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, September 30, 2009

Who are you?






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?

Wednesday, September 23, 2009

You can run but you can't hide!

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.
video

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?

If at first you don't succeed


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.

Wednesday, August 19, 2009

Wow its been a while!!!



Sorry all. Summer is my busy season, and while I have been snapping lots of photos and working on my research, I have not been very religious in my postings. I will try to do a better job from here on out.

So, some good news, I have my second manuscript accepted for publication in Marine Biology. I still need to make some minor revisions, but that was still very exciting.
My abstract was accepted as an oral presentation at the upcoming CERF meetings in Portland, Oregon.
I am trying to save money for a diving trip to Fiji this January, where while I hope to participate in many fun dives, I also hope to do a research project involving seagrass meadows there.



But onto the current research- we are seeing larger scallop sets this year than all the previous years combined. In 4 spat collection dates, we have already collected over 30,000 seed scallops. That may not seem like many, but its more than the previous 4 years of monitoring combined. This seems to indicate that the multiple spawning sanctuaries we have set up are working, and in past years may have seeded pockets of spawning individuals in other portions of the bay. This is good news for bay scallops and Long Island. However, I must not be to quick to celebrate, as there is a lot that can happen between now and November 2010, when this years scallop set will be old enough to harvest.






This is also good for my actual research, one aspect of which is examining the roles seagrass patch architecture might play in recruitment, growth and survival. While I have been working on the recruitment and growth aspects of this project, but I had not been observing recruitment to my mats. This has changed this year - likely a combination of a slight change to my recruitment collector design and the apparent increase in larvae in the water column - I have collected ~700 scallops on my artificial seagrass units. This was very exciting. In my two collections thus far, there seems to be a natural experiment going on - in three weeks, the collectors went from an average of 124 per square meter to 56 per square meter - a 50% reduction in a 3 week time frame. This is likely due to predation, but I will have a better idea in the next 4 weeks when I have 2 more collections. This was all very exciting to me.

Even more exciting, is that in addition to seeing scallop seeds set on eelgrass, we are also starting to find scallops set on species of macroalgae. This will hopefully start to shift some of the old ideas that only eelgrass is suitable for bay scallops, because we are observing in the Peconics scallops in and on many other potential habitats!







Lots of exciting things. Stay Tuned!

Tuesday, May 19, 2009

Scallop surveys!


So I went diving on Monday to do some more of the benthic surveys. During the summer, from June through November, we have our spat collectors in the water to track larval settlement. In November and December, we do benthic surveys at our collector sites so we can see if what comes up in the collectors is translating to the bottom. Then, in the spring, we go back to the same sites to determine the over winter mortality. These dives are exciting, because in the last year we are seeing more scallops here than we have seen in previous years, which indicates the restoration effort is probably working. But aside from the scallops, I often see a lot of other cool things. Every dive I observe spider crabs, mud crabs and whelks, those are fairly common. Some commonly seen fish include gobies and cunner. But occasionally I come across cool things, like this fluke, Paralichthys dentatus:



I also saw this skate, which I believe to be a little skate:

And some sort of mud shrimp:


And finally, these two crabs teaming up to try to eat the whelk:

Some sort of comb jelly (in the bottom of the photo)
And, as always, lots of scallops!!!!



Scallops make comeback

"RANDEE DADDONA PHOTO These well-fed Peconic Bay scallops were raised in a hatchery on Cedar Beach in Southold. The work of local biologists to boost populations of the delectable shellfish, devastated by brown tide in the mid-1990s, is paying off. "

this article was just highlighted in the Suffolk Times. Yes it is a local paper, but this is pretty big news - the best scallop year in the Peconics since 1995. That's nothing to laugh at. We are keeping our fingers crossed, but so far, the results are looking good!
The highlights:
-The largest bay scallop sanctuary in the world
- 500.000 scallops
- Commercial landings from last November and December in the Peconics were the highest they have been since 1995
- Scallop stocks in some local waters are 13 times higher than they were 5 years ago

Sunday, May 17, 2009

CYANEAAAAAAAAAAA!!!!!!!!!!!






WATCH OUT, INVASIVE OF THE JELLIES!!!!! Good thing I am immune to stinging cells!

Its the most wonderful time of the year!



