Today is legendary! Why, you ask? Well, we are celebrating TEN YEARS of DSN posts. That’s right – if you go wayyyyyyyyy back in the archives you will note that the proto-Deep Sea News empire began with a little post by Dr. M on December 13, 2006.

What were we all doing in 2006? Well as for myself (this is Holly speaking), I was just starting my PhD research in good ol’ London towne. I was listening to a lot of Pussycat Dolls, and Christina Aguilera was going through that weird jazz phase. I was smoovely fixing nematodes on glass slides to the tune of Chamillionaire, and I had just signed up to this cool new website called Facebook.

As you can fathom, a lot has changed in 10 years. The DSN crew has moved forward and onwards in our careers, many of us metamorphosing from wee little student trainees into Real Scientists. Our list of contributors has changed and evolved. We write different types of posts now (should we remind Dr. M that he used to use DSN as a cruise blog?). In light of recent world events, our message and mission has become increasingly urgent.

But other things haven’t changed – our Core Values, although not formalized in writing until 2011, have always been a fundamental part of Deep Sea News. The passion, enthusiasm, and dedication of all of our past and present writers will never change. And of course I still listen to the Pussycat Dolls (because how can you NOT?)

So in celebration of our site’s 10 year anniversary, here we present you with our Top Ten (and then some) posts in DSN History:

2006 

Wetting my toes

Kim: Do I need to explain that the very first post on DSN is also that years highlight? It’s real, it’s sweet and it kicked off ten years of online shenanigans!

2007 

Just Science Weekend: They Eat Their Young

Jarrett: I <3 DSN in 2007. You can feel the online science world trying to figure out what it was. DSN was a more news-y place, with a heavy dose of reportage on the deep sea, like this awesome interview of sub pilot David Guggenheim. But amidst that, DSN was also figuring out who it was going to become – and this gem of a piece from Peter Etnoyer epitomizes the future, showing us that not only are deep sea fish all around us in our everyday lives, but man, do they sure like to cannibalize their babies. Mmmmmm….babiez.

2008

Dumping Pharmaceutical Waste In The Deep Sea

Rebecca: 2008 was a year or short-and-sweet posts, punctuated by long and well-researched articles on everything from coral age to deep ocean waves. DSN found a unique voice in being a place not just to report on the latest news, but also provide a scientist’s perspective on the way news about the ocean is reported in the press. This was also a year of raising awareness, with Dr. M’s post on pharmaceutical dumping in the deep as a perfect example of how blogs can call attention to unique and important stories that the press might miss.  

2009 

Holly: My favorite thing about 2009 is the epicness of Kevin Zelnio, best summarized with these two posts:

TGIF: TOTELY AWSUM SEE KUKUMBR!!!11!!!!11!

This post is a HILARIOUS animated video about a very boring sea cucumber, complete with rock guitar soundtrack. I think I just re-watched it like five times.

Thank You for Caring About Ocean Education!

(the more serious and dedicated size of Zelnio, where he coordinated a campaign at DonorsChoose.org and raised over $4800 from our readers. This campaign funded Ocean Education projects in K-12 classrooms around the country!)

2010 

All the coverage of the Deep Water Horizon Spill

Kim: Let’s be real, the Macondo well blowout sucked for the Gulf. But in terms of science, DSN was on it providing weekly updates and posting readable summaries of technical reports. The entire archive is here folks.

How To Cuddle Your Lady Right, by Smoove A

In this epic post, Miriam describes how one microscopic crustacean makes all the right moves and makes the mating happen. All biology textbooks should be written like this.

2011

From the Editor’s Desk: The Giant Squid Can Be A Panda For The Ocean

Holly: First of all, I love the 2011 Editor’s Desk posts because Craig very epically summarized himself with a minimalist icon of his bald head and beard. Second, the Giant Squid is WAYYYY more awesome than those damn dolphins and whales that everyone keeps going on about. And I prefer my cuddly mascots with lethal beaks and suckers, thank you very much.

From the Editor’s Desk: The Future of Deep-Sea News

This is the post where we formalized our now infamous core values – they were the brain child of the very first DSN retreat at the Georgia Aquarium, a weekend of meeting rooms and champagne in a rotating sky hotel. One of those things turned out better than the other.

2012 

#IamScience: Embracing Personal Experience on Our Rise Through Science

Jarrett: This post embodies DSN at it’s best. Kevin Z. takes us on his deeply personal and emotional journey into science. It’s a kind of story rarely told, and one that so many need to hear.

How presidential elections are impacted by a 100 million year old coastline

In this post, Craig connects American history with geological history, and ties it all together to understand how both impacted the 2012 presidential election. This post exploded the internet.

2013 

Kim: 2013 was just so awesome, I couldn’t just pick one!

10 Reasons Why Dolphins Are A$$holes

Do I even need to explain?

A field guide to privilege in marine science: some reasons we lack diversity.

When Miriam left DSN, she went out with a deeply important and thoughtful list. If you are an ally and want to see marine science grow, read this piece.

How many people does Kaiju need to eat everyday 

Sure we love all the creatures of the deep, but we also love Hollywood’s imaginary beasts as well. Craig answers some serious questions regarding the metabolism of the monsters in Pacific Rim.

The 60 foot long jet powered animal you’ve probably never heard of

In case you didn’t know what Rebecca’s niche in the online ecosystem, this is it. Someone found a giant gelatinous tube in the sea, she identifies it, and the internetz go wild. Rebecca, helping jellies go viral since 2013.

True Facts about Ocean Radiation and the Fukushima Disaster 

SPOILER ALