Moiseev et a!: Effects of pot fishing on the physical condition of Chionoecetes opilio and Chionoecetes bairdi 
235 
both the Bering Sea (Fig. 1) and the 
Sea of Okhtosk (Fig. 2). In the areas 
where we conducted our investiga- 
tions, surface temperatures typically 
vary from 4°C to 12°C in summer and 
from -1.5°C to 3°C in winter. Sur- 
face salinities generally vary between 
32.2%e and 33.0%e. In area I of the 
Bering Sea (Fig. 1) and in area I of the 
Sea of Okhtosk (Fig. 2), the 2 species 
occur together. At crab habitat depths 
of 50-350 m, water temperatures 
range from -0.5 to 5.5°C through- 
out the year and salinity varies from 
33.2%c to 34%c. 
Crab capture and handling 
Collection of crabs and experimental 
work were carried out on a crab boat. 
The fishing gears that we used in this 
study were square pots of the “Ameri- 
can” type and conical pots of the “Japa- 
nese” type (Moiseev, 2003). Both types 
of pots were covered with nylon-twine 
webbing (mesh size: 60-70 mm). Crabs 
caught with commercial pots were 
maintained in large tanks supplied with 
natural seawater. Water temperatures 
during the holding period ranged from 
4°C to 10°C. These tanks were covered 
with tarpaulins to reduce stress effects 
of light on the crabs. All individuals 
were tagged with a piece of rubberized 
fabric marked with a unique number; 
a tag was attached to a crab claw with 
a plastic clip-strip. Because of the ten- 
dency for autotomy of limbs in southern 
Tanner and snow crabs, all manipula- 
tions were carried out quickly with the 
greatest possible care. During holding 
periods, no crabs died or showed signs 
of stress in the form of impaired reflex- 
es (Moiseev et al., 2012). 
For this study, experiments were 
limited to crabs that met the following 
criteria: 1) morphometrically mature 
males had completed a terminal molt 
between 1.5 years and a few months 
previously, according to criteria in Co- 
meau and Conan (1992) and Sainte- 
Maria et al. (1995); 2) carapace width 
for snow crab was 110-150 mm, and 
carapace width for southern Tanner 
crab was 120—155 mm; 3) crabs were 
without apparent physical injuries or 
limb loss; and 4) crabs were in perfect 
condition as revealed with a vitality 
index (VI). 
168°E 172°E 1 76°E 18CPE/W 178°W 
Figure 1 
Map of areas where experiments and sample collection were conducted in the 
western Bering Sea in 2006-10 for our study of effects of commercial fishing 
with crab pots on the physical condition of the snow crab (Chionoecetes opilio) 
and southern Tanner crab (C. bairdi). Area 1 was near the Koryak Coast, and 
area II was the shelf and slope near Cape Navarin. 
140°E 1 44°E 1 48°E 152°E 
156°E 
160°E 
Figure 2 
Map of areas where experiments and sample collections were conducted in 
the Sea of Okhtosk in 2006-10 for our study of effects of commercial fish- 
ing with crab pots on the physical condition of the snow crab ( Chionoecetes 
opilio) and southern Tanner crab (C. bairdi). Area I was on part of the Western 
Kamchatka shelf, area II was on the shelf and continental slope on the beam 
of the Babushkin Gulf, and area III was in the central area of the northern 
Sea of Okhtosk. 
