. During the first six months of the program, the most common beachcast seabirds were Common Murre (Uria aalge) and Sooty Shearwater (Puffinus griseus). Two significant deposition events occurred: greater than 400 Common Murres were deposited along beaches in the southern half of the bay during late August (cause undetermined), and greater than 400 birds were impacted by a spill event in the northern half of the bay in October. Although designed largely to identify long-term patterns, this monitoring study has demonstrated its usefulness in resource management over a short six-month period.
Brown, Kristin M. (1), Deirdre C. Scholar (1), Gary B. Griggs (1), Bruce M. Richmond (2)
1. University of California, Santa Cruz, Earth Science Department
2. U.S. Geological Survey, Coastal and Marine Geology Program, Menlo Park, CA
COASTAL MONITORING IN THE MONTEREY BAY SANCTUARY DURING AN EL NIÑO WINTER
The winter coastal storms during the 1982/83 El Niño caused irreversible cliff retreat and beach erosion along much of the California coast. Many homes and businesses were damaged or destroyed, seawalls destroyed and cliffs failed. During 1982-1983, the climatic signal indicating the onset of an El Niño event was either not detected or appreciated. Subsequent studies of the event were conducted but did not include changes in beach morphology. Early detection of the current El Niño event from climatic and oceanographic indicators allowed field studies to be conducted prior to the onset of the El Niño winter storm activity. Initial beach profiles will be used as a baseline from which to document significant coastal change.
The U.S. Geological Survey and the University of California, Santa Cruz Coastal Geology Lab are cooperatively conducting field surveys at ten beaches along a 25 mile stretch of coast in the Monterey Bay National Marine Sanctuary. Eight beaches in Santa Cruz including Natural Bridges, Its Beach, Cowell Beach, Main Beach, Seabright Beach, Harbor Beach, Corcoran Lagoon, and Capitola Beach are being regularly surveyed. North coast sites have been established at Yellow Bank and Scott Creek Beaches. In an effort to document the effect of a major El Niño winter on beach morphology and beach sand volume change in the Monterey Bay National Marine Sanctuary, shore normal profiles with GPS accuracy have been established. These profiles are also used in conjunction with vertical aerial photography to monitor coastal change.
Initial surveys were conducted in September and October of 1997, prior to winter storms. Currently, profile data is collected monthly and surveying will continue through summer, 1998.
Caffrey, Jane M. (1), Sue Shaw (2), Mark Silberstein (2), Andrew De Vogelaere (3), Michelle White (2), Kathleen Thomasberg (4)
1. Elkhorn Slough National Estuarine Research Reserve, 1700 Elkhorn Road, Watsonville, CA 95076
2. Elkhorn Slough Foundation PO Box 267, Moss Landing, CA 95039
3. Monterey Bay National Marine Sanctuary; 299 Foam St, Monterey, CA 93940
4. Monterey County Water Resources Agency, P.O Box 930, Salinas, CA 93902-0930
NUTRIENT INPUTS TO ELKHORN SLOUGH, CA: INTERPRETING AN 8 YEAR RECORD OF VOLUNTEER WATER QUALITY MONITORING
Elkhorn Slough National Estuarine Research Reserve (ESNERR) and the Elkhorn Slough Foundation (ESF) have been supporting a volunteer monitoring program since 1988. Twenty four stations are sampled monthly for temperature, salinity, dissolved oxygen, pH, turbidity, nitrate, ammonium, and dissolved inorganic phosphate. This program represents a partnership among ESNERR, ESF, Monterey County Water Resources Agency, and highly dedicated volunteers.
One significant result is an appreciation of agricultural inputs of nutrients, particularly nitrate. Intensive fertilization of row crops such as strawberries and artichokes can lead to extremely high nutrient concentrations in the freshwater reaches of the Slough seasonally. At the head of Elkhorn Slough, nitrate concentrations can exceed 500 µM during the winter rainy season, although average concentrations are usually about 16 µM. Nitrate concentrations are excessive in the lower Salinas River and old Salinas River Channel, which drains into the lower reaches of the slough. Concentrations usually exceed 1,000 M and are highest during the summer months. Nitrate concentrations have increased significantly since the 1970s with peak concentrations in the 1990s an order of magnitude higher than 1970s measurements. In contrast, peak concentrations of ammonium and dissolved inorganic phosphate have doubled over the 20 yr period, although ammonium and dissolved inorganic phosphate concentrations average 7 and 4 M, respectively, at all stations.
Cochran, S.A., and Jacobs, J.R.
University of California Santa Cruz
HYPERSPECTRAL TOOLS FOR EARLY DETECTION, RAPID ASSESSMENT AND ECONOMICAL MONITORING OF ANTHROPOGENIC INPUTS TO ESTUARINE ECOSYSTEMS
We are developing hyperspectral scanning and imaging techniques for identifying, assessing, and monitoring the effects of point and non-point source inputs to the estuarine ecosystem of Elkhorn Slough. Previous work, mainly in terrestrial systems, has shown that reflectance spectra of higher plants are sensitive (within hrs/days) to a variety of physical, chemical and biological stresses, and that such spectral changes are powerful indicators of both acute and chronic environmental stress.
