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...
Seriously, what is this crab? I saw them diving, and they just seemed to look a bit different to me. Mottled coloration, more roundish shape, odd looking claws. At first I thought it might be an invasive from Asia that has established in the Caribbean and some southeastern states, Charybdis sp., but the numbers of lateral spines or teeth and teeth between the orbits are not right. So maybe its something else from the tropics, a casualty of Gulf Stream transport and meandering eddies? Any ideas?
I use the term run lightly, however it kind of looks like they are waddling back and forth rather than swimming doesn't it? Scallop swimming is very funny, much funnier on video than it is when your actually underwater. This video was taken from one of our planting sites for the restoration effort in the peconics. While all bay scallops possess the ability to swim, and many do, for some reason, the scallops at this particular site seem to do it all the time. It might be a water quality thing, as the clarity here is typically lower than that at other sites we plant, but whatever the reason is, its always a fun dive.
For some reason I cannot seem to post the long video, its not loading. You can try to view it here. See if you can spot the little seed scallop swimming up off the bottom (its ok if you don't, I had to watch 3 times to see it). Also notice the healthy scallops in a habitat dominated by macroalgae and no eelgrass. Interesting, isn't it?
Try, try again? Well last year I submitted a manuscript to the Journal of Shellfish Research for publication about the field studies I was doing with scallop survival in different habitats. It was rejected outright. I was dejected. But, I took a while to think about it, took all of the reviewers comments and decided that I could make the paper work, somehow, and try again. Even though I won an award for this work when I presented it as a student at the National Shellfish Association's 100th annual meeting, things needed to be worked out. With the co-authors, I set out to re-write the manuscript in a more readable and presentable manner. We cut out the extemporaneous materials, the unquantified text and thought we had something still worthy of publication. We wanted to get out information out there: that the introduced alga, Codium fragile, could serve as a potential predation refuge for the bay scallop, in a similar manner to native eelgrass. The data was the same, the way it was presented was different. I went to the benthic ecology meetings in Texas and presented the work there to get more feedback. I tried submitting it to another journal. This time the results were different. Success!!!!! My manuscript was accepted to Marine Biology. No proofs yet, but still very exciting to know the work was deemed worthy for peer-reviewed publication. But this whole saga has helped me re-direct a portion of my dissertation work, one in which I focus on multiple aspects of the impacts of Codium on bay scallops - not just short term (1 week long trials) survival. I placed adult scallops in eelgrass, Codium and bare sediment to monitor their gonad indices and growth over a 10 week period. I have placed juvenile scallops at the same locations as well as other locations with codium and eelgrass. These are still out in the field. In addition to monitoring their survival and growth (in predatory exclusion cages), I am also monitoring water quality conditions such as chlorophyll, in addition to sediment conditions such as benthic chlorophyll and porosity. Hopefully soon I will have a better grasp on the way scallops and Codium interact.
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.