December 21, 2006

A Stacked Deck: The Ecology of the Blue Crab

To put it mildly, the cards are stacked against the blue crab population in the Chesapeake Bay area. In the past 60 years, the human population of the area has jumped from 3.7 million to almost 18 million and, subsequently, farming and industry has exploded (it is often joked that everyone on the eastern shore of Maryland is a chicken farmer), leading to waterways filled with ferrous compounds, nitrates and phosphates.

Essentially, the Chesapeake has become a sink for these pollutants running through 141 streams and five rivers from six states—New York, Delaware, Pennsylvania, Maryland, Virginia and West Virginia. Only one percent of the pollution actually make it into the Atlantic Ocean. There are vast regions of the Chesapeake dubbed “dead zones” for the high levels of oxygen depletion; often these sections are completely devoid of oxygen.

The blue crab, like most decapods, has a multiple larval stages, including the four to seven stage zoea, the megalops, and followed by several stages of juvenile. Once fertilized, the female travels out of the bay, seeking shallower waters with high salinity content. The female dies after depositing her offspring, leaving them to live a largely planktonic lifestyle at the top of the water column, until they have reached the juvenile stage and can return to the waters of the Bay.

As you can see, the life cycle of these creatures is already very delicate. But pollution is only half the problem.

Along the coast of Georgia, scientists have found that blue crabs are being parasitized by a dinoflagellate called Hemotodinium perezi. While not all of them are infectious, dinoflagellates are phylogenetically related to the disease causing apicomplexans and are most well known for toxic blooms like red tides.

Crustacean “blood” is called hemolymph, so named for their lack of separate circulatory systems of mammals. The parasite breaks down these hemolymph cells by consuming hemocyanin, the protein responsible for oxygen transport in crustaceans (analogous to our hemoglobin). H. perezi essentially suffocates its host by limiting the distribution of oxygen through the crab.

This factor, coupled with the oxygen depleted “dead zones” caused by warmer waters and eutrophication could spell disaster for the blue crab population in the Chesapeake Bay. Keep in mind that all of these factors, including the infection, are human induced. Any change in an organism’s habitat can cause unforeseen consequences.

The Chesapeake Bay Program has reestablished some of the estuarine ecosystem, reducing phosphates by 27 percent and nitrates by 16 percent, but the human population of the area continues to increase.

Next semester (my last!) I’m hoping to get more info on research being done to conserve the area’s wildlife, including the blue crab. I know for sure that UMCES is looking closer at the specific processes that drive the crabs from lower estuarine areas to the bay itself and hoping that this research will present conservation alternatives.

I have a feeling that the area needs more voices defending the Chesapeake. As much as I love seeing “Save the Bay” bumper stickers on SUVs, it takes more than a sticker to get anything done.

The Evolution of Crab Balls

The University of Maryland Center for Environmental Science recently published an article discussing some progress in blue crab research and conservation, and mentioned a related report:

The Chesapeake Bay blue crab population has stabilized, but at historically low levels according to a recent report by the Chesapeake Bay Commission’s Bi-State Blue Crab Technical Advisory Committee.

Though the news isn’t quite heartening, it’s better than nothing.

Blue crab populations have been declining tremendously over the past few decades, not only threatening a population of the animals, but also endangering fishermen and families. So before everyone prepares their crab balls for Xmas (probably shipped in from Indonesia), I’d like to spend a couple of posts discussing the blue crab—its history and ecology.

Blue crabs (Calinectes sapidus) are part of a large order of crustaceans* called the decapods—literally ten foot, which refers to the number of thoracic legs (also called pereopods; legs on the thorax of the animal). The first three thoracic legs have been modified for feeding, while the back two are used for movement. In the case of the blue crab, a brachyuran or swimming crab, the last pair of pereopods is equipped with paddles to propel the animal through the water.

It is interesting to see adaptational trade offs in organisms so similar. The decapods have all evolved different means of protecting themselves. Lobsters have size and a thick exoskeleton on their side, while hermit crabs crawl into a snail shell to protect their relatively weak carapace. As a true crab, Calinectes has evolved a carapace well suited for swimming; escape is as good a defense as any.