Using scanning and imaging, we are examining the terrestrial-aquatic interface, recording the reflectance spectra of higher plants, as well as those of algae and aquatic organisms that dominate intertidal floras. We will evaluate the extent and timing of plant stress associated with nutrient and fertilizer inputs. We intend to identify biological signals indicative of pollution, map the extent of the effects, and monitor seasonal changes. This technology will provide a powerful tool for assessment of current management programs in the Slough.
Edwards, Brian D., James V. Gardner, and Jamie L. Stocking
U.S. Geological Survey, Menlo Park, CA 94025
CHARACTERISTICS OF SURFACE SEDIMENT ON THE MONTEREY BAY NATIONAL MARINE SANCTUARY SHELF - CARMEL TO THE GOLDEN GATE
This on-going study is part of a larger multi-disciplinary and multi-agency effort to map characteristics of biohabitats on the Monterey Bay National Marine Sanctuary continental shelf. We collected sediment samples at approximately 400 station locations from Carmel to the Golden Gate using a sampling design based on the EPA/EMAP grid. The design allows us to statistically evaluate the distribution of many attributes including textural variables (e.g., mean grain size, sorting) and physical properties (e.g., wet bulk density) of shelf sediment. Correlation of these variables combined with interpretations from high-resolution seismic-reflection profiles, bottom photographs collected simultaneously with sampling, and available swath-mapping coverage allow us to map facies distributions and draw inferences as to areas of erosion, deposition, and sediment bypass.
As an example of this data set, preliminary mapping based on more than 100 surface samples shows a nearshore modern sand belt, a mid-shelf mud-rich belt, and an outer shelf (relict?) sand belt. First order trend-surface analysis of mean grain size throughout the study area reveals regional coarsening toward the Golden Gate. Residuals on the trend (differences between observed values and trend values) identify concentrations of coarse-grained sediment offshore Half Moon Bay and Monterey and concentrations of fine-grained sediment offshore Pigeon Point and the mid-shelf region west of the Salinas River mouth that are not predicted by the trend.
Eittreim, Stephen L., Roberto J. Anima and Andrew Stevenson
US Geological Survey, Menlo Park, CA 94025
MAPPING THE CONTINENTAL SHELF OF THE MBNMS
The US Geological Survey is investigating the seafloor geology and active geologic processes within the Monterey Bay National Marine Sanctuary (MBNMS). One of the principal goals of the MBNMS project is to acoustically image the continental shelf at better than 1-m pixel resolution. To this end we have collected side-scan-sonar data and constructed mosaics of the data at 40-cm pixel-resolution. A total of over 1000 square kilometers of the continental shelf in the Monterey Bay area have been mapped to date.
In the acoustic backscatter imagery presented in this poster of the northern Monterey shelf, high backscatter is caused by rock outcrops, coarse-sand deposits, and the pipeline seen west of downtown Santa Cruz. The inner shelf of northern Monterey Bay, out to about 40-m water depth, contains a modern wave-cut platform of outcropping bedrock. Rythmic patterns of high-reflectivity south of Santa Cruz represent coarse sand deposits, presumably in transit along the inner shelf/coastal zone. Such sands periodically fill the Santa Cruz small boat harbor channel and must be removed by dredging on a regular basis.
The seafloor maps and other results from this project will be available on our web sites as well as distributed via CD-ROM in 1999.
Elder, Christine, Scott Hennessy, Laura Lee Lienk, Bob Curry and John Oliver
Watershed Institute, California State University Monterey Bay
Moss Landing Marine Laboratories
WATERSHED RESTORATION ACTIVITIES OF THE WATERSHED INSTITUTE, CSUMB
Lack of fresh water is the most important environmental problem facing Salinas Valley, and indeed most of the warm temperate, arid and semi-arid regions of the world. In the Salinas Valley (and much of California), groundwater storage has been dramatically depleted by overpumping, and surface water retention has been drastically decreased by the ditching and draining of wet corridors (i.e. rivers, creeks, sloughs and wetlands). However, in regions such as agricultural Salinas Valley where historic wet corridors remain largely unpaved, these impacts can be reversed. Fresh water can be captured along restored wet corridors and retained in ponds no larger than those already successfully maintained by beavers and farmers. Once vegetated with native plants to create a thick wetland sponge, these ponded areas efficiently clean water while increasing flood protection and groundwater recharge - all critically important for the maintenance of human communities as well as our highly endangered wetland ecosystems. The Watershed Institute's mission is to demonstrate by example that the restoration of natural water retention and reuse systems is the most ecologically and economically effective and sustainable response to our freshwater crisis. Since 1991, we have gained access to over 30 properties, initiated restoration on 400 acres, and followed through with maintenance; integrated all restoration and monitoring into the CSUMB science program (ESSP) and the broader local community; supported and expanded the Return of the Natives program in watershed education involving over 10,000 students, teachers, and other members of the community in restoration.
