Why I HATE spider crabs!

I know, I know “hate” is a strong word, but I can’t think of a more appropriate way to describe my invertebrate nemesis. Spider crabs may be responsible for more failed eelgrass plantings under my watch than any other cause. OK, maybe not ANY other cause as we did really mess up on the site selection thing in the 90’s, but it’s got to be up there…

Above is a picture of a spider crab (Libinia emarginata) eating one of our transplants at the Sag Harbor test plot site. It isn’t bad enough the we can never seem to get plants to survive in Sag Harbor (I’ll write about this soon), now we have crabs yanking out plants as fast as we can plant them! Maybe this has been the problem all along?

In this case I just happened upon the unsuspecting culprit as he casually munched on one of our shoots like he was eating a celery stick filled with peanut butter. He couldn’t have started more than a minute or two before I got in the water.

In the past we have witnessed spider crabs uprooting and dislodging transplants as they always seem to show up right after we plant. They must be attracted to the good smells coming from the disturbed sediments. In most cases they rip out a few shoots along one edge of the plot and back in amid the shelter of the new patch. I can hardly blame them as there is literally nothing else on the bottom at most of these sites (see my “Oasis Effect” comment).

The typical sign of crab damage is a shoot cut cleanly off at a 10-30% angle. This kind of damage is common and it does not seem to harm the plants too much if the trimming is minimal. Occasionally, we do see more crushing type wounds and these are likely caused by crabs as well.

I must say that it is almost (do I dare say it) cute when the young "decorator" spider crabs cut off SMALL pieces of shoot (thus the use of the term “cute”) to add to the forest on their back like a sniper customizing his ghillie suite to blend in with the surrounding landscape.

This time the damage was clearly catastrophic to the shoot and there was no chance of recovery. After I took a couple shots with the camera I grabbed the crab and decided that he was going to be sacrificed in the name of science to see how much he actually consumed.

Once back in the boat a fatal blow to the carapace allowed me to dig through the goo that is a crabs innards. I was somewhat surprised to find that most, if not all, of the eelgrass sections were still lined up at or near the crabs mouth parts.

Later that day, back at the lab, I photographed what came out of the crab and was surprised to find a small leaf tip. Since the shoot that he was eating when I found him was not missing any tips, this obviously came from another shoot. Through my frustration I had a warm feeling knowing that there was one less multiple offender in Peconic Bay.

-ChrisP

So much field work so little time…

The last two weeks have delivered nearly perfect weather for field work and we have definitely taken advantage of it! The tides were also cooperative allowing us to get in and out of the creek at almost any hour. As a result, I have spent more time in the boat and underwater than at my desk. I’m not complaining, just stating a fact.

Over the next couple days I want to report on some of what we did. There is much to report, both good and bad, including monitoring at restoration sites, discovery of a new meadow at Fishers Island and other interesting observations.

-ChrisP

Planting Grass on Mars?

On June 5th we got in our first plantings of the “Seepage Project”. At this point we are one site down and two to go… I need to wait for the groundwater crew to better define the other two sites before we can plant them.

This site, on the east side of Jessup’s Neck, appears to be a major upwelling area as indicated by the dark staining of rust red on an otherwise tan sandy bottom. It literally looks like a moonscape with silver bubbles. Even when we dig down into the sand it shows evidence of reduced iron with a strong dark blue color.

It is getting late to transplant in the PE, but I am hoping that the temperature moderation of the groundwater will help to reduce the stress on the plants. The control plots outside the seepage will not have this benefit, if there is any.

Kim and I were able to plant out four 1m2 plots, two in the seepage and two outside of the seepage. Now its time for Brad and his crew to follow plant growth and survival. Since they plan to destructively sample (remove plants over the summer) we also planted a plot for us to follow over the coming months.

As part of this project we also deployed two temperature loggers under half cement blocks on the sediment surface. If there are any differences between the flow and no flow sites, these should pick it up.

While we were planting we witnessed something that we have never seen before, a clam spawning. Check back for a note and pictures describing this event.

-ChrisP

The Robins Island Plots Thrive…

In order to track the progress of our various test plantings throughout the region we typically schedule monitoring visits at least monthly throughout the growing season. Sometimes, especially during late summer when we can begin to lose plants to stress, it is useful to monitor more often, if possible.

