Marine microscopy weekend

Friday 20th to Monday 23rd May 2016

What a weekend of diversity: every element of weather other than snow, a super biodiversity of organisms and an eclectic mix of participants, the numbers of which probably broke the weekend’s record – 21 and counting! Particularly welcome were a Ukrainian couple, Sasha and Marysya Rudska who had fought their way on public transport across the country from London where they work to the Dale Fort Field Centre in Pembrokeshire. Marysya is an illustrator and rather than join the normal crowd of photomicrographers she drew and painted exquisite pictures of the biodiversity instead.  These should appear on her website soon.

Marysya Rudska completing a drawing of GammarusMarysya Rudska completing a drawing of Gammarus [by Julian Cremona]

The weekend followed a familiar pattern. Although the majority of participants arrived on Friday 20th May a few set up in the lab the day before. As always bench space was at a premium. Plenty of biological material was available for the arrival: a preserved sample trawled on Skomer Marine Nature Reserve from the previous day, freshly collected fringe seaweed from Dale rockpools, fresh kelp fronds covered with hydroids from Neyland marina, plus a variety of marine organisms collected from the shores that day. The forecast for Saturday was not brilliant and so a series of plankton trawls was made late in the afternoon at several sites around Dale.

The moment the first trawl was hauled into the boat a glistening, slimy edge to the net gave a sign of what was to become a slight frustration for the weekend. Every sample was full of Phaeocystis globosa. This diatom forms a colony by secreting a huge ball of gelatinous slime with large numbers of diatoms over the surface. Sometimes over a centimetre across the gloopy mess filled the mesh of the phytoplankton net restricting what was caught. A zooplankton net (much larger mesh size) was also tried with some marginal success. One advantage of the Phaeocystis was that it impeded the movement of the zooplankton and some organisms were easier to photograph. A bloom of Phaeocystis is usually caused when silica is exhausted, phosphate reserves are low and inorganic nitrogen becomes available (Dr Friedrich Pfeil, 2011). This was the first time such a bloom has been recorded at Dale in over 20 years.

Despite the heavy rain overnight, by 10 a.m. on Saturday it stopped and the wind died down, so later in the morning fresh plankton samples were obtained with Phaeocystis still in abundance. Laminaria holdfasts were collected from the pontoon in the middle of the Haven. This wealth of material kept everyone busy for the rest of the day.

Collecting kelp holdfasts from the pontoonCollecting kelp holdfasts from the pontoon

On that same day Dale Fort was hosting its 4th Marine Research Symposium with around a hundred amateur or professional marine biologists present. An invitation was extended to them to visit the Quekett laboratory during their lunch and breaks. A steady stream occurred throughout the day, with a number so engrossed with the microscopy they missed their following sessions by remaining in the lab! This may have slowed the amount of photography and sample checking but some good contacts were made. The delegates make some very nice comments about the Quekett on the Centre’s Facebook page and Twitter page (search for @quekettmicro).

Visitors in the laboratoryVisitors in the laboratory [by Jeremy Poole]

Visitors in the laboratoryVisitors in the laboratory [by Jeremy Poole]

Visitors watching a video being madeVisitors watching Sinclair Stammers making a video with his Sony NEX-FS700 camera on an Olympus BH-2 microscope [by Jeremy Poole]

Noteworthy specimens reported during the day were: tunicate larvae, zooea crab larvae, a megalopa stage, all stages of nauplii, veliger larvae, copepods and several interesting (difficult to identify!) polychaete larvae including an early stage Myrianida. Diatoms were not in profusion but a good range was present including: Coscinodiscus, Thalassiosira, Chaetoceros, Odontella, Bacillaria, and Nitzschia species.

In the evening three excellent talks were made. Firstly, Jeremy Poole told us the story behind his buying a second-hand scanning electron microscope last year, setting it up, and where he is in the complexity of its operation. This was followed by an intriguing and amazing, if somewhat technical, insight into Spike Walker’s ever-expanding experimentation into lighting methods. The final talk was a shortened version of Phil Greaves presidential address about Branchiopods. A fascinating and entertaining review. A very good evening.

Sunday dawned bright, sunny and warm, ideal for a foray to the Gann Lagoon near the Fort.

Sampling at the Gann LagoonSampling at the Gann Lagoon [by Joan Bingley]

The trawl here brought in large numbers of the polychaete larvae of Polydora but even more numbers of the marine rotifer Synchaeta.

Polychaete larva of PolydoraPolychaete larva of Polydora ×250 [by Chris Adams]

Netting brought in a variety of crustacea including opossum shrimps and amphipods. Out on the saltmarsh we looked at the marine rove and carabid beetle colonies living in the mud.

Rove beetleRove beetle [by Sinclair Stammers]

I made a request of Jeremy to take the tiny (4mm long) Bledius unicornis home to photograph the head of a male under his SEM. Five days later the super image arrived!

Head of male Bledius unicornisHead of male Bledius unicornis [by Jeremy Poole]

The evening slide show of participants’ work was a great success as we had various invited guests from other courses held at the Centre. Unfortunately, Sinclair Stammers’ superb filming would not run on my laptop, but you can view it here:

Sinclair Stammers’ video: Click the arrow to start; click the symbol left of “vimeo” for full screen

In all a very successful weekend enjoyed by all and hopefully repeated at the same time next year.

Report by Julian Cremona

Colourful fringe seaweedsColourful fringe seaweeds [by John Tolliday]

Sphaeroma rugicauda (an isopod)Sphaeroma rugicauda (an isopod) [by John Tolliday]

Epitokous planktonic stage of syllid polychaeteEpitokous planktonic stage of syllid polychaete [by Mike Crutchley]

Larval paddleworm on Phaeocystis globosaLarval paddleworm on Phaeocystis globosa [by Julian Cremona]

Phil Greaves and Spike WalkerPhil Greaves and Spike Walker [by Sinclair Stammers]

Sampling from a muddy poolSampling from a muddy pool [by Sinclair Stammers]

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