Engel, Jonna (1) and Rikk Kvitek (2)
1. Biology Department, UCSC
2. Earth Systems, Science & Policy Department, CSUMB
EFFECTS OF COMMERCIAL TRAWLING ON A BENTHIC COMMUNITY IN MONTEREY BAY NATIONAL MARINE SANCTUARY
Bottom trawling is one of the most disruptive and widespread human induced physical disturbances to marine bottom communities. We used a comparative approach to test the general hypothesis that persistent trawling decreases bottom habitat complexity and biodiversity and benefits prey important in the diet of some commercial fish species. We compared an area off central California subjected to the highest levels of trawling intensity ("HT" area) to an area subjected to the lightest levels of trawling intensity ("LT" area). Three seasons of infaunal data was collected and significant differences between study areas included 30% to 70% more oligochaetes in the HT area, 25% to 70% more ophiuroids in the HT area, and over 25% fewer polychaete species in the HT area Fall seasons. The amphinomid polychaete, C. pinnata, was three times more abundant in the HT versus the LT area Fall seasons and had 25% to 75% higher biomass in the HT compared to the LT area. Fish gut content analysis showed that some commercially valuable flatfish diets consist of a high proportion of C. pinnata whose population apparently thrives under trawling disturbance. This study helps clarify the potential impacts of high intensity trawling and provides incentive to conduct large scale, long-term manipulative studies in marine reserves (no fishing zone) that will more broadly assess the impact of trawling on the many interdependent inhabitants of marine bottom communities.
Gong, Allison J.
Department of Biology, University of California, Santa Cruz
THE EFFECT OF FEEDING AND STARVATION ON ALLOCATION TO STROBILATION IN AURELIA
The scyphozoan jellyfish Aurelia has a bi-phasic life cycle consisting of a pelagic medusa and a benthic polyp. The polyp represents the clonal stage of the life cycle and clones in two ways: (1) budding, to produce other polyps; and (2) strobilating, to produce medusae. In a laboratory study, I compared allocation to strobilation in two feeding treatments. Polyps fed frequently strobilated for a longer period of time, produced more medusae, and made larger medusae. While the number of days to first strobilation was the same for both treatments, the frequently fed polyps had a shorter inter-strobilation time than polyps fed infrequently. Polyps in the two feeding treatments did not differ in body volume allocated to strobilation.
Henkel, Laird A. (1) and Kriss K. Neuman (2)
1. Moss Landing Marine Laboratories
2. California Department of Parks and Recreation, Marina State Beach.
ANTHROPOGENIC THREATS TO SEABIRDS AND SHOREBIRDS OF MONTEREY BAY
More than 100 species of seabirds and shorebirds use the pelagic, nearshore, and shoreline habitat of Monterey Bay. These include several endangered or threatened species. Although Monterey Bay receives some protection as a part of the Monterey Bay National Marine Sanctuary, threats to the bay's avifauna still exist. Threats can be grouped into five categories: (1) direct human disturbance, (2) pollution, (3) commercial fisheries interactions, (4) introduced predators and competitors, and (5) habitat loss. We present recommendations for reducing and avoiding specific threats within each category.
Hester, Michelle M. (1,2), Nathan P. Fairman (1), William J. Sydeman (1), and Julie A. Thayer (1)
1. Point Reyes Bird Observatory
2. Moss Landing Marine Laboratories
ABUNDANCE, REPRODUCTION, AND PREY OF RHINOCEROS AUKLETS AT AÑO NUEVO ISLAND, CALIFORNIA, 1993 TO 1997
Breeding population size, reproductive performance, and prey utilization of the newly colonized population of Rhinoceros Auklets, Cerorhinca monocerata, on Año Nuevo Island (ANI) were investigated from 1993 to 1997. The percentage of burrows occupied by breeding pairs (estimated using a miniature burrow camera) averaged 85%. From 1993 to 1997, the estimated number of breeding birds increased 98% (102 to 202 birds). Immigration from Southeast Farallon Island, California, to ANI has been observed. During the first two years after nest box installation, productivity was low, only 33% of the breeding pairs produced independent offspring. Productivity of pairs in nest boxes increased from 1995 to 1997, but was significantly less than that attained by pairs in natural burrows. Chick growth rates (linear phase) ranged from 7.0 to 10.6 g/day, and were significantly greater in 1995. Northern anchovy, Engraulis mordax, dominated chick diets from 1993 to 1995. Parents foraged on juvenile Sebastes and Loligo in higher proportion than anchovies in 1996 and 1997, respectively. A comparative analysis using National Marine Fisheries Service mid-water trawl data indicated that adults in general did not feed chicks the most abundant resources in their foraging area and chick provisioning may be significantly affected if northern anchovy stocks decline. Through long-term monitoring of this population, we can assess how changing environmental conditions in the Monterey Bay National Marine Sanctuary affects biological production at several trophic levels.
