Another plume

Researchers from USF have found what they believe to be a large, subsurface plume of oil. Six miles wide and as deep as 3,300 feet. This one is stretching toward the northwest, toward Mobile and Dauphin Island.

Grolar bears

A second hybrid bear has been killed on sea ice in the Northwest Territories. Tests have revealed that this one is a second-generation hybrid, the offspring of a female grizzly-polar bear hybrid and a male grizzly bear. It's believed that such hybrids will become more common as climate change forces grizzlies into more northern climates, and disappearing sea ice forces polar bears onto the mainland.

New species

Very cool stuff here. The Top 10 new species described in 2009 from the International Institute for Species Exploration at Arizona State. Three new fish species - the psychedelic frogfish, the dracula minnow, and Omar's banded knifefish. Can't make this up.

Cladoceran fashions

Nice look at a morphological response to predation pressure in Daphnia in Swedish lakes. Water fleas studied in the lakes in the Orekilsalven River basin show two very different types of responses. In lakes in the upper reaches of the system, female Daphnia have relatively large bodies topped by a fairly small "cap" (an anterior extension of the carapace). Those found further down the river system show reduced body size, but a larger cap.

Hans Lord from the Department of Zoology at University of Gothenburg thinks that the different morphologies are an indication of the ostracods response to a widening suite of predators. The larger cap makes the cladocerns harder for invertebrate predators to manipulate. Smaller body size, on the other hand, makes the animals less visible to sight-feeding fish. The cap, being transparent, gives protection against invertebrate predators without making them more visible to fish.

Male Daphnia don't show the same morphology - no cap. This is likely due to different selective pressures. Males need to be able to find females and mate quickly. A big cap gets in the way.

In females, the large caps are a summertime phenomenon. This could be the result of different types of predatory pressures with changing seasons, or it may refect the greater viscosity of cold water. Can't swim through thick water wearing a big hat.

Fish o' the Day - Gulf sturgeon

Watched an episode of "River Monsters" this afternoon that I had DVR'd while I was at the coast. Jeremy, breathless as always, was tracking down a lake monster in Alaska. After eliminating other possibilities, he decided to travel to the Columbia River to catch a white sturgeon to prove the identify of the Alaskan beast. OK, Jeremy's an entertainer, not a scientist. Still, his mention of the jumping Gulf sturgeon suggested tonight's FOD. Gulf sturgeon, Acipenser oxyrhynchus desotoi, are appearing in increasing numbers as they migrate up Gulf Coast rivers. It's become enough of an issue that the Florida Fish and Wildlife Conservation Commission recently issued an advisory suggesting that boaters slow down on the Suwannee River to avoid collisions with airborne sturgeon.

The Gulf sturgeon was recognized as a subspecies about 50 years ago. It's virtually indistinguishable from the Atlantic sturgeon (A. oxyrhynchus oxyrhynchus) - apparently you have to dissect them and measure the spleen. Gulf sturgeon are listed as threatened, with critical habitat including Florida's Suwannee, Apalachicola, Choctawhatchee, and Escambia Rivers, as well as the Pascagoula and Pearl Rivers in Mississippi. They're big fish, reaching 8 feet and 200 pounds. Gulf sturgeon are anadramous, spending part of the year coastal marine habitats and returning to rivers in spawning migrations. While in the Gulf, sturgeon apparently remain over seagrass beds or shallow muddy bottoms near shore. In the spring, they move upriver, spawning near the headwaters, and then spend the summer months in deep river water or near spring mouths. rs, returning to estuarine or gulf waters during the coolest months of the year. Sub-adult fish also participate in this migration. During the warm summer months, gulf sturgeon congregate in the deeper sandy and rocky bottom areas of rivers as well as near the mouths of springs. Interestingly, they seem to do most, if not all, of their feeding during the winter months when they are in coastal habitats. There, they feed on a variety of benthic animals including mollusks, crustaceans, and worms.

The reasons for jumping are unclear, although it's speculated that it may allow individuals to maintain contact with another. It's also been suggested that it may allow them to rid themselves of ectoparasites.

A brief video of a jumping Suwannee sturgeon....

A double dip of night music...

...and another history lesson. Jackson Browne then, and now. Actually, I had his hair in the 70s. Not any more.



Pretty sure I've used that line, too. "Don't confront me with me my failures..."

Time stops for no man. Do it now.

Can it get any more desperate?

They say that lessons learned at great expense are learned best. This one should stick with us a while. What say you, Ms. Palin?

BP's last shot?




