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...
Wednesday, August 27, 2008
More updates - Fun Diving...
Well, I just talked about Monday's work diving - searching and collecting the recruitment squares, and then replacing them. But we ended up finishing that fairly quickly this time (only a couple of hours) and we had a prospective student for next fall (09) with us - a former Master of Science student from Dauphin Island Sea Lab who currently works for a consulting firm in Florida and deals with habitat restoration and monitoring, and inparticular, seagrass restoration and monitoring. The day ended earlier than usual at my field site, so we stopped at a couple of other spots on the way home to do some fun dives, and so I could show my friend around. First, we stopped at the long lines in Orient Harbor (which I talk about here in my first ever post.) Now the long lines essentially are just that, rows of lines with anywhere from 100-200 or more lantern nets hanging so that the scallops are suspended mid water column - out of the reach of predators on the bottom and not exposed to air from above. (On a side note, lantern nets make great closet additions - hanging a five tiered net or two in your closet eliminates the need for a dresser, for example, and they are good to store food in as well). Now I mention the long line site, bc I have dove on it quite a few times this summer and it always creeps me out - the water is murky (it is Long Island, afterall) and you just see these large dark objects come into view just hanging there, motionless,fouled with all sorts of algae, squirts, tunicates and sponges. When I am working with the nets, opening them under water, reaching in to sample scallops , sometimes I get spun around and another net hits me in the back, or a line from the bottom of the net hits my fin - this always freaks me out just a bit. Either way, they are cool to see so we went there, looked at the nets, where I tried to get a picture of some of the fouling organisms. We also went to the bottom near the nets to see any scallops released near the nets and to just look around and see what we could find - and we had quite the find - a mantis shrimp, just walking around, and at one point looking right at me! Pretty awesome. Next we stopped over at a healthy Zostera bed at Hay Beach on the northeast side of Shelter Island, especially since our visitor is particularly interested in seagrass. We saw some pretty cool stuff there as well, including juvenile flounder just swimming around. There were also cunner, tautog, and pipefish. We also found a few whelks and a scallop spat! And of course, lots of silversides following us around, as we were stirring things up. Now silversides are nearly impossible to catch with the camera, at least for me, since they are almost transparent and blend in with the water, plus they swim around so fast, but I was able to capture a few of them here (oh and that out of focus blog at the center in the upper half of the photo is a comb jelly, or ctenophore). All in all a fairly good day!
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
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.