Alaska Groundfish Diet Data
February 22, 2018
The Resource Ecology and Ecosystem Modeling Program at the Alaska Fisheries Science Center maintains a North Pacific groundfish diet data time series that dates back to the early 1980s for many species. Diet data are from samples collected during NOAA Fisheries assessment surveys and include diet composition by predator species, year, and region.
The groundfish trophic interactions database consists of diet data collected from key groundfish throughout the Northeast Pacific (Table 1). Our samples are primarily collected from trawl caught groundfish by NOAA scientists aboard research surveys. We also utilize Fishery Observers to collect samples from regions and seasons outside of our survey areas. Fish stomach samples preserved in the field are returned to the lab for analysis and account for the majority of our database. A small number of samples are analyzed at sea in a qualitative manner and account for the remainder of our data. Our data are categorized into five regions: Bering Sea, Gulf of Alaska, Aleutian Islands, Beaufort Sea, and West Coast.
Our database is maintained in Oracle 11g and is composed of four basic tables. The primary diet table is the Predator-Prey (PredPrey) table, which contains data on each stomach analyzed. Within this table are data on the size, weight, sex, stomach fullness and maturity of each predator along with the taxon, number, weight, and state of digestion of each prey within a given predator’s stomach. Identification information about the vessel, cruise, haul number and specimen number of each predator sampled are also kept in the PredPrey table to allow unique identification of each sample as well as cross-referencing to other tables. The Haul table contains spatial, temporal and physical data for each location at which we have fish stomach samples. Within the Haul table are latitude, longitude, date, bottom and gear depth, surface and gear temperature, gear type as well as vessel, cruise and haul identifiers. The Prey Length (PreyLen) table primarily contains size information of commercially important prey found in the stomach contents that were in adequate condition to allow measurement. In this table we have standard length (mm) of fish prey, carapace width (mm) of brachyuran crabs (snow, Tanner, Dungeness), and carapace length (mm) of anomuran (king) crabs and pandalid shrimps. Along with the prey data, the corresponding predator length as well as the vessel, cruise, haul identifiers and specimen number are maintained. Finally the intestine table contains intestine data of those species, primarily small-mouthed flatfishes, from which we examined intestine contents in addition to stomach contents. This table is fundamentally structured the same as the PP table. Combined, these tables currently account for over one million records. A complete description of our database entities and attributes can be found in our Database description.
Additionally, we have an eastern Bering Sea groundfish food habits database donated to us by Japanese scientists who collected these data on Japanese research vessels from 1979 to 1985.