Jaffe, Bruce (1), Roberto Anima (1), Deirdre Scholar (2), Marlene Noble (3), Chris Malzone (1) and Don Canestro (3)
1. US Geological Survey, Menlo Park
2. UC Santa Cruz, Coastal Processes Group
3. UC Santa Cruz, Diving Safety Program
MOBSEE: AN EXPERIMENT MEASURING WAVES, CURRENTS, AND SEDIMENT TRANSPORT ON THE INNER CONTINENTAL SHELF NEAR DAVENPORT, CA
The exchange of sediment between the North Coast inner shelf and Monterey
Bay is poorly understood and is essential basic information for managing
the Sanctuary. Transport of both littoral material and fine-grained
sediments in the Sanctuary is important. Littoral transport supplies
sand to beaches that provide both the recreational area for millions
of visitors annually, and buffer the shoreline from wave attack. Transport
of finer-grained sediments may carry pollutants or contaminants from
terrestrial runoff and offshore.
The MOnterey Bay SEdiment Exchange (MOBSEE) study is taking field measurements on the inner shelf near Davenport to improve the understanding of sediment movement into and out of the Bay. In full implementation, there will be two shallow-water environmental monitoring stations, one in 10-15 m water depth and the other in 20-25 m water depth. Both stations will record data for one year. Instrumentation at the stations monitors currents, water levels, waves, bed level changes, temperature, salinity, water clarity, and material suspended in the water column. This study collected its first data in October 1997. The MOBSEE stations are the inner part of a line of five USGS environmental monitoring stations across the shelf. The offshore stations, part of a companion study, are moorings that measure similar parameters through-out the entire water column. These moorings, in place since August 1996, will help us answer questions about mid- and outer shelf flow and sediment transport. Information about these studies and data from the early deployments are presented in this poster.
Kim, Stacy L., John S. Oliver, and Peter N. Slattery
Moss Landing Marine Laboratories
DECADAL PATTERNS IN A SANDY SUBTIDAL COMMUNITY: EFFECTS OF DECREASED OCEANIC PRODUCTIVITY
As the field of ecology matures, we can look at patterns over decadal time scales. Communities in soft-bottom marine habitats (6 to 30 m water depth in Monterey Bay) were divided into two general zones. A shallow zone (<14 m) was primarily occupied by small, mobile crustaceans. The deeper zone (>14 m) was dominated by tubiculous and burrowing polychaete worms. A short term (1971-1976) study in this area revealed that species abundances and diversities remained constant, and the zonation pattern was consistent and controlled by wave action. In 1997, biodiversity had decreased at all stations sampled. The abundances of individuals had also decreased, to one-tenth the densities found in the early 70's. This decrease is most marked in long-lived species, resulting in relatively high abundances of opportunistic, weedy species. The communities, especially at the deeper sites, have shifted from ones dominated by sedentary predators to ones dominated by mobile scavengers. The remarkable loss of diversity and number of animals are indicators that there has been a major shift in this ecosystem in Monterey Bay. This agrees with information from oceanic studies on the coast of southern California that have observed a marked decrease in the productivity of planktonic communities over the same time frame. It suggests that the shift in the California Current system, caused by global changes in climate, is having strong effects both locally and regionally. This is the first example we know of that reveals how a regional decrease in productivity impacts the structure of extant marine communities.
Kvenvolden, Keith A. (1), Frances D. Hostettler (1), Robert J. Rosenbauer (1), Thomas D. Lorenson (1), Paul R. Carlson (1), Erika J. Clesceri (1), Augusta Warden (1), and William T. Castle (2)
1. U.S. Geological Survey
2. California Department of Fish and Game.
OIL RESIDUES ON THE COASTLINE OF MONTEREY BAY NATIONAL MARINE SANCTUARY
Oil residues can often be observed on the shores of the Monterey Bay National Marine Sanctuary. We have undertaken a detailed organic geochemical study of several such residues and have compared our results with those obtained from nearby inland and offshore oil seeps and from produced crude oils from California. Distributions of acyclic and cyclic aliphatic hydrocarbons and carbon isotopic compositions of whole oil residues were used for the comparisons. All samples have unusually heavy carbon isotopic compositions, ranging from -21.9 to -23.7 per mil (PDB), characteristic of crude oils sourced from the Miocene Monterey Formation of California. Our coastal oil residues all contain the terpane biomarker, 28,30-bisnorhopane, a compound also characteristic of crude oil from the Monterey Formation. An inland and an offshore seep with carbon isotopic compositions of -22.0 and -22.1 per mil (PDB), respectively, are within the range of values obtained for the coastal residues; however, aliphatic hydrocarbon distributions in the seeps do not correlate well with distributions in the coastal residues. Because the coastal oil residues apparently are extensively distributed within the Sanctuary, we believe that their source is likely natural and not spilled oil products. Although we have been unable as yet to identify the specific natural sources, our geochemical results suggest that the original source is the Miocene Monterey Formation.
Lindquist, David C.
