Seagliders

They're unmanned submersibles that can be equipped with a variety of sensing devices, and they're being deployed in the Gulf to determine whether there are, in fact, vast underwater plumes of oil. Preliminary evidences says there are.

A nice resource...

...from the NY Times.

Tracking the spill

Fish o' the Day - Gulf kingfish

Another Gulf coaster, this one closely associated with sandy beaches. The Gulf kingfish, Menticirrhus littoralis, known commonly along the coast as "whiting", is one of the more common fish in the surf zone on Gulf beaches. Like the spotted seatrout, it's a member of the Family Sciaenidae, the drums. Whiting reach lengths of about 18", and typically weigh a pound or two. There are a couple of other kingfish species that share the same geographic range - the southern kingfish (M. americanus) and the northern kingfish (M. saxatilis) have dark markings on the bodies, while M. littoralis tends to be uniformly silver, with some darker pigmentation on the rear of the caudal fin. All have a single chin barbel. M. littoralis is fond of high energy beaches, while its congeners like calmer areas with softer bottoms.

Whiting apparently spawn offshore in the spring, after which the young fish recruit to the surf zone. They're benthic feeders, taking worms, small bivalves, and other invertebrates. They're a popular fish for surf casters, and one of your most likely catches if you simply take a rod and reel, bait up with a piece of frozen shrimp, and toss it beyond the breakers. That is, if you can avoid all the hardhead catfish long enough for a whiting to find it.

Positive side effects?

Sometimes, all you can do is laugh...

Night music, and the Great American Novel

What's your candidate? I'm sure everyone has their own horse in this race, depending on histories and tastes. My personal list these days has three entries - Moby Dick by Herman Melville, Blood Meridian by Cormac McCarthy, and Shadow Country by Peter Matthiessen. Moby Dick is, of course, a pretty traditional choice. Like most, I was forced to read it in high school. Unlike most, I loved it. I mean, it's about whales. Shadow Country is a recent addition. I read and enjoyed the three books that were blended to form it (Killing Mister Watson being the best known), but the combined, trimmed-down version is, I believe, Matthiessen's masterpiece. The caveat - it deals with the part of the world I love. Again, I'm biased. So, two of my choices must be taken with a grain of salt.

That leaves Cormac McCarthy's brutal masterpiece, which tells the story of the bloodthirsty Glanton gang's forays into Mexico in pursuit of Apache scalps. Quite frankly, Western's aren't my thing - I'm not that guy that seeks out old reruns of Rawhide and has DVD collections of Pale Rider and The Outlaw Josey Wales. Still, I've never read anything as powerful. As American, with all the good and bad things that implies. And Judge Holden is, in my mind, the single most powerful figure in American literature - the only one that compares is Ahab himself. Caution - it's not for the faint-hearted.

So, it pleases me that the lead singer (Ben Nichols) of a favorite band (Lucero) released a solo album built around Blood Meridian. It was an ambitious undertaking, but I think he pulled it off. Here's the opening track.

So, do we believe this?

BP says that the new cap they've placed on their leaking wellhead is capturing 1,000 or so barrels of oil a day. That's a fairly small fraction of the estimated 10,000 - 20,000 barrels thought to be escaping, but the BP officials think that the percentage capture will go up as they close additional vents. The vent closure will be conducted in a way as to minimize the formation of hydrates which would interfere with the operation of the cap.

Here's an animation from BP that explains how the process is supposed to work. Let's just say, I'm not confident.

How to be attacked by a shark

The beaches of Florida's Volusia County, particularly the stretch in and around Daytona Beach and New Smyrna Beach, are fairly infamous for the number of shark attacks that occur there. The vast majority are fairly inconsequential, although lethal attacks are certainly not unheard of. The Florida Museum of Natural History at the University of Florida maintains the International Shark Attack File in which they track shark attack records. Here you can see their compilation of Florida's 629 confirmed, unprovoked shark attacks between 1882 and 2009. Volusia County boasts 239 attacks, more than double the runner-up (which happens to be Brevard County, just to the south of Volusia). It's worth noting that none of the Volusia attacks have been lethal. In fact, only 13 of the total 639 have resulted in fatalities. The reason is that most of the sharks involved, and, in fact, most of the sharks found in nearshore waters are smaller species like spinners, blacktips, blacknoses, etc. You'll get the occasional tiger or bull, but they're few and far between. Still, shark attacks are a serious thing in Florida, where everything depends on tourism and tourism depends on water. And going in the water depends on, well, you know.

