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The Decline of Seagrass Meadows

Zostera! Eelgrass, Zostera marina, is a flowering, marine vascular plant that remains submerged all the time. This is quite a feat for vascular flowering plants, and only a few dozen species world wide are capable of growing completely submerged in a marine environment. Eelgrass creates and extremely important habitat, its upright structures and complex root system create a 3-D living space for many different types of animals. It is (or was) the dominant habitat forming SAV (submerged aquatic vegetation) throughout much of the coastal waters in the northeastern United States. Unfortunately, for various reasons, eelgrass meadows have seen drastic declines, and in many locations eelgrass only exists in a mosaic of small patches. This is extremely bad news as many of the important, and formerly important, commercial and recreational fisheries of the northeast US are dependent on Zostera at some part of their life cycle as a nursery and foraging ground. Some of the species are finfish like tautog, bluefish, fluke, winter flounder, porgies, while others are shellfish such as blue mussels, hard clams, oysters, bay scallops, and blue crabs. Many of the aforementioned species support or once supported vibrant fisheries. Many of those fisheries have collapsed, also for various reasons. However, is it possible there is a link between the crash of the fisheries, the decline of Zostera and the failure for recovery on both ends?

Bay Scallop on Eelgrass

Argopecten on Zostera! Bay Scallops, Argopecten irradians , have developed a very close relationship with eelgrass, Zostera marina. As larvae, they are passively transported, and tend to settle in eelgrass meadows when the current is dampened by the 3D structure of the seagrass. This same 3D structure provides post-set juvenile scallops a spatial refuge from predation. Even as larger juveniles and adults, scallops are capable of, and have been shown to, actively select eelgrass habitats.

Other species also use eelgrass

grass shrimp A number of other species utilize eelgrass as a habitat. Included are grass shrimp, like the Palaemonetes pugio, other decapods such as blue crabs, bivalves such as hard clams, gastropods (snails), and numerous fish species, including winter flounder, tautog and cod.

Today on the Interwebs!

There has been a lot of really interesting posts on the internet over the last few days, so I thought I might concentrate some here in yet another LINK DUMP!

Over at Southern Fried Science, Andrew continued in his series of gear reviews, this time talking about how important and cheap  proper sunglasses can be.  Additionally, resident shark expert David gave his thoughts on the latest “sharks eating humans” commercial by Snickers, and gave us a run-down about whether MPAs work or not.

Over at Cephalove, Mike talks about how we can build a better blogosphere.

Chuck at Ya Like Dags does a Research Blogging post about North Pacific Dogfish officially being recognized as a different species.

Dr Al Dove has just embarked on a research cruise to study the deep reef platform off of Brazil known as Abrolhos.  Check it out at Deep Type Flow.

Apparently, smaller, short-lived corals are more disease resistant and resilient.

Whale threesomes! Need I say more?

Deep Sea News had a busy couple of days.  First Dr. M highlighted his article from WIRED where he talked about a mass extinction of scientists who study species. Dr Bik followed up that sentiment with a post of her own about the issue. And Mirian just posted a couple of ocean education opportunities for students and educators.

And in the news, Dubai’s artificial islands are sinking and channels filling in (shocker, right?) and in Japan, corals are moving poleward as fast as 14km a year! Crazy!

1 comment to Today on the Interwebs!

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