Well, maybe not the most wonderful. But it's close. I've been diving a couple times now, and it is so much better than sitting in the lab. Plus an added benefit is that the water is still pretty clear this time of year. So we have been diving to monitor the spawner sanctuary sites - the 2 bottom planting sites and the long lines. Basically we do quadrat counts of the scallops on the bottom to get an idea of the mortality from time point to time point, and we sample a set of scallops to look at growth, gonad index and condition index. For the long lines we sample scallops from the end lines and the center line to look at growth, GI and CI.

Wednesday, May 6, 2009

The Nature Conservancy Awarded $500,000 for Seagrass Restoration Research in Long Island and Connecticut Waters


Research to Assess and Tackle Issues of Seagrass Die-Off in Local Waters

Cold Spring Harbor, NY — May 1, 2009 — Seagrass has received a significant boost thanks to a $500,000 research grant (H.R. 1105, the Omnibus Appropriations Act of 2009) co-sponsored by Congressman Timothy Bishop (NY-01) and Congresswoman Rosa DeLauro (CT-03). These overlooked, but essential underwater flowering plants, form dense stands in shallow salt-water bays and harbors, and provide critical habitat for local fish and other marine life.

Read the rest here.

We all know the story here, at least if you have been following my blog, but seagrasses are vital ecosystems that serve important nursery and foraging habitats for many fin and shellfish. Many of the species are also of economic importance, which is garnering eelgrass more attention. This is big news for Long Island, since there are numerous critical gaps in the information necessary to successfully manage and restore eelgrass. And, while there may be other suitable habitats in the Peconics for my study organism, the bay scallop, eelgrass is the preferred habitat.

To learn more about seagrasses, and eelgrass in particular, check out Seagrass.LI. Also, check out this new blog by a marine biologist from Canada.


Tuesday, May 5, 2009

Of all days to forget my camera...


So, no, that picture isn't from my first day of diving this year (which was yesterday). Unfortunately, I didn't bring a camera with me, but we dove on one of our free plant spawner sanctuaries and the above photo is a picture from last October when we planted the scallops. Of course on the day I didn't have a camera, I saw a juvenile hake of some sort as I was moving aside some macroalgae to look for scallops. If I had to guess, I would say it was a red hake, Urophycis chuss, but without the camera and a snapshot, I can't say for sure. That may not sound very exciting, but its not something I have seen in the field, only collected in trawls. While counting scallops, I also observed a scallop trying to swim with a oyster drill attached to its shell. It was unable to swim properly, and upon further inspection, the drill had already drilled a clean hole into the shell, which means it was likely attached for a while. There was also a grass shrimp eating some sort of annelid worm. It was funny, because as I dropped my quadrat, I saw this yellowish thing moving around. When I got a closer look, I saw the shrimp holding the worm and the worm was still wriggling around. It reminded me of when I was younger and we kept African clawed frogs in our fishtank and fed them earthworms. The frogs would shove them into their mouths with their front legs and the worms would try to wiggle out. Very entertaining. So, yeah, I wish I had my camera.
But now for the good news. Last fall we planted approximately 170,000 scallops in Hallock Bay, on the North Fork of Long Island, near Orient Point. The year before, we planted similar densities of scallops in Hallock Bay, but they experienced extremely high over winter mortality, likely due to dense macroalgae and associated low dissolved oxygen under the canopy. We weren't sure what to expect this year, since last spring, we only observed about a 2-3% survival. Last fall we chose a new site, slightly deeper, solid bottom, more current, and less algae cover. Well it seems at first glance like the new site has paid off. By my quadrat counts alone, I would guess that we are seeing between 30-50% survival of the scallops we planted last fall. That exceeds our expectations. Overwinter mortality is usually a large source of natural mortality, however, the scallops are still small - between 28-40mm, so they are not yet above the size threshold for predation. In fact, at the site we observed many cluckers and cracked cluckers, broken shells, and predators including mud crabs and spider crabs. Luckily, the water is already warming up (it was 13.5 C yesterday) so they should start growing. In another planting site we checked, with less water exchange and slightly warmer temperatures (15.5 C), we observed approximately 3-5mm growth on the scallops already (we can tell the new shell growth due to the growth ring laid down during the winter). This bodes well for the scallops planted in Hallock, because they should start growing pretty soon!
On a final note, we went over to my grass mat site. All the buoys were gone, probably because Hallock was covered with ice this winter (in fact, it is a popular ice boating site). I was concerned with the ice ruining my mats, but on a quick inspection, the grass mats all seemed to be ok. I'll be getting in the water at my site in 2 weeks for a more in depth inspection, as well as to remark my site with new buoys. But so far, so good!