Last week we made our second monitoring visit to the Robins Island test plots that looked so good in April. If you remember my last post on this site I mentioned that these plots were the best that I have ever seen in over 15 years of work in the Peconic Estuary. However, as they say in the investment commercials “past performance is no guarantee of future results” or some such thing.

Having said this, I could not have been happier with what we observed on May 29th. The day was perfect for monitoring. The sun was shining and there was a slight breeze, not enough to produce a chop in the lee of the island, but just enough to keep the “noseeums” away.

As we approached the plots we could clearly see the dark circles against the tan of the surrounding sand. I was relieved that they were still there. Fortunately or unfortunately, depending on how you want to look at it there is literally nothing on the bottom at this site except for what we planted; No algae, no crabs, no whelks, no anything...just as we like it. In areas like this our plots normally experience the “oasis effect” (I think I just made that up) meaning that any crab, whelk or moonsnail in the area eventually arrives and rips or plows out the grass looking for food. For some reason, this does not happen here.

Given the water clarity I could almost count the shoots from the boat, but that would clearly not be accurate enough for our work. What was apparent from above was that the plots contained many flowers indicating that there will likely be a nice seed set this summer.

In my mind the flowers are a mixed blessing. On one hand they indicate how well the site is performing. On the other hand they also mean that the site will lose shoots after seeds are released some time mid summer.

For those who don’t know a certain number (about 10%) of vegetative shoots typically develop into reproductive shoots, set seed and die. This appears to be initiated some time during the winter or very early spring and no one really knows what causes an otherwise normal shoot to differentiate. What is clear however is that as a result of this process the shoot density after flowering always drops proportional to the amount of flowering.

As usual Steve handled the counting as he has the most skilled and experienced of us. When there are flowers we count them separately so we can account for the eventual loses and we also want to calculate flowering percentage.

Based on the numbers from April to May the plots have shown an 8% drop when the reproductive shoots are included. Mean flowering percentage was 15.8% which will translate into an approximately 30 shoot loss per plot by mid summer. However, we also expect additional lateral shoots to form in the coming weeks so this number COULD be overcome be increases in additional vegetative shoots.

We also checked on the Hog Neck Bay plots on the same day. They looked good, but not as good as Robins Island. Check back for an update on these plots soon.

-ChrisP

Attack of the Sea Robin!

I know, I know they’re not known for being vicious, but as I found out this week, Sea Robins can be very aggressive. While minding my own business documenting some of our newest test plantings off Little Ram Island (Shelter Island) I was accosted by a male Sea Robin in breading color.

Kim and I were just completing a rock planting in about 8 feet of water and I wanted to document the extent of our work with some “before” pictures to compare to what will hopefully be great “after” pics as the grass spreads. You’ll have to check back to see if this actually happens.

Anyway, while I was busy taking pics, I saw this guy approach pretty close and start to do wide circles around me in and out of the extent of my visibility. Most fish we come across, except for our flounders at St. Thomas, which is another “fish” story, are very wary of us and either dart away as we approach or stay away from us completely.

I have experienced a menhaden (aka Bunker) school close up in the LIS that reminded me of a show on the Discovery or the National Geographic Channel as the metallic school morphed around me as it passed. I have also had stripers circle me as well. However, in both cases if I exhaled the fish instinctively moved away.

This time was different! What I thought would be another quaint encounter with a docile denizen of the deep turned into a case of aggravated assault.

At first I thought this guy was simply there to clean up a couple of the spider crabs that I had sacrificed for the cause. Yes, I must admit that I like to offer up spider crabs to nearby fishes as there are more spider crabs out there than we can shake a stick at…and they like to dig up our plots. The phrase to “kill to birds with one stone” comes to mind but “to kill two crabs with one stone” is right on target. Back to the story; this guy had more on his mind than the free handouts though.

As I innocently went about my business getting some great shots of the plantings apparently he grew tired of me trespassing in HIS territory. That’s when it all changed. As I looked down in the viewer to look at a previous pic he suddenly charged me and spread his wing-like pectoral fins out and almost hit me in the face. I couldn’t believe it!

