So I am sure that everyone has been posting ad naseum about Hurricane Irene. I don’t want this to be another such post. However, I did want to share some video and photos from the east end of Long Island, particularly Hampton Bays (where I live) and the Stony Brook-Southampton Marine Station.
Despite all the warnings and conjuring up memories of the 1938 “Long Island Express”, Irene came through Long Island early Sunday morning as a high tropical storm, bringing 60-70 mph winds and lots of rain to the Island. However, it also crossed at high tide on the same day as a moon tide (so already higher than normal). So there was some damaging storm surge, although less than originally forecast. We got off relatively lucky out on the east end, with what appeared (at least to me) as limited damage (although we are due for a big one).
The following is a video and some photos from the marine station which I took Sunday morning around 11 am (~3-4 hours after the hurricane crossed Long Island and ~3 hours after high tide):
There was considerable damage to Montauk Highway where it runs next to Shinnecock Bay at Swan Beach:
The town dock on Little Neck Road, down Old Fort Pond from the Marine Station was lost:
Jackson’s Marina was devastated:
Even the canal flooded and had large waves running down it:
All in all, it was not as bad as it could have been, at least out by me, and it did bring with it one surprise – a pelican!
This post is not intended to say that we got it bad out here – quite the contrary. The real damage seems to be where the torrential rains turned into massive floods in NY, NJ and Vermont. Thoughts and prayers to all those who are affected in those areas.
Well, it actually kind of is impressive. A documentary was broadcast on British Channel 4 (don’t ask me, I have no idea) about a science experiment conducted on an elephant carcass to examine what happens after death. While I can’t access the full video (I’ve tried, but you can too here), I was able to get a trailer off Youtube:
It seems pretty impressive, and I am bummed I haven’t been able to watch the full show. Hopefully sometime soon it will become available.
But reading the article got me to thinking about whale falls. I mean if you think what happens to this dead elephant is impressive, just imagine what the ultimate fate is for dead whales, some of which are 10 times the size of elephants. These are called whale falls, as the whales carcass sinks to the bottom of the deep sea. The process isn’t nearly as rapid as the above video, and whale falls undergo a series of successional communities, supporting life for years after the whale has died. (That’s not to say the elephant carcass doesn’t support some sort of community for longer time periods, I am guessing there is all sorts of microbial activity that is affected by the nutrient pulse long after the elephant’s bones have been picked clean, it just doesn’t make for good television).
Whale falls are rather impressive deep sea features. But to imagine how impressive these things are, we first need to consider the deep sea floor. We are talking about life at the bottom of the ocean here – there is no light (with the exception of any biogenic light). There is also little food on the bottom. One reason, of course, is that with no light, there are no producers. Most of the organisms that inhabit the deep sea floor have adapted to life with a small drizzle of organic particles from the surface waters. This rain of detritus (wouldn’t that be an awesome band name?) is known as the biological pump, and is one of the mechanisms of carbon sequestration in the deep sea. This is great in shallow waters, where this productivity reaches the bottom. However, due to simple sinking, horizontal transport, and use, only about 1% of the surface organic matter reaches a depth of 1000 meters, and much of the stuff that reaches the bottom are refractory particles – essentially particles that are barely usable.
Image from earthobservatory.nasa.gov
But species have adapted to this environment. In fact, there is a surprising amount of diversity found on the deep sea floor. There are a some theories as to why this might be the case such as the stability time hypothesis which states that organisms, given enough time, will become specially adapted to very narrow niches (although this theory is less supported now). Another hypothesis is that of intermediate disturbance – disturbances reset the clock, so to speak, allowing more species to compete and prevents preventative exclusion. At some intermediate level of disturbance there is expected to be the maximum amount of species. Some of this is also likely attributed to the wide array of habitats, including the muddy abyssal plains, hyrdothermal vents, seeps, seamounts, and canyons. Regardless, there is a lot of diversity on the deep sea floor. (In fact, you can learn about many of these things over on Deep Sea News, if you aren’t already following them, you should!)
Image from PLOS one
So now, picture you are out on this deep sea floor, where there is a high diversity of organisms, but low abundances. There is limited food. Then this giant whale carcass comes crashing down. I am sure you can imagine what happens, but first, a little more about whales, and their importance to the benthos. Their mere actions in the water column might be vital to the global carbon pump. Whale waste contains high concentrations of nitrogen and iron. These recycled nutrients enhance phytoplankton activity, known as the “whale pump,” which, in turn, stimulates the biological pump. Granted, there are complex interactions going on, but simply, whale excrement facilitates alga growth, which in turn, facilitates flux to the bottom. So whales are already good. But what happens when that whale dies? Well, we know they (mostly) sink to the seafloor, and deliver all that carbon sequestered in their tissues to the bottom.
