588 



Fishery Bulletin 92(3). 1994 



a wide range of measured lengths at both RES 1 and 

 RES 2, whereas at all other stations they show a more 

 narrow, unimodal distribution. This distribution 

 could be the result of several intrusions of surface 

 water and larvae into the inner fjord. 



Growth 



The growth rates in Resurrection Bay were close to 

 those reported for larvae from other geographic ar- 

 eas (Table 3), including Shelikof Strait and Auke Bay, 

 which are located in the Gulf of Alaska at latitudes 

 similar to Resurrection Bay. Temperatures in the 

 upper layer in Resurrection Bay were slightly lower 

 in early May 1989 than those observed in Shelikof 

 Strait and Auke Bay at the same time of year 

 (Kendall et al., 1987; Pritchett and Haldorson, 1989; 

 Fig. 2). The low temperatures in the inner basin in 

 May reflect delayed warming of the upper water col- 

 umn relative to the shelf outside the fjord. Thus, it 

 may seem that the fjord in early spring provides less 

 favorable conditions for growth than the shelf, con- 

 sidering the lower temperatures inside the fjord. 

 However, salinities also differ between the shelf and 

 the fjord, resulting in a more pronounced stratifica- 

 tion inside Resurrection Bay. Stratification of the 

 water column will reduce vertical mixing and can 

 result in an earlier onset of phytoplankton and zoop- 

 lankton blooms. In spite of differences in tempera- 

 ture, stratification, and vertical distribution (Kim, 

 1989; Pritchett and Haldorson, 1989), growth rates 

 are very similar in Shelikof Strait, Auke Bay, and 

 Resurrection Bay 



We detected no difference in growth rate between 

 stations RES 2 and RES 4 in Resurrection Bay. This 

 result is not surprising, given the proximity of the 

 stations and the similarity in water properties. The 

 growth rates, especially at the outer station, may be 

 biased because only fish from the shallowest samples 



were aged. Larvae from the upper layer may not ad- 

 equately represent the whole population. More 

 samples would be needed to accurately test for dif- 

 ferences in growth between stations. To test for 

 interannual differences, data from additional years 

 are needed. Differences in growth rates are most com- 

 monly attributed to variations in water temperature 

 and prey concentration. The primary prey of first 

 feeding walleye pollock are copepod nauplii ranging 

 in length from 100 to 300 pm (Kamba, 1977; Clarke, 

 1978). Smith etal. (1991) found over 20 copepod nau- 

 plii (150-350 pm length) per liter throughout May 

 1988 in Resurrection Bay with numbers exceeding 

 100 per liter in mid-May. These prey concentrations 

 are sufficient for successful feeding of larval walleye 

 pollock (Paul, 1983; Haldorson et al., 1989b). Under 

 these conditions growth of larvae in Resurrection Bay 

 is not food limited. Growth rates in Resurrection Bay 

 were also similar to those observed in the laboratory 

 under optimal feeding conditions and at a higher tem- 

 perature (Bailey and Stehr, 1988), further suggest- 

 ing that growth was not food or temperature limited. 

 Many studies have documented the effects of wa- 

 ter temperature on growth of fish larvae (Houde, 

 1989). Laboratory studies have shown that first-feed- 

 ing walleye pollock larvae reared at 5.5°C are more 

 successful at capturing prey than larvae reared at 

 3 C (Paul, 1983). Brown and Bailey ( 1992) found geo- 

 graphical differences in growth for juvenile walleye 

 pollock that could be attributed to differences in tem- 

 perature as well as nutrient levels. In our study, tem- 

 peratures in the larval environment ranged from 3.5 

 to 6.3°C and growth rates fall well within the ob- 

 served range of growth in other habitats. 



Hatching and spawning 



Hatch dates in Resurrection Bay fall well within the 

 range of observed hatch dates in other parts of the 