It took me a second to process what had just happen in the rush of activity, but I realized he meant business as he circled even more vigorously. At that point we were done with our work and I was more than happy to leave this proud male to his own devices as I doggy paddled back to the boat with my tail between my legs. I had to give it to him for sticking up to something that was much larger. And, let’s face it I know when I had been summarily beaten…

-ChrisP

Seahorses off Shelter Island!

Call it luck…call it an amazing coincidence, but on the year when we planned to initiate a Seahorse Research project in the Peconic Estuary we found natural seahorses! That’s right, natural seahorses happy and healthy in the PE!

This past January I had met Todd Gardiner from the Atlantis Marine World Aquarium when we gave back-to-back lectures at the Friends of Flax Pond Winter Lecture Series at the Childs Mansion in Old Field. I had never participated in a “tag team” lecture before, but this one was arranged in such a way that I presented the habitat side (eelgrass) and Todd discussed the fisheries (seahorses).

While listening to Todd’s talk I became aware of the plight of local seahorses (Hippocampus erectus) and the fact that their numbers appear to be dropping, even in the Great South Bay where he regularly finds them. He also discussed that there was no current protection for this species and that large numbers are being harvested for the pet trade.

As usual, my mind raced with new project ideas. If we are already planting eelgrass in the PE why not team up with Todd and introduce seahorses as we plant our eelgrass? If this works we could introduce habitat and the animal it supports almost simultaneously. Not really, since there would have to be a delay as the grass becomes established and attracts suitable food for the seahorses, but that is the basic concept.

As a follow up, Ali and I had a meeting with Todd to see how we could coordinate our efforts. It was decided that we would work with Todd as he is THE local expert and he typically has a supply of both hatchery reared and wild caught seahorses on hand at the aquarium during the summer.

This year we planned to introduce a number of seahorses into different sized natural and/or planted plots in the PE to see what size is big enough for these little creatures. For obvious reasons we want to find the smallest size that will still support an adult pair. This way, when we plant this fall we know what sized plots to establish so that the seahorses get what they need.

On May 28th part of our project took a quantum leap forward. While scouting for new planting sites off of Little Ram Island Kim found a very small remnant patch of grass. As she was taking pictures of this dwarf (6”) tall grass she found a pair of seahorses clinging to the base of the plants. As you can imagine she was more that just a little excited.

On the same day a dive at another site with very short grass in shallow water also yielded a number of healthy looking seahorses. Apparently seahorses are alive and well in the Gardiners Bay.

On the following day and early this week we found additional animals, all in small patches of grass east of Shelter Island. In my 15 years of diving in the PE I have NEVER seen a seahorse and now we know exactly where to look for them!

We look forward to following these guys and learning more about them. Hopefully, what we learn this summer will allow us to adapt or eelgrass planting methods to the point where we can introduce seahorses back into the central and western PE at one of more of our planting sites…

-ChrisP

HAB’s hit the area HARD…

This spring has brought unwelcome visitors to the area. Harmful Algae Blooms! Our old friend and archenemy of eelgrass and shellfish, the “Brown Tide” (Aureococcus anophagefferens), has hit Great South Bay hard and is creeping east at an alarming rate. Another species, nicknamed the “Mahogany Tide” (Prorocentrum minimum) (see photos) has also been sighted in local waters. First time I’ve heard of that one. What is happening?

Fortunately we are in capable hands as Robert “Mac” Waters, Supervisor for the Suffolk County Department of Health Services, Bureau of Marine Resources has been sending out almost daily email alerts detailing the geographic spread and intensity of the bloom as his team tracks the invasion.

This has already caused the cancellation of a long overdue NYSDOS-sponsored aerial mapping effort for eelgrass in the SSER where you can’t see the bottom and the Peconics for logistical reasons. In addition, we had planned to follow up on a seeding project we conducted at the Blue Points Property owned by TNC, but this was also scrubbed given the nonexistent vis.

