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Antarctic krill stock distribution and composition in the Elephant Island and King George Island areas, January-February, 1988
Antarctic krill stock distribution and composition in the Elephant Island and King George Island areas, January-February, 1988
Information is provided on the distribution, size and maturity composition of Antarctic krill (Euphausia superba) stocks in the Elephant Island and King George Island areas, and at repeatedly sampled sites to the north of each island, during January-February, 1988. The overall distributional patterns of different sizes and maturity stages demonstrated a seasonal progression of those observed in the Antarctic Peninsula region during November-December, 1987 by Siegel (1989). The krill sampled at each island site represented different size-maturity groups and demonstrated different horizontal and vertical distributional characteristics. These distributional differences may be related to the demographic differences and/or hydrographie differences between the two sites. © 1993 Springer-Verlag., Cited By (since 1996):2, CODEN: POBID, Invertebrates
Antarctic research bases
Antarctic research bases
Contemporary studies of chemical contamination in Antarctica commonly focus on remnants of historical local releases or long-range transport of legacy pollutants. To protect the continent's pristine status, the Antarctic Treaty's Protocol on Environmental Protection prohibits importation of persistent organic pollutants. However, some polybrominated diphenyl ether (PBDE) congeners exhibit similar properties. Many modern polymer-containing products, e.g., home/office furnishings and electronics, contain percent levels of flame retardant PBDEs. PBDE concentrations in indoor dust and wastewater sludge from the U.S. McMurdo and New Zealand-operated Scott Antarctic research bases were high. Levels tracked those in sludge and dust from their respective host countries. BDE-209, the major constituent in the commercial deca-PBDE product, was the dominant congener in sludge and dust, as well as aquatic sediments collected near the McMurdo wastewater outfall. The pattern and level of BDE-209 sediment concentrations, in conjunction with its limited environmental mobility, suggest inputs from local sources. PBDE concentrations in fish and invertebrates nearthe McMurdo outfall rivaled those in urbanized areas of North America and generally decreased with distance. The data indicate that reliance on wastewater maceration alone, as stipulated by the Protocol, may permit entry of substantial amounts of PBDEs and other chemicals to the Antarctic environment. © 2008 American Chemical Society., Cited By (since 1996):48, Antarctica, CODEN: ESTHA
Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica
Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica
The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are some generalizations regarding responses which will aid future management of stations. © 2014 Stark et al., Antarctica
Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica
Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica
The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are some generalizations regarding responses which will aid future management of stations., Export Date: 19 October 2015
Antibodies to phocine herpesvirus-1 are common in North American harbor seals (Phoca Vitulina)
Antibodies to phocine herpesvirus-1 are common in North American harbor seals (Phoca Vitulina)
Phocine herpesvirus-1 (PhHV-1) has been associated with morbidity and high mortality in neonatal harbor seals (Phoca vitulina) along the Pacific coast of California (USA) and in northern Europe. Seals dying with PhHV-1 associated disease in California primarily have histopathologic evidence of adrenal necrosis or adrenalitis with herpesviral inclusion bodies. Little is known about prevalence of exposure to PhHV-1, modes of disease transmission, and viral pathogenesis in free-ranging harbor seal populations. To evaluate the prevalence in North America, 866 serum samples collected between 1994 and 2002 from harbor seals captured or stranded on the Pacific and Atlantic coasts of North America were assayed by enzyme linked immunosorbent assay (ELISA) for evidence of PhHV-1 exposure. Samples from three harbor seal age classes (pre-weaned, weaned, and subadults/adults) were obtained from each of four regions to compare exposure among sex, age class, and region. We found increasing prevalence with age as 37.5% of pre-weaned pups, 87.6% of weaned pups, and 99.0% of subadults and adults were seropositive. When accounting for age, no associations between seropositivity and sex or location of harbor seals were detected. These data indicate that PhHV-1 is endemic in the harbor seal populations of North America. © Wildlife Disease Association 2003., Cited By (since 1996):7, Marine Mammals, Birds & Turtles
Antimicrobial Properties of Silver Cations Substituted to Faujasite Mineral
Antimicrobial Properties of Silver Cations Substituted to Faujasite Mineral
A goal of our study was to find an alternative to nano-silver-based antimicrobial materials which would contain active silver immobilized in a solid matrix that prevents its migration into the surrounding environment. In this study, we investigated whether silver cations dispersed in an atomic form and trapped in an ion-exchanged zeolite show comparable antimicrobial activity to silver nanoparticles (NPs). The biocidal active material was prepared from the sodium form of faujasite type zeolite in two steps: (1) exchange with silver cations, (2) removal of the external silver oxide NPs by elution with Na2EDTA solution. The modified biocidal zeolite was then added to paper pulp to obtain sheets. The zeolite paper samples and reference samples containing silver NPs were tested in terms of biocidal activity against an array of fungi and bacteria strains, including Escherichia coli, Serratia marcescens, Bacillus subtilis, Bacillus megaterium, Trichoderma viride, Chaetomium globosum, Aspergillus niger, Cladosporium cladosporioides, and Mortierella alpina. The paper with the modified faujasite additive showed higher or similar antibacterial and antifungal activities towards the majority of tested microbes in comparison with the silver NP-filled paper. A reverse effect was observed for the Mortierella alpina strain.
