Energy Content of Arctic Forage Fish
Ron Heintz1, JJ Vollenweider1, Matt Callahan2, Ann Robertson2, Mark Bryce Barton3, Leandra Sousa4, Franz J Mueter5, Stella Mosher2, John Richard Moran2, Elizabeth Logerwell6, Kevin M Boswell3, Todd Sformo4 and Ed Farley2, (1)NOAA NMFS, Alaska Fisheries Science Center, Juneau, AK, United States, (2)NMFS/NOAA, Alaska Fisheries Science Center, Juneau, AK, United States, (3)Florida International University, Department of Biological Sciences, North Miami, FL, United States, (4)Department of Wildlife Management, North Slope Borough, Barrow, AK, United States, (5)UAF, College of Fisheries and Ocean Sciences, Juneau, AK, United States, (6)NOAA/NMFS/Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, Seattle, WA, United States
Abstract:
Global changes in climate conditions are most extreme in high latitudes and have the potential to restructure Arctic marine fish assemblages. Of concern is the ability for fish to adapt to changing habitats, the potential for range expansion from lower latitudes, and resultant introduction of competitors and/or predators. Bioenergetic models are useful tools to understand potential cascading trophic effects, and fish energy density is a key parameter in these models. We present energy density (kJ/g dry mass) values for 28 Arctic fish species collected in the Chukchi and Beaufort Seas between 2005 and 2014. Pacific herring (Clupea pallasii) was the most energy-rich species (25.0 kJ/g), followed by two species of primary importance to subsistence people, Arctic cisco (Coregonus autumnalis) and Bering cisco (Coregonus laurettae) (24.9 kJ/g and 23.5 kJ/g, respectively). The abundant and ecologically important Arctic cod (Boreogadus saida) was the most energy-rich gadid, averaging 22.7 kJ/g and having 6% more energy than walleye pollock (Theragra chalcogramma) (21.5 kJ/g) and 11% more energy than saffron cod (Eleginus gracilis) (20.5 kJ/g). In general, pelagic species such as juvenile Pacific salmon (Oncorhynchus sp) had the highest energy content, whereas benthic species such as sculpin (Cottidae), flatfish (Pleuronectidae), eelblennies (Stichaeidae) and eelpouts (Zoarcidae) were amongst the lowest. The high energy content of Arctic cod and their ubiquitous distribution in the water column makes them valuable prey for both demersal and pelagic predators.