Image ChEss website
Now the whale is on the bottom. The impact on the sea floor is immense. One whale carcass is close to the equivalent of 1000 years worth of marine snow falling at once. Now, there is tens to a hundred tons of organic matter and nutrients, a veritable all-you-can-eat buffet of sorts. Which reminds me of an expression I was told the other day – How do you eat a whale? Give up? One spoon at a time! Ok, ok I digress. It becomes a site teeming with life, and a biodiversity hot spot. Professor Craig Smith at the University of Hawaii has made a career of investigating these deep sea features. Some of the organisms found at whale falls are also found at hydrothermal vent systems, leading some researchers to believe that these communities act as stepping stones, allowing dispersal of organisms between vents. There is also a succession of animals which colonize and utilize whale falls, so if you visit a whale fall over a period of time you might find entirely different communities. There are even worms that eat whale bones! This is a truly amazing progression of carbon and nutrient transfer from one giant organisms to thousands of deep sea floor animals.
Image from MBARI
So, that is impressive. Granted, I’ll give you the entire elephant being devoured in days. But whale falls can support entire different communities of organisms for years. And while I am sure I have gotten some of the information a little wrong, there are definitely sites you should check out to learn more, such as MBARI, Dr Craig Smith’s site, and Deep Sea News. There is also a really nice write-up about whale falls at the Audubon Magazine.
Well I finally picked up a copy of the this month’s National Geographic with the artificial reef article in it. And by picked up I mean borrowed from a waiting room, but I have to go back on Thursday and will return it then, so I am no thief. Anyway, I briefly blogged about this article already when I was depressed about winter weather and longing to be someplace else, preferably warm, and diving. That’s because I love diving. And sometimes, there’s nothing better than diving on wrecks. Sometimes. Don’t get me wrong, there is plenty of cool things to see on naturally occurring bottom. But artificial reefs created by wrecks are definitely very cool (so is this video).
Image from Pangea-yep.com
But actually reading the article, in print, and seeing the pictures, made me want to blog about it all over again. This time, though, I will concentrate a little more on artificial reefs themselves. Artificial reefs are quite simply structures artificially sunk by man to create a hard bottom in an otherwise sandy and structure-less habitat. The idea is to mimic some of the functions of naturally occurring reefs – namely, by providing a hard, 3-dimensional structure that sits in the water column. These reefs are intended to attract and enhance many marine species, in particular, finfish. In fact, fisherman have been sinking things for decades (probably even centuries) to attract fish, so this is not a particularly novel idea. However, the number and magnitude of artificial reefs has certainly expanded greatly in recent years (Edit – as Dr Alan Dove pointed out in the comments below, there have been numerous “natural” or unintentional wrecks sunk over the years. So the rate of sinking artificial reefs might not have increased, but I imagine the rate of intentionally sunk reefs has). Typically, “Artificial reefs” just consisted of junk. Now, many have expanded to be large decommissioned ships, subway cars, and oil rigs (and other cool things). And even more recently, companies are creating artificial reefs from concrete, such as Reef Balls, which I think are pretty cool (and, if you are lucky, when you die, you can be commemorated for eternity as an artificial reef ball! Sign me up!).
It might not happen over night, but eventually these sunken structures become teeming with life. Swirling currents around these structures can kick up and contain plankton, which attracts small planktivorous fish. These little guys, in turn, attract larger piscivorous fish. In addition to seeking food, many fish arrive simply to seek shelter in the many nooks and crannies that artificial reefs provide. But its not just fish. The artificial structures also become colonized by invertebrates and macroalgae, creating a crusty layer of living organisms growing as a living shell of sorts on the submerged structure. This living structure offers more nooks and crannies for smaller creatures, and provides food for numerous species that inhabit the reef. It essentially becomes just like a natural, living reef, with the only difference being that the underlying structure is man-made. Typically, when we think of artificial reefs, we think of tropical locations. However, they are also used in many temperate coastal waters to enhance fisheries, including Maryland, South Carolina and New Jersey. Here, they create ecosystem structure typically only present on the few limestone rocky outcroppings that stick out of the sand bottoms.
Despite providing food and shelter to numerous species, there are certainly detractors, and artificial reefs aren’t without certain cons. One major concern is that some things are just tossed in the ocean as junk, but that companies/organizations/municipalities/entities use the “artificial reef” moniker as an excuse to dump crap. Its cheaper to just toss things into the water than dispose on land, and so sometimes, things are called reefs just as an excuse. That is bad. Additionally, many things that are sunk have toxic substances on them, which can actually do more harm to the environment, leaking contaminants for the life of the reef. It is for these reasons that there are now strict, stringent regulations for sinking artificial reefs.