Moss Landing Marine Laboratories
ASSESSING THE IMPACTS OF EROSION ON THE TROPHIC RELATIONSHIPS OF THE DOMINANT FISHES OF ELKHORN SLOUGH
Levee breaches during the 1980s have increased the tidal volume of Elkhorn Slough and have exacerbated already high rates of erosion throughout the Slough. To assess the potential impacts of erosion on fish trophic ecology, feeding habits were analyzed at four stations which have experienced different rates of erosion. These data were then compared to data taken in the 1970s. Of the eleven species collected during this study, significant differences were found in the diets of the topsmelt, Atherinops affinis, and two prior polychaete and mollusc feeders: Pleuronectes vetulus, the English sole, and Phanerodon furcatus, the white surfperch. Comparison of the combined feeding habits of fishes at each station showed decreases in the proportions of polychaetes and molluscs, increases in crustacea and detritus, and reduced trophic diversity. Analysis of invertebrate abundance at these stations showed similar results. These differences were less evident at the station least affected by erosion. These data indicate that erosion has altered the trophic relationships of fishes in Elkhorn Slough, creating a more homogeneous system as fish species shift their diets to fewer available prey.
Lonhart, Steve I.
Department of Biology, University of California Santa Cruz
COMPARISON OF FUNCTIONAL FEEDING MODES AMONG BENTHIC INVERTEBRATE PREDATORS
The recent northward expansion of Kellet's whelk from Point Conception to Monterey Bay introduced a novel feeding mode to the guild of invertebrate predators in Monterey Bay. Unlike native sea stars that feed with an eversible stomach, invasive whelks prey on benthic invertebrates using a prehensile proboscis. Using two sea star species and Kellet's whelk from southern California as predators, this study was designed to 1) compare predator consumption rates; 2) determine predator prey preferences; and 3) assess prey anti-predatory defenses. Prey were either consisted of a single predator and a constant density (n=6) of a single prey species. Midway through the experiment, prey species were switched. Preliminary results indicate that T. brunnea is consumed at a higher rate, preferred, and poorly defended relative to T. eiseni.
U.S. Geological Survey, Menlo Park, CA
POLLEN STUDY SHOWS CHANGES IN VEGETATION AND CLIMATE FROM THE LAST GLACIAL MAXIMUM TO THE PRESENT IN THE MONTEREY BAY AREA: NEAR DISAPPEARANCE OF THE REDWOODS
Pollen and spores were analyzed from a sediment core obtained at a depth of 3400 m on the Monterey Submarine Fan. Of the 33 pollen and spore types recognized, the four most abundant are pine, redwood, oak and Compositae, the latter including plants such as thistles, dandelions, sunflowers and ragweed. The relative abundance of these four pollen types was used to define five pollen zones. The oldest zone [Carbon-14 dated at 19,350-16,800 years before present (B.P.)] is characterized by very abundant pine and rare fir pollen, reflecting the vegetational response to the cold climatic conditions during the Last Glacial Maximum. Note that the redwoods, so commonly associated with the Monterey Bay area, were very rare in the region at this time. Overlying this "glacial" vegetation zone is one representing a transitional climatic regime (16,800-12,410 years B.P.), characterized by appreciable amounts of pollen from river-dwelling alders and a form of green algae (Pediastrum) restricted to living in freshwater ponds and shallow lakes. Taken together, their presence is indicative of an improvement in climatic conditions and may reflect an increase in nutrient-rich coastal runoff. The upper three zones (12,410 years B.P. to the present) are characterized by decreasing pine pollen and increasing frequencies of redwood, oak and Compositae. They reflect the Monterey Bay region's vegetational response to the warming climatic conditions after the retreat of the glaciers in the Sierras and elsewhere in the United States.
Murray, Dawn A. (1,2)
1. Monterey Bay Aquarium Research Institute
2. University of California Santa Cruz
DISTRIBUTION, ECOLOGY AND LIFE CYCLE ANALYSIS OF MESOPELAGIC SCYPHOMEDUSAE IN MONTEREY BAY, CALIFORNIA: OBSERVATIONS FROM SUBMERSIBLES AND LIVE SPECIMENS
The mesopelagic zone is relatively constant with respect to temperature,
salinity and oxygen concentrations. Gelatinous zooplankton play an important
role in this zone as both predator and prey. Cnidarian medusae are abundant,
species rich and feed on a variety of prey items. Members of the class
Scyphozoa may be found from the surface to deep in the water column,
aggregating in patches near oceanic fronts. The purpose of this study
is to correlate the distributional patterns of mesopelagic coronate
scyphomedusae with the appearance of subsurface water masses.
Data for this study were collected with Monterey Bay Aquarium Research Institute's (MBARI) remotely operated vehicle (ROV) Ventana. Initial analysis will emphasize data from 1989 to 1993. This study will also examine the biology and ecology of coronate scyphomedusae in Monterey Bay, California. Observations will be recorded on prey selection, nematocyst type, life history and behavior both in the laboratory and in situ.
