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Los Alamitos, CA, United States

Jiao Y.,Virginia Polytechnic Institute and State University | Rogers-Bennett L.,University of California at Davis | Taniguchi I.,Marine Region | Butler J.,Southwest Fisheries Science Center | Crone P.,Southwest Fisheries Science Center
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2010

Many marine species exhibit temporal variation in individual growth. Yearly variation in growth has been identified for red abalone (Haliotis rufescens) in southern California, USA, but has not been previously incorporated into growth models. In this study, Bayesian hierarchical models were developed to describe variability in growth rates for the Johnsons Lee red abalone population. Although the Bayesian hierarchical modeling estimates are close to estimates of the nonhierarchical highly parameterized model that assigns an estimate of parameters to each data period when the sample sizes are high, the hyperparameters in the hierarchical model are more useful in incorporating the temporal variability into the stock assessment. By ignoring temporal variability, confidence intervals of the estimates of growth can be unrealisti-cally narrow, possibly leading to bias when these models are used for developing biological reference points such as F 0.1,F max, or F x%. The use of a Bayesian hierarchical approach is generally suggested for future growth modeling and for per-recruitment models that include growth when determining precautionary management decisions.

Bush S.L.,University of Rhode Island | Bush S.L.,Monterey Bay Aquarium Research Institute | Hoving H.J.T.,Monterey Bay Aquarium Research Institute | Huffard C.L.,Wildlife Conservation Society | And 2 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2012

Squids of the family Bathyteuthidae have generally been infrequently encountered in their deep-sea habitat. Remotely operated vehicles were used to observe seven individuals in situ in the Monterey Submarine Canyon, CA, USA. One of these was a female Bathyteuthis berryi holding a sheet with approximately 360 embedded embryos. Examination of this female after collection revealed the presence of a seminal receptacle on the buccal membrane. We present some potential costs and benefits of post-spawning egg care, a strategy that is now known for two families of deep-dwelling squids, but may turn out to be more common with the increasing exploration of the deep sea. © Copyright Marine Biological Association of the United Kingdom 2012.

Carlisle A.B.,Stanford University | Litvin S.Y.,Stanford University | Hazen E.L.,Southwest Fisheries Science Center | Madigan D.J.,State University of New York at Stony Brook | And 3 more authors.
Marine Ecology Progress Series | Year: 2015

The use of nursery areas by elasmobranchs is an important life history strategy that is thought to reduce juvenile mortality and increase population growth rates. The endothermic salmon shark Lamna ditropis uses the California Current System (CCS) as a nursery area, though little is known about how juveniles use this ecosystem. Juvenile salmon sharks consistently strand along the west coast of North America. Strandings in the southern CCS occurred throughout the year, while those in the northern CCS were limited to summer and autumn, when mean sea surface temperatures were warmest. Strandings primarily occurred when water temperature was between 12 and 16°C, suggesting that juveniles occupy a relatively narrow thermal niche. Stable isotope analysis (SIA) indicated that juveniles primarily feed on offshore meso- and epipelagic prey from the outer shelf, slope, and oceanic habitats as opposed to inshore and coastal habitats, although sharks appeared to move closer to shore prior to stranding. Generalized additive models indicate that the probability of stranding was greatest when mean water temperatures were relatively high (∼14°C) and sharks were exposed to acute cold-water events (∼9°C) during coastal upwelling. This suggests that juveniles are thermally limited and stressed by upwelling events, resulting in bacterial infections that are the proximate cause of the strandings. © Inter-Research 2015 · www.int-res.com.

Miller R.E.F.,Marine Region | Gotshall D.W.,Sommerset Rise | Karpov K.A.,Karpov Marine Biological Research
California Fish and Game | Year: 2014

In 2003, marine protected areas (MPAs) were established offshore of the northern Channel Islands, California. The MPAs are surveyed by remotely operated vehicle (ROV) as part of a larger, ongoing effort to evaluate their effectiveness. To determine macroinvertebrate species distribution and richness, we analyzed the ROV video data collected at five paired sites during 2007-2009. Percent occurrence was used to estimate species richness. Macroinvertebrates observed included harvested species and species with structure-forming potential. Fifty-three invertebrate species were identified along with 20 higher taxonomic complex level classifications when identification to species level was not possible. Two of the five site-pairs formed clusters in two different cluster analyses. Site clustering suggested an island effect or clinal change in the biogeographic regions from the Oregonian Province through the Transition Zone to the Californian Province. The ROV surveys yielded new depth records for three invertebrate species. In addition, the cnidarian Stylaster californicus was found offshore of Santa Rosa Island, expanding its documented distribution within the northern Channel Islands.

Satterthwaite W.H.,National Oceanic and Atmospheric Administration | Satterthwaite W.H.,University of California at Santa Cruz | Mohr M.S.,National Oceanic and Atmospheric Administration | O'Farrell M.R.,National Oceanic and Atmospheric Administration | And 10 more authors.
Transactions of the American Fisheries Society | Year: 2014

Managing weak stocks in mixed-stock fisheries often relies on proxies derived from data-rich indicator stocks, although there have been limited tests of the appropriateness of such proxies. For example, full cohort reconstruction of tagged Klamath River fall-run Chinook Salmon Oncorhynchus tshawytscha of northern California enables the use of detailed models to inform management. Information gained from this stock is also used in the management of the untagged, threatened California Coastal Chinook Salmon (CCC) stock, where it is assumed that a cap on Klamath harvest rates effectively constrains impacts on CCC to acceptable levels. To evaluate use of this proxy, we used a novel approach based on genetic stock identification (GSI) data to compare the two stocks' size at age and ocean distribution (as inferred from spatial variation in CPUE), two key factors influencing fishery exposure. We developed broadly applicable methods to account for both sampling and genetic assignment uncertainty in estimating total stock-specific catch from GSI data, and propagated this uncertainty into models quantifying variation in CPUE across space and time. We found that, in 2010, the stocks were similar in size at age early in the year (age 3 and age 4), but CCC fish were larger later in the year. The stocks appeared similarly distributed early in the year (2010) but more concentrated near their respective source rivers later in the year (2010 and 2011). If these results are representative, relative fishery impacts on the two stocks might scale similarly early in the year, but management changes later in the year could have differing impacts on the two stocks. This novel modeling approach is suited to evaluating the concordance between other data-limited stocks and their proxies, and can be broadly applied to estimate stock-specific harvest, and the uncertainty therein, using GSI in other systems. Received May 31, 2013; accepted August 14, 2013. © 2014 Copyright Taylor and Francis Group, LLC.

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