I’m not sure what it is this year, but the kelp we’re seeing in the Southern Gulf of Maine is just fracking huge. Last year, yeah, there were kelpy areas, and there were kelps that were ~1-1.5 meters long, which, you know, impressive. But this year…
It started when Team Dive (this summer, we have Team Marsh – #marshlife – and Team Dive going on) hit up the outer Boston Harbor Islands. We hadn’t been out much since winter. They found vasty fields of Laminaria digitata and Saccharina latissima (well, with their super-long stipes, they looked like S. longicruris, but it looks like they are now the same species – e.g., Cho et al. 2000 and others). How big? Twice the size of a grad student!
But this was at the mouth of Boston Harbor. Maybe a fluke, or eutrophication?
As we kept working up in Salem Sound, though, the kelp seemed…well…big! But, eh, still urban-ish, still maybe an urban thing… (although it was *not* so big last summer).
If anywhere should be free of the urban influence, it should be Appledore Island in the Isles of Shoals. It’s a few miles offshore, and has lots of microenvironments. And yet, everywhere we look – big-arse kelp! Super dense kelp area where last year an intern almost lost her mind counting kelp stipes? Still mind-exploding. Except now you have to count stipes by feel while your face gets wrapped up in the giant lasagna-blades of Saccharina. And it’s just as big.
It’s everywhere! Even in the wave-protected low-kelp density Heterosiphonia sites, while we do find lots of smaller kelps, the monsters still abound. See how it compares to the size of Team Dive.
This isn’t to say it’s *all* that huge. A size distribution from the site that piece came from for reference:
But, still, what is up with this? Big kelps coupled with very cold water temperatures of course has my California trained brain thinking more time with high nutrients, but I don’t know whether that relationship is as strong here in the southern Gulf of Maine. It’s making me very excited to see the oceanographic work that comes out in the next year or so to see just what forces are driving all of this!
And even more curious to know what’s going to happen next year, as we’re seeing massive numbers of tiny urchin recruits (and a lot of sea star recruits) often folded up in the eroding tips of many of these big honkers. Or on Desmerestia, like ornaments on a Christmas tree (240 in a square meter plot yesterday!).
Cho, G. Y., H. S. Yoon, S. M. Boo, and C. Yarish. 2000. Atlantic kelp species Laminara longicruris and L. saccharina (Laminariales) are conspecific. Journal of Phycology 36:12–13.