Nicholson, T. (1,2), D. Mellinger (2), and J. Harvey (1)
1. Moss Landing Marine Laboratories, Moss Landing, CA
2. Monterey Bay Aquarium Research Institute, Moss Landing, CA
INVESTIGATION OF THE SOCIAL FUNCTION OF UNDERWATER VOCALIZATION DISPLAYS BY MALE HARBOR SEALS OFF MONTEREY, CA
Male harbor seals presumably communicate fitness or social status during underwater vocalization displays. This communication may function to attract females, establish underwater territories, or maintain dominance hierarchies. We present evidence indicating that the social function of underwater vocalizations is primarily a display among males to establish and maintain dominance. Further, differences in social status may correspond with vocalization characteristics such as call duration and frequency. To evaluate these hypotheses, from August 1996 to July 1997, we recorded 238 vocalization events by 45 individually identified adult males. Vocalizing seals were either ignored or attracted attention of nearby adult males. Nearby males responded by approaching and "attending," or posturing submissively nose to nose with the vocalizing male. Analyses of nine repeatedly recorded individuals indicated that younger, smaller adult males (n=6) were rarely (<3%) attended during underwater vocalization displays and never attended by more than one other male at a time. In contrast older, larger adult males (n=3) consistently (>85%) attracted attention of nearby adult males. Maximum number of seals simultaneously attending these males during underwater vocalizations was five (mean = 1.9, SE = 0.2). Further, attended males produced longer (mean = 3.3 s, SE 0.2), and lower frequency (mean = 186.1 Hz, SE 13.0) roars than ignored seals (mean = 2.0 s, SE 0.1; mean = 222.0 Hz, SE 8.0). These results indicated that underwater vocalization displays by males function to establish and maintain dominance relationships, and seals may use acoustic cues to mediate social relationships and determine seal attractiveness.
Raskoff, Kevin A. (1,2)
1. Monterey Bay Aquarium Research Institute
2. Department of Biology, University of California, Los Angeles
DISTRIBUTIONS AND TROPHIC INTERACTIONS OF MESOPELAGIC HYDROMEDUSAE IN MONTEREY BAY, CA: IN SITU STUDIES WITH THE MBARI ROVS VENTANA AND TIBURON
The biology and ecology of the mesopelagic cnidarians are being examined using the Monterey Bay Aquarium Research Institute's ROVs Ventana and Tiburon. Video observations, CTD/O2 data, and laboratory studies are coupled to provide information on the distributions and behaviors of many cnidarian taxa. This poster gives the most recent data on the vertical distributions and trophic interactions of the hydromedusae in the Monterey Bay and associated submarine canyon. The vertical distribution of many medusae are concentrated in bands of occurrence that are often exclusive of one another. Feeding behaviors, prey preference, and digestion times are investigated with ROV video analysis and laboratory experimentation. Gut content analysis shows a diverse prey assemblage while digestion time studies have implications toward the impact of mesopelagic medusae on the midwater ecosystem as a whole.
Richmond, Bruce M., and Ann E. Gibbs
U.S. Geological Survey, Coastal and Marine Geology Program, Menlo Park, CA
COASTAL IMPACTS OF AN EL NINO SEASON
Every winter, storms in the Pacific Ocean create large waves that attack
the west coast. During El Niño winters, Pacific Ocean storms
are often more intense and frequent, thereby increasing the amount of
wave attack along our shores. High waves, elevated sea level, and extreme
rainfall are commonly associated with El Niño events. The combination
of elevated sea level and storm waves can result in extensive coastal
erosion while high rainfall events can result in landslides and coastal
flooding. One benefit the coast derives from landslides and flooding
is the introduction of sediment to the littoral zone for later beach
The El Niño winter of 1982/83 was particularly devastating along the California coast, wreaking havoc on beaches and coastal properties. Available data indicate that the current 1997-98 El Niño event is as strong or stronger than the 1982/83 event, however, it is very difficult to predict exactly where the greatest storm impact will occur. Storm tracks are guided by the position of atmospheric high and low pressure cells which in turn are related to such complex phenomena as the jet stream. Scientists have recognized the strong signals of the present El Niño but at present they cannot accurately predict the area of maximum effect.
Roletto, Jan (1), Leslie Grella (1), Joe Mortenson (2), Lisa Hug (1) and Thomas Ryan (3)
1. Gulf of the Farallones National Marine Sanctuary
2. Farallones Marine Sanctuary Association
3. San Francisco Bay Bird Observatory
BEACHED MARINE MAMMAL SURVEYS ALONG THE CENTRAL CALIFORNIA COAST
In 1993, the Gulf of the Farallones National Marine Sanctuary began Beach Watch, a long term shoreline monitoring program. Of the 33 species of marine mammals known to occur off of central California, 13 species have been documented during the standardized, Beach Watch surveys. Approximately 70 percent of the animals documented by the museums were initially found during these surveys. Of the animals encountered by the museums (n = 98), two were found and completely removed before Beach Watch was able to document the carcass, thus eliminating them from the Beach Watch baseline data set; Beach Watch documented 177 animals. Pinnipeds are the most common marine mammal taxa found along the central California coast. The highest counts of pinnipeds are found near the breeding and rookery area, at Año Nuevo State Reserve and Island. The scheduled surveys conducted through Beach Watch, find more animals than the ad hoc findings of the museums. Counts are highest at long, sandy beaches. When reviewing stranding rates, i.e. number of animals per km surveyed there is a high rate near Año Nuevo (0.4/km for pinnipeds at Gazos Creek and Cove Beach). But small beaches known to collect numerous dead birds and debris, Kirby Cove, Rodeo and Muir Beaches, have a moderately high pinniped encounter rates (0.2/km, 0.1/km and 0.1/km, respectively). Mortality of California sea lions peaks during the post-breeding and migration months of September and October (0.1/km and 0.2/km, respectively), with the lowest numbers during their peak feeding months for central California, January, February and March (<0.1/km, 0/km, <0.1/km, respectively). This project uses trained volunteers to collect data for resource trustee agencies, at an annual savings to the government of $290,000,
Starr, Richard M. (1), Korie A. Johnson (1), and John Heine (2)
1. University of California Sea Grant Extension Program
2. Moss Landing Marine Laboratories
TECHNIQUES FOR ASSESSING MOVEMENTS OF DEEPWATER ROCKFISHES
Recent stock assessments conducted by the Pacific Fishery Management
Council indicate large population declines for commercially harvested
rockfishes. These declines have led to discussions about the need for
alternative fishery management strategies, such as the use of marine
fishery reserves. An understanding of fish movements is critical information
needed to properly design reserve size, shape, and location. In this
project we are studying the range and frequency of fish movements in
Soquel Canyon in Monterey Bay.