But one of the biggest complaints against artificial reefs is the very reason they are created in the first place – they concentrate fish. The complaint is that these concentrations make fish easier targets for fishermen, and can be potentially harmful to specific species. According to the NatGeo article, some biologists believe that this artificial enhancement of certain fishes, can be extremely detrimental to stocks. One such fish that is likely being negatively impacted by artificial reef structures is the red snapper, which concentrate around the structures and become easy targets for fishermen. In other words, these artificial reefs might make fishing as easy as shooting fish in a barrel. Obviously, acting as fish attractants with easy access can be harmful to fish populations, and some might argue that recreational fishermen are quite capable of decimating fish stocks, even in the absence of commercial fishing pressure
Clearly there are pros and cons of artificial reefs. However, it is my opinion that the pros outweigh the cons. And an easy way to eliminate the major negative impact of artificial reefs – the potential to overfish exploited stocks due to large congregations of target species around these structures – is to incorporate reefs into marine reserves and no-take zones. Yes, this might defeat the purpose of the reefs, and many will argue against this. I am not suggesting all artificial reefs become no take zones, but by leaving some as no take refuges, the reefs could serve there original purposes. While there is some debate as to the usefulness of marine reserves on highly mobile species, it stands to reason that artificial reefs create habitat where there is otherwise none, and enhances the local ecology of the area of the reef, enhancing species abundance and diversity. Plus, they are just awesome to dive on.
Editor’s Selection IconWell I haven’t done a Research Blogging post in a very long time. But I was inspired by this news release I read today about crabs spilling onto the Antarctic peninsula with warming waters. On a recent voyage to Antarctica, marine biologists collected digital images of these deep water predators moving closer to shallow coastal waters which have been excluded from for potentially millions of years, because the shallow coastal waters, until recently, have been too cold to support these predators. This can be devastating to the coastal shelf community in Antarctica, which has adapted no defenses in the absence of these predators – many organisms here have thin shells or don’t burrow into sediments.
My friend and fellow Southampton College alum, Molly, recently blogged about this issue. She is currently doing graduate work at the University of Alaska Fairbanks on snow crabs, so she loves crabs (as her blog title suggests). The idea is that, as the above article states, these crabs are moving closer to the Antarctic shelf, and this can have devastating impacts on the local fauna there. It was highlighted in a National Geographic article in 2008.
According to research, the Antarctic coastal shelf experienced a cooling trend starting around 40 mya, and the waters, due to the cooler temperatures, essentially became devoid of many types of predators. The subsequent community had evolved over those millions of years in the absence of major durophagous predators – known for their shell crushing abilities. The major predators in these bottom waters are slow moving invertebrates, and the community developed over time accordingly. Now as surface waters are warming, crabs are able to enter these new areas from the depths, and can have potentially harmful impacts.
At first, this might seem counter-intuitive – typically bottom waters, and the deep ocean, are very cold, and the water warms as you get shallower. This is not the case on the Antarctic shelf, where the shallow waters are actually colder than the surrounding deep waters. This is due to the cold Antarctic circumpolar current, which runs clockwise around Antarctica, isolating its cold water and continental shelf from crabs and fish with bony jaws.
However, the absence of crushing predators was not due to geograhic isolation of the Antarctic continental shelf (although Antarctica is oceanographically isolated, the barriers of biological invasion in this case are physiological, according to Richard Aronson, professor of biology at the Florida Institute of Technology, and others in 2007). Physiologically, the crabs are unable to process magnesium in their blood at the normal shelf water temperatures, resulting in narcotic effects. So the crabs, for millions of years, had stayed away. The resulting shelf community, consisting of epifaunal suspension feeders, lacked the typical defense mechanisms seen in other benthic environments where soft bottom bethos have been evolving with predators in an evolutionary arms race. As already mentioned, the archaic communities of the Antarctic shelf, consist of animals with thin shells which don’t burrow. So one could imagine that if these crab predators were allowed to move into these coastal waters, it could have devastating consequences on the community there.
This is not a crab you would encounter in the Antarctic, however, it is as close a figure to the "arms race" - crab claws, thick clam shell - as I could find on the interwebs.
Range expansions are something that are particularly interesting to me. The lifting of physiological barriers due to temperature will allow biological invasions of numerous species. How these species interact with native species is of great concern. In particular, predator-prey relationships between novel predators and naive prey can restructure communities in warming oceans. Despite its perceived isolation, this research suggests that Antarctica will not be immune to these impacts (and it fact, polar regions are likely to experience a greater magnitude of temperature change).
And the real news here, is not only is there evidence the crabs are moving closer to these shallow shelf communities, but that it is occurring at a much more rapid rate than anticipated.
