Zimmermann and Goddard: Biology and distribution of Atheresthes stomias and A. evermanni 



363 



of water temperatures for Kamchatka flounder (0.7° 

 to 5.9°C) was similar to the range for arrowtooth 

 flounder (0.3° to 5.9°C), the highest catch rates of 

 Kamchatka flounder were distributed over a nar- 

 rower temperature range (3.8° to 4.2°C). 



Arrowtooth flounder catch rates were high on the 

 eastern Bering Sea continental shelf (7.3 kg/ha), espe- 

 cially in waters between 100 m and 200 m ( 17.7 kg/ha), 

 on the eastern Bering Sea continental slope 

 (8.8 kg/ha), and the fish occurred throughout the 

 Aleutian Islands (Fig. 5). The Kamchatka flounder 

 geographic distribution was similar to that of 

 arrowtooth flounder ( Fig. 6 ), except that Kamchatka 

 flounder were not caught along the Alaska Penin- 

 sula, nor in the Gulf of Alaska. Kamchatka flounder 

 were much less abundant than arrowtooth flounder 

 in the eastern Bering Sea, especially on the shelf (1.2 

 kg/ha), and about half as abundant as arrowtooth 

 flounder on the slope area (4.6 kg/ha). However, in 

 the deepest half of the slope area (500 m to 800 m), 

 the catch rate of Kamchatka flounder (1.5 kg/ha) was 

 about twice that of arrowtooth flounder (0.7 kg/ha). 

 Kamchatka flounder occurred on the northwest tip 

 of the eastern Bering Sea shelf, whereas arrowtooth 



flounder were absent from that area. Arrowtooth 

 flounder catch rate was high along the north side of 

 the easternmost Aleutian Islands bordering the 

 southern Bering Sea ( 16.4 kg/ha), where more than 

 half of the total biomass for the entire Aleutian Is- 

 lands occurred (Harrison, 1993). Kamchatka floun- 

 der generally decreased in abundance from west to 

 east along the Aleutian Islands ( Harrison, 1993 ). The 

 easternmost Aleutian Islands were the southeastern 

 border of their distribution, where the catch rate was 

 low (0.7 kg/ha). In the rest of the Aleutian Islands 

 area, Kamchatka flounder had a slightly higher catch 

 rate (3.1 kg/ha) than arrowtooth flounder (2. 9 kg/ha), 

 particularly in the 300 m to 500 m depth interval 

 (10.8 vs. 2.0 kg/ha, Harrison, 1993). 



Data provided from the Fishery Observer Program 

 of the AFSC indicated the presence of Kamchatka 

 flounder in the Gulf of Alaska as far east as 154°26'W, 

 but in limited numbers and at great depths (Con- 

 rad 5 ). The identification of Kamchatka flounder oc- 



5 Conrad, M. 1994. Alaska Fisheries Science Center, Fishery 

 Observer Program, 7600 Sand Point Way NE, Seattle, WA 

 98115. Personal commun. 



70 E 



1 75 E 



63°N 



62 N h 

 61 N I 

 60"N \ 

 59 -N i 

 58 N 

 57'N 

 56 N I 

 55"N 

 54' N 

 53 N 

 52 N 

 51 N 



5CTN 



% 



ISO w 



175 W 



170 W 



500m 



• «• • • •••• 



„ JnW 57 N 



xfsQ 56N 



&9 jto m j£ 



Aleutian Islands 





-.*■* 



»■ 



Gulf of Alaska 



- 54' N 

 53°N 

 52°N 



- 51"N 



50"N 



170 E 



1 75 E 



180 W 



175'W 



I 70 W 



165 ' W 



160 W 



155°W 



Figure 5 



Map of arrowtooth flounder. Alhrn-sth,-.-, stomias, CPUE (kg/ha) over the eastern Bering Sea shelf and slope, 

 in waters off the Aleutian Islands, and in Gulf of Alaska areas. The 50-. 100-, and 200-m bathymetnc contours 

 are not included in the Aleutian Islands and Gulf of Alaska areas owing to complicated bottom topography. 