So, a group of researchers at UF combined the shark attack statistics with observational data gathered by staking out Volusia County beaches. The goal was to attempt to determine what factors play a role in shark attacks - what is it that makes people victims.

That's a great idea, and I certainly wouldn't put down research of this type. But let's cut through some of the chaff. We find out that most of the attacks are on young, white males, who are attacked most commonly on their legs. And most attacks occur on the weekend. I hope there's a little more analysis coming here. Because, thus far, you've told me that you've got a better chance of being attacked if you go in the water than if you don't.

There's more information, of course, and some of it has value. Attacks are more common in early morning and late afternoon than at mid-day. That may also reflect greater utilization by surfers as a result of higher waves, but it could also tell us something about activity patterns of the fish. Attacks are more likely at new moon and full moon. That could, again, be related to wave patterns and therefore surfing activity. More likely, it has to do with shark activity. Perhaps most intriguing, people wearing black and white swimsuits are attacked more than those wearing other combinations. Now, I haven't looked closely enough to judge whether there are simply more people wearing black and white swimsuits. I don't think that's the case. If it's not, then it suggests that the resulting contrast may make the victim more visible. That's a little troubling, when the prevailing argument for shark attacks in one of mistaken identity.

So, if the idea of being shark bait doesn't appeal to you, put on your green swimsuit and swim on the quarter moon in the middle of the day. And don't be a young white male. Otherwise, you're on your own.

Fish o' the Day - Florida pompano

Another coastal fish that will be seeing some hurt in the coming months. If you've spent much time on Gulf beaches, you've doubtless had juvenile pompano nibbing around your toes. Trachinotus carolinus is a jack, in the Family Carangidae. It's deep-bodied form is different from many of the jacks, which tend to be a bit more streamlined. Pompano also lack the scutes (specialized scales) on the caudal peduncle (the region where the body tapers into the tail) that that are found on most jacks. They're silvery in color, often with a greenish tint on the dorsal surface that trends to yellowish below. They're fond of warmer waters, ranging throughout the Gulf and along the Atlantic Coast from Brazil to Massachusetts. Their occurrence at higher latitudes is a summertime phenomenon. Pompano begin spawning in the Gulf in early spring, and the young individuals start showing up on sandy beaches in April and May. Late in the fall, the fish will move out into deeper water. The juveniles feed on small invertebrates, like amphipods, copepods, and larval forms of other crustaceans. As they grow, they begin feeding on larger inverts like mole crabs and coquina. Although they can reach lengths of almost two feet and weights of 8 pounds, a 2-3 pound pompano is a nice one.

Pompano grow rapidly, reaching lengths of about 8" in a year. They mature rapidly, at a year or two, and their entire lifespan is only 3-4 years. This attribute, coupled with their tolerance of a wide range of environmental conditions, has made them an attractive candidate for aquaculture. These prospects are being investigated in a number of locations, notably at Mote Marine Lab.

Of course, pompano aquaculture wouldn't have much of a future if it weren't for the fact that they're an excellent food fish. They're the hero of a lot of dishes, the most notable probably being the Pompano en Papillote made famous at Antoine's in New Orleans. While we'll admit to eating a few, we like them when they're still in the water too.

How not to stop the leak.

Let me count the ways.

From the coast...

Some CNN videos detailing various aspects of the disaster.

Something that BP would probably rather not think about...



And, from Acme Oyster House...



The president says he's furious. I think it's time to let a little of that fury show.

And the Florida coastline

We had discussed a camping/fishing trip to Big Lagoon State Park - an attempt to get one last coast trip in prior to everything changing. It appears that we may have waited too long.