A quote by Dr. Aronson from the new article: “If you look at the warming trends on the peninsula, you would expect that the crabs would come back in 40 or 50 years,” Aronson said from his office in Melbourne, Fla. ”But boom, they’re already here. This is the last pristine marine system on Earth and it could get destroyed”.
This is big and bad news for the Antarctic bottom communities. Clearly, this is something that should be monitored closely. But it is not in any means an Antarctic phenomenon. In many regions where warming is taking place, range expansion of novel predators can occur. This is something all benthic communities could experience in the near future.
Aronson, R., Thatje, S., Clarke, A., Peck, L., Blake, D., Wilga, C., & Seibel, B. (2007). Climate Change and Invasibility of the Antarctic Benthos Annual Review of Ecology, Evolution, and Systematics, 38 (1), 129-154 DOI: 10.1146/annurev.ecolsys.38.091206.095525
Aronson RB, Moody RM, Ivany LC, Blake DB, Werner JE, & Glass A (2009). Climate change and trophic response of the Antarctic bottom fauna. PloS one, 4 (2) PMID: 19194490
Thatje, S., Anger, K., Calcagno, J., Lovrich, G., Pörtner, H., & Arntz, W. (2005). CHALLENGING THE COLD: CRABS RECONQUER THE ANTARCTIC Ecology, 86 (3), 619-625 DOI: 10.1890/04-0620
Thatje, S., Hall, S., Hauton, C., Held, C., & Tyler, P. (2008). Encounter of lithodid crab Paralomis birsteini on the continental slope off Antarctica, sampled by ROV Polar Biology, 31 (9), 1143-1148 DOI: 10.1007/s00300-008-0457-5
Because I couldn't have a climate related article without citing the Church of the Flying Spaghetti Monster
Recently, CBS covered a story of researchers investigating the pattern on shark skin, and how it is able to resist fouling organisms that are common on other long lived, large marine vertebrates such as whales and turtles. This has major implications for the boating industry, and come companies have already begun to capitalize on the unique structure of shark skin to use as coatings for boats. This isn’t necessarily news, as shark skin coating has been investigated as an anti-fouling mechanism for the NAVY for some time. The idea behind that research is that a) fouling organisms settle on ship hulls and grow, increasing drag forces of the hull in the water, b) this increased drag reduces the ships efficiency and adds considerable cost to powering the vessel, and c) the pre-existing anti-fouling methods are either cost and time prohibitive (hauling the ship out on dry dock) or extremely harmful to the environment (such as using copper or tin based bottom paints). The adverse affects of the bottom paints used were extremely harmful to the environment, leading to accumulation in the sediments of ports and bioaccumulation through the food chain. The adverse affects led to the ban of tributyl-tin , TBT, bottom paint in the US and many countries abroad. Additionally, some states are beginning to ban copper based paints as well.
In comes the shark skin, whose scales and denticles (tiny “skin teeth” ) are arranged in a diamond shaped pattern. The pattern of sharks skin is already effective at reducing drag forces. So by merely mimicking the pattern, drag should be reduced along a ships hull. Add to that the lack of spores being able to settle onto this skin pattern, and you have a bottom coating that is much more efficient for boats and more safe for the environment.
But now, researchers are interesting in a different kind of biofouling – bacteria and the medical industry. Some research, according to the CBS article, indicates that Sharklet patterned plastic had significantly reduced numbers of bacteria on it when compared against a smooth plastic sheet. This has major implications for the health industry, as some bacteria are difficult to kill, and many places like hospitals and doctor’s offices, as well as schools and public offices, are bacterial breeding grounds (although I guess technically anywhere is a bacterial breeding ground of some sort). This material may be important for use combating infections, by coating commonly touched places with the shark skin patterned material.
Recently, a few articles started appearing about the dramatic loss of oysters throughout the world, and how in many areas, they are “functionally extinct.” The article from ScienceBlogs talks about the findings of an international research team lead by Dr. Mark Luckenbach of the Virginia Institute of Marine Science. In over 70% of the 144 estuaries studied, current oyster levels are at 10% or less of historic levels. They estimate that over 85% of the world’s oyster reefs have been lost. The amount of loss exceeds any other shallow water benthic marine habitat that has been similarly studied. Obviously, this can cause problems.
