Tuesday, August 19, 2008

New Arrival!

Things continue to fall into place for our seahorse project as if by design.

While I was on a brief vacation my father called to report that he had found yet another seahorse in his aquaculture gear in the Peconics. It seems that the general lack of grass in the area makes the cages some of the hottest real estate for the few seahorses that pass through.

This time it wasn’t another female but a pregnant male. Just what we were looking for! The photo above isn’t great, but I didn’t want to disturb the expecting father just for a money shot.

As I write this, Kim is busy getting the lab ready for what we hope will be the arrival of a bunch of new “ponies”. These little guys are notoriously difficult to raise, but we are gearing up for rotifer and artemia culture so that we can give them the best chance for survival.

I hope to be able to report that we have been able to get a heard of little ones through the first couple weeks of their life and to the point where they are easy to feed.


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...


Tuesday, August 12, 2008

Docks and Eelgrass?

Last week I had the pleasure of heading over to Fishers Island for the annual “Founder's Day” when the Town Board and other “officials” go over to this distant outpost of Southold to discuss the issues. It truly is a beautiful place that everyone should visit at least once. There is one supermarket, one (public) restaurant, one general store/deli…you get the idea.

We had been over to the island to collect seeds the day prior and the weather was nice, but the ride over this day was pretty hairy as the waves really rocked the ferry from side to side. A couple of the less seaworthy on board didn’t fair too well as we passed under Plum Island and hit some real big rollers. I’m glad I didn’t witness anything first hand, but I am told that there were a few green faces in the cabin.

The main reason I was going over, besides the free lunch, was to work with Mark Terry and John Sep of Southold Town to conduct a preliminary dock survey. The Southold Town Board is developing new dock law and wants to establish design standards for Fishers Island based on the unique physical and environmental conditions and needs of the residents.

We knew from our previous work that the Island is one of the last strongholds for eelgrass in the Town, but we have never took the time to observe how the docks and eelgrass interact. We don’t make it a habit of anchoring in and around docks or other structures.

Starting on the east end of the island and working our way west along the north shore, we visited every dock along the way in a small lobster boat provided by a local resident. At each station they measured depths at the end of the dock and took photos for reference. I jumped in the water at most of the docks to look for grass and take pictures so Mark and John could also see what was going on.

Well I can’t say that I was surprised, but it looks like eelgrass can thrive under a dock if the conditions are right. The combination of mostly N/S orientation, clear water and height above the water enabled grass to grow under most of the structures we visited in Fishers Island Sound. There were a couple cases where the dock was wider and lower than a neighbor, or the orientation was such that light was apparently reduced to the point of limiting grass growth. I didn’t snorkel in the harbors as there is very little grass there.

There was also an issue with grass growing under the docks if they extended into a deep water meadow of 10 feet or more. (we need to further investigate this observation to narrow down this depth precicsely). Apparently the combination of water depth, reducing light, as well as the shade of the dock limits growth.

One thing that was a little surprising was the effect of floating docks and boats. All of the floating docks resulted in loss of grass. In all cases the dock resulted in an unvegetated shadow in the grass meadow. In one case the clearing was “L” shaped. However, in cases where there was surrounding grass it seemed to thrive under the walkway leading to the float.

With regard to boats it was fairly clear that the presence or absence of grass was related to depth in the slip. If the water was deep enough the boat did not appear to have an impact. If it was shallow or the boat had excessive draft the impacts included scouring, shading and loss of grass under the vessel.

In some cases the docks also had a boat house or similar structure. In all cases, these structures reduced light to the point that grass could not persist in the shadow.

This was all very exciting and encouraging for our first look. I look forward to getting out there to take a closer look at some of these areas in an effort to refine the design standards. It should also be noted that these observations on Fishers do not indicate how grass and docks will interact on the mainland as there are issues with water clarity and water quality before the impact of these fixed structures is considered...


Seed collection season is over!

This past week we completed what will likely be one of our most productive seed collection seasons to date. Our seed work varies greatly from year to year depending on our needs for restoration and level of effort. Well, kind of like buying a lottery ticket in the hopes of winning it big, we jumped in head first this year.

As anyone in the field of eelgrass restoration knows, seeds are the way to go, IF you can get them to work for you. That is a big “IF”… Some sites work very well while others fail dismally. It is not that uncommon to get good seedling recruitment and I like to say that anyone can do this. Long-term survival is the hard part. In our area it seems like most seedlings die before they reach maturity unless they are growing near established plants.

For this reason seeds can be used to increase the genetic diversity within transplanted sites. This season many of the seeds will be used for fall broadcasting into ongoing restoration sites where we want to increase shoot density and genetic diversity. For something different a large portion will be held for growout into adult shoots that can be used in spring transplant efforts.

Our seed collection season begins some time in Late June to early July in parts of the South Shore Bays (e.g., Shinnecock Bay) and Bullhead Bay in the Peconic Estuary (if we collect there which we didn’t this year). There is then a little lull until late July as the plants in western Gardiners Bay mature.

Following this there is a large collection window beginning in early August for our Long Island Sound and Fishers Island sites. Given the density and size of the flowers off Fishers, we concentrated much of our work here this year.

I’m not sure if this year was a banner year or if we just hadn’t noticed how productive Fishers Island was. Our collection site is located just south of South Dumpling Island west of Flat Hammock. Here, most flowers are over 7 feet tall and a handful will fill ¼ of one of our bags. We were actually able to fill a bag in less than 10 minutes! If we tried hard it could be done in 5 minutes…

This may not sound too impressive unless you compare it to one of our sites with smaller, widely spaced flowers where it can take 1 hour to fill a bag.

Our collections were so extensive this year we had to borrow some tank space in the Shellfish Hatchery (Thanks Mikey!) as well as set up an outdoor tank next to our greenhouse. In the coming weeks the seeds will be separated from the flowering shoots and we will be left with what we hope is a large amount of seeds.

I look forward to broadcasting these in the hopes of adding to our restoration work.