Florida

Those of you that have been reading SKTS for a while know that the content is largely driven by the classes that I'm teaching at the time. Thus far, there's been a lot of fish (that'll continue), a lot of evolutionary biology (ditto), with liberal doses of conservation biology, vertebrate zoology and assorted other items. This fall, I'll be offering my class in Subtropical Ecology, where my intrepid band of explorers and I investigate habitats around the state of Florida, ranging from longleaf pine forests and pitcher plant bogs in the north to mangrove forests and coral reefs in the Florida Keys. So, that content will be coming. Here's an early offering.

Florida is characterized by a series of ridges, like the Trail Ridge, that run from north to south down the peninsula. These ridges bear abundant marine fossils in their sandy deposits. A new study out of Gainesville indicates that the marine nature of these elevated ridges results from isostatic rise of the land, rather than elevated sea levels. The peninsula, and its ridges, have risen as the result of the lowered density of crust deposits as acidic waters dissolve some of the limestone making them up. As the crust lightens, it's lifted by the mantle beneath. That's till going on, at a rate of about .05 mm per year. Unfortunately, that's not enough of an increase to keep up with rising sea levels, estimated at about 3 mm per year. Enjoy your waterfront property while you can.

A very, very old river

It's not really biology, but it's certainly related. Plus, I'm fascinated by rivers and I don't think I'm alone in that. Anyway, new mineral analyses reveal China's Yangtze River to be 45 million years old, about 40 million years older than had been previously thought.

That motivates me to do a little looking into the Yangtze's fish fauna. I don't know that much about it, with the exception of the almost mythical Chinese paddlefish - which might well be extinct. Future FOD.

How many species?

A basic question, for which we still don't have a good answer. Lately, we've seen numbers like 30 million thrown around routinely as a possibility. A new study appearing in American Naturalist suggests the number is likely considerably lower than that. The sticking point is in our knowledge of tropical arthropods, which without question make up the lion's share of remaining, undescribed species. Previous studies have suggested that there might be tens of millions of unknown insect species in the tropics. The new study, led by Andrew Hamilton from the University of Melbourne, uses applied probability modeling to estimate, to estimate that there is a 90% likelihood that there are between 2 and 7 million tropical arthropods, with the estimate centering at 3.7 million. After throwing in reasonable estimates for undescribed species in other groups (and ignoring the bacteria, which are something of a taxonomic black hole right now), they come up with a best estimate of about 5.5 million species on the planet. That's a heckuva lot less than most of the estimates we've seen over the last couple of decades. The new estimate still means, however, that some 70% of arthropods remain unknown.

Whale evolution

Just how fast was the early evolution of whales? The diversity of the group is fairly remarkable - almost 100 existing species of a wide range of sizes and filling a range of niches. A great many fossil species that have come and gone. All living forms are descended from a common ancestor that lived relatively recently, about 35 million years ago. The perception is that whales must have hit on a big new idea, evolutionarily speaking, that triggered an evolutionary explosion. Is that actually the case? A new paper coming out of UCLA and appearing online at Proceedings of the Royal Society B explores this question.

Employing a variety of computational and molecular techniques, the researchers demonstrate that whales, early in their evolution, had begun to diverge along different lines. This is clear from an examination of the size and trophic habits of early whales. Early on, small whales feeding on fish, moderately-sized whales feeding on squid, and large, plankton-feeding whales were already present 25 million years ago, and that triumvirate of whale niches exists largely unchanged today. There are exceptions, of course, Killer whales, somewhat unique in their preference for feeding on other mammals, have only evolved their large size within the last 10 million years or so.

Fish o' the Day - spotted seatrout

With the oil beginning to wash up on the shores of Dauphin Island, and friends and students reporting a slick less than 10 miles off the Pensacola beaches, it seems appropriate to spend a couple of FODs paying tribute to some of the great fish of the Gulf Coast. Quite honestly, fish have always been a big part of the coast experience. I'm afraid that won't the the same for a while.