Thursday, April 30, 2009

We've only just begun... soon enough


That's right. It is getting to be that time of year where we will be getting back into the water. As a matter of fact, I will be diving for the first time this season on Monday. I can't wait. We are going to do quadrat counts at some scallop planting areas, start our spring surveys, and start our gonad index monitoring. I am really looking forward to it. I am also going to check on my grass mats for the first time since November, which I am looking forward to. Keep your fingers crossed that they are all still there. In other news, I am still working on my proposal but hope to defend it within the next 3 weeks. With the help of an undergraduate, I have finished processing all of my scallops from last fall. I am also working with our lab tech on some methods to run the tissues through an elemental analyzer to approximate the carbohydrate, lipid and protein content. Finally, I am getting organized for the upcoming field season.

On a side note, tomorrow night I will be giving a talk as part of the public lecture series hosted by SoMAS at Stony Brook Southampton. It will be part of a student symposium of sorts for the Stony Brook-Southampton Coastal and Estuarine Research Program, SCERP. Things get started at 7 and talks start at 7:30.

Monday, March 9, 2009

Scallops returning to the Outer Banks?


According to the Virginian-Pilot, bay scalloping has been pretty good this year out of the outer banks, pretty good news, after not having the fishery open at all for a couple years. Read the article here, the picture is from the article.

Back from benthics


So for the past few days I was in Corpus Christi, TX, for the Benthic Ecology meetings. It was great. It was smaller this year than in years past, and I think the coziness lead to much better interactions between people this year. I think my presentation went well (nobody threw shoes at me or anything like that). I was also able to visit the Texas State Aquarium and I frequented Crawdaddy's (the website doesn't do this place justice) for meals. I mean it doesn't get better than no frills, cheap beer and fried food. Best crawfish and fried okra I ever had (ok, first crawfish and okra I ever had), but they also had really good gumbo, and their service staff was incredibly friendly (although I imagine that just might be the way things are in Texas). The bar scene wasn't too shabby either. But for the business aspect of things, I saw a number of really good talks and interesting posters. There was a large contingent from VIMS, whose talks ranged from bay scallops to blue crabs to oysters to seagrass, whose talks and posters were very good. There is a lot of good work going on down there. DISL was also well represented, with numerous talks and posters, many of which focused on fisheries and trophic interactions. Overall, it was a very good conference. I was able to talk to alot of people about my research and theirs - a few people working with scallops, some about blue crabs (which I hope to work with in the future) and a bunch of people about artificial seagrass units. All in all, I think this meeting was much better in terms of interaction, and I look forward to attending next year in North Carolina!!!

Monday, February 16, 2009

My personal fish tank

No scallop news to report this time of year. I am in the process of getting my proposal together to defend it this spring, re-writing a manuscript, getting together a presentation for the upcoming Benthic Ecology Meetings, and taking two classes. Crazy right? But somehow, I have found time to renew an old hobby of mine, tropical fishkeeping. When I was growing up, my dad always had fish tanks, and when I was old enough, I started getting tanks of my own. Eventually, between me and my father, we had somewhere between 13-15 fish tanks throughout the house and basement. I tried to continue the hobby in college, but it is hard when you move every 8 months. So I have been out of the hobby for a few years, but was able to obtain a 20 gallon fish tank last September, and I set it up with freshwater (marine ornamentals are difficult and expensive, both in livestock and equipment). Originally, I just had some tetras (lemon tetras mostly) and after the tank cycled, I added some neons as well. After Christmas break, I added some angelfish and catfish. But I always wanted discus. They are some of the most difficult freshwater fish to keep, requiring very specific water quality (low pH, soft water, low nitrogen, high temperature). My father and I tried to keep them a long time ago, but kept having difficulty - which was disheartening, considering we had kept just about every other type of freshwater fish with relatively few problems. Discus are kind of like the holy grail of freshwater fish - breeders kept secrets for decades. But when I went to the pet store the other day, I saw discus at the right size (silver dollar) and the right price (29.99, 4 for 100). My water seemed right (temp ~80, but easily raised, pH ~6, etc) but I still wasn't sure. I probably wouldn't see discus this quality at this price again (especially if the economy gets fixed), but I had two angelfish (body size ~ a quarter) who were now established in the tank for over a month, and the tank was small. Both angelfish and discus are specialized cichlids from the floodwaters of the Amazon river, laterally compressed to swim between the submerged trees. Cichlids, by nature, can be rather territorial and aggressive by nature, and although angelfish and discus are generally regarded as gentle, there was some hesitation on my part. 20 gallon tanks are small - only 24 inches long - and with the angels being established, there isn't room for the discus to escape potential attacks. I thought long and hard. I spent about an hour watching the fish and talking to the store attendant. Finally I decided I won't have another opportunity to get the discus at this price, and I figured I would give it a try. This was yesterday. They seemed to acclimate fine, however, I raised the temperature in my tank anyway, from 80 to 85 (I was hoping only to come up to 82-82, but my heater is not that specific). Then I turned off the light and went to bed. I forgot to consider the potential for the dissolved oxygen to drop when I raise water temperature, and I woke up this morning with all the former residents (tetras and angels) gasping for air, and one of the catfish already dead. I was freaking out. I could not have this. I dropped the temperature back down to just over 80, took an inch of water out so the filter exhaust would stir the water better, and rushed to school to borrow an air pump for the time being. But I had class, so I couldn't stay and watch. I just kept my fingers crossed. When I got home today, I was surprised. All the fish seemed to be breather normally, swimming around, and all were eating (even the discus, after only 1 day!) Catastrophe averted, for now. I will take pictures soon.

