Juvenile Steelhead Distribution, Migration, Growth and Feeding in the Columbia River Estuary, Plume and Ocean Waters

Transcription

1 Juvenile Steelhead Distribution, Migration, Growth and Feeding in the Columbia River Estuary, Plume and Ocean Waters Elizabeth Daly (OSU) Richard Brodeur (NWFSC) Julie Scheurer (ARO) Laurie Weitkamp (NWFSC) Jessica Miller (OSU) Brian Beckman (NWFSC)

2 Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science 6:62 80, 2014 American Fisheries Society 2014 ISSN: online DOI: / ARTICLE Juvenile Steelhead Distribution, Migration, Feeding, and Growth in the Columbia River Estuary, Plume, and Coastal Waters Elizabeth A. Daly Cooperative Institute for Marine Resources Studies, Oregon State University, Hatfield Marine Science Center, 2030 Southeast Marine Science Drive, Newport, Oregon 97365, USA Julie A. Scheurer, Richard D. Brodeur, and Laurie A.Weitkamp National Oceanic and Atmospheric Administration, Northwest Fisheries Science Center, Hatfield Marine Science Center, 2030 Southeast Marine Science Drive, Newport, Oregon 97365, USA Brian R. Beckman National Oceanic and Atmospheric Administration, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, Washington 98112, USA Jessica A. Miller Coastal Oregon Marine Experiment Station, Department of Fisheries and Wildlife, Oregon State University, Hatfield Marine Science Center, 2030 Southeast Marine Science Drive, Newport, Oregon 97365, USA

3 Background Relatively little known about estuary and ocean life cycle despite being the third most abundant species caught in both areas during most years Steelhead migrate to the ocean in late spring and early summer, and unlike other salmon species, they do not spend much time in the estuary and nearshore areas. Instead, they move quickly offshore to oceanic feeding grounds, bypassing the normal coastal migration route used by other salmon species

4 Outline Examine abundance and distribution of steelhead caught in the Columbia River estuary, plume and ocean for difference by season and year Examine a number of biological parameters (size, condition, growth, diets and feeding intensity) by year and region of capture Relate these to survival of steelhead under different ocean conditions

5 Estuary purse seine methods Sampling at edges of deep channels Every other week, mid April to late June Monthly sampling during July- October Fine mesh purse seine (10 m deep)

6

7 n=468

8 Ocean Methods Sampling along transects on shelf out to deepwater beyond shelf Every year during the last week of May and June One transect a day over 7-10 day period Fished large trawl (336 m 2 ) in surface waters for 30 min. All trawling in daytime

9 Sample size and clip rate Hatchery Wild Year Adjusted W Adjusted H Mark Rate %

10 Steelhead salmon catches in May and June: unmarked and hatchery May June Father and Son 48 o LaPush WA 48 o WA Queets River Unmarked 47 o Grays Harbor Willapa Bay 47 o Hatchery 46 o Columbia River 46 o Cape Meares OR OR 45 o 45 o Newport 125 o 124 o 125 o 124 o

11 May steelhead distribution Father Son o LaPush Queets R. North Latitude 47 o 46 o Grays Harbor Willapa Bay Columbia R. WA OR Cape Meares 45 o 126 o 125 o 124 o n= o 124 o West Longitude n= o 124 o n=41 0 to to to 2 2 to 5 5 to 20

12 Fork length * * * * Hatchery Unmarked 160 Fork length (mm) n/a * n/a * * * * * Year

13 Body condition Estuary Ocean Marked Unmarked Condition residual n/a n/a * * Year

14 Recent Growth Rates Insulin Growth Factor Marked Unmarked Estuary Marked Estuary Unmarked 70 IGF (ng/ml) 60 * * Year

15 Feeding intensity Estuary Percent feeding intensity n/a Ocean Marked Unmarked n/a * * * Year

16 Mean fork length (mm) IGF (ng/ml) Marked Unmarked Distance offshore (km) Marked Unmarked Distance offshore (km) Steelhead vs. Distance Offshore Condition Residual Percent feeding intensity Marked Unmarked Distance offshore (km) 5 11 Marked 37 Unmarked Distance offshore (km)

17 Are we missing steelhead in the plume? Abundances, EPS vs Plume ( ) Chin 1 Coho Steelhead 12 Length frequency ( ) Peak CPUE or fish/km Percent of fish Estuary Plume 2 0 Estuary Location May 3 trans Length bin (mm) Mean FL (mm) Plume: EPS:

18 Estuary diet 23% 3% 1% 17% Amphipod (non Corophium) Corophium 4% 11% Fish Insect Non food (plant and plastic) Unidentified material Other 40%

19 Ocean diet composition by year 100 n= Percent weight of prey eaten EUPHAUSIID DECAPOD AMPHIPOD COPEPOD PTEROPOD INSECT OTHER GREENLINGS SABLEFISH ROCKFISH COTTID SANDLANCE OTHER FISH Year

20 Cluster Analysis by Year SIMPROF a b c Samples Resemblance: S17 Bray Curtis similarity Prey Category Contribution % Group a Other fish Rockfish Euphausiid Group b Euphausiid Other fish Decapod Group c Decapod Euphausiid 8.49 Other fish Similarity

21 Diet composition by year 100 n= Percent weight of prey eaten EUPHAUSIID DECAPOD AMPHIPOD COPEPOD PTEROPOD INSECT OTHER GREENLINGS SABLEFISH ROCKFISH COTTID SANDLANCE OTHER FISH c Year b a

22 Percent empty stomachs (% BW < 0.5%) Percent Empty Stomachs Marked Marked Ocean Ocean Unmarked Unmarked Ocean Ocean Marked Estuary Unmarked Estuary Hatchery Years Only 5 fish

23 Conclusions Distribution: Present in estuary during late April through early June Widespread and present at all transects mostly in May Not sampling far enough west to capture all juveniles Different migration patterns than coho and Chinook Need to determine genetic stock of origin for offshore fish Hatchery Wild: Hatchery fish are longer, but wild fish are fatter Hatchery fish have more empty stomachs No difference in growth rates and marine residency times (Not shown) Need to examine diet differences Diet: Interannual variability related to ocean conditions and survival Wide variety of prey, fish most important (but also crab larvae and euphausiids)

24 ACKNOWLEDGEMENTS NMFS/NWFSC all those who go to sea to help collect data and process in lab Funding from: NOAA and BPA