From 1994 through 2012 Tanner crab were identified as premolt, held through a molt, and then measured to determine growth per molt.

The importance of high relief structure containing biotic habitat to rockfish and other species remains largely unknown. This data set was created to examine the importance of this habitat for Pacific ocean perch, northern rockfish, and dusky rockfish. These data were derived from four research cruises that occurred between May 2012 and December 2014. During the cruises, video data was recorded of habitat associations, plankton samples were collected, temperature profiles were recorded, and several types of biological samples were taken from trawl captured rockfish. These data will be recorded in several tables in an access database and video files will also be available.

To study the effects of ocean acidification we examined the effects of ocean acidification on the larval stages of the economically important southern Tanner crab, Chionoecetes bairdi. Ovigerous females were reared in one of 3 treatments: control (ambient pH ~8.1), pH 7.8, and pH 7.5 for 2 years. Larvae in year 1 were from oocytes developed in the field whereas larvae in year 2 were from oocytes developed under acidified conditions. Larvae hatched each year, were also exposed to 3 pH treatments to examine starvation-survival, morphology, condition, and calcium/magnesium content. Approximately 300 larvae were stocked in multiple treatments for testing the effect of pH. Hatching success was measured as the total % of larval hatched from a full clutch while duration was the number of days over which hatching occurred. Hatching success did not differ among treatments in 2012 but varied between 46 to 87% in 2013 dependent on pH treatment. Larval mass was highest in pH 7.8 in 2012 and lowest in the control, however in 2013 the highest larval mass was in the control water. There were only small (not significant) changes in magnesium or calcium content among treatments in 2012 however, the reduction in both minerals at higher pH was greater in 2013. There was higher percent carbon and nitrogen contents in pH 7.5 larvae in 2013. The morphology of Tanner crab larval was assessed from 200 larvae stocked in multiple 2 L beakers. There was no effect of treatment on larval morphometrics. In 2012 and 2013, we examined if embryos developed under acidified conditions affected larval morphology by assessing 15 newly hatched larvae from each treatment. There was again no effect of treatment on larval morphometrics. Starvation survival experiments were performed in 1 L sized PVC inserts. In both years larvae from embryos that developed in pH 7.5 water survived about 3 days longer than those that developed in control water. However, in 2012 larvae from embryos that had developed in pH 7.8 water were similar to control larvae whereas in 2013 they were intermediate between the control and pH 7.5 larvae. The overall effects of treatment at the larval stage appeared to be better condition and initial survival at lower pH, however multiple years of treatment led to lower survival.

The Resource Assessment and Conservation Engineering Division (RACE) of the Alaska Fisheries Science Center (AFSC) conducts bottom trawl surveys to monitor the condition of the demersal fish and crab stocks of Alaska. These data include catch per unit effort for each commercially important crab species at a standard set of stations in the eastern Bering Sea. This is a subset of the main database. Excluded are certain non standard tows and other types of data collected other than species id, species size category, species catch per unit effort (number per square nautical mile), water temperature and depth.

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.

To study the effects of ocean acidification we examined the effects of ocean acidification on the embryo stages of the economically important southern Tanner crab, Chionoecetes bairdi. Ovigerous females were reared in one of 3 treatments: control (ambient pH ~8.1), pH 7.8, and pH 7.5 for 2 years. Embryos in year 1 were from oocytes developed in the field whereas embryos in year 2 were from oocytes developed under acidified conditions. Datasets associated with this study include Brooding Duration, Carbonate Chemistry, Embryo Morphology, and Embryo Stages. Embryo stages assessed monthly included detailed developmental stages from the prefuniculus formation through the prehatching stage. Embryo stages were not different among pH treatments. Embryo morphology included egg area, egg diameter, yolk area, yolk diameter, embryo area, eye area, and eye diameter. Each morphological characteristic varied according to pH treatment using a principal component analysis.

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.

Juvenile rockfish were observed amongst coral, sponge, cobble, and gravel habitats. Rockfish utilized coral habitats more than any other, while gravel was the least utilized. Sponge and cobble habitat utilization was intermediate to coral and gravel. Predation of young-of-the-year rockfish by sculpin predators was greatest in gravel habitats and lowest in coral habitats.

The project consisted of a nearshore fish, invertebrate, and habitat survey in northern Bristol Bay, Alaska. A 32-ft. gillnet vessel, the F/V Willow was chartered for the survey, and we also used a 20-ft. aluminum skiff with 90-hp. motor for shallow water work. The survey was staged out of Dillingham, Alaska and took place from July 26-August 8, 2009.The main gear types used during the survey were a beach seine and a bottom beam trawl. A surface pair trawl (towed by the vessel and the skiff) was deployed in one location. Using these gear types, we sampled from the shoreline to 17 m depth, as well as surface waters ~1 km from the shoreline. Catches were sorted to species, enumerated, and when possible weighed using spring scales. Length measurements were taken for most species. Voucher specimens were preserved in 10% formalin for confirmation of species identification. A small number of samples were frozen for age and energetics analysis . Photographs were taken of most species. Small, datalogging conductivity-temperature-depth recorders (CTDs) were deployed on the trawl gear, and also placed on temporary moorings in several locations to study fluctuations in temperature and salinity over tidal cycles. We also recorded habitat variables at beach seine sites according to the methodology used in the Nearshore Fish Atlas of Alaska. During July 26-August 1, 2009 sampling was conducted in Nushagak Bay. High wind and waves hampered the sampling throughout this entire week and largely determined possible sampling locations. Two days were completely lost due to weather. On August 3 we traveled from Dillingham to the west side of the Nushagak and from August 4-8 sampling was conducted along the Nushagak Peninsula and in Kulukak, Nunavachak, Ungalikthluk, and Togiak Bays. During most of this time we experienced high winds but they did not hamper the sampling to the same degree as in the Nushagak. On August 8 we traveled back to Dillingham.