Thanks to Adam Zyglis at The Buffalo News

School lessons

Schools of fish, that is. A major problem with the development of "wind farms" for the harvesting of wind energy is the availability of space. Traditional horizontal-axis turbines have big propellors and must be spaced far apart to avoid interference. Newer vertical-axis turbines use a vertical rotor and more may be placed in a smaller array. Graduate students at the California Institute of Technology have determined that the placement of such vertical turbines in specific arrays may yield significantly higher energy gains by taking advantage of the manner in which air moves through the array. Their model - schools of fish. The vortices created by fish moving in a school can be used to understand how one turbine may influence those around it. The Cal Tech researchers believe that the application of these principles may result in a ten-fold increase in the wind energy that can be generated from a given area.

New strategy

Sit in the sun, warm up your body, and drive the ladies mad. Well, it works for damselflies. New research in Behavioral Ecology and Sociobiology indicates that damselflies with warmer bodies have greater mating success. Female preference for the hot guys is apparently driven by the prospect of a warmer territory in which to lay eggs, leading to greater reproductive success.

Have to say...

...I'm asking the same question.

Why is BP still in charge?

Night music

Music has a unique ability to take you back to a certain time and place. This song certainly does. The memories have taken a beating, but the message still resonates.

Fishing strategies

Been reading/hearing Callum Roberts' An Unnatural History of the Sea, which documents the millenium-long history of our overexploitation of marine resources. Which makes this new paper in PNAS more intruiging. It suggests that we may be using the wrong model. The buzz-phrase these days is "ecosystem-based fisheries management", an approach designed to minimize the impact of fishing on marine ecosystems. The prevailing line of thought in such fisheries has been to employ highly selective methods that remove only certain species of specific sizes. The new work from a group of authors led by Shijie Zhou of CSIRO suggests that less selective methods might actually have lower impact. Zhou suggests that "production could actually increase through the better use of non-target species, while reducing unsustainably high catches of target species...".

More hammerheads

Currently, the hammerhead sharks are represented by eight (or nine, depends on who you listen to) species in the Family Sphyrnidae. Although all of them have the characteristic "cepahalofoil", the distinctive, flattened head from which the group draws its name, they show a lot of diversity in both size and in the shape of the head. The bonnethead (Sphyrna tiburo) reaches lengths of about a meter and has a fairly narrow, spade-shaped cephalofoil. The great hammerhead (Sphyrna mokarran), on the other end of the spectrum, sports the classic "hammer" and can reach 6 meters in length. New research appearing in Molecular Phylogenetics and Systematics describes work done by researchers at the University of Colorado and the University of South Florida employing DNA analysis to analyze the family tree of the hammerheads. The researchers used both mitochondrial (4 genes) and nuclear DNA (3 genes) in their examination of the evolutionary history of the group. They discovered that the ancestral hammerhead appeared relatively suddenly some 20 million years ago. It was a big fish, comparable to the larger of the living species. Small size apparently evolved twice in the development of today's smaller sharks. The cepahalofoil has been strongly acted upon by natural selection to create divergence in the lineages leading to modern hammerheads.

Fish o' the Day - Southern stingray

It's proving difficult to get back into a routine. Lots of news items sitting here on my desk, but still feeling residual laziness. Not gonna worry about it too much - summer semester will be here soon enough. For now, the return of FOD.

Spent quite a bit of time wade-fishing Santa Rosa Sound last week, and saw plenty of stingrays. They're almost like alligators in the Everglades - very impressive to see such a high density of a large predator. Dasyatis americana is widely distributed through the tropical and temperate Atlantic and in the Gulf and the Caribbean. They can be big, reaching a "wingspan" of as much as 6 feet. A really big one may push 200 pounds in weight. Their claim to fame, of course, is the "sting" or barb, which is a modified denticle found about a third of the way down the long, whip-like tail. Grooves on the barb carry a proteinaceous poison which can certainly cause some problems for someone unfortunate enough to be "stung." It's rare, however, as stingrays will usually do whatever they can to avoid a confrontation. The most dangerous situation occurs when a wader or snorkeler steps on or swims over a partially buried stingray in shallow water. The toxin can be partially denatured by hot water, and this is a fairly effective first aid prior to a visit to the doctor.

Southern stingrays feed primarily on crabs and mollusks, although they'll take an occasional small fish if they can get one. They're ovoviviparous, meaning that they give birth to live young. After the smaller male impregnates the female, the eggs hatch out internally. The female then gives birth to five or so young rays.

On Monday, I kept an eye on a good-sized ray, perhaps three feet across, that shared with me the sandy edge of a Santa Rosa Sound seagrass bed in about two feet of water. I assume she was keeping an eye on me as well, and eventually she took flight into the deeper waters of the Sound.

OK, back at it...

...after a much-needed break with a very unique, very special family. Plan to crash tonight, and then start doing some catching up tomorrow.

