Nearshore Fish Assemblages of the Northeastern Chukchi Sea, Alaska

Abstract

The Arctic ecosystem is changing rapidly, yet information on nearshore fish assemblages for the northeastern Chukchi Sea is extremely limited. To address this information gap, we sampled nearshore fish assemblages with a beach seine and a small bottom trawl at six stations in the northeastern Chukchi Sea in August 2007, 2008, and 2009, and in September 2009. Catch and species composition differed by gear type and between sample periods, including the two in 2009. A total of 16 039 fish representing 18 species were captured in 24 beach seine hauls, and 3108 fish representing 24 species were captured in 48 trawl tows. Beach seine catch was dominated by capelin (83%), and trawl catch was dominated by Arctic cod (56%). Species that were good discriminators between gear types were capelin (seine) and slender eelblenny (trawl), and unidentified small sculpins were the most common taxa caught with both gear types. Capelin and Arctic cod captured by either gear type were mostly juveniles (judging by size). Variability among sampling periods in catch and species composition within gear types can likely be attributed to annual variations in environmental conditions, including differences in water temperature (range: 2˚–9˚C). The shallow nearshore environment of the northeastern Chukchi Sea provides important habitat for many fish species and is extremely vulnerable to disturbance. Loss of sea ice from global warming may open up formerly inaccessible areas to oil and gas exploration, vessel traffic, and commercial fishing. Thus, long-term monitoring of nearshore fish assemblages in the Alaskan Arctic is necessary for managers to make informed decisions in this fragile environment.