AFSC/RACE/GAP/Conrath: Delayed discard mortality of the North Pacific giant octopus
공공데이터포털
The majority of octopus bycatch occurs in Pacific cod pot fisheries and recent data collected by North Pacific Groundfish Observers indicate that immediate mortality of octopus caught in these fisheries is very small. The objectives of the proposed research were to examine the delayed mortality of E. dofleini captured in Pacific cod pot fisheries. These data are necessary to make sound management decisions for octopus based on appropriate scientific information. This data set contains observations and measurements on the condition, weight, and survivorship of North Pacific giant octopus that were caught as bycatch in commercial fishing operations utilizing pot gear to target Pacific cod. These octopus were captured during commercial fishing operations that occurred during three fishing seasons from January 2014 through February 2015. These commercial fishing operations occurred in the central Gulf of Alaska in either Shelikof Strait or Marmot Bay. Data collected included information on octopus condition, size, sex, and injury presence. Other data collected included the location of capture, water depth, octopus air exposure time, water temperature, and gear soak time. These octopus were transported to the Kodiak sea water facility and held for a period of several months. During this period data were collected on condition, injury presence, and survivorship at 21 days. After this period octopus were held for an additional five to six weeks to assess growth within the laboratory. Octopus were fed to satiation every 72 hours during this period. Food was weighed prior to feeding and remaining food was weighed after a four hour period. The final food weight was corrected for water soaking time. Octopus were weighed once per week during this period of time. Several metrics of octopus feeding and growth were measured after this period including specific growth rate, absolute growth rate, absolute feeding rate, specific feeding rate, feeding efficiency, and daily growth rate.
AFSC NPRB Conrath Conners Octopus Studies 2009-2011 Kodiak Alaska Life History and Habitat Pot Gear
공공데이터포털
Data collected during 2010-2011 field studies of giant Pacific octopus Enteroctopus dofleini for NPRB. Includes data on habitat pot gear study: fishing locations, pot types, deployment and retrieval dates, and catch in pots (octopus and bycatch). Also includes specimen data (sex. weight, mantle length, gonad maturity, gonad weights, GSI) from octopus in life history study. Life history specimens come from pot gear fishing and donations from commercial fishermen.
NPRB711 Quantification of unobserved injury and mortality of Bering Sea crabs due to encounters with trawls on the seafloor
공공데이터포털
The potential for unobserved mortality of crabs encountering bottom trawls, but not captured, has long been a concern in the management of Bering Sea fisheries. We evaluated how many such crabs die, including snow, Tanner and red king crabs, and demonstrated changes to trawl gear that substantially improved crab survival.
AFSC/NMML: Killer whale surveys in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska, 2001 - 2010
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This dataset is a compilation of line-transect data collected on surveys in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska, 2001 - 2010. All the surveys were conducted with similar methods using line-transect protocols, allowing effort to be quantified, but there were differences in transect design in some years (some surveys were systematic, some were not). Sighting information for all cetacean and at-sea pinniped species was collected. The database was compiled with the intent of including all surveys with sighting data on killer whales, in order to assess killer whale population biology in this region. Surveys included in this database are 2001 - 2007, 2009 and 2010 NMML killer whale surveys.
AFSC/RACE/SAP/Urban:Tanner Crab Handling Mortality
공공데이터포털
Fish and invertebrates that are unintentionally captured during commercial fishing operations and then released back into the ocean suffer mortality at unknown rates, introducing uncertainty into the fishery management process. Attempts have been made to quantify discard mortality rates using reflex action mortality predictors or RAMP which use the presence or absence of a suite of reflexes to predict discard mortality. This method was applied to Tanner crab, Chionoecetes bairdi, during the 2010-2012 fisheries in the Bering Sea. Discard mortality in the fishery is currently assumed to be 50% in stock assessment models, but that rate is not based on empirical data and is widely recognized to be in need of refinement. Over 19,000 crab were evaluated using the RAMP method. The estimated discard mortality rate was 4.5% (SD = 0.812), significantly below the rate used in stock assessment models. Predicted discard mortality rates from the 2010-2012 study were strongly correlated with the air temperature at the St. Paul Island airport in the Pribilof Islands. Using this relationship the discard mortality rate from 1991-2011was estimated at 4.2% (SD = 1.08).