A long time ago (about 35 years ago, if you must know), my friends and I spent a few remarkable summers wade-fishing the seagrass beds of Santa Rosa Sound in search of spotted seatrout, or "specks", as everyone along the coast knows them. The first day that I stumbled on our "honey-hole", I waded out in waist deep water and started casting a top-water lure over a dense Thalassia bed. About ten casts later, I was landing a gator speck that would have pushed 10 pounds. Through that summer and the next, we caught a lot of really beautiful fish. Then, very suddenly it seemed, they were gone. Hours of fishing would produce only a couple of smallish fish. We blamed the gill-netters that had descended on the same waters in numbers, and there was probably some truth to that argument. Certainly, the fish seemed to have made a bit of a comeback since Florida's ban on gill-netting passed in 1994. Now this. I fear they'll be a long time coming back.

The spotted seatrout, Cynoscion nebulosus, is not a trout at all, but a member of the Family Sciaenidae. That's the drums, the family that contains the redfish and the Atlantic croaker. They're sleaker and more streamlined than most of the drums, actually bearing a superficial resemblance to the trout and salmon. One of their most distinctive features is the pair of large, canine teeth at the front of the upper jaw. The body is silvery, with many small dark spots over over the upper part of the back and extending onto the fins. Unlike many of the drums, there are no chin barbels. They can reach lengths of 3 feet weigh and can weigh over 15 pounds, but a 3-pound speck is a nice one. Juveniles feed primarily on small crustaceans, while the adults take small fish and shrimp.

Seatrout reach maturity from 1-4 years of age, depending on sex and location, and spawn in coastal waters and estuaries. They're a classic example of a fish that depends on estuaries, seagrass meadows, and salt marshes as nursery habitats. They're reasonably tolerant of a wide range of environmental conditions - I guess we're about to find out how tolerant they are of oil.

Dino buddy

The first dinosaurs appear in the fossil record about 230 million years ago, showing up in South America and Madagascar fauna around the same time. They coexisted with a number of other reptile groups for perhaps 30 million years before rising to dominance at the close of the Triassic Period about 200 million years.

Among the reptilian groups that bumped shoulders with the budding dinosaurs during this time were the aetosaurs, a group of Triassic herbivores armored with heavy bony plates. The early aetosaurs were fairly small - less than a meter - but some of the later forms got quite large. They included Typothorax, which has been known from fragmentary New Mexico fossils for over 100 years. A new paper in the Journal of Vertebrate Paleontology (summarized here at Science Daily) describes two new, very complete fossils that have shed new light on this animal, one of the last of the large herbivores that existed prior to the rise of the dinosaurs.

The new specimens, representing a species known as Typothorax coccinarum, reveal an animal about 2.5 meters in length, half that of the largest aetosaurs. They were completely encased in bony armor, even down to the overlapping plates that ran down the legs onto the feet. They were quadrupeds, but the front half of the body was considerably lighter and more delicate than the rear. The front legs splayed out to the side of the body, while the hind legs were held beneath the body pillar-like. Their anatomy suggests that might have fed by grubbing in the soil in much the same fashion as modern-day armadillos. In fact, Dr. Andy Heckert, one of the study's authors suggests that T. coccinarum looks like an animal "designed by a committee combining a cow with a crocodile and an armadillo."

Fish o' the Day - bluegill

How mundane is that? Bluegill? Still, I'm always surprised at the number of people that been familiar with this fish since they were kids, but still know relatively little about it. In fact, a significant percentage don't even know that it's a bluegill.

Round these parts, people regularly go "brim" fishing (actually, they go brim fishin', if you want to know the truth). You might occasionally find someone who spells it "bream" - might even be a little uppity about it. You'll even find quite a few folks who refer to them as perch, although perch are in a completely different family.