I confess to complete confusion regarding the Deepwater Horizon mess. The Florida panhandle, as of today, has yet to see landfall. But there's a tremendous amount of oil out there, and it going to wind up on someone's marshes, beaches, reefs, etc. Right now, we're in that nasty mode of thinking - send it somewhere else. We see the same line of thought with hurricanes, at least since the devastation of the last decade reminded Gulf Coast residents that a hurricane is not a reason to party. This spill is different - there's a sense of dread all up and down the coast, and we'll no doubt all suffer. I'm currently thinking about my friends in the Keys who are dependent on healthy reefs. It appears likely that the Florida Loop Current will take a significant amount of oil their way. There are few ecological systems more fragile. I guess it's appropriate to say, "Hope for the best." I'm just not sure what the best is right now.

There were a few unusual aspects of beach life this week, but I want to do a little background work before getting into them.

See you tomorrow.

Southbound

We'll be headed for the coast in the morning. Not sure how much you'll see of me for the next week or so. I expect I'll be checking in, especially if something interesting comes up. At the very least, I should be able to provide an update on the situation down there. But, I need some time off. Those of you that have been up close and personal the last few months know that.

I'll leave you with Bon Iver, and a tip o' the hat to Chris. Have a good break - see you soon.

Fish o' the Day - Dunkleosteus

Our first no-longer-with-us-FOD. Dunkleosteus terrelli was a placoderm, an armored group that were among the first groups of jawed fishes, and lived some 370 million years ago during the latter part of the Devonian period. His claim to fame is his size - Dunkleosteus could reach 30 feet in length and weigh upward of three tons. They're best known for their bony skulls and blade-like jaws - we don't really have a good idea what the rear of the fish might have looked like, and have extrapolated from similar species. Dunkleosteus had no teeth, but employed the beak-like plates on the jaw to slice and dice its prey. A detailed analysis of jaw structure reveals that they may have had one of the most powerful bites of any predator that ever lived. When Dunkleosteus opened its mouth, the upper jaw lifted and the lower jaw simultaneously dropped - unusual among jawed vertebrates. When the jaws slammed shut, they delivered a force of perhaps 8,000 pounds per square inch. Great white sharks and some of the alligators generate similar forces among living animals.

Dunkleosteus, clearly a top predator, apparently prowled inshore waters in search of food. It's unclear whether they also cruised the open ocean.

Now, for some completely inaudible commentary...

Fish trails

The Green River formation is famous for its fossil fish, which lived some 50 million years ago in what is now known as Fossil Lake. The site, now part of Fossil Butte National Monument in Wyoming, has yielded a rich and diverse group of Eocene fish, including Notegoneus osculus. That's him at left. Now, Emory paleontologist Tony Martin has interpreted trace fossils in the ancient lake bed to see into the past.

Martin's specialty is ichnology, that branch of geology/paleontology that deals with the traces left by organisms. While neoichnologists might interpret tracks or burrows to understand behavior of living organisms, paleoichnologists do them one better. They examine the fossilized evidence of past behavior and use it to add to our understanding of the biology of long-dead species.

Martin and his co-workers employed high-resolution digital images and mathematical analyses to determine that the traces left on the deep bottom of Fossil Lake were likely produced by an 18 inch N. osculus as is used the fins on the posterior part of its body to wriggle across the bottom and employ its subterminal mouth to feed on benthic organisms.

Martin actually visited Small Southern a couple of years ago. One of my colleagues has collaborated with him on many projects, and was able to persuade him to present a seminar for our students. As good a guy as he is a scientist.

Fish o' the Day - electric eel

Not really an eel, but a member of the knifefishes (Order Gymnotiformes), Electrophorus electricus is certainly one of the more impressive fish you could hope to see. Reaching six feet in length and weighing up to 40 pounds, the electric eel inhabits rivers and creeks in South American river basins like the Amazon and the Orinoco. They're obligate air-breathers, with a heavily vascularized mouth lining that acts as a lung. They get as much as 80% of their oxygen from the atmosphere, and must come to the surface to gulp air every ten minutes or so. They generate electricity using three pairs of abdominal organs that make up about 80% of their body mass. Electrophorus actually produces two different types of electrical impulses. High voltage blasts, generated by stacks of thousands of electroplaques, may be of 500 volts and generate a current of about an amp. Low voltage pulses, generated by the Sach's organ, are used primarily for electrolocation. There is some ability to control the intensity of the impulse, employing lower voltages for hunting while saving the really powerful blasts for when needed. They've got a lot of energy in reserve, and are capable of producing intermittent shocks for periods of over an hour.

Little known fact - the male electric eel may use saliva to make a nest, into which the female may place almost 20,000 eggs.

Good video here...

It's Commencement Day

With a head full of doubt, and a road full of promise...


decide what to be and go be it.

Good luck, guys.