Cruise Day 4: Mud, mud, and boulders

Day 4 started for the team with a gorgeous morning at one of the world’s foremost research facilities, the Friday Harbor Marine Labs, which is affiliated with the University of Washington (owners of the Clifford A. Barnes). Ian had visited Friday Harbor back in 1999 long before starting his PhD work; its amazing that it really hasn’t changed much in that time! The morning was calm – so far the team has enjoyed really nice and smooth weather, making work at sea much more enjoyable!

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…begins a new day in Friday Harbor

Frosty! 

After a quick transit to the first station, the excellent scientific support technician (Brandi Murphy and Meegan Corcoran) set the trawl into action, which yielded – surprisingly – few echinoderms aside from a couple of Parastichopus. Surprising because evidently there have been numerous sea stars recovered from these waters in the past – could be a fluke of where we sampled, or could be a result of the disease – time will tell.

Next, the team headed north to Roche Harbor, where they took some time to find a non-muddy, non-rocky sandy bottom on which to sample. After a very brief dredge (due to concerns of getting snagged), the team recovered a couple of cucumbers and a single Henricia ornata. Cucumbers seem to be the norm at most stations!

Next, the team proceeded northeast to the top-most point of Orcas Island. After the Van Veen grab revealed mostly mud, we were a little concerned about the outcome of the trawl. However, upon retrieval, the team recovered something unexpected: Two giant skate (ray) egg cases, which were quickly returned to the water, and single specimens of Luidia foliata, and Crossaster papposus, along with more Parastichopus.

Exciting, if not unexpected, specimens!

On the track to Bellingham, the team performed another station east of the northernmost point of Orcas Island, but didn’t recover any echinoderms. Then, after a transit to Lummi Island (which was never heavily monitored during the disease event from 2013 – 2014), the team found a few interesting Holothurian specimens but no stars.

This cruise has been a real eye-opener of benthic terrain. The bottom of the sound and straits is not only a mosaic of shell grit, mud, sand, and clay, but most of it is not well defined by charts. We tried to hit 30 – 50m depth at each station in sand (according to the charts), but at the last few stations for the day, the ‘sand’ was actually ‘clay’. This poses interesting questions about transmission of the disease: populations of sea stars on the islands are almost isolated from the mainland, since most sea stars have a really hard time moving over fine silty muds.

At the final station, the team was initially excited about the possibility of sea stars, but as the trawl landed on deck it became clear that it wouldn’t pan out…

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Giant pile of cake batter (or worse) muds from a ‘sandy’ site (according to charts).

Nevertheless, the team found some interesting specimens today, and sampled bottom sediments for the presence of SSaDV. Tomorrow, the team heads south as we make our way back to Seattle. Overall, we are learning lots about the benthic ecology and oceanography of the Salish Sea!

 


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