Thursday, August 14, 2008

Catch and Release Seahorse

If you remember back to an earlier post I mentioned that we had initiated a Seahorse Project. We chose this species as it relies heavily on eelgrass for its prime habitat and it is clearly more charismatic than any other species we deal with. Although we work with them all the time a “Snail Project” doesn’t sound half as interesting…

Our goal is to link habitat restoration (eelgrass plantings) with species enhancement (seahorse breeding and release). Our first goal was to determine the minimum plot size that would support an individual or pair of seahorses. This way we could target future plantings as dedicated seahorse habitat.

In June, a lucky find, gave us the opportunity to begin this process. My father, who has oyster bags in Peconic Bay called to tell me that he found a healthy seahorse IN one of his bags. I made arrangements to go over to Water Mill and pick the little guy up fully expecting him to be a little worse for the wear given he was dropped to the deck with a couple hundred oysters.

Upon arrival, I was pleasantly surprised to find that he was in perfect health and had an interesting and unusual yellow/orange color. The others that we have observed are typically gray, black or brown. This little guy really stood out in a crowd.

What to do with this guy? At first we kept him in our greenhouse for a few days to observe him and see whether he would eat in captivity. Sure enough, he started to feed on small shrimp (actually amphipods) in the large tank he was held in. However, I was concerned about the extreme temps in this tank and the fact that it could harm him in some way.

It was time to get him back in the bay. We quickly decided to place him in one of our transplant plots at Robins Island. This site seemed ideal in that the grass was thriving and shallow, relatively calm waters.

On June 18th, we delivered the seahorse to his new “home” with the hope that we could return in future weeks to check on his progress.

In the weeks that followed, we observed our little friend in or adjacent to the original plot on a couple occasions. Outside of the plots there is basically nothing on the bottom except for the occasional clump of Codium, but even these are few and far between given the lack of rocks or shells. On our last visit in late July we did not find him in the original plot or on the adjacent Codium.

Fast forward to last week (August 8th) when we went out to do our regular plot counts at a number of our sites in the PE. The summer heat and crabs have wreaked some havoc on our plantings in the bay, as it always does, but the plots were still there.

Unfortunately the shallow plot, where we placed the seahorse, was almost entirely lost, reduced to only a few shoots. This is not surprising as we fully expect to lose the shallow and/or the deep plots for these plantings. Unfortunately, the seahorse was also not visible.

Fortunately, as Kim counted the second plot she found our seahorse. With this we decided to bring him back to the lab to reside in a specially designed tank with temperature control and a good supply of food.

Our firs foray into the world of seahorses proved to be productive. As a result we have learned a few things. First, our 1m2 plots appear sufficient to support at least one individual seahorse. Second, these guys seem to have a certain amount of site fidelity once they get to suitable area. In this case this individual stayed in our plots for 50 days.

Over the next few months our Project Seahorse will become a reality...


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