Zostera marina is a seagrass species, commonly known as eelgrass, that is found on both coasts of the United States, as well as in Europe. Unfortunately, Zostera is disappearing all over the place, including right here in New York. This could have devastating impacts on animals that rely on eelgrass as foraging grounds, or, as is the case with scallops, use it as a refuge from predation. This is its story, as seen through the eyes of an aspiring graduate student...
Well, I finally got my bee tags from the Bee Works. It took a while to get, bc they were out of stock when I ordered them and were accidentally shipped to the wrong place (Southampton instead of Cutchogue, but I got it figured out). Anyway, I got them, and so I glued them onto my scallops yesterday. I will measure the scallops on Sunday and they will get deployed to my mats on Monday. At the same time, I will also be removing set 2 of my recruitment squares and putting out set 4. I will keep you posted about that, but I wanted to throw these pictures of the marking process up here. Enjoy!
As part of our free plant scallop monitoring, I went diving in Flanders Bay, the westernmost of the Peconic Estuary system, to do quadrat counts and collect scallops for gonad index analysis - we can use this to see if and when the scallops have spawned. The counts revealed ~2 scallops per square meter - much lower than the original planting densities, but still fairly decent numbers considering the un-ideal bottom. That said, I saw a northern puffer (YAY!) in my first quadrat. This is exciting because their numbers have been severely reduced in recent years. However, puffers are potential scallop predators, so I don't know how excited I should be. However, they may also inhibit mud crab predation on scallops. Either way, it was exciting. I saw sea nettles, tons of comb jellies (ctenophores), that puffer, tons of silversides, blackfish and cunners, whelks, mud crabs, and of course scallops - oh and some red beard sponges. It was actually a pretty decent dive. Take a look at the pictures.
Well, I checked on my mats last week... everything looked good. I had to go back today to pick up my first set of recruitment squares. But more on that later. This week was the first "spat week" of the summer, well the first official spat week anyway. 6 weeks ago we placed out the first set of spat collectors at 24 different sites throughout the Peconics. Three weeks after that, we deployed the second set. Tuesday and Wednesday, we retrieved the first set we deployed (having soaked for 6 weeks) and dropped in set #3. The idea behind the collectors is that we place mesh bags in the water with a plastic mesh insert that larval scallops and other organisms will settle on when they are ready to come out of the water column. Of course, we are most interested in scallops, but we also monitor other things that we catch in these nets, including jingle shells, blue mussels, mortons egg cockles, and arc shells among the bivalves, and slipper shells, lacuna snails, and lunar dove snails among the gastropods. We also often get numerous mud crabs, although sometimes they get in through holes in the collector. Anyway, on Tuesday we collected over 1,000 scallop spat, which is the most we have ever collected this early in the season (this is now the 4th year of the monitoring). That means that we had an earlier spawn than normal this year, at least an earlier first spawn for scallops. Additionally, we observed a large mussel set, which is unusual, since we hadn't seen one this large either, especially considering there are no substantial mussel populations near our collectors. Either way, it was very exciting! On Wednesday, we didn't collect nearly as many, but it was still encouraging, because the collectors we checked were not near any known scallop populations or spawning sanctuaries, so the fact that we found as many as we did was very good!
So taking this good news, I went to my site today to retrieve my recruitment squares. I was not sure what to expect. My grass mats are in Hallock Bay, were we did free plant scallops last winter, but also where our spat collectors recovered very few scallop spat throughout the whole little bay (<10). sticklebacks , killifish, silversides, cunner, tautog, and sea bass, and lots of mud crabs, climbing my seagrass!!!! Very exciting day indeed, even though I didn't get any spat and lost all my pictures!
Oh, and as an aside, during a lunch break on the boat on Tuesday, we hauled up on a beach in Little Bay in Orient Beack State Park. There is a tidal pond there and I observed sheepshead minnows mating! Pretty awesome week...
I am a marine biologist that is currently attending graduate school at the School of Marine and Atmospheric Sciences, Marine Sciences Research Center, of Stony Brook University, New York. I am very interested in marine ecology and have been focusing my studies on bay scallop interactions with their habitats. I plan to investigate various anthropogenic impacts on bay scallop populations for my PhD dissertation. This blog will highlight the details of my graduate research, from bay scallop-eelgrass interactions as previously mentioned, to alternative habitats for scallops, such as Codium, to trophic cascades, and more. Enjoy!
Eelgrass is an important habitat for multiple marine species, including the bay scallop
Scallop on Artificial Eelgrass
This tethered juvenile bay scallop attached itself to my artificial eelgrass...
The decline of eelgrass meadows
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?
Eelgrass, Zostera marina, a temperate seagrass species, providing a vital habitat for numerous marine species
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Scallops in eelgrass
Some adult bay scallops we planted in eelgrass for a free release survival experiment we conducted
If you live in coastal zones, urge your local and state representatives to push for environmental issues that you are concerned about. Ask for more stringent rules regarding the destruction of existing eelgrass. Encourage restoration programs to be set-up. Call your state and national representatives and ask them what they are doing to protect our precious resources. Practice safer boating and know the undersea terrain - i.e., don't drive your boat in very shallow water. Avoid clamming in eelgrass meadows.