Application of an ion-exchange separation technique and thermal ionization mass spectrometry to 226Ra for radiometric age determination of long-lived fishes
Application of an ion-exchange separation technique and thermal ionization mass spectrometry to 226Ra for radiometric age determination of long-lived fishes
To improve the accuracy and precision of radiometric age determination using 210Pb: 226Ra disequilibria in otoliths of fishes, a technique was developed incorporating an ion-exchange procedure followed by isotope-dilution thermal ionization mass spectrometry (TIMS) to determine 226Ra. This technique counts ionized radium atoms directly; therefore, the uncertainty of the technique is superior to conventional radio-decay dependent techniques. Calcium and barium are major components of the otolith matrix that can interfere with TIMS analysis of radium. To remove these interferants, an ion-exchange separation procedure was developed. This procedure was tested by applying it to otolith samples from three fish species in three separate radiometric ageing studies. The resultant separations and TIMS determinations indicate that the procedure efficiently separates radium from calcium and barium. Measured 226Ra activities for each species were similar to previous radiometric ageing studies, with the exception of one sample. When results were compared with traditional 226Ra determination techniques, radon emanation and α-spectrometry, the separation procedure with isotope-dilution TIMS had significant advantages. Samples over three times smaller than attempted in other studies were processed with decreased uncertainty and processing time., Cited By (since 1996):30, Fish and Fisheries, CODEN: CJFSD
Application of bomb radiocarbon chronologies to shortfin mako (Isurus oxyrinchus) age validation
Application of bomb radiocarbon chronologies to shortfin mako (Isurus oxyrinchus) age validation
Age estimation is an issue for the shortfin mako, Isurus oxyrinchus, because of disagreement on vertebral band-pair deposition periodicity. In the 1950s-1960s, thermonuclear testing released large amounts of radiocarbon into the atmosphere, which diffused into the ocean through gas exchange. This influx created a time-specific marker that can be used in age validation. Annual band-pair deposition in the porbeagle, Lamna nasus, was validated in a previous study and indicated preliminary annual deposition in the shortfin mako, using four samples from one vertebra. In the present study, age estimates from 54 shortfin mako vertebrae collected in 1950-1984 ranged 1-31 years. Ageing error between readers was consistent, with 76% of the estimates ranging within 2 years. Twenty-one Δ14C values from eight shortfin mako vertebrae (collected in the western North Atlantic in 1963-1984) ranged -154.8‰ to 86.8‰. The resulting conformity with the Δ14C timeline for the porbeagle supported annual band-pair deposition in vertebrae of the shortfin mako. © 2006 Springer Science+Business Media, Inc., Cited By (since 1996):19, Fish and Fisheries, CODEN: EBFID
Application of color infrared aerial photography to assess macroalgal distribution in an eutrophic estuary, upper Newport Bay, California
Application of color infrared aerial photography to assess macroalgal distribution in an eutrophic estuary, upper Newport Bay, California
Newport Bay is a large estuary in southern California that is subject to anthropogenic nutrient loading, eutrophication, and hypoxia. Ground-based methods of assessing algal extent for monitoring and management are limited in that they cannot provide a synoptic view of algal distribution over comparatively large areas. The goal of this study was to explore the application of color infrared aerial photography as an alternative for analyzing the changes in the abundance of exposed macroalgae. Three surveys combining remote sensing (color infrared aerial photography) and ground-based sampling to quantify macroalgal mat coverage were carried out in Upper Newport Bay (UNB) between July and October 2005. Airborne photographs (scale 1:6000) collected during daytime low tides, clear skies, and appropriate sun angle were digitized to 25-cm resolution, orthorectified, georegistered, and combined into three mosaic composite digital images: one for each survey. During each aerial photography survey, macroalgal percent cover was measured on the ground by the point-intercept method in a 6.25-m2 area at ca. 30 locations distributed along the water's edge throughout the intertidal mudflat area. There were three main types of cover: Ulva spp. (green algae), Ceramium spp. (red algae), and bare surface (mud and mussel beds). To analyze similarities between spectral signatures in the images and cover types, the pixels corresponding to the ground samples from each survey were grouped into clusters based on similarity of their spectral signatures. To establish relationships between spectral signatures in the images and cover as determined from ground data, pixels in each composite image corresponding to ground samples from the same day that were characterized by > 90% of one