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.

Predawn at Coos Line station 7

By Curtis Roegner
June 17, 2016

We have enjoyed calm seas and light downwelling-favorable winds during the first 3.5 transect lines comprising the southern end of our sample range (42.0-43.5oN). Despite this, upwelled water is present at each of our inshore stations, with surface salinities ranging 32-33 psu and there is a moderate phytoplankton bloom with chlorophyll levels in the 9-10 mg/m3 range. Offshore, maximum chlorophyll concentrations are low (1 mg/m3) and located within subsurface peaks at 30-40 m.  At all stations, surface waters are supersaturated with oxygen (>100%), but at the nearshore shelf stations, bottom oxygen saturation ranges from 33-39% at 80 to 100 m depths. We first encountered Columbia Plume-influenced water this morning (S<32; T>14) at the offshore station, and we expect lower salinities at offshore stations as we continue heading north.

Dungeness crab megalops larvae beneath the microscope. The final free-swimming larval stage before they settle to the seafloor as benthic (bottom-dwelling) juveniles.

Neuston samples have been dominated by Pleurobrachia ctenophores at inshore stations, and so far we have sampled ZERO By-the-Wind-Sailors (Velella velella), in contrast to their wide distribution last year.  We have sampled larvae of Pacific saury, rockfish, and Irish lords in the neuston, but few crab megalopae, perhaps not unexpected since we are past the peak settlement season (for Dungeness crab Cancer magister anyway).  The first C. magister megalops were found yesterday evening at the inner most station of the Coos Bay Line (see below).

Weather forecasts suggest a few days of strong upwelling winds are in our future - it will be interesting to see how the chlorophyll, oxygen, and biota respond.  

All other operations are proceeding normally.  Trawl catches continue to be low in the fish department but we are catching lots of interesting gelatinous critters called pyrosomes, that are actually not very gelatinous at all, at the offshore stations, which are definitely indicative of offshore water closer to shore.  Will report more on this later.  Science team and crew caught some albacore off the back deck this morning, a sure sign of warm (<15 C) water.  Looking forward to some yummy tuna poke for dinner!

Tagged: Prerecruit

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