NOAA scientists in Alaska have proposed six areas in the eastern Bering Sea as habitat areas of particular concern (HAPCs) for skates because they function as skate nurseries.
Nursery sites have been found on flat sandy areas at the tops of undersea canyons, such as the Pribilof Canyon in the eastern Bering Sea. These canyons may possess the best water conditions for development and successful hatching of skate embryos. Scientists estimate there are 16-19 such nurseries in the eastern Bering Sea for the eight most abundant skate species.
In the North Pacific, skates have been found to take more than 3 years to develop inside their egg case due to cold water temperatures. Because skates produce only a small number of offspring each year, they rely on high survival rates of juveniles to maintain healthy population levels.
Scientists say the health of the skate population is a good indicator of overall health and productivity of Alaska’s marine ecosystem. Skates play a key role in the marine ecosystem as a food source for sperm whales, Pacific halibut, cod, Steller sea lions, and sharks.
Skates are also becoming a trendy food source for people. A small commercial fishery for skates developed in the Gulf of Alaska in 2003 and could expand to provide even more economic opportunities in the future. Maintaining a robust skate population is not only important to Alaska’s ecosystem but also to its economy.
So why is there concern for skate nurseries? Skate experts say that during the lengthy development time that eggs and embryos are on the sea floor, they are highly susceptible to disturbance, damage, or destruction from fishing gear that contacts this same area. Fishing vessels generally try to avoid areas that are known to have high concentrations of skate eggs because egg cases get tangled in gear. These cases are difficult to remove from trawl gear and add additional trip time, cost and fishing effort.
It seems it would be in the best interest of both the skates and the fishing industry for vessels to avoid the skate nursery areas.
At its June 2012 meeting in Kodiak, Alaska the Council announced that it will consider opportunities for finding out more about skate nurseries, including directing NOAA Fisheries to monitor the areas that were identified as ‘habitat areas of particular concern’ for changes in egg density and potential effects of fishing gear. They will need help from the fishing industry to identify areas of skate egg concentration and assistance in identifying research needs. The Council is also considering making research and monitoring of skate egg concentration a high research priority.
The Council plans to make a final decision on the HAPC proposal at its meeting in Anchorage in December.