cover type were attributed to that cover type. Ground samples comprised of a mixture of cover types were used for accuracy assessment. Before classification, each digital image was transformed by the Minimum Noise Fraction Rotation method to remove noise and enhance contrast between the classes. For classification of each composite image, the Spectral Angle Mapper scheme was used: all pixels in each image were attributed to the identified classes and the areal extent of each class was estimated. According to these assessments, the macroalgal coverage in UNB increased from 37% in July to 57% in September to 80% in October, and during this time Ulva spp. replaced Ceramium spp. as the dominant alga. This analysis showed that color infrared aerial photography is an effective tool for assessing estuarine, intertidal macroalgal coverage. © 2007 Estuarine Research Federation., Cited By (since 1996):6, Seaweeds
Applying marine habitat data to fishery management on the US west coast
Applying marine habitat data to fishery management on the US west coast
Recent experience in implementing legal requirements to designate and protect Essential Fish Habitat for groundfish off the US west coast is providing an opportunity to develop a feedback loop between science and policy for habitat- and ecosystem-based management that mirrors the traditional stock assessment/harvest management paradigm. The stock assessment/harvest management feedback loop dates back to the 1940s and has strongly influenced the development of the marine fishery management in frastructure and associated research programs. Assessment of marine habitat and the related establishment of regulatory policies by west coast fishery managers offer the potential for a similar feedback loop and the tailoring of research and infrastructure to improve the information available for decision-making., Cited By (since 1996):2, Fish and Fisheries
Aquatic mating strategies of the male pacific harbor seal (Phoca vitulina richardii)
Aquatic mating strategies of the male pacific harbor seal (Phoca vitulina richardii)
Compared to the harem and resource defense systems of terrestrial mating pinnipeds, males of aquatic mating species appear unable to monopolize females or resources. We investigated movements, acoustics, and aquatic territorial behavior of male harbor seals, Phoca vitulina richardii, in Elkhorn Slough, California, using VHF telemetry, hydrophones, and acoustic playback experiments. During the mating season 22 males increased time spent in the water and away from haul-out locations, exhibiting activity patterns similar to Atlantic subspecies. Two acoustic display patterns were observed. At one location multiple males aggregated to display with acoustic activity peaking one month before peak estrus. At two other locations, lone males displayed primarily during peak estrus. Acoustic display areas were non-adjacent with a mean ± SE size of 4,228 ± 576 m2, similar to harbor seal display patterns in the Moray Firth, Scotland. Underwater playbacks of male vocalizations were used to define territorial boundaries by inducing responses from territory-holding males. Four solitary males defended adjacent territories (mean area 39,571 ± 18,818 m2) along a travel corridor, similar to observations of harbor seals at Miquelon, Newfoundland. Acoustic display stations appeared to be subcomponents of larger territories. Males exhibited site fidelity to territories for at least 2-A yr. Females moved through territories freely. The establishment of male-display territories along female-traffic corridors resembles terrestrial systems described as hotspot leks., Cited By (since 1996):15, Marine Mammals, Birds & Turtles, CODEN: MMSCE
Arrested development of giant kelp (Macrocystis pyrifera, Phaeophyceae) embryonic sporophytes
Arrested development of giant kelp (Macrocystis pyrifera, Phaeophyceae) embryonic sporophytes
Delayed recruitment of microscopic stages in respouse to cyclical cues is critical to the population dynamics of many annual and seasonally reproducing perennial seaweeds. Microscopic stages may play a similar role in continuously reproducing perennials in which adult sporophytes are subject to episodic mortality, if they can respond directly to the unpredictable onset and relaxation of unfavorable conditions. We experimentally evaluated the potential for temporary reduction in limiting resources (light, nutrients) to directly delay recruitment of giant kelp (Macrocystis pyrifera (L.) C.A. Agardh) gametophytes and embryonic sporophytes. Laboratory cultures were subjected to limiting conditions of light and nutrients for 1 month and then exposed to non-limiting conditions for 10 days. Gametophytes in all treatments failed to recruit to sporophytes after 2 weeks, suggesting they are not a source of delayed recruitment in giant kelp. Sporophytes in light-limited treatments, however, survived and grew significantly slower than non-light-limited controls. When stimulated with light, light-limited sporophytes grew from 2 to >10 times faster than unstimulated controls depending on nutrient availability. These results suggest that limiting resources can delay recruitment of embryonic giant kelp sporophytes for at least 1 month. Flexible timing of recruitment from embryonic sporophytes may enhance persistence of continuously reproducing perennial species when macroscopic adults are subject to episodic large-scale removals., Cited By (since 1996):24, Seaweeds, CODEN: JPYLA
