Habitat use and diet of juvenile surf smelt and Pacific sand lance in Puget Sound, Washington
Presentation Abstract
Forage fish, such as Pacific sand lance (Ammodytes hexapterus) and surf smelt (Hypomesus pretiosus) are important components of the marine food web where they serve as prey for birds, other fish, and marine mammals. However, factors such as habitat use patterns and feeding ecology for many forage fish species are poorly understood. Considering that nearshore eelgrass habitats in Puget Sound are used as nursery and rearing grounds by other fish species, we used beach seine hauls to investigated the use of nearshore eelgrass beds by the juvenile life stages of these fish relative to areas lacking vegetative substrates. We also investigated fish catches in open shorelines vs. embayments. Our study objectives were to measure fish abundance within each of the habitat types and identify important food items for both of these forage fish species. We completed 330 beach seine hauls at 11 study sites in central Puget Sound during late spring-early summer. Sampling was stratified to include daytime and nighttime conditions, and we captured more than 2,500 surf smelt and 59,000 sand lance. Although total catch was dominated by sand lance, these fish were captured infrequently but in very high numbers. For surf smelt, the highest percentages of fish were captured in embayments with bare substrates (38%), and the lowest percentages were captured in embayments with eelgrass (14%). Nearly all (>99%) of the sand lance were captured in bare habitats and a slightly higher percentage of fish were captured in embayments (56%) compared to open shorelines (43%). Diet analysis revealed that surf smelt had a preference for cyclopoid copepods and cladocerans, which plankton surveys showed were not a highly available food item in our study area. Sand lance were more opportunistic feeders as evidenced by presence of the relatively abundant calanoid copepods in their diet.
Session Title
Forage Fish Management and Conservation in the Salish Sea
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Poster
Genre/Form
conference proceedings; presentations (communicative events); posters
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Forage fishes--Ecology--Washington (State)--Puget Sound; Pacific sand lance--Ecology--Washington (State)--Puget Sound
Geographic Coverage
Puget Sound (Wash.); Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Habitat use and diet of juvenile surf smelt and Pacific sand lance in Puget Sound, Washington
2016SSEC
Forage fish, such as Pacific sand lance (Ammodytes hexapterus) and surf smelt (Hypomesus pretiosus) are important components of the marine food web where they serve as prey for birds, other fish, and marine mammals. However, factors such as habitat use patterns and feeding ecology for many forage fish species are poorly understood. Considering that nearshore eelgrass habitats in Puget Sound are used as nursery and rearing grounds by other fish species, we used beach seine hauls to investigated the use of nearshore eelgrass beds by the juvenile life stages of these fish relative to areas lacking vegetative substrates. We also investigated fish catches in open shorelines vs. embayments. Our study objectives were to measure fish abundance within each of the habitat types and identify important food items for both of these forage fish species. We completed 330 beach seine hauls at 11 study sites in central Puget Sound during late spring-early summer. Sampling was stratified to include daytime and nighttime conditions, and we captured more than 2,500 surf smelt and 59,000 sand lance. Although total catch was dominated by sand lance, these fish were captured infrequently but in very high numbers. For surf smelt, the highest percentages of fish were captured in embayments with bare substrates (38%), and the lowest percentages were captured in embayments with eelgrass (14%). Nearly all (>99%) of the sand lance were captured in bare habitats and a slightly higher percentage of fish were captured in embayments (56%) compared to open shorelines (43%). Diet analysis revealed that surf smelt had a preference for cyclopoid copepods and cladocerans, which plankton surveys showed were not a highly available food item in our study area. Sand lance were more opportunistic feeders as evidenced by presence of the relatively abundant calanoid copepods in their diet.
