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Friday, 24 May 2013

Dive at Little Kettle Pool

Yesterday, after unrelieved ugly weather for several days, we decided to "get wet" … Diving never fails to lift our spirits. The contrast between the grey, cloudy, windy stormy weather and the beautiful colours and marine animals under the surface is guaranteed to change your mood.
Actually, the dive was not all that spectacular as dives go. We wear dry suits which keep our bodies warm in this cold water. Only our heads and hands get wet.

We found all surfaces were covered in a full layer of sediment - something we're quite used to from diving in Howe Sound near Vancouver. Whenever we mistakenly touched the leaves of the kelp forest, huge clouds of sediment rose around us. We were only 15 feet deep so it's very hard to maintain a proper distance from things as you breathe in and out - one deep breath can take you to the surface instantly. I tried to lean on the bottom to adjust my buoyancy. That was a mistake, as clouds of sediment rose up and I seemed prepared to go down another 20 feet in the almost-liquid mud. Luckily my buoyancy mistakes didn't bother Larry and he was still able to take a few good photos.

Once we edited our photos we were delighted with the things we had seen. Some of them are probably very ordinary to professional folks (divers and scientists) but they're new to us. We saw stars: asterias rubens, marthasterias glacialis and asterias rubens (sun stars and common stars), the protanthea simplex anemone which has apparently only recently been found in western Scotland. We saw an awful lot of tunicates - the dendrodota gossularia tunicate is an animal which can occur in densities from 50-60,000 specimens per square meter.

My favourite was the paguras bernhardus (common hermit crab) which is pictured here.
As you possibly didn't know, hermit crabs are arthropods who select the old shells of dead snails to carry around as protection. As the hermit crab grows, he has to select a series of new/dead shells which are of a more appropriate size. Mating is achieved by the male choosing a female who happens to be exchanging shells. It's thought she gets interested in him because he can protect her naked body with his shell while he's covering her.

You'll see his claws are covered in little spines … you can also see he's carrying a load of something on his back. It looks like a load of grasses. However, these are hydroids and are themselves animals (even though they look like plants). They are called hydractinia echinata. When they were larvae, they floated out from a colony of hydroids … and they actually selected this very hermit crab shell. The relationship between hydroid and crab is mutually beneficial - the hydroid gets more food flowing past because of faster movement through the water, and the crab gets protection from the stinging cells of the hydroid. Our I.D. book feels the hydroid larva can tell our crab was alive under the dead shell because snails are so VERY slow and hermit crabs are so VERY speedy!

At 24/05/2013 13:48 (utc) our position was 57°19.54'N 007°14.84'W

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