The Underwater Times article mentions the term “functionally extinct” when referring to current oyster populations – that in some areas, oyster populations are less than 1% of historic levels, mainly due to overharvesting, disease, and invasive species introductions. But what does “functionally extinct” mean? In this sense of the term, it is when a species experienced such a reduced population that said species no longer plays a role in the functioning of an ecosystem. Obviously, the loss of any players in an ecosystem can be devastating. But oysters are a foundation species, providing a variety of ecosystem functions that renders them more important to their estuarine ecosystems than many of the other species. Oysters create biogenic 3-D structure in the forms of reefs, which build up from the seafloor and in many locations emerge from the water, particularly at low tide. This structure provides a plethora of microhabitats and niches for a variety of species to live. In addition, since oysters are filter feeders, they play an important role in nutrient cycling in estuaries, packaging things in the water column (plankton, particulates) and delivering them to the bottom where they are consumed and utilized. During this process, oysters actively clear the water column, increasing light penetration to the bottom and potentially allowing valuable submerged macrophytes to grow, adding structure to the reef and surrounding area, creating even more habitat. A number of species depend on this habitat for food ad shelter, as they are valued nursery and feeding grounds for numerous estuarine species. This function is vital to fisheries, as many finfish spend a portion of their lives foraging around oyster reefs. So when the articles suggest that oysters are becoming functionally extinct, it has serious repercussions for the ecosystem as a whole.
Clearly, the loss of oyster reefs are problems both economically and ecologically. However, some research suggests all is not lost. Stricter harvesting laws, fewer baymen, and no-take sanctuaries have helped maintain oyster populations, albeit low populations, in some areas. Better and more successful management is the first step towards saving oysters, and the report made the following suggestions for restoring and maintaining oyster reefs:
The prohibition of harvests where oyster populations constitute less than 10% of their prior abundances, unless it can be shown that dredging and other harvest methods do not substantially limit reef recovery.
New thinking and approaches to ensure that oyster reefs are managed not only for fisheries production but also as fundamental ecological components of bays and coasts that provide invaluable ecosystem services.
Steps to ensure that harvests, particularly those carried out by dredging, do not damage the remaining reefs.
Regular monitoring of reef conditions.
There is plenty of other relevant information out there about oyster reefs, research, and the issues facing them. I particularly recommend the blog In the Grass On the Reef, which focuses on research underway by Florida State researchers on salt marshes and oyster reefs. In particular, they update posts about their research in ways which are easy to understand with great visual aids including photos and videos. Definitely check that one out.
Lionfish from my Fiji dive trip. It was upside down under a coral ledge
So wow. I’m not saying it has anything to do with me, but I made a post about lionfish a few months back, and had a very special guest blog by colleague Amber Stubler about her experience capturing lionfish with a spear gun and eating them. A commenter was concerned about that post, indicating that some research is showing that lionfish may contain ciguatera poisoning, so I had already decided to do a new post about that. But then, in the last 2 days, lionfish are making the news – first in Florida, then in the US Virgin Islands.
In Florida, dive master Randy Jordan of Emerald Dive Charters is the self-proclaimed “lion-tamer.” He has caught 331 lionfish to date, including his most recent haul, a 16 inch (!) 2 and a half pound fish. According to Fishbase, thats about as big as they get. According to the article, Jordan is scheduled to give a lecture on the subject on February 26th at the Loxahatchee River District meeting to talk about his special device to catch these invaders.
Then just yesterday, an article about the invasion problem in the USVI, where the lionfish now number in the thousands. The governing agencies there are planning meetings with divers, fishermen and businessmen to discuss the problem and how to combat it, and, in particular, to get divers and fishermen to report their kills. The worry is that these invasive voracious predators will wreak havoc on the local reefs and hit the major tourism industry.
Lionfish are getting a lot of attention currently. And I have advocated the consumption as an eradication plan. But as I mentioned, commenter John Rubattino from the USVI had commented his concerns about ciguatera poisoning being prevalent in fish caught there. This would create a major problem, as ciguatera is a food poison, and when humans consume fish that contain the toxin, they often experience nausea, vomiting, diarrhea, pain, dizziness, vertigo, chills, rashes, and other symptoms.
So how does one get ciguatera poisoning? Again, its a food poisoning which results from eating large predatory tropical fish which contain the poison. According to the CDC, these fish include barracuda, certain snappers and groupers, jacks, king mackerel and hogfish. But where does the toxin come from, since these fish don’t produce it themselves? Tiny microalgae. In particular, this toxin is produced by a harmful dinoflagellate known as Gambierdiscus toxicus. When it grows, it often settles on reef structure and macroalgae where it is consumed by herbivores and small predators. Then these fish are consumed, and so on and so forth up the food chain. But the toxin is not harmful to the fish. So the large predators listed above contuinue to accumulate (a process known as bioaccumulation, also here, one of the reasons why you shouldn’t eat too much tuna or many other fish due to mercury) the toxin. Then, when humans eat those fish, they get extremely ill.