Why all the confusion? It's probably attributable to the diversity of the group to which they belong, a little heritage, and a little laziness on the part of the general public. Bluegill are in the Family Centrarchidae, one of 18 centrarchids in Alabama alone. Of those, 11 are considered to be "sunfish" the relatively small, deep-bodied members of the genera Lepomis and Ambloplites. Back in the day, a trip to the creek with your cane pool and a can of worms might yield several species that looked enough alike to be all lumped together as "brim". This term likely owes its origins to a group of European cyprinids belonging to the genus Abramis and known colloquially as bream, to which the sunfish bear a superficial resemblance. It's likely that settlers in the American South simply christened the fish they caught in their streams and rivers with a familiar moniker.

Nominal confusion aside, the bluegill (Lepomis macrochirus) is quite a fish. It's the sunfish of choice, the one that is typically stocked in ponds and lakes, and, probably, the first fish caught in the lifetime of most Americans. That's a pretty significant honor, fishly speaking. They're native to most of the eastern U.S., and have been widely transplanted. The common name comes from a characteristic blue edging on the gill rakers. The species epithet, macrochirus, means "large hand", and is probably a reference to their characteristic size. In fact, bluegill anglers often refer to bringing home a string of "hand-sized" fish. They get larger - the world record, taken from an Alabama lake, is close to 5 pounds.

Bluegill have figured heavily in some significant ecological research, including optimal foraging studies examining prey utilization. Small individuals are usually plankton-feeders, filtering small prey from the water using long, delicate gill rakers. As the fish mature, they move to a diet of insects and their larvae. And, of course, they're fond of worms.

Forgotten?

So, what about the non-commercial species in the Gulf? Well, don't be surprised if they slip through the cracks of this nightmare. A case in point...

The largetooth sawfish, Pristis perotteti, native to the tropical Atlantic, was known from the northwestern Gulf but has not been encountered there in years. In May, just a few weeks after the Deepwater Horizon disaster, P. perotteti was proposed for federal endangered species status, a protection already afforded to its sister species, the smalltooth sawfish (P. pectinata). The smalltooth sawfish remaining in the U.S. are confined largely to coastal waters of the lower peninsula of Florida.

Given the benthic nature of sawfish and their dependence on crustaceans and mollusks, they will doubtless suffer a heavy blow as oil impacts coastal estuaries.

On a related front...

...NOAA has added Gulf waters showing areas of oil sheen to those previously closed to fishing. This brings the total closed area to 60,683 square miles, about 25% of the federal waters in the Gulf of Mexico.

And, if you're a fisherman and would like to contact BP regarding a claim - DIAL 1-800-440-0858.

Next...

After the well-publicized failure of top-kill, BP has a whole 'nother idea. Now we can all sleep soundly.

Their crack response team of Larry, Curly, and Moe now plan to attack the leak on three fronts. First, after pumping some 30,000 barrels of mud into the well in an attempt to block the flow of oil, BP engineers will reverse the approach. They will use equipment and pipes already present, but will instead try to carry the oil to surface and capture it. In addition, plans are underway to saw through the pipe below failed blow-out preventer (BOP) to allow the installation of a cap that will sit atop the BOP and direct oil into a pipe to the surface. Finally, BP is moving forward with the last-resort solution of relief wells that will reduce pressure at the wellhead and allow the installation of an additional BOP on top of the first.

BP is "confident it will succeed." So, there you go - nothing to worry about.

Tale of two tuna

A new paper appearing at PLoS One compares the spawning habitat of bluefin and yellowfin tuna in the Gulf of Mexico, and finds bluefins to have much more specific requirements than their yellow-finned cousins. Researchers used accidental bycatch reports as well as tracking data to determine that bluefin move into the Gulf in the spring months and seek out specific areas - notably continental slope regions in both the northeastern and northwestern Gulf. Yellowfin, on the other hand, are present in the Gulf throughout the year and show much more generalized habitat preferences.

There's bad news here for bluefin. The species is already in trouble - they were considered for endangered status this Spring. The region of the Gulf that they seek out, right about this time of year, also happens to be the region impacted by the Deepwater Horizon spill.

Break's over

Classes start on Tuesday for what will be a hectic summer session. So, I'll be back to a routine and should be posting more regularly. Good break with some time for family, and some time to recharge. Now, it's time to go back to work.