Artisanal fisheries and reproductive biology of the golden cownose ray, Rhinoptera steindachneri Evermann and Jenkins, 1891, in the northern Mexican Pacific
Artisanal fisheries and reproductive biology of the golden cownose ray, Rhinoptera steindachneri Evermann and Jenkins, 1891, in the northern Mexican Pacific
The golden cownose ray, Rhinoptera steindachneri, was one of the most abundant species landed in artisanal elasmobranch fisheries in the northern Gulf of California (Baja California and Sonora) and Bahía Almejas, Mexico during 1998-1999. In the northern Gulf of California, R. steindachneri was most frequently observed during summer months (11.4% of elasmobranch landings, catch per unit effort (CPUE) = 6.8 individuals/vessel trip) and was rare during winter (0.1%, CPUE = 0.1). In Bahía Almejas, its relative abundance was greater during August (5.2%) than June (0.3%), a trend also evident in CPUE (August = 1.2, June = 0.1). The mean size of R. steindachneri landed in the Gulf of California was 64.3 ± 12.8 (S.D.) cm disc width (DW). Median size at maturity for Gulf of California specimens was similar for females (70.2 cm DW) and males (69.9 cm DW). Fecundity was found to be one offspring per female, with parturition estimated to occur from late June-August. Size at birth was estimated at 38-45 cm DW after a gestation period of approximately 11-12 months. Greater maximum sizes (to 104 cm DW) and embryo sizes (to 43 cm DW) were observed in Bahía Almejas. The large size at maturity, low fecundity, and long gestation period determined for R. steindachneri indicate that this species could be particularly susceptible to overexploitation. © 2006 Elsevier B.V. All rights reserved., Cited By (since 1996):20, Fish and Fisheries, CODEN: FISRD
Aspects of the life histories of grass rockfish, Sebastes rastrelliger, and brown rockfish, S. auriculatus, from southern California
Aspects of the life histories of grass rockfish, Sebastes rastrelliger, and brown rockfish, S. auriculatus, from southern California
We collected data on age-length and length-weight relationships, age and length at first maturity, and spawning seasons of grass rockfish, Sebastes rastrelliger, and brown rockfish, S. auriculatus, off southern California. In addition, we also collected data on fecundity of grass rockfish. For both species, males and females grew at the same rates and von Bertalanffy age-length parameters for grass rockfish were l(∞)=51.3 cm, k=0.11, t0=-2.41 and for brown rockfish l(∞)=51.4 cm, k=0.16, t0=-0.55. Male and female grass rockfish matured at about the same length and age, between 22 and 28 cm and between 2 and 5 yr. There was also little difference between the sexes for brown rockfish; they matured between 19 and 32 cm and between 3 and 6 yr. Grass rockfish spawned from January to March, peaking during January; brown rockfish spawned from January to June (and perhaps August), also peaking in January. Fecundity of grass rockfish ranged from about 80,000-760,000 eggs., Cited By (since 1996):10, Fish and Fisheries, CODEN: FSYBA
Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa
Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa
New information is presented on the reproductive biology of 22 southern African skate species. Sex ratios for most species were relatively even. Sexual dimorphic differences in disc shape were evident in all species, but the total length (LT) to disc width (D) relationship was significantly different in only three species, and the LT to weight (W) relationship significant in just five species. Sexual dimorphism relative to maximum total length (LTmax) was absent in all but the two largest species. Males and females of the same species grow to a similar L Tmax except those whose LTmax is >1.5 m LT. Size at first and 50% (LT50) sexual maturity was approximately the same for both sexes in all but the two largest species. First maturity occurred at >60% of LTmax for all species for which sufficient data were available, and most (n = 18) matured at >75% LTmax. The large size at maturity relative to LTmax suggests that growth slows or is partially suspended following sexual maturity. The egg cases of 15 species are described, and a key to their identification is presented. Egg cases in utero were observed throughout the year suggesting that most species reproduce year-round. © 2007 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved., Cited By (since 1996):20m, Fish and Fisheries, CODEN: ICESE
Assessing California's bar-built estuaries using the California Rapid Assessment Method
Assessing California's bar-built estuaries using the California Rapid Assessment Method