So I did some research on the itnerwebs about lionfish and ciguatera. Lionfish already produce their own toxin, present in their spines, but the thought was as long as they were processed carefully, that would not be harmful to humans. Surprisingly, there is little information about lionfish and ciguatera. There are a few posts from the Caribbean Oceanic Restoration and Education (CORE) Foundation in the USVI about lionfish with ciguatera, and how to proceed. Attached 5. Ciguatera is a .pdf from the Caribbean Epidemiology Centre about ciguatera cases in the Caribbean.
So its now out there and at least something to think about. There haven’t been many reported cases, but it might be worthy of investigation in the future. Obviously, lionfish present a considerable risk to the coral ecosystems they are invading, and so eradication must be considered. A simple way is to encourage locals to fish and eat them, and hopefully fish them out. However, if they might present a risk to human consumption, this idea needs to change. Research is warranted to resolve these issues.
The premise of the article states that scientists in New Zealand are using artificial seagrass to help boost fish stocks. Seagrass is an extremely vulnerable marine habitat, with worldwide losses. In some places where lush underwater meadows used to exist, the grass has been replaced by barren sediments. This can have an impact on fish stocks, as many marine species utilize seagrass as a habitat for at least some portion of their life cycle. So it comes as no surprise that scientists want to try to replenish fish stocks by enhancing seagrass. This is apparently what they are trying to do in a bay in New Zealand. Although, I imagine that the researchers are actually using ASUs to test affects of fragmentation on local fisheries species and not to actually be used to enhance species, it is interesting none-the-less.
I have a certain affinity for all things fake seagrass. Why? Well, a portion of my dissertation research involves using artificial seagrass units (ASUs) to investigate the impacts of patch size and shape (perimeter, area, and P:A ratios) has on scallop recruitment, survival and growth. As I mentioned already, seagrasses are important habitats, and bay scallops have long been known to associate with seagrass. Scallop populations are currently undergoing varying degrees of restoration (depending on location) but with restoration comes certain issues – namely, how are these little guys going to be affected by declining seagrass. In many areas where scallop populations crashed, seagrasses have also diminished in extent. Since seagrass is important for scallops, a decline in seagrass cover can have implications for scallops and their restoration. For my work, I use 2 sizes of seagrass mats, 8.5 and 17 square meters, and 2 shapes – a circle and 4 pointed star to maximize perimeter. Just in case those numbers don’t mean much to you, the small circles are just over 3 meters in diameter, the large circles around 5 meters across. The large star is 7 meters from tip to tip. These ASUs have 500 shoots per meter, consisting of 4 blades of polypropelene ribbon. It was quite the undertaking, and required many beer and pizza nights for fellow grad students, as well as help from local schools and scout troops.
I have generated some interesting, and unexpected, data. There is a wealth of literature out there about the impacts of fragmented seagrass habitats, patch configuration, edge effects, etc, that has been accumulating over the last 15 or so years. Going into the experiments, I had a pretty good idea about what I would expect to see – more scallop recruits along the edges of the mats, but higher predation at the edge. Growth to be slowest in the centers of the mats, etc. However, not everything happens the way I planned or anticipated. In particular, I have been working up some of my recruitment data, and I did not see a “settlement shadow” or edge effects due to predation. What is a “settlement shadow?” Essentially, bivalve larvae can be assumed to be passive particles, moving at the mercy of the currents. As a current comes into a seagrass meadow, the flow is attenuated. Particles settle out along the edge, and become diminished with distance into the meadow. Hence, recruitment is expected to be highest along the edges of seagrass meadows (and, also, the edges of my ASUs). On the opposite end of the spectrum, survival is expected to be the lowest along the edge, since predators are likely to have more access along the edges, and thus predator encounter with scallops should be higher. However, this isn’t what I saw. The reason? The dominant predator in my particular system is a small mud crab – not likely to be impeded by seagrass structure and essentially ubiquitous throughout the ASUs. This tells me the dominant process structuring post set scallop communities on my grass mats is predation, and the predator is apparently not impacted by fragmentation. This could have implications for restoration. I haven’t finished all the analysis yet, but it was pretty interesting. I just presented some of this work at a graduate symposium last week, and plan on presenting it again at the National Shellfish Association annual meeting in March.
Who would have thunk it? Another snowstorm. So far this one isn’t as bad, but according to NOAA, we could expect up to 7-13 inches total though tonight. Ugh! You know, I don’t mind the snow. It’s nice. An inch or two. You wake up and everything looks clean, but it doesn’t really affect driving or work. But no, for some reason, the climate decided to unleash her wintery fury on the Northeast. I’ve been out on Long Island for about 10 years, and typically, we don’t get much snow. Before the 2009-2010 winter, I only remember one big snowstorm. Last winter we had another one. This winter, this is the 4th! Four storms, some worse then others, but all with large amounts of accumulation. And now I am tired of it. I already talked about how much I’d rather be somewhere else. Honestly, this winter is really downright depressing. It’s starting to feel like the flight of the skajaquada out there (that’s right, I just referenced Green Jello!). I just can’t wait for spring to start!