My main concern at this time is two-fold. First, how far into Shinnecock Bay will the BT spread? We have plans to work in western parts of the bay this year, but that will likely be on hold for now. What about the eastern half though? Will it move east of the canal? Also, if it does move into the eastern part of the bay will it pass north through the Shinnecock Canal and into the Peconic Estuary? That would really be a bummer…our Red Cedar Bluff site, that is doing so well, is very close to the canal.

At this point all we can do is sit back and let the SCDHS do their job. Every day we watch the numbers come in like some defeated general getting casualty reports from the field. Hopefully, this will end some time soon. If not, we could lose even more eelgrass.

I’m just glad that BT doesn’t bloom in Long Island Sound….yet!

PHOTOS TAKEN BY PHIL DeBLASI, SCDHS

-ChrisP

The Perfect Storm: September 11th 2007

Last fall during a heaving storm we lost much of what was one of the most incredible meadows in the Peconic Estuary. We are used to seeing meadows in the PE slowly wither over time as multiple stressors take their toll and they get smaller and smaller and smaller until they reach a point of no return and don’t come back the next year. In the last 15 years this has happened in Southold Bay, Northwest Harbor, Orient Harbor and many other sites I would rather not mention...

The Orient Point meadow was different though. This large meadow located in the cool clear waters near Plum Gut was one of our favorites and it showed no signs of stress or the slightest inkling of a problem, because up until September 2007, there was no problem.

For almost 10 years we have marveled at this site. From a practical point of view it was easily accessible by boat or truck and provided us with an endless supply of naturally uprooted shoots for transplant stock or seeds for our seeding efforts. In both cases we couldn’t collect 1% of what was available so we were confident that we were not having an impact. Our monthly dives here confirmed this.

Then came September 11th 2007… From my office window at Cedar beach in Southold, 12 miles west, which just happens to share the same exposure as Orient Point, I could see that it was bad, but I didn’t know how bad. I did take note of the fact that the wind never seemed to stop and the waves were crashing on our beach for almost two whole days.

But eventually as it always does, the storm stopped and we got back to the routine field work or early fall, collecting shoots and stockpiling them in our greenhouse for the upcoming restoration season. Everything was good, or so we thought…

It wasn’t until October 16th, when we happened to visit Orient on one of our regular shoot collection missions that we realized something was wrong, very wrong. Steve and Kim had gone out as they often do, but this time the report back was that not only were there no shoots to collect, but even worse, the meadow had vanished! The bottom was naked and only a few plants remained where previously there were more than 500 in a square meter.

When I got the news I was in disbelief. How could this be? What happened? Eventually, I thought about the storm we had in September and pieced together the timeline based on our dive logs. We had been to the site on September 1st and there was NO sign of anything wrong.

A search through the NOAA weather buoy archives provided the proof that I needed. A perfect storm of wind direction, intensity and duration had started on September 11th and ran into the 13th. Average seas in the area were 3-4’ over an 18hr period! Somehow the wind had passes south of Plum Island and north of the Gardiners Island ruins hitting Orient at an oblique angle that proved devastating.

My first dive on the site was on October 18th. When I dropped in I was shocked at what I saw. It looked like someone had come along and cut off all of the shoots, especially in the middle to deeper areas. Despite this devastation I was able to pick out some clues that told the story. One interesting observation was the fact that the rhizome mat was still intact throughout the meadow so the storm was not violent enough to rip the plants out entirely. What appears to have happen was even more bizarre. As I looked closely at what remained I found that the terminal ends of the rhizomes (where the shoot had once been attached) were frayed and rotting. This led me to the conclusion that the waves had actually taken the leaves and either rocked them back and forth and/or twisted them to the point where they simply broke off.

On a more positive note, there were still small clumps of plants next to larger rocks that apparently afforded some protection. Even more surprising was the fact that the inner, shallowest edge appeared to weather the storm better than the deeper areas. I must admit that this part did not make sense. The fact that the rhizome mat and most of the sediments were still there also means that there was the potential for seedling recruitment.

What is the fate of the Orient Point meadow? Is it lost forever? Will it recover?

In a future post I will describe subsequent observations at this site and a project we have recently initiated to track what we hope will be natural recovery over the coming years. As the old saying in ecology goes: “Mother Nature abhors a vacuum”; I just hope she fills it with eelgrass and not algae in this case!

