Northwest Fisheries Science Center

Newportal Blog

A gateway to oceanographic adventures from the Newport Line and beyond

Blog on ocean conditions along the Newport Line and the northern CA Current.

Juvenile Salmon Survey Concludes!

By Cheryl Morgan
Posted on July 9, 2015


Juvenile salmon catches

We have completed another very successful juvenile salmon survey. We conducted 45 fish trawls over 8 days of sampling and captured mostly juvenile coho and Chinook salmon.  We also caught juvenile chum and sockeye salmon, as well as a few steelhead and cutthroat.  There are seven species of native salmonids in the Northern California Current.  We caught 6 of the 7 species; the only species we didn’t catch on this survey was pink salmon!

 

These juvenile salmon catches are a part of our Ocean ecosystem Indicators suite of data that provide outlooks for adult salmon returns to the Columbia River.  This year, the catches of juvenile Chinook salmon were on the lower side of our 18 year time series, while the catches of juvenile coho salmon were about average.

Juvenile salmon condition

The condition of the juvenile fish is another important measure of how these salmon are faring. Condition, in this case, means how “fat” or “skinny” a given fish is for its length.  “Fatter” fish have a better chance of survival.  During this survey, we noted that the juvenile Chinook salmon looked in relatively good condition, while in general the juvenile coho salmon tended to look like they were in poorer condition.  We will have to wait until these fish are necropsied (dissected) in our lab in order to see if our visual observations during the survey are correct.

 

 

 

 

 

 

Harmful Algal Bloom

The Harmful Algal Bloom (HAB) off the west coast was in full swing during our survey and our zooplankton samples were brown and gooey and difficult to filter. We also collected smaller samples to look for the harmful algae.  Here are some HAB samples from Queeets River, WA, ranging from stations 3 to 24 nautical miles offshore and you can see how the bloom is most intense closer to shore.

 

 

 

 

Jellyfish

Another interesting finding that we have not observed over the past 18 years was a change in the jellyfish species composition.  We always catch a large number of the sea nettle jellyfish (Chrysaora fuscescens).  However, this June, the sea nettles were almost entirely absent from our samples and instead we caught unpreceded numbers of the water jelly (Aequorea sp., photo).

This has been seen by other surveys this summer off of California and southern Oregon, but we are unclear why.  During previous surveys, we find that the water jelly is associated with warmer water, therefore their high abundance this year might be linked to the warm ”blob” of water that is still persistent in the northern Pacific ocean.

 

 

 

 

 

 

 

 

 

 

Marine Birds and mammals

Click here for this exciting update!


Tagged: Salmon Survey, HAB

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