We see the same evolutionary pathways in the cephalopods (squid, octopus, nautilus) although as an offensive solution rather than a defensive one. Ancient cephalopods were split into two groups, the ammonites and the nautili, both equipped with thick, tough shells. As bony fish became increasingly adept at hunting, cephalopods had to become faster and more efficient. Shell were reduced and exchanged for the swimming power of muscular siphons, propelling Today only one species of cephalopod retains its shell in any significance: the ancient Nautilus. The ammonites have been extinct for some time now.

Evolution has favored the quick in these cases. But in order for early decapods to become successfully streamlined, the abdomen, including the telson or tail, had to become less of a hindrance. For the past 100 million years, it has slowly curled inward, so to speak, contained entirely under the carapace of the crab, which itself had to expand, giving the crab its well-known shape. This process was theoretical until:

the 1930s [when] the missing link, Eocarinus, showed that [the origin of crabs] must lie among the Pempiphicidea, an extant group of lobsters.

Fossils are hard to come by, especially in the world of invertebrates, and crustaceans are no exception. Recently a man in North Carolina stumbled across a fossilized Pleistocene crab, rare and unknown until recently. He told the local paper of his visit to a fossil seminar at the local aquarium:

“I went over to the aquarium and stopped the show,” he said. “Right away [he snaps his fingers] she said it could be 3 millions years old. That’s when man started walking upright if you believe in that evolution stuff.”

Whether or not you believe in that “evolution stuff”, blue crab populations in the Chesapeake are at historical lows. Next time I’ll explain the life cycle, ecology and major environmental problems involved in the decline of the blue crab.

*As an aside, the crustaceans are an incredibly diverse group of invertebrates, especially when it comes to modes of reproduction. They reproduce sexually and asexually, can be spermatophoristic, gonochoristic or hermaphroditic and are fertilized both internally and externally.

December 20, 2006

Probs & Solns

I'm having internet issues in the mountains of PA, so bear with me this week. I'll definitely have something substantial up by the weekend (probably the evolutionary history and ecology of the blue crab).

In the meantime, go and read these fine carnivals:

Tangled Bank #69: War on Christmas

Philosopher's Carnival #40

Be back Friday.

December 15, 2006

News, Websites and Art Shows

My personal website is completed sans fiction samples. I am also in the process of setting up Heather's site, complete portfolio of her art: paintings, comics, illustrations, graphic art and written works - research, childrens lit.

Also, if you are in the Annapolis, Maryland area, please give us a visit at her show:

Stop by and say hi!

I'll be on vacation and connectionless starting tonight. But you can expect a few substantial posts in the next couple of weeks. I have unfinished business with dinosaur thermoregulation, and I want to explore mimicry, extinction, the modern state of science fiction: probs & solns, the ecology and evolution of the blue crab, telomeres and maybe some bits on wild boar evolution.

Stay tuned. I'll be around.

Carnival News: Festival of the Trees #7 and Oekologie

Festival of the Trees

This is the third call for submission for Festival of the Trees #7. You can send you entries to thevoltagegate [at] gmail.com or by using the Blogcarnival form.

Also, Oekologie, the first ecology and environmental science carnival in the 'Sphere is set up and ready to go. The first edition will be hosted by Jen on January 15th, so please send your submissions to her via e-mail - jpinkly [at] mchsi.com - or with the Oekologie Blogcarnival form.

You can help us out by spreading the word about Oekologie on your blog. We need contributors and hosts! All the details are on the Oekologie blog, so give a visit and lend a hand.

The Physics of Superman Returns

Have you seen Superman Returns? I watched it for the first time tonight, and I thought it was pretty decent, but with all that physics still bumping around in my head after finals, I made a nerdy observation of this scene (not the best quality, but you get the idea):



Superman lifts half of a giant yacht out of the water, broken in two by a spire of rock (the movie could have been called Superman Hefts; the guy spends the whole movie lifting bigger and bigger objects). The boat is sinking straight down, perpendicular to the water, broken side up. He grips the yacht by one of the protruding beams at the break point, and flies upward, toward the sky. My question is, wouldn't his antigravitational force pushing down on the boat cancel out the force he was applying to lift it out of the water?

I know it's a silly question. He's Superman and he flies and he's not necessarily bound to the laws of physics, but I am curious. It wouldn't really be an issue if he was pushing the boat upward from bottom, but he was flying upward while gripping the vessel, simultaneously applying force upward and downward at more or less the same point.