-ChrisP

Overcoming muddy sediments?

As I have noted in several previous blogs we have observed that the grass in most of our muddy bottom creeks and harbors around Long Island has disappeared. There are many theories as to why this happened, but on the top of the list is the stress associated with growing in muddy, highly organic, anoxic (lack of oxygen) sediments.

One theory is that low light and/or high water temperatures (or some other stressor) combined with sediment anoxia kills the plants by poisoning the meristem. This appears to have a significant impact on young seedlings.

Sulfide toxicity has been held out as the main culprit in this scenario. The problem is how can we control sulfur concentrations in the marine environment? The answer is we probably can’t since sulfur is everywhere!

One way around this may be to somehow alter the sediment is such a way that it does not go completely anoxic. This might be achieved by lowering the amount of organic matter and/or increasing sediment texture (from silts to sands). Since lowering organic matter is nearly impossible we have considered changing the texture by adding a thin layer of sand to the surface of the mud. In theory, this should allow oxygen to penetrate the surface sediments and prevent sulfide build-up at the base of the shoot.

We decided to try this out at Noyack Creek in Southampton where we already have a large number of seedlings that resulted form last year’s restoration work. Over the last couple days we set out 30 small tubes isolating individual seedlings on the bottom. The experiment involves doing nothing to the seedling (control) or either adding 1cm or 2.5cm of sand to the surface of the sediment surrounding the seedling. The hope is that we will see a difference in survival and growth between these three treatments in the coming weeks.

At this time all the seedlings look great and there is no sign of stress whatsoever. However, we observed a similar thing a few years ago when thousands of natural seedlings recruited to this site. That year the seedlings looked great during May and early June, but by the end of June they were ALL dead.

We’ll keep checking on our seedlings weekly to see what happens over the next two months. It would be nice if everything survives, but I must admit that I might be more pleased if only the sand treatments survive.

-ChrisP

Eyes in the sky...

It is not that often that you get a chance to do research from a helicopter. So, when I got the call that a local businessman offered to donate a nice block of flight hours in his new turbine-powered helicopter and personally fly us around the East End to do some seagrass survey work, you didn’t have to ask me twice. My answer was “Great, when can we start!” Luckily, the reply was “What are you doing tomorrow afternoon?”

The effort has been tentatively called “Flying LEAP” for the Long-island Eelgrass Assessment Program…our businessman-pilot is used to dealing with the military, so a catchy acronym is a must.

Although everyone knows that aerial surveys are THE way to go when trying to map and run trends analysis data for eelgrass meadows the lack of public dollars and bureaucratic momentum means that this is often not possible. In this day of satellite imagery and every other new fangled means of remote sensing you would think it could be done form our desk. Maybe it can if you are with the US Defense Department but for us lowly civilians it’s just not going to happen.

Take the Peconic Estuary as an example. We were involved with a fixed wing aerial survey and ground truthing effort dating back to 2001. This was the first and last time this was done for the region; pitiful, but true. Now Google Earth and Microsoft Live Search Maps make things a little easier, but there is only so much you can do with existing photo sets which were clearly not acquired for the purposes of mapping seagrasses. I’m not complaining mind you, just stating a fact.

If we could go where we want, when we want (times of good water clarity, low tide, low wind and low sun angle) then we can really capture some great images. This is where our friend and his helicopter come in…

Over the last couple weeks we have been running flights over various parts of the Island, photographing existing meadows, current restoration sites and scouting for new restoration sites. We typically run with three cameras, one video and two still in most cases, to catch all the action. Through this effort we have found entirely new areas of grass that were unknown to us as well as gotten a “bird’s eye view” of our restoration sites around the Island. There is no substitute for seeing the grass from above with your own eyes.

Our flights over Shinnecock and Moriches Bays were especially productive as we had an absolutely PERFECT day with a low tide, no wind and great water clarity. It seemed like we could almost see fish in the grass. We are excited to follow up on these observations and get out in a boat and visit some of these interesting areas.

It is hoped that we can continue this work into the summer and fall, especially when the water is clear. We have already learned so much and would like to continue…plus, it beats any day in the office!

Thanks again, friend, and fly safe!

-ChrisP