Monday, January 19, 2009

Atlantic sharks at risk due to over-fishing - Devastating for scallops?


The cracked bay scallop shell indicates crab predation.

Over-fishing is a relatively hot topic these days. One group of fishes that are particularly threatened are sharks - because they are large, long lived, and have relatively few offspring. Here an excerpt from a recent article online:

"GENEVA – More than a quarter of sharks in the northeast Atlantic Ocean face extinction with some species already wiped out in certain areas due to over-fishing, a conservation group said on Monday.

Twenty-six percent of sharks, rays and chimaeras are threatened with extinction and another 20 percent are in the 'near threatened' category, the Switzerland-based International Union for the Conservation of Nature (IUCN) said in a statement."

This has the potential to be devastating to bay scallops. With the loss of sharks, which are large apex predators, their prey is released from a predation pressure. This, in turn, allows populations of shark prey to expand - these include smaller sharks, skates, and rays, which are typically benthic feeders which eat shellfish. One species in particular has increased to such numbers, the cownose ray, that it has devastated the bay scallop fishery in North Carolina. This has been documented by scientists for the past 8 years, and recently made Science magazine in 2007. Luckily, we don't have the large feeding aggregations of cownose rays here in New York, and as far as I can tell, we haven't seen large increases in skates, at least not in areas where we have bay scallop populations.

Although it is possible that we are seeing other trophic cascade-type effects, some of which I plan to investigate in my thesis research. I don't want to get into too many details until I know if I am doing this for sure, but its possible that loss of some local fishes has released crabs from predation pressure, allowing them to forage more freely on their prey, juvenile bay scallops included. By the way, I am working on my proposal right now and it is killing me! Can't wait until it is all over!

Thursday, January 15, 2009

"Nub" scallops


Most bay scallops live less than 2 years, and so a concentric growth ring is usually only laid down once. Typically seed scallops reach a size threshold, 35-55mm by the end of their first growing season. However, some scallops are less than 20mm when the growth ring is set. These could be the product of fall spawns, and there is some thought that these scallops don't spawn before they are large enough for their first harvest, that is, they are likely to live into and spawn in a 2nd year. Some populations consist of more than 50% of these "nub" scallops. This has been a particular problem in places like Nantucket, where large portions of scallops have small growth rings. In order to harvest a bay scallop, it must have a clear growth ring, however, "nub" scallops have such small rings, they often appear as ringless adults. This has drastically shrunk the harvest of scallops in this area. That is, until this year, when an emergency regulation was passed to save the harvest. The legislation stated that now scallops could be harvested if they were greater than 2.5 inches in shell height OR if they had a 10mm growth ring - this means that ringless adults (nub scallops) can be harvested if they are greater than 2.5 inches. I don't know if I agree about this legislation, mostly because very little is known about nub scallops and their potential importance for spawning in the 2nd year. I did think it was interesting that bay scallops have been in the news recently.

The photos were taken by Steve Tettelbach and borrowed from a poster presented at last year's 100th annual National Shellfish Association meeting.