So what’s the deal? In case you were wondering, NOAA does a good job of simply explaining winter storms and what to do if your caught in one (although I have a different idea – move somewhere without snow!) But there has been some theories thrown out there as to why we are experiencing harsh winters, and these are tied to Arctic sea ice cover (or lack thereof). Now I am not a climatologist, so I am not going to pretend to understand everything about the drivers of climate and weather. But one driver of our current weather pattern is the Arctic temperature anomaly, which is strongly negative this winter. This means that the Arctic is experiencing unusually high pressure and warmer temperatures, shifting the low pressure and lower temperatures to the mid latitudes (yep, thats us! Side note, if I am incorrectly interpreting the Arctic anomaly, please correct me). So this climate pattern is likely driving our local weather. One of the effects of a negative Arctic anomaly is less sea ice extent, and in December of 2010, Arctic sea ice cover was the lowest recorded since satellite imagery started in 1979.
The lack of sea ice could be what’s driving these weather patterns. According to a CBS/AP article, the cold air that is normally bonded in the Arctic is instead bringing that air to our mid-Atlantic region. The article suggests that there is a very strong connection between ice cover and winter temperatures – when the temperature warms, the ice melts. This exposes the dark ocean surface, which absorbs hear, further melting the ice and continuing on in a cycle. This sentiment has been echoed by many researchers and in many news publications. What is fairly clear is that a warming Arctic, with less sea ice, can impact temperatures on a regional scale and thus affect weather patterns. Snow cover in the northern hemisphere can be linked to Arctic ice extent. Remember weather and climate are different things. Weather is local atmospheric conditions on a short time scale, whereas climate is how those atmospheric conditions behave and change over long time periods. But by changing climate patterns, local weather can be affected, and thus despite an overall warming trend, some places could actually experience harsh winters. It is winter here. So it is cold. That doesn’t mean it’s cold everywhere, and it is no evidence that there is no climate change. And actually, this clip from the Daily Show I think puts it best (oh no, it’s dark and getting darker! this proves global darkening!):
Obviously, we are at a chicken and egg scenario here. What is causing what – is the negative Arctic anomaly causing the lack of sea ice, or is the lack of sea ice causing the negative Arctic anomaly? I’m not sure. But what I can say is that regardless, as global temperatures warm, the extent of Arctic sea ice will decrease. This warming of the Arctic can prevent the cold air from being bound in the region, forcing colder air father south, and impacting our winters. So when nay-sayers claim that global warming can’t be happening because we are getting all this snow, you can explain to them that A) that climate is long term patterns which are predictable, whereas weather is short term phenomena are not predictable and do not indicate any patterns or change and B) warmer Arctic oceans does actually mean more snow for us down here in the mid Atlantic and Northeast. Just because snowstorms happen in one region doesn’t negate climate change. Just because temperatures start to fall in the winter does not mean that on average, the mean global temperature isn’t increasing.
Think what you will about the tropical fish trade, but it introduces lots of children to science. How? In order to successfully maintain a fish tank, you need to understand about chemistry, biology and ecology. Even the most simple books talk about the nitrogen cycle, bacteria, different species, water quality requirements, food requirements, and how fish might interact with each other. Add in some of the plants (freshwater) and corals and macroalgae (marine) you have to start to balance nutrients and light into the equation as well.
I always had fish tanks, for as long as I remember. It is actually why I became interested in marine science in the first place. My dad always kept tanks, and then when I was old enough (aka, had a job that could support the hobby) I had my own tanks as well. What better place than to work at a tropical fish store! I got a lot of things at cost, accumulated a lot of equipment and knowledge. My father and I subscribed to magazines, had an extensive library, joined aquarium societies and attended meetings. In fact, my first aquatic conference ever was the American Cichlid Association conference. At our peak we had ~15 fish tanks. It drove my mom crazy so most of them were in the basement (along with one of those preformed ponds you buy at home depot, where we kept 5 turtles). My pride and joy was an eight foot long 180 gallon Lake Tanganyika cichlid tank. For 4 feet of the tank I had rocks piled to the surface, sloping down toward the center. At the opposite end, I had bare sand and shells. I had quite the community – a lot of your typical species, the brichardis and leleupis, the julies, many of which were constantly breeding. I had a colony of L. multifasciatus shell dwellers. Some L. tretocephalus. (Most of these fish used to be in the genus Lamprologus, hence the L, however, some of them have been removed. The hobby still uses Lamprologus to describe many of these fish) But the real specimens were a largish 7 line Frontosa and a mature Lamprologus tetracanthus with bright yellow speckles. I loved that tank. But I went to college, and obviously that wasn’t going into a dorm room. But we had lots of other tanks. And I’ve done it all. Marines. Reefs. Discus. Rainbowfish. Malawi cichlids. Guppies. South American. Asian. Planted tanks (with DIY CO2). I’ve bred fish. I loved it. But its a hard hobby to keep up in tough times. Its expensive, and when you start paying rent and living on a graduate student wage, you have to start to make choices. Now, I only have one 29 gallon fish tank, devoted to Tanganyikan cichlids, perhaps in an attempt to relive my glory days. But I digress.
