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.

For the smell of it

Some interesting interdisciplinary work going on at the University of Bath to investigate the sense of smell in hammerhead sharks. Chemist Jonathan Cox is collaborating with fluid mechanics experts to examine the way in which the unique head structure of the sharks facilitates water flow through their nasal passages. CT scans of museum specimens were used to design a model of the head and nasal chambers. The model was then used in in a flow chamber to investigate the manner in which olfactory information is collected as the shark moves through the water.

So...

...who's seen this? I mean the off-Broadway show, The Rap Guide to Evolution by Baba Brinkman. It is, apparently, the real deal.

They're still fishing on the Gulf Coast

Spoke with a former student and friend who operates two charter boats out of Orange Beach. I had left him a message last week inquiring about setting up a possible fishing trip during our beach stay next week, and actually felt a little guilty when the severity of the oil spill disaster became more clear. As of now, however, the slick is being held off the Florida coast by a friendly northerly wind. Boats are still fishing - apparently a lot of cobia being taken. Artificial reef fishing is still yielding red snapper - catch and release only. Two future FODs.

Anyway, the fam may be able to make a fishing trip. At least until the wind changes.

Great Carrier Reef

As of now, the world's largest artificial reef is still free of oil. The USS Oriskany, a 1950s-era carrier, was scuttled off Pensacola in 2006 in about 200 feet of water. It has provided a unique dive site, with the upper platform reaching 70 feet below the surface and the main deck at about 130 feet. As of now, the oil is still some 90 miles away from the site. Hoping the winds stay favorable - but it's almost surely just a matter of time.

Fish o' the Day - goosefish

A friend and former colleague (Hi, Don) asked today whether I had done an FOD on the anglers. There's apparently an article on them in the new Discover magazine, which I'll have to check out. Actually, the anglers include a pretty wide variety of fish belonging to almost 20 families. The sargassumfish, which we discussed a few weeks ago, is in the Family Antennariidae, while the really funky deep-sea guys belong to a variety of families in the Superfamily Ceratoidea. We'll get to them eventually. Tonight, let's talk about a little more user-friendly angler - one you might have dined on.

The goosefish, Lophius americanus is also sometimes known as the American angler. It's found in the Atlantic off the American coast, in depths ranging from just a few feet to over 1000. They can be large, up to 4 feet and 50 pounds. They're eye-catchers too, dorsoventrally flattened with a very broad head and a big mouth equipped with sharp, rearward-directed teeth. The first dorsal ray is modified into a lure, as is often the case in the anglers. The pectoral fins are modified into leg-like extensions that help them crawl along the bottom.

It's harvested for its flesh, which is sweet and white, not unlike lobster. Just don't tell people what they're eating.

The lure in action? Here you go...

Someone let the fences go...

...here at Small Southern and we do, in fact, need a gunslinger. But for now, I'm hanging up my shooting irons. Somebody else can fight the bad guys for a while.



But there's always tomorrow.

Fishing

Hope to do some of the recreational variety next week, if I can find oil-free waters. This is about the commercial variety, though. New research appearning in Nature Communications and summarized at Science Daily indicates that the decline of oceanic fish stocks may be even more severe than we thought. So much so, in fact, that today's British trawl-fishing fleet must expend 17 times the effort to catch the same tonnage of fish than the sail-powered fleet of the 1880s. The greatest decline has been in halibut, although haddock, plaice, cod, and other have also shown dramatic falls.

Just in time for the download of my new IPod companion. I'll be "reading" Callum Roberts' The Unnatural History of the Sea, which deals with our long history of overuse of marine resources. So, expect updates.

So, who's the kid with the prominent brow ridge?

A new study in Science details the results of a draft of the Neanderthal genome, based on DNA extracted from 40,000 year old bones found in Croatia. The results indicate a strong possibility that Homo sapiens may have interbred with Neanderthals after departing Africa, perhaps 80,000 years ago.

Fish o' the Day - ladyfish

Return of FOD.

As we prepare for some time on a threatened coast, I'll focus on one of the more obvious fish species that tourists see off Gulf beaches. The ladyfish, Elops saurus, is one of several species in the Familiy Elopidae, and they're found throughout coastal waters of the temperate and tropical Western Atlantic. In fact, they don't handle cold weather well at all and have been reported as a component of cold-water fish kills. The long, slender body is silvery and covered with tiny cycloid scales. Their large, terminal mouth is equipped with a nice set of sharp teeth. E. saurus are sometimes referred to as ten-pounders (thought that's a giant) or (mistakenly) as skipjack. A more common size is a couple of feet in length, and a couple of pounds. They move up and down Gulf beaches like those on Santa Rosa Island in large schools, feeding voraciously on schools of baitfish. They can provide good sport if you can get into a feeding frenzy with some light spinning tackle or a fly rod.

The elopids are close relatives of tarpon and bonefish, and share with them the eel-like leptocephalus larva. After offshore spawning, the larvae apparently move into estuaries to develop.