In September and October of this year, we used SCUBA to surgically implant acoustic transmitters in 9 rockfish (8 greenstripe rockfish and 1 bocaccio). The Delta submersible was then used to place 4 hydrophone/receivers along Soquel Canyon to continuously record information from the transmitters. In addition, two S4 current meters were placed on the adjacent shelf to record physical data in the region. In early January, the Monterey Bay Research Aquarium Institute's ROV Ventana was used to retrieve the four hydrophone/receivers and two current meters. We are now in the process of analyzing the data for patterns in horizontal and vertical movements.
Storlazzi, Curt D. and Gary B. Griggs
University of California, Santa Cruz Coastal Geology Laboratory
INFLUENCE OF EL NIÑO-SOUTHERN OSCILLATION EVENTS ON THE COASTLINE OF CENTRAL CALIFORNIA
The storms of early 1983 inflicted major damage to many developed portions
of central California's coastline. Because these storms coincided with
an extreme El Niño-Southern Oscillation (ENSO) climatic anomaly,
and a ENSO anomaly on the same order of the 1982-83 event has developed
in 1997, there is considerable interest in determining if a relationship
exists between historic ENSO events and coastal storm damage in central
California. Time series of precipitation, cyclone activity, de-trended
tidal elevation, and oceanographic data from offshore buoys were compiled
for the period from 1910 to 1995. These climatic signals were compared
with records of local storm damage and previously published time histories
of the 19 ENSO events for the same period.
The variations in cyclone activity, significant wave height, and sea surface elevation over the 86 years correlated extremely well with all of the ENSO events. The long term rainfall records did not correlate well with all of the ENSO events; when compared to only the more severe ENSO events, however, a clear correlation was shown. A strong association between ENSO events and storm damage along the coast of central California was established. Approximately 76% of the 62 storms that caused significant coastal damage from 1910 to 1995 occurred during ENSO events while only during 3 events (1917-1919, 1965, 1972-73) was there no recorded damage. The coast is struck on average by 1.2 damaging storms every ENSO year (1.6 and 3.6 damaging storms every lower and higher intensity ENSO event, respectively) versus only 0.3 damaging storms every non-ENSO year.
VenTresca, David A., Marty L. Gingras, Michael D. Donnellan, Jennifer L. Fisher, Richard H. McGonigal, Nicholas H. Wolff, Robert S. Hornady, and Joshua N. Plant.
California Department of Fish and Game
THE POTENTIAL OF MARINE RESERVES TO ENHANCE NEARSHORE FISHERIES: ASSESSMENT OF FISH POPULATIONS IN POINT LOBOS STATE RESERVE AND BIG CREEK ECOLOGICAL RESERVE
Rockfishes (Sebastes spp.) are an important and heavily exploited component of sport and commercial fisheries in central California. Since 1956, the Central California Marine Sport Fish Survey has monitored nearshore recreational fisheries. We have found that the catch-per-unit-effort and proportion of large rockfishes taken by central California's nearshore rockfish sport fisheries have declined since the 1970's, particularly in areas close to ports. We are presently evaluating aspects of marine reserves as an alternative management and enhancement strategy. Marine reserves have been reported to enhance fisheries in other geographical areas, but limited information is available to evaluate their effectiveness relative to California's sport and commercial rockfish fisheries. Both Point Lobos State Reserve (established 1973) and the recently established (1994) Big Creek Ecological Reserve (BCER) offer a unique opportunity to evaluate the effects of a reserve on the rockfish resource. The first step for determining future benefits to adjacent and distant fisheries is to obtain baseline information on species composition, densities, and length frequencies of rockfish populations within and adjacent to Point Lobos and BCER. We are presently assessing the population parameters of fishes (primarily rockfishes) in nearshore habitats within and adjacent to these reserves using SCUBA surveys. Species composition and densities are determined visually using random and permanent transects, and length-frequency distributions are measured using quantitative underwater videography. We are also currently conducting a side-scan-sonar survey of BCER to characterize available fish habitat.
