Loher et al.: Growth of Paralithodes ccimtschaticus 
573 
model was derived from data from Bristol Bay, but it con- 
sidered only individuals >81 mm carapace length, well 
above the size at which multiple yearly molts are expect- 
ed. Weber’s (1967) work was based on juvenile crabs col- 
lected more than 40 years ago at Unalaska Island (Fig. 
1) in the eastern Aleutian Islands, which is located west 
of Unimak Pass and the coastal shelf break and which 
is oceanographically separated from Bristol Bay by the 
southern origins of the Bering Slope current. Stevens and 
Munk’s (1990) growth model was based on data from the 
Kodiak region (Fig. 1); a separate growth model was de- 
veloped by Stevens (1990) to consider the eastern Bering 
Sea, but it relies on Weber’s (1967) findings regarding the 
growth of early juvenile crabs. 
Accurate growth rate information is important to prop- 
erly calibrate the length-based recruitment model and also 
to determine appropriate time lags between spawning and 
subsequent recruitment. Given the likelihood of temporal 
and geographic variability in growth rates, it is likely that 
the Bristol Bay stock exhibits growth rates different from 
those observed at different locations by the aforemen- 
tioned researchers. Environmentally induced changes in 
molt schedule resulting in considerable variability in size- 
at-age is a common feature in Crustacea (e.g. Hartnoll, 
1982; Hill et al., 1989; Huner and Romaire, 1990; Wain- 
right and Armstrong, 1993; Tremblay and Eagles, 1997) 
and probably also in red king crab (Stevens, 1990; Stevens 
and Munk, 1990). Thus, further analysis of the growth 
of prerecruit crabs within Bristol Bay is needed. In our 
study, we analyzed growth of early juvenile red king crabs 
in Bristol Bay by fitting growth equations to length-fre- 
quency data collected between 1983 and 1991. We com- 
pared the inferred growth rate for Bristol Bay with that 
determined from identical models fitted to Weber’s (1967) 
data, and with two sets of length-frequency data avail- 
able for the Kodiak region (Dew, 1990; Donaldson et al., 
1992) to assess whether application of these growth rates 
to Bristol Bay crabs is appropriate. We then expanded our 
analyses to include older prerecruit crabs in Bristol Bay 
by analyzing length-frequency distributions from 25 years 
of southeast Bering Sea trawl survey data in order to iden- 
tify growth patterns associated with strong year classes 
and in order to elucidate size-at-age characteristics dis- 
played by the population. 
Materials and methods 
Figure 1 
Map of western Alaska, showing the locations of 
Bristol Bay, Unalaska Island, and Kodiak Island. 
results of Weber (1967), who collected early juvenile red 
king crabs at Unalaska Island in 1958 and 1959, as well 
as data collected in the Kodiak region from 1987 to 1989, 
originally published in Dew ( 1990), and from 1990 to 1991, 
originally published in Donaldson et al. (1992). Note that, 
in the present paper, all ages and year-class designations 
are referenced to approximate settlement date. That is, 
they refer to the postsettlement age of benthic crabs and 
do not include the larval phase or the egg incubation 
period. This postsettlement age should be taken into con- 
sideration for applications in which the year when eggs 
were extruded is important. 
Bristol Bay Waters of the Bering Sea east of 163. 5°W 
longitude and south of 59°N latitude will be considered 
“Bristol Bay.” This area is larger than the area that is 
often referred to as Bristol Bay; it is more typically con- 
sidered the “southeast Bering Sea.” However, because we 
also report information from Unalaska Island, also in the 
southeastern Bering Sea, we choose to make a distinction 
between Bristol Bay and Unalaska Island in order to avoid 
confusion. In 1983, surveys of juvenile red king crab abun- 
dance were conducted throughout the Bristol Bay region 
(Fig. 2A) with surface-deployed try-net otter trawls and 
a rock dredge, during three sampling periods: 18 April-7 
May, 2—17 June, and 9-23 September (McMurray et al. 3 ). 
Growth of early juvenile red king crab 
Growth of early juvenile crabs, from settlement through 
approximately 3 years after settlement, was examined 
by using catch data from targeted sampling in Bristol 
Bay obtained from three sources: 1) work conducted in 
1983 under the auspices of the Outer Continental Shelf 
Assessment Program (OCSEAP) (documented in McMur- 
ray et al. 3 ), 2) OCSEAP work conducted in 1985 (previ- 
ously unpublished), and, 3) work conducted in 1991 by the 
National Marine Fisheries Service (NMFS; documented 
in Stevens and Macintosh 4 ). In addition we reviewed the 
3 McMurray, G., A. H. Vogel, P. A. Fishman, D. A. Armstrong, 
and S. C. Jewett. 1984. Distribution of larval and juvenile 
red king crab ( Paralithodes camtschatica) in Bristol Bay. U.S. 
Dep. Commer., NOAA, OCSEAP Final Report 53( 19861:267-477, 
Anchorage, Alaska. [Available from D.A. Armstrong at: School 
of Fisheries and Aquatic Sciences, Univ. Washington, Box 
355020, Seattle, WA 98195.] 
4 Stevens, B. G., and R. A. Macintosh. 1991. Cruise 91-1 Ocean 
Hope 3: 1991 eastern Bering Sea juvenile red king crab survey, 
May 24-June 3, 1991. U.S. Dep. Commer., NOAA, NMFS, 
AFSC, RACE. Seattle, Washington. [Available from B. G. Ste- 
vens at AFSC Kodiak Laboratory, National Marine Fisheries 
Service, 301 Research Court, Kodiak, Alaska, 99615.] 
