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.

Fall Transitions

By Jennifer Fisher
Posted on October 27, 2017


We left the safe harbor of Newport under sunny skies and headed out to conduct our biweekly sampling yesterday afternoon. The forecast was for windier conditions than we generally prefer, but we hadn't been out since Oct 4th, so we were eager to sample as far offshore as the weather allowed.

Heading out under sunny skies.

In mid-October, we had our first substantial winter storm with 40 kt south winds and 23 foot seas.

These winter storms mix the water column, and we generally get warmer water conditions across the shelf with little zonation compared to the summer upwelling that strongly stratifies the Oregon shelf with cold nutrient rich waters inshore and warmer oceanic water off the continental shelf.

We arrived at our first sampling station and we were astonished at how clear the water was- an indication that little phytoplankton were blooming. Our plankton nets came up clean, but our sieves were still filled with tiny organisms, Ctenophores, and lot's of Porcellanid crab larvae.

Not much phytoplankton captured but lots of small crustaceans and larvae that are difficult to pick out here.

 

As we moved farther offshore, the water became even clearer. There were many young krill (furcilia) at our sentinel station- NH-5. Unfortunately, after we pulled the bongo on board, the Captain said we'd have to turn around, but not because of weather as we were intending, but because the boat was overheating. This was a good call, because as we were making our way back to Newport, the engine became very hot and we had to transit very slowly back home. We were thankful we were only 5 miles offshore instead of 25 miles off when this happened.


The live plankton sample we brought back to the lab revealed what appeared to be a shift in the zooplankton community. At first glance, the most noticable difference was the absence of female Calanus copepods that have been very abundant all summer. Further investigation will tell us just how much the community has changed.

The CTD data showed that the near bottom temperatures at NH-5 were just above the long term average and the low oxygen we were seeing in August and September had completely dissipated from the strong winds and large seas we encountered mid-October.

We rarely get to see the Yaquina Bay bridge during daylight hours since we are normally returning many hours after the sun has set.

We'll be headed out in early November, sampling out to 85 miles offshore. Stay tuned as we see how the ocean changes during this fall transition time.


Tagged: NH Line

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June 2017
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