Walder, Ronald K. (1), Michael S. Foster (1), and Andrew DeVogelaere (2)
1. Moss Landing Marine Laboratories, Moss Landing, CA 95039
2. Monterey Bay National Marine Sanctuary,
, Monterey, CA 93940
RECOVERY OF ROCKY INTERTIDAL ASSEMBLAGES FOLLOWING THE WRECK AND SALVAGE OF THE F/V TRINITY
In April 1996, the fishing vessel Trinity ran aground on a rocky shore of the Monterey Peninsula. Subsequent salvage operations included rolling the vessel to a shore-based crane and using tractor tires as cushions to minimize habitat crushing. This event resulted in 108 m2 of physical damage from the grounding, 287 m2 of possible diesel fuel impacts, and 143 m2 of physical damage from the salvage operation. Biological recovery is being investigated quantitatively within three assemblages: low intertidal surf grass, mid intertidal mussel and mid/high intertidal red algae. Moreover, recovery is being qualitatively assessed in a unique rubble bed and sand pits created by the vessel and tractor tires during overnight stoppage of the salvage operation. Finally, a potential rocky shore restoration technique is being developed for future large scale disturbances by transplanting boulders with intact biological assemblages. As of December of 1997 recovery within areas has occurred slowly. Overall, disturbed plots in the mussel and red algal assemblages contained species indicative of the intact, adjacent assemblages. However, their percent cover in both cases was relatively low. Within the surf grass assemblage, only one species indicative of that assemblage, Corallina vancouveriensis, has colonized the disturbed areas. In addition, 89% of transplanted boulders persisted with their associated plants, providing habitat and a potential source of spores. Comparisons between impacted and adjacent control areas suggest that spilled diesel fuel had no impacts. Recovery of this rocky shore is clearly a multi-year process and different for each assemblage. The restoration techniques can potentially enhance natural recovery. Salvage efforts would be less destructive by minimizing operation time.
Weise, M.J. and J. T. Harvey
Moss Landing Marine Laboratories
PINNIPED INTERACTIONS WITH SALMON FISHERIES IN MONTEREY BAY, CALIFORNIA
Pinniped populations along the California coast and adjacent waters have increased substantially during the past several decades. Corresponding to these increases, fishermen have observed an increasing loss of fish to California sea lions (Zalophus californianus), and Pacific harbor seals (Phoca vitulina richardsi) in the sport and commercial salmon fisheries in Monterey Bay, California. To assess the effects of pinnipeds on the salmon fisheries dockside and onboard surveys of the commercial and recreational salmon (Onchorynchus sp.) fisheries were conducted in the summer of 1997 at the three ports in Monterey Bay. For the commercial and recreational salmon fishery combined, 952 surface takes of salmon by pinnipeds occurred. California sea lions were responsible for 939 takes or 98.6 % of the surface takes and Pacific harbor seals accounted for 13 takes or 1.4 % of the surface takes. The total probable loss (surface takes plus below surface takes) of the legal catch was 11.5 % for the commercial fishery, 10.6 % for the Commercial Passenger Fishing Vessel (CPFV) fishery, and 27.7 % for the personal skiff fishery. Comparison of the number of takes in proportion to the number of fish hooked in the commercial and recreational salmon fishery suggests there is a significant difference during May, August and September, coinciding with the annual sea lion migration, with significantly lower depredation in June and early July when adult sea lions are on breeding colonies. In comparison to previous research, the commercial and recreational salmon fishery in Monterey Bay has experienced at minimum a doubling in depredation by pinnipeds since the early 1970's and early 1980's, and a slight increase since 1995. Pinnipeds are opportunistic predators switching prey species depending on the availability of fish when they are abundant. Fecal samples indicate that sea lions preyed heavily on schooling fishes, such as Market squid, Northern anchovy, Pacific hake, and White croaker. Species commonly taken by harbor seals were schooling fish and bottom fish, including Spotted cusk-eel, Pacific sandab, Dover sole, and California tonguefish. Aerial and ground surveys of pinniped were conducted along the Central California coast with low counts of adult California sea lions in June and July coinciding with their annual migration to breeding colonies.
Wilson-Vandenberg, D. A., K. A. Mayer, and P. Reilly
California Department of Fish and Game, 20 Lower Ragsdale Drive, Suite 100, Monterey, CA 93940
A DECADE OF ON BOARD SAMPLING: HOW CPFV CATCHES MEASURE UP
The California Department of Fish and Game's Central California Marine Sport Fish Survey has been observing anglers on board Commercial Passenger Fishing Vessels (CPFVs) since 1987 in the Monterey area, and from Fort Bragg to the Morro Bay area since 1988. Data collection has included information on species composition, fishing effort, discard rates, and total length on a reef by reef basis on CPFV trips fishing for rockfishes and lingcod. Two primary components of the catches, blue and yellowtail rockfishes, have not shown declining trends in catch per unit effort (cpue) or mean length over time. Concerns have been identified for two species groups which are also taken in commercial catches, including 1) several nearshore benthic species, as well as 2) chilipepper and bocaccio which have exhibited apparent declines in cpue and/or mean length. Changes through time will be discussed including comparisons with historical data.