This dataset supports efforts to estimate the abundance and trends in population size of Alaska harbor seals. Annual surveys of harbor seal populations are fundamental to estimation of seal abundance, distribution, and trends, which in turn are essential for stock assessment, conservation, and management. The most feasible approach to determining harbor seal distribution and abundance is to use aircraft to count seals when they haul out of the water and are visible. Harbor seals in Alaska occupy a geographically extensive range from approximately long. 172ºE to 130ºW (over 3,500 km east to west) and from lat. 51ºN to 61.5ºN (over 1,000 km north to south). Estimation of the abundance of harbor seals statewide requires broad-scale aerial surveys and these surveys have been conducted by NOAA Fisheries, the Alaska Department of Fish and Game, and other collaborators since the early 1980s. This dataset reflects counts of harbor seals from surveys conducted between 2003 and 2011.

This data set is from a series of laboratory experiments examining the interactions between red and blue king crabs and habitat. We examined how density and predator presence affect habitat choice by red and blue king crabs. Further experiments determined how temperature and habitat affect predation by year-1 red king crab on year-0 blue king crab. Finally, long-term interaction experiments examined how habitat and density affected growth, survival, and intra-guild interactions between red and blue king crab.

Juvenile red and blue king crabs (Paralithodes camtschaticus and P. platypus) were exposed to three pH levels: ambient (pH 8.1), pH 7.8, and pH 7.5 for three weeks. Oxygen consumption and feeding ration were determined immediately after exposure to treatment water and after three weeks exposure. Growth can be calculated from the wet mass observations.

Multiple stressor studies are needed to better understand the effects of oceanic changes on marine organisms. To determine the effects of near-future ocean acidification and warming temperature on juvenile red king crab (Paralithodes camtschaticus) survival, growth, and morphology, we conducted a long-term (184 d) fully crossed experiment with two pHs and three temperatures: ambient pH (~7.99), pH 7.8, ambient temperature, ambient +2 degree C, and ambient +4 degree C, for a total of 6 treatments.

Stock assessment of Alaskan red king crab, Paralithodes camtschaticus (Tilesius, 1815), can be improved by incorporating reproductive output, which requires an understanding of the size-fecundity relationship, interannual and seasonal variability in fecundity, and maternal size effects on embryo and larval quality. We collected red king crab egg clutches from Bristol Bay, Alaska, in summer of 2007-2010 and autumn of 2007-2009 and estimated fecundity. A monitoring project examining the size-fecundity relationship began in 2012 and data is collected every other year.In June 2009 and 2010 we collected embryo clutches of recently extruded red king crab embryos in Bristol Bay, Alaska, to assess embryo quality based on dry weight, carbon and nitrogen content. To assess larval quality, we collected ovigerous females from Bristol Bay in 2007 and reared them in the laboratory until larval hatching in 2008. Larval quality based on dry weight, carbon and nitrogen content, and time to 50% mortality under starvation conditions was assessed.

Rearing crustaceans communally for aquaculture, stock enhancement or research often results in high rates of cannibalism and low yields. One potential strategy to reduce loss from cannibalism is to rear crustaceans in individual cells. As small holding cell size can result in decreased growth or increased mortality, it is essential to identify the optimal holding cell size, both for mass culturing efforts and for experimental design purposes. In this study, we reared juvenile red king crab, Paralithodes camtschaticus, (3.67 to 8.30 mm carapace length) in 20, 40, and 77 mm diameter holding cells and monitored growth and survival over a 274-day experiment.

This data set is the results of a laboratory experiment. Juvenile red king crab and Tanner crab were reared in individual containers for nearly 200 days in flowing control (pH 8.0), pH 7.8, and pH 7.5 seawater at ambient temperatures (range 4.4-11.9 C). Survival, growth, and morphology were measured throughout the experiment. At the end of the experiment, calcium concentration was measured in each crab and the dry mass and condition index of each crab were determined.

Stock assessment of Alaskan red king crab, Paralithodes camtschaticus (Tilesius, 1815), can be improved by incorporating reproductive output, which requires an understanding of the size-fecundity relationship, interannual and seasonal variability in fecundity, and maternal size effects on embryo and larval quality. We collected red king crab egg clutches from Bristol Bay, Alaska, in summer of 2007-2010 and autumn of 2007-2009 and estimated fecundity. A monitoring project examining the size-fecundity relationship began in 2012 and data is collected every other year.In June 2009 and 2010 we collected embryo clutches of recently extruded red king crab embryos in Bristol Bay, Alaska, to assess embryo quality based on dry weight, carbon and nitrogen content. To assess larval quality, we collected ovigerous females from Bristol Bay in 2007 and reared them in the laboratory until larval hatching in 2008. Larval quality based on dry weight, carbon and nitrogen content, and time to 50% mortality under starvation conditions was assessed.