631 



Habitat, age, and diet of a forage fish 

 in southeastern Alaska: Pacific sandfish 

 (Trichodon trichodon) 



John F. Thedinga (contact author) 



Scott W. Johnson 



Donald G. Mortensen 



Auke Bay Laboratory 



11305 Glacier Highway 



Alaska Fisheries Science Center 



National Marine Fisheries Service 



Juneau, Alaska 99801-8626 



Email address for J F Thedinga John Thedinga(Snoaa gov 



Forage fish are an important part 

 of Alaska's marine ecosystems and 

 coastal areas. Forage fish are a criti- 

 cal food source for numerous ground- 

 fish, marine mammals, and seabirds 

 (Wespestad'; Allen and Smith, 1988: 

 Paul et al., 1997; Yang and Nelson, 

 2000; Mecklenburg et al.. 2002). 

 Little is known, however, about the 

 life history characteristics or habitat 

 of many forage fish species in Alaska, 

 including Pacific sandfish [Trichodon 

 trichodon; Fig. 1). Only two articles 

 have been published on the life history 

 characteristics of Pacific sandfish in 

 Alaska. Paul et al. (1997) investigated 

 size-weight-age profiles, size at matu- 

 rity, and fecundity of Pacific sandfish 

 in the northern Gulf of Alaska, and 

 Bailey et al. (1983) examined size and 

 diet of juvenile (<55 mm fork length 

 [FL]) Pacific sandfish in southeastern 

 Alaska. Some Pacific sandfish catch 

 data are also available for the Bering 

 Sea, Prince William Sound, and 

 southeastern Alaska (Isakson et al., 

 1971; Orsi and Landingham, 1985; 

 Allen and Smith, 1988; Brodeur and 



Livingston, 1988; Sturdevant et al.-, 

 Orsi et al., 2000). Pacific sandfish 

 burrow into sand, usually at depths 

 shallower than 150 m, and can reach 

 a maximum size of about 300 mm 

 (Marliave, 1980; Mecklenburg et al., 

 2002). 



Pacific sandfish are commonly 

 found in nearshore waters of the 

 southeastern Bering Sea and Gulf 

 of Alaska. There is no commercial 

 fishery for Pacific sandfish in Alaska, 

 but sailfin sandfish (Arctoscopus ja- 

 poniciis) are commercially fished and 

 cultured in Japan and Korea (Okiya- 

 ma, 1990). In particular, information 

 is scarce on the biology and habitat 

 of Pacific sandfish, especially for 

 southeastern Alaska. Shoreline de- 

 velopment and global climate change 

 (e.g., increased water temperature 

 and sea level) may adversely affect 

 Pacific sandfish populations because 

 of the relatively specialized nearshore 

 spawning sites and one-year incuba- 

 tion period of this species (Marliave, 

 1980). 



1 Wespestad, V. G. 1987. Population 

 dynamics of Pacific herring (Clupea 

 pallasii). capelin (Maltotus villosiis), 

 and other coastal pelagic fishes in the 

 eastern Bering Sea. In Forage fishes of 

 the southeastern Bering Sea; proceed- 

 ings of a conference, November 1986, 

 Anchorage, AK, p. 55-60. U.S. Dep. 

 Interior, Minerals Management Service, 

 OCS Study MMS 87-0017. 



2 Sturdevant, M. V., T. M. Willette, S. 

 C. Jewett. E. Debevec, L. B. Hulbert, 

 and A. L. J. Erase. 1999. Forage fish 

 diet overlap, 1994-1996, APEX Project: 

 Alaska predator ecosystem experiment 

 in Prince William Sound and the Gulf 

 of Alaska, 103 p. Exxon Valdez Oil 

 Spill Restoration Project Final Report 

 (Restoration Project 98163C), Auke Bay 

 Laboratory, National Marine Fisheries 

 Service, 11305 Glacier Highway, Juneau, 

 Alaska. 



The focus of our study was to pro- 

 vide new information on the general 

 biology of a little known forage fish 

 species. Objectives were to determine 

 habitat preference, age, size, and di- 

 et of Pacific sandfish. To accomplish 

 this, from 2001 to 2004, we captured 

 Pacific sandfish with a beach seine in 

 July and March and with a mid-wa- 

 ter trawl in May near The Brothers 

 Islands in southeastern Alaska. 



Materials and methods 



Fish capture and habitat 



Pacific sandfish were captured with a 

 beach seine at The Brothers Islands 

 in southeastern Alaska (Fig. 2). We 

 seined 10 sites in summer (July 

 2001-2003) and in winter (March 

 2002-2004) in a variety of near- 

 shore habitat types (Table 1). Habi- 

 tats sampled included steep bedrock 

 outcroppings, rocky bottoms with 

 understory kelps (e.g., Laminaria), 

 eelgrass {Zostera marina), and sand 

 beaches. We used a 37-m variable- 

 mesh beach seine that tapered from 

 5 m wide at the center to 1 m wide 

 at the ends. Outer panels were each 

 10 m of 32-mm stretch mesh, inter- 

 mediate panels were each 4 m of 6- 

 mm square mesh, and the bunt was 

 9 m of 3.2-mm square mesh. We set 

 the seine as a "round haul" by hold- 

 ing one end on the beach, backing 

 around in a skiff with the other end 

 to the beach about 18 m from the 

 starting point, and pulling the seine 

 onto shore. The seine had a lead line 

 and a float line so that the bottom 

 contacted the substratum and the 

 top floated on the surface. All seine 

 sites were sampled during daylight 

 and within two hours of low tide 

 (range -i-l.O to -1.5 m below mean 

 lower low water). After retrieval of 

 the net, the entire catch was sorted, 

 identified to species, counted, and a 

 subsample was measured for length. 



Manuscript submitted 16 May 2005 

 to the Scientific Editor's Office. 



Manuscript approved for publication 



1 December 2005 by the Scientific Editor. 



Fish. Bull. 104:6.31-637 (2006). 