I'm no physicist. Anyone have any ideas (besides "It's just a movie, Jeremy.")?

Mother & Daughter Bio Students Graduating Sunday from FSU

We did an article for the final issue this semester on two biology students - a mother and daughter - graduating together this Sunday. It's a neat little story, starting, surprisingly enough, with the events on September 11, 2001. They are both friends, coworkers and classmates of mine who deserve the recognition.

From "A Long Journey for Mother & Daughter":

According to Frederick Robertson, "Instruction ends in the schoolroom, but education ends only with life." This is surely the case for mother and daughter Sherrie Noonan and Lindsay Wilson, who are both slated to graduate from Frostburg State University with a B.S. in Biology this Sunday.

Sherrie Noonan is a mother of two, and has had a busy educational career. Out of high school, Sherrie attended Allegany College and received a 2-year degree in Mental Health Technologies. In her later twenties, she began work as an addiction counselor for the State of Maryland, a job she maintained for eleven years.
In the eighties, Sherrie returned to school, this time to Frostburg State, in order to catch up with increasing requirements for her job as a addiction counselor.

"I guess they wanted me to get into Psychology or something, but I found English a little more interesting," said Sherrie with a laugh.

The nineties were a whirlwind of activity and change for Sherrie. After receiving her degree in English, she then pursued a Master's degree in Education. In 1995, after talking with a friend, they opened the original Tombstone Caf�, which Sherrie was involved with for five years. She spent some more time in the restaurant business, before deciding it was time to return to school.

"The Biology degree was the one I always wanted, but never got," said Sherrie. "I figured I might as well do it now before I become too old to remember stuff, so I came back."

Sherrie's time in pursuing a Bachelor's degree has been an especially interesting one, since her daughter has been pursuing the same degree at the same time. Lindsay Wilson has had an interesting journey as well, starting her collegiate career at a college on Staten Island in New York City in 2001. With the horrible events that took place on September 11th of that year, Lindsay's perspective, and location, changed.

It's a nice story to cinch up the semester for TBL.

December 13, 2006

Happy Belated, Erasmus

Darwin's pops had a birthday yesterday. Swing on over to PALAEOBLOG for a bit on his life and works.

Mammalian Diversity in Mesozoic Greater than Expected

Scientists in China have described a new mammal from the middle Mesozoic:

Scientists have discovered an extinct animal the size of a small squirrel that lived in China at least 125 million years ago and soared among the trees. It is the earliest known example of gliding flight by mammals, and the scientists say it shows that mammals experimented with aerial life about the same time birds first took to the skies, perhaps even earlier.

Until a couple of years ago, Dr. Cifelli said, most scientists held the view that such early mammals were simple shrew-like creatures that cowered in the shadows of the dominant dinosaurs, and now “this adds a new dimension to our knowledge of early mammals.”

It's nice to finally see some concrete evidence of this level of diversity in the Mesozoic (and probably other periods noted for dinosaurs). It's hard enough for large bones to fossilize, but for small skeletons and ectoskeletons (not to mention soft-bodied organisms) the chances are even slimmer.

Volaticotherium antiquius, which is the sole inhabitant of a brand new order of mammals, was an insectivore, its tail and limbs "elongated" and well adapted for life in the trees, and possessed a large patagium, a flap of skin connecting fore and hind limbs which would have given Volaticotherium the ability to glide, much like flying squirrels or sugar gliders.

I can't help but wonder if they'll find an ancient white-gloved moose and two Russian spies nearby.

December 12, 2006

Controlling the Mind and Body

In reference to his book Parasite Rex, Carl Zimmer has been blogging about parasites that change the behavior of hosts as a function of reproduction (he also has a great clip from David Attenborough's Planet Earth, one of Cordyceps fungi invading and "sprouting" from an ant's body).

I was reviewing some ecology material for my final tomorrow, and I thought I would share another strange, behavior altering relationship between the European starling, an acanthocephalan (spiny-headed worm) Plagiorhyncus, and a pill bug, Armadillidium vulgare.

