195 
Demersal fish assemblages of the 
northeastern Chukchi Sea, Alaska 
Robert M. Meyer 
USGS Biological Resources Division, Eastern Regional Office 
1 700 Leetown Road 
Kearneysville, West Virginia 25430 
Abstract .—We documented the dis- 
tribution and abundance of demersal 
fishes in the northeastern Chukchi Sea, 
Alaska, in 1990 and 1991, and de- 
scribed 1990 demersal fish assemblages 
and their relationship to general 
oceanographic features in the area. We 
collected samples using an otter trawl 
at 48 stations in 1990 and 16 in 1991, 
and we identified a total of 66 species 
in 14 families. Gadids made up 83% and 
69% of the abundance in 1990 and 1991, 
respectively. Cottids, pleuronectids, 
and zoarcids together made up 15% of 
the species in 1990, 28% in 1991. The 
number of species, species diversity (H), 
and evenness (V') generally were 
greater inshore than offshore and 
greater in the south than in the north. 
There were significant differences in 
ranks of species, species diversity, and 
evenness at 3 of 8 stations sampled both 
years. From data collected in 1990, 3 
nearshore and 3 offshore station group- 
ings were defined. The northern off- 
shore assemblages had the fewest spe- 
cies, lowest diversity and evenness, and 
least abundance, whereas two southern 
assemblages had the most species, high- 
est diversity and evenness, and great- 
est abundance. We determined that 
bottom salinity and percent gravel were 
probably the primary factors influenc- 
ing assemblage arrangement. 
Manuscript accepted 9 September 1996 
Fishery Bulletin 95:195-209 ( 1997). 
Willard E. Barber 
School of Fisheries and Ocean Sciences 
University of Alaska Fairbanks, 
Fairbanks, Alaska 99775-7220 
E-mail address: wbarber@ims.alaska.edu 
Ronald L. Smith 
Mark Vallarino 
Institute of Marine Sciences 
University of Alaska Fairbanks 
Fairbanks, Alaska 99775-722 0 
The distribution and abundance of 
commercially important demersal 
fishes inhabiting temperate and 
tropical seas are relatively well 
studied (e.g. Pearcy, 1978; Mahon 
and Smith, 1989; Weinberg, 1994). 
Results from such studies have been 
used to examine relationships be- 
tween environmental factors and 
fish assemblage distributions. Im- 
portant environmental variables 
that have been identified include 
sediment type, water depth, bottom 
temperature, and bottom salinity. 
Overholtz and Tyler ( 1985) found 
that six species assemblages on 
Georges Bank, northwestern Atlan- 
tic, remained consistent over depth 
for a number of years. Fargo and 
Tyler (1991), sampling at depths of 
18-240 m in Hecate Strait off Brit- 
ish Columbia, found four species 
assemblages separated by depth. 
Pearcy ( 1978) described shallow and 
deep demersal fish assemblages in 
the northeast Pacific Ocean off the 
coast of Oregon at depths ranging 
from 70 to 102 m. Although there 
was an interaction between depth 
and sediment type, he concluded 
that depth was a primary factor and 
that sediment type was of second- 
ary importance. Mahon and Smith 
(1989) looked for interactions be- 
tween sediment characteristics, 
water depth, bottom temperature, 
and bottom salinity but concluded 
that assemblages were related more 
to depth than to other attributes. 
Scott ( 1982 ) reported that although 
fish distributions were related to 
sediment types, the latter was re- 
lated to depth. Studies of other 
fishes indicated that temperature 
and salinity are important; Jahn 
and Backus (1976), using salinity 
and temperature to characterize 
slope waters, the Gulf Stream, and 
northern and southern Sargasso 
Sea waters in the Atlantic Ocean, 
concluded that mesopelagic fishes 
associated with slope and Gulf 
Stream waters were distinct and 
different from fish assemblages as- 
sociated with the other two water 
masses. Bianchi (1992, a and b) de- 
termined that water depth, bottom 
temperature, bottom salinity, and 
