Stevenson and Lewis: Skate bycatch in the commercial groundfish fisheries of Alaska 
213 
Table 3 
Observed skate catch (in tons) by region, gear type, and target species reported in Alaska’s groundfish fisheries for 1998-2008. 
Target species is defined as the predominant species (by % weight) in the catch. * = less than 100 tons. 
Region 
Gear type 
Target species 
>*/ 
\-y 
cjT „ 
A/ / 
& 
$ 
.21 
sfi 
<?'>" 
A 
0° 
^ v 
<t%o" 
V 
:> 
o & cy 
■ %•* %y' 
Other 
Total 
1367 
26,675 
* 
8967 
2714 
94,766 
* 
2067 
* 
* 
793 
5597 
448 
3445 
* 
* 
286 
2566 
1823 
32,187 
* 
9061 
3794 
102,929 
5630 
144,177 
Bering Sea 
Nonpelagic trawl 
2606 
18,400 
2476 
1677 
* 
Pelagic trawl 
* 
* 
8912 
* 
* 
Longline 
90,314 
* 
206 
967 
461 
Aleutian Islands 
Nonpelagic trawl 
491 
* 
* 
* 
* 
Pelagic trawl 
* 
* 
* 
* 
* 
Longline 
3850 
* 
* 
256 
497 
Gulf of Alaska 
Nonpelagic trawl 
437 
756 
* 
1393 
* 
Pelagic trawl 
* 
* 
* 
* 
* 
Longline 
1486 
* 
* 
* 
443 
All areas 
Nonpelagic trawl 
3534 
19,177 
2563 
3123 
101 
Pelagic trawl 
* 
* 
8967 
* 
* 
Longline 
95,650 
* 
208 
1229 
1401 
Total 
99,222 
19,253 
11,738 
4366 
1504 
1021 
* 
1072 
1077 
443 
262 
744 
* 
* 
843 
* 
140 
319 
493 
544 
as training methods and identification tools 
are further refined. 
Patterns of species composition in OSC 
generally parallel recent biomass estimates 
for regional skate populations derived from 
bottom trawl surveys. Bathyraja parmifera 
accounts for the large majority of OSC, 
which is not surprising given that B. par- 
mifera is the most abundant species of 
skate encountered in bottom trawl surveys 
conducted in Alaska waters (Stevenson et 
al., 2008). In fact, B. parmifera is particu- 
larly common on the Bering Sea continental 
shelf, where its populations make up about 
95% of the total skate biomass (Acuna and 
Lauth, 2008; Lauth and Acuna, 2009) and 
where commercial fishing effort for wall- 
eye pollock, Pacific cod, and flatfishes is 
concentrated. Many of the other species 
encountered by observers in the Bering Sea 
are recorded from fishing activity on the 
upper continental slope, where B. aleutica, 
B. maculata, and B. interrupts populations 
100 
All skates 
q R. binoculata 
o- B. rhina 
• — B. parmifera 
« — B. aleutica 
+ — B. maculata 
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 
Year 
Figure 2 
Overall mean percent retention of skate catch in commercial fisheries 
for each year from 1998 through 2008 (gray bars), as well as mean 
percent retention for Raja binoculata , R. rhina , Bathyraja parmifera, 
B. aleutica, and B. maculata. 