Working at the store, I was able to select fish from the wholesalers, meet breeders, reorder stock, and just in general, learn about the operation of the business. One day I might run my own store, or wholesaler. Or I might work at an aquarium, since I liked the store so much. And it made me want to pursue something having to do with fish as a career. Originally I thought I would go to school, learn more about these animals, and aquaculture, and I would go do it myself. Cut out the middle man. Make millions (hahahaha boy was I delusional). So I chose a school that wasn’t terribly far from home that had a good marine science program – the now defunct Southampton College of LIU (long story short, LIU shut down the campus to save money, then the state of NY purchased it and it became part of Stony Brook, then due to budget restraints, Stony Brook-Southampton is now closed as well). So I came to school, met some great people, and learned to SCUBA dive my first winter. This was incredible. I couldn’t believe I was missing out. Then, through the school, I volunteered at the New York Aquarium. At the time, I thought that was a dream job. It wasn’t, but through no fault of the aquarium. I actually love the New York Aquarium. I just realized that I didn’t want to just feed and clean all the time. So I went diving again. Then I did an internship with the National Marine Fisheries Service, doing Hudson River fish trawl surveys. That was fun. I loved it, although, in retrospect, I wish I had done my own project. Then I spent a semester at sea, traveled to the South Pacific, and started working at the school’s marine station. Eventually I received a scholarship to stay for a summer and do research which involved diving and seagrass (hence Zostera), took a job doing diving work for the USGS in Florida and now am back in school for the past 5ish years.
The moral of the story? Keeping fish tanks got me started down this path. Obviously, everyone who keeps a fish tank doesn’t end up a scientist. But I do think they hold considerable value, regardless of your thoughts on the trade itself. And so when I read about the freezing temperatures in Florida, I don’t just get worried about the price of orange juice going up. I worry about the hundreds of tropical fish farms where many species you see in the local pet stores are bred and raised. This winter has been particularly harsh for them.
Over half of all the tropical fish sold in the US come from Florida farms (the other half come from Asia). Typically, these fish sell best in the winter, since people are home more often (back in school and work from summer vacations, longer nights, etc) and can pay more attention to their tanks. The industry generates a $45 million dollar economy for the Florida farms. At least it did. The recession has already slowed the aquarium hobby, and more and ore people are buying electronics than anything else. Don’t get me wrong, I have a lot of fun playing games on the Wii, but I would never choose a Wii over a fish tank. Maybe that’s my personal preference. But when I see these computer programs to run simulated fish tanks, like on Facebook, it drives me crazy. Just get one! It doesn’t have to be big, but its both fun and enriching. It is a learning experience. Anyway, the farmers are suffering the losses of millions of fish, which will hurt the already slowed industry. According to a NY Times article, “A severe guppy shortage has already emerged, according to distributors, while fish farmers statewide expect losses of more than 50 percent as African cichlids, marble mollies, danios and other cheerful-looking varieties sink like pebbles to the bottom of freshwater ponds across Florida.”
“It’s bad,” said David Boozer, executive director of the 120-member Florida Tropical Fish Farms Association. “We were hoping for an economic turnaround to pull us up by our bootstraps, and that may happen, but we certainly didn’t need 10 days of subnormal temperatures.” – NY Times
It tough times for farmers in general in Florida due to the freeze. But while tomatoes and oranges are more in the mainstream, not too many people think about fish farms. Most hobbyists pay no attention to where they come from, they just see them in the store and bring them home. But, I share a personal connection with these struggling fish farmers, and wanted to share. Hopefully things return to normal, damages can be minimized, and their ponds can be restocked. Hopefully they didn’t lose a considerable amount of business to the Asian market due to this weather pattern. I can’t imagine not having a fish tank, and am shocked at how few people now keep them. I encourage all of you to go ahead, get yourself a small set up. You will enjoy it! Here is a picture of my current fish tank (don’t mind the algae, I don’t!):
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!
Is a useful experimental tool to mimic natural seagrass while controlling many factors, such as density, canopy height, leaf number, which are usually confounding in natural eelgrass meadows.
Scallops seem to love this stuff!