Plagiorhyncus infects the pill bug, growing until it reaches a vertebrate infection stage called a cystacanth. The starling eats the infected pill bug and becomes infected itself, allowing the parasite to complete its life cycle by releasing eggs into the bird's digestive tract. I'm sure you can fill in the blanks from here. A hint: Armadillidium likes to eat bird poop.

This cycle is pretty standard in parasite-host relationships. What is unique about Plagiorhyncus is the way it exploits both the pill bug and the starling.

Plagiorhyncus drives Armadillidium out of its usual haunts, moist dark areas under rocks or flower pots. Armadillidium, chemically altered, is suddenly out in the open, and more susceptible to attack from above.

The neat thing is, this only happens when Plagiorhyncus has reached its cystacanth stage. Even more interesting, think about the evolution of such a relationship, how many parameters had to be aligned in order to produce such a situation.

It's mind boggling to be sure, but not so startling, considering the close proximity and vast diversity of life on earth. Relationships of all kinds are to be expected in an interactive global community so large. It's kind of nice that we haven't found them all; we certainly are unsure of all the mechanisms and phylogenies. Yet.

Aside: I want to be David Attenborough when I grow up.

December 11, 2006

A Very Special Xmas Gift for the Poacher in All of Us

This Christmas, you and yours can poach endangered animals together without ever leaving your couch, thanks to Cabela's African Safari/Alaskan Adventure:



Man, those elephants are bloodthirsty!

Talk about social responsibility. The cover of African Safari features a rhinoceros viciously charging a hunter. The back depicts all of the animals you can kill, most of them endangered, like cheetahs and rhinoceroses.

I never liked Grand Theft Auto for the same reasons I dislike the idea of this game; not because the fear of some abstract danger of corruption, but because it's just plain crass (and not cleverly so). I'm not naive enough to believe that the people that play Cabela's African Safari are going to buy an elephant gun and start blasting endangered animals, I just thought we might be past the point where murdering life-like animals and people was so appealing.

Festival of the Trees: 2nd Call for Submissions

Festival of the Trees

This is the second call for submissions for Festival of the Trees #7, which will be hosted here on January 1st (which probably lets on that I have no plans for New Years).

If you've written anything about trees - science of, poems, essays, metaphysical analyses, papers, news articles, press releases, mission statements, treatises, etc. - or posted some neat pics or artwork of trees, send your link to me at thevoltagegate [at] gmail [dot] com or by using this nifty Blog Carnival form. Either way it will reach me.

The carnival will be themed, just in time for the new year.

Deadline is December 30.

December 10, 2006

Complexity Fueled by Oxygen

Has anyone seen this?

A sharp increase in the amount of oxygen in the air may have sparked the evolution of complex animal life. Chemical analysis of 580-million-year-old rock sediment shows oxygen levels in the deep ocean surged upwards just before large creatures appeared on the sea floor.

Researchers have long thought that the emergence of complex life forms — strange creatures called Ediacarans — was likely sparked by an increase in oxygen that such animals would need to live. But proof of this theory has been scant.

Two papers, published by Nature and Science this week, both conclude that oxygen levels at this time did indeed shoot upwards in the deep seas. The air at that time, it now seems, probably had about 15% of today's oxygen levels.

Looks like I'll be spending some time in the library tomorrow reading those articles. Here's another PR about the article published in Science (via PALEOBLOG).

December 9, 2006

A Showdown in Blog Village: How Not to Debate

I try to stay out of creation/evolution debates for the most part, but it irks me when ignorance goes unchallenged.

I've been entangled in a predictable, laborious back and forth with a young earth creationist on Blog Village (btw, if you haven't joined the Blog Village list yet, you should; it's a great community and Dirty Butter is a gracious host).

My question was very simple originally: How can you deny decades of evidence? It is a sincere desire of mine to know how people can avoid reality in any case. This is but one aspect. My question was honest and I was not searching for a point by point debate.

I should have known better. We've run through the gammit: molcular machines and irreducible complexity, radiometric dating, the exclusivity of the scientific community, the evolution of the eye, the universe filling population, copy/pastes from creationist websites, methodological naturalism, the scientific concensus, the media's two-sides, molecular homology, logic games, etc, etc.

Then I get this last night:

Anyone who is so narrow-minded as to think there are not two sides to this issue really deserves to have their comments deleted; however, being that if I were to do that you would probably begin personal attacks on me I won't do that.

