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August 2014
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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.

3 dives and no sea sickness

So yesterday was a little rough… I mean the weather wasn’t terrible, but there was still some swell from the days of wind previous.  So during our safety stop, I was feeling it a little bit, so I only did the one dive and took an early boat ride back.

Today, sea was almost like glass, did 2 dives outside on the fore-reef,  and then one inside the lagoon.  Saw some cool things – invasive lionfish, big schools of creole wrasses, bluehead wrasses, giant queen cocnh, and lots of other fish.  However, this site was fairly impacted, so not so much live coral as the reef I saw yesterday.  Oh well.  Was still fun to get 2 dives in outside and not feel like total crap.  And diving in the lagoon was cool, despite it being so shallow, it was nice to be able to lay down and just look.  In the lagoon, we saw inking sea hares, a peacock flounder, yellow ring sting ray, little crabs, another sharptail eel, spiny lobster, and lots more fish.  So cool.

I haven’t loaded my pictures from today yet, but I’ll leave you with a few more photos from earlier in the week/weekend.

Enjoy!

French Grunt

 

Some sort of small bass, dunno the name

Indigo Hamlet

Common octopus?

Lesser electric ray

Mating sea hares

Lizardfish!

 

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