Abstract Bar-built estuaries are generally found at the mouths of smaller watersheds with seasonal precipitation, episodic streamflow and seasonal swell dynamics. Low streamflows and constructive wave forces form a sand bar at the mouth isolating the stream from the ocean, creating a ponded lagoon, and inundating the surrounding marsh plain. Bar-built estuaries are wide spread in California comprising over 50 percent of California's more than 500 estuaries. By connecting terrestrial, freshwater, and marine realms bar-built estuaries are complex and dynamic providing great habitat and ecosystem services. California has suffered some of the highest losses of wetland habitats, and the wetland habitats of bar-built estuaries continue to be threatened by further development, pollution, and climate related changes including diminished streamflows and sea level rise. Given this loss and threat we developed a California Rapid Assessment Method (CRAM) to assess the condition of California's bar-built estuaries. CRAM uses visual indicators to accurately reflect current wetland condition with regards to buffer habitat, hydrology, physical complexity, plant diversity and structure, and landscape influences. Here we validate this method by comparing results of CRAM for bar-built estuaries to other accepted measures of wetland condition that we simultaneously collected with CRAM including vegetative surveys, water nutrient levels, and GIS landscape scale measures of stress for 32 sites throughout California. CRAM correlated well with each of these three independent methods of assessing condition. Notably, the Environmental Monitoring and Assessment Program (EMAP) number of natives metric significantly correlated with CRAM Index and all Attribute scores. The strong correlations of CRAM to nutrient levels is particularly important considering the documentation of the negative impact of nutrients on fish populations, the use of bar-built estuaries by juveniles of commercially important species, and the nursery role of bar-built estuaries for maintaining imperiled populations of species such as steelhead. GIS measured percent impervious, percent agriculture, and percent dams all correlated well with expected CRAM Attribute scores at appropriate watershed scales relative to the area of inference for each CRAM metric. Further, CRAM for bar-built estuaries works well throughout California's diversity of environmental conditions and regardless of geography, timing, or whether the bar was open or closed during the survey. We hope that the availability of CRAM combined with available data repositories will enable local, state, and federal decision makers to better manage, restore, and conserve valuable bar-built estuaries in the face of continual threats like development, drought, and sea level rise.
Assessing avian predation on juvenile salmonids using passive integrated transponder tag recoveries and mark-recapture methods
Assessing avian predation on juvenile salmonids using passive integrated transponder tag recoveries and mark-recapture methods
Many populations of coho salmon Oncorhynchus kisutch and steelhead O. mykiss are listed under the U.S. Endangered Species Act. Until recently, the role of avian predation in limiting recovery of coho salmon and steelhead in central California coastal watersheds has been overlooked. We used recoveries of passive integrated transponder (PIT) tags from Año Nuevo Island (ANI), a breeding site for several species of piscivorous seabirds, to estimate predation rates on juvenile salmonids and identify susceptible life stages and species responsible for predation. A total of 34,485 PIT tags were deployed in coho salmon and steelhead in six watersheds in San Mateo and Santa Cruz counties. Tags were deposited on ANI by predators after ingestion of tagged fish. Because tags were not removed from the island and were detected on multiple sampling occasions, we were able to use mark-recapture models to generate a corrected minimum predation estimate. We used POPAN, a variation of the Jolly-Seber model, to generate an estimate of gross population abundance, which accounted for tags deposited on the island but not detected during surveys. Detections of 196 tags from surveys conducted between autumn 2006 and spring 2009 were incorporated into the model, producing a gross population estimate of 242 tags (SE = 9.8). Addition of tags detected between autumn 2009 and 2010 to the abundance estimate from POPAN produced a new minimum estimate of 362 tags on ANI. Western gulls Larus occidentalis probably were the primary predator depositing tags on ANI. Minimum predation estimates ranged from 0.1% (Soquel Creek) to 4.6% (Waddell Creek) of outmigrating coho salmon and steelhead smolts. Predation was potentially greater given still unquantified deposition of tags off-colony and destruction of tags during digestive processes of predators. Finally, avian predators targeted estuary-reared fish, which contributed disproportionately to adult populations, further impacting imperiled salmon populations. © American Fisheries Society 2012., Marine Mammals, Birds & Turtles, CODEN: NAJMD

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