I'm sure you're familiar with the Matthew effect. Being that the science as a whole has closed its mind as you have, evolutionists automatically get more recognition.

Not only am I narrow-minded, I am probably a troll as well. And "evolutionists" have more fun.

I can understand frustration in any debate, but I have a hard time reconciling personal attacks or threats:

I will never take the liberty of a personal attack as you have done, as I do not know you as a person. I respect people's opinions enough that I will hear them out even if I do not agree. I have never deleted a non-spam comment on my blog just because it conflicts with my feelings or opinions.

It is sad that you threaten to do so. When you publish something on the web that you know will spark debate, prepare for it, and accept it when it comes. That's a blogger's (and any writer's, for that matter) responsibility.

I am not arguing to convince you; I know that is not possible. I am arguing to provide real evidence and resources for others that may read your opinions and feelings and construe them as evidence.

When you put yourself out there with an opinion, always expect that someone holds a contrary notion, and potentially will voice their opinion in return. The blogosphere, in particular, thrives on this concept.

To begin threats of moderation because you disagree says something about the confidence you have in your argument. I have no desire to insult anyone, but as I said, I find it difficult to allow the misinterpretation of evidence to propagate.

December 8, 2006

A Short History of the Eastern Hemlock, Part II

In Part I we looked at the eastern hemlock's northwestern progression after the last ice age,

(click to enlarge)

and the frequency of the hemlock along a slope-oriented moisture gradient:



The distribution pictured above is almost exactly the case in the Laurel Hill old growth stand. The hemlocks are dense at the moist valley bottom, surrounding and shading Laurel Hill Creek and At the different levels of the gradient, not only does the abundance of trees differ, but the composition of the ecosystem. There is a "no-man's land" of sorts between each level that ecologists called ecotones.

Ecotones are imaginary lines between ecosystems where the area exhibits characteristics of both ecosystems (such as the moist, dark hemlock stand, and the relatively dry, bright red maple stand). Ecotones are usually hubs of activity in forest communities where you'll find a greater diversity of organisms than within the bordering ecosystems separately.

STANDING IN AN ECOTONE You can immediately see the difference
in ecosystems here, with the hemlocks downslope (above) and the
deciduous community upslope (below). I found many different types
of fungi and moss in this area that were not present in either community.


Like most other evergreen forests, eastern hemlock stands blanket the floor with a thick, spongy layer of needles. The needles of these trees contain a high level of tannin, a highly acidic, highly astringent compound that deters consumption by microbes and herbivores.

Nutrients in the soil are transported from tiny streams on the ridge, funneling down and enriching the valley, finally coalescing into what are called "black runs." These are streams specifically associated with hemlock growth, dark and highly acidic from the tannin content of decaying needles.

With such a high concentration of nutrients in the valley, the relatively closed canopy of the hemlock stand and the acidity of the black runs, it is no wonder that hemlock communities support a wide array of ferns, mosses, lichens, fungi and other shade reliant, nutrient absorbing organisms.

A FOREST WITHIN

Old growth stands of any tree are able to support a vastly more diversified ecosystem than new stands, not only within itself, but also along its borders. More stands need to be protected and set aside for study and educational purposes so we can look back into a world that existed long before civilization took its grip on the planet.

***Special thanks to Dave Bonta for the invite up north. I would love to take you up on the offer if I get up your way, Dave!

December 7, 2006

FSU's Crime of the Century?

I just got this in my school e-mail today:

Would the student who borrowed the Cavalerro Collection Catalog from [edited], the curator for the Compton museum, please return this item at your earliest convenience.

I'm assuming when they say "borrowed" they mean "stolen"; why else would they send out a mass e-mail? Unless the curator can't remember who he gave it to, which doesn't seem very likely, knowing him.

The Compton Museum aka the Exploratorium

The catalog contains an entire listing of all of the taxidermic animals donated to the university a few years ago by a wealthy benefactor. The catalog also has comprehensive information about the insurance values of each piece.

Whoops.

Early Morning Links

Jon Turney at science books blog is a tad critical of Discover magazine's recent top 25 science books listing. Rebecca Skloot has a few issues as well.

The AT Wire looks at some new Battlestar Galactica mods actually based on the new series.

Sciencejunky reviews an interesting find: the pyramids are not entirely composed of natural rock. Some of the blocks are man-made, like concrete.

Interviews with God this week is just damn funny.

Look out! Jen Pinkley is doing some science, in two parts. She also includes a nice review of bacteria's role in the environment.

Geez, pick a blog: Water flows on Mars, people.

December 6, 2006

Hargh! Tangled Bank #68 Is Up, Mates

Take a voyage on the HMS Tangled Bank with # 68.

Residential Scale Renewable Energy Research and Outreach Program Begins

My article about the renewable energy research just came out today, following this post from last week.

Soysal and his associates will be constructing a small station on FSU campus with two photovoltaic solar panels (2 kW) and a 45' wind tower (1.8 kW; much like the one pictured at left). The energy product of the station will power a small building on campus; the excess will be sold back to Allegheny Power.

The data from this station will be streamed 24/7 and available online as soon as the website is up.

Next semester there will also be a renewable energy symposium, during which students will present papers and essays regarding renewables and the research done at that point on campus. Soysal is inviting professionals from across Maryland to attend.

One of Soysal's goals is to engage the entire campus, bolstering interdepartmental cooperation:

The project will be an interdisciplinary effort involving several departments on campus, providing students and faculty with hands on experience directly related to course material.

Soysal recently attended and participated in a wind power debate in a FSU sociology class. English professors are excited about the potential for student papers. The biology department will monitor the wind turbine's effect on bird and bat populations.

Soysal is equally concerned with the environment:

"Anything an engineer does has an effect on the environment," said Soysal. "We have an ethical role to investigate a project fully before it is built and its effect becomes irreversible."

Perhaps he will be able to initiate the first few steps to wean Western Maryland from coal dependence.

Soysal is heading the project, which will be ongoing. I'll have more on it next semester.

December 4, 2006

Heinlein, Sturgeon Disappoint

The semester is almost at an end, and I've only had time to finish two books outside of required class material (riveters like "Reporting Technical Information"): by More Than HumanTheodore Sturgeon and Stranger in a Strange Land by Robert Heinlein.

I could have chosen better. Both books turned out to be sappy, unrealistic, self-consciously preachy and contrived.

More Than Human follows a rotating cast of idiot savants - twins that can teleport, but cannot speak, a "fool" who can read minds, an omniscient baby that never grows up, another telepath that lacks empathy - who cannot be successful in the world as a single entity without the help of his/her incomplete friends. They have adventures of abuse and ridicule and psychosis and come together in the end to form a new species of human, Homo gestalt.

It sounds like a neat story in summary, but there was very little science in any of it. Sturgeon was better off writing short stories. There was a definite vibe of self loathing/freaks unite going on in More Than Human, exactly the reason why I can't stand Neil Gaiman's "science" fiction (Gaiman named the main character in American Gods "Shadow"; I almost put down the book right then).

Stranger in a Stranger Land was just plain ridiculous. Heinlein gets so much praise from science fiction buffs, and I have yet to figure out why.

A human being named Mike Smith was raised with Martians his entire life (who are kinda like Buddhist Ents) and brings his crazy ideas to Earth, learning to become a human, eventually starting his own hedonistic church and trying to save mankind with unrestrained love. Bleh.

Heinlein doesn't know the meaning of the word "subtlety." He basically places himself into the body of an old crotchety lawyer/know-it-all who grumbles and philosophizes and is always right about each situation in the story. It's profoundly irritating when an author does that. Every character should be a little piece of you, not the whole.

Women get a pat on the bottom on every page, homosexuals are "a wrongness" and the male driven dialogue is filled with little zingers (oh, snap!). The entire book is completely unbelievable; every character is psychologically impervious to catastrophy and therefore worthless to the reader. I actually wanted Mike to die a terrible death after the halfway mark.

And he does. Just like a true savior. *sniffle*

MTH was written in 1953, and was probably the first of its kind in the science fiction genre; for that fact, it gets my respect. SiaSL came out in the tulmultuous 1960's and was trying to preach unity, I suppose, through sex and freedom, before they figured out that sex and responsibility are perhaps more closely tied.

I'll stick with Asimov, Vance and Bester for now.