Sargassum

Sargassum

It was such a beautiful day today (70 degrees and sunny in the middle of October?!), I couldn’t help but take the opportunity to stop by Old Silver Beach in Falmouth after work. The most notable thing on the beach was the seaweed that had washed up. Piles of Sargassum had accumulated in the wrack line and at the waters edge. The algae could quickly be identified as belonging to the genus Sargassum based on a handful of unique characteristics: a stem-like axis, with distinct foliar appendages resembling leaves, and berrylike airbladders. Additionally, all Sargassum ranges in color from yellow-brown to dark brown. So, I was pretty sure that’s what I’d found.

However, like many, I had previously been under the impression that all Sargassum was tropical, and mainly restricted to the Sargasso Sea, a large floating mass of gulfweed in the middle of the North Atlantic gyre. However, it turns out that there are a variety of species of Sargassum, some of which grow subtidally, attached to rocks, and have ranges that extend as far north as Massachusetts. One species of Sargassum that is present locally is Sargassum filipendula, which is perhaps what was at Old Silver today? And although it grows attached to subtidal rocks, it is not uncommon for it to become detached and washed ashore.

sargassum

Other notable sightings included a gorgeous sunset (which is happening surprisingly early this time of year – 5:57pm today) and a handful of Ring-billed Gulls (Larus delawarensis) playing in the surf. The majority of these gulls spend the majority of their breeding season in inland areas, but winter along the coast. They are smaller than our common Herring Gull and have yellow legs and a yellow bill with a black band around it. For more information about the Ring-billed Gull, check out this All About Birds page.

oldsilver_sunset

ringbilledgull

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