Beaufort Sea, Blog, FFF, Field Season, Science

Field Find Friday: Alaria esculenta

The Stefansson Sound Boulder Patch is the largest kelp bed on the Alaskan Arctic coast, but it is not the only one. On Wednesday, Katrin Iken, the Dunton brothers, and I took the RV Proteus east to to dive a small kelp bed in Camden Bay.

Camden map
Places of note. Location of kelp bed in Camden Bay is starred.

This was my first time making this run and it was really interesting to see more of the Beaufort Sea Coast. We passed Flaxman Island, the location of Leffingwell’s cabin, from which Ernest de Koven Leffingwell explored the area in the early 1900s, resulting in the first accurate map of the Alaskan Arctic coast and the first scientific description of permafrost.

20170726_145701 (2)
The east end of Flaxman Island is eroding into the sea (like lots of other Arctic coastlines)

We dove two sites in Camden Bay. The first site was pretty similar to shallow sites in the Boulder Patch: Lots of red algae, the dominant kelp was Laminaria solidungula.

But the next site was, very unexpectedly, entirely dominated by a different kelp species – Alaria esculenta. There was no Laminaria solidungula to be found!

Alaria esculenta is a relatively widely distributed kelp. It’s fairly common on the coast of Ireland and the UK, where it is harvested for food.

Visibility underwater was horrible, but here is a pic of an Alaria that I collected. The tile is 10×10 cm.

We collected some cobbles from the seafloor as well, and are finding a very different assemblage of algae and invertebrates covering the rocks.

As an ecologist, the differences between these sites are super interesting. Why are they so different if they are so close??? Unfortunately, this is not a question we can answer in one field season. Right now we can only posit that maybe it was the shallower depth…or maybe warmer temperatures…or…

The view east from our second dive site

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