Sargassum Stowaways, Part One

When the wind changed directions yesterday, it brought to Grand Case the sargassum that has been amassing on St. Martin’s eastern shores for several weeks. In the North Atlantic’s Sargasso Sea, this algae provides shelter for a variety of organisms, such as juvenile fish and invertebrates. So, even though the bay was rough and cloudy, we went out to investigate the floating patches of sargassum.

I found it was possible to find some shrimp amongst the sargassum, although it was tough to do while snorkeling. Instead, I developed another approach, grabbing clumps of sargassum and shaking them out over a plastic bowl. Using this method I was able to to find a variety of creatures, mostly shrimp of different sizes and colors. I also found a few small crabs, including one very strange looking larval crab.

Did they really come all the way from the Sargasso Sea? I’m sure some of the critters could have joined the floating caravan as it has travelled this way, but I would guess many or most of them are, like the sargassum, far from their normal home. Apparently there are a variety of shrimp from the genus Latreutes and others that are residents of the sargassum, often adapted in color and shape to be well camouflaged in that environment.

What is their fate? It would seem that they’re mostly doomed as their homes wash up on the beach. Even if they manage to stay in or get back to the water after their sargassum is gone they would make an easy meal with no place to hide. In the meantime, anyone with a bucket and a little patience can explore an ecosystem that’s traveled hundreds of miles to visit our island.

Below are some photos of crustaceans taken from sargassum, mostly a variety of shrimp. If you look closely, you can see eggs on the underside of some of the shrimp, and organs through their transparent shells.

One Response to “Sargassum Stowaways, Part One”

  1. Sargassum Stowaways, Part Two | Les Fruits De Mer Says:

    […] figuring out how to find the critters hiding in the sargassum, I couldn’t help but do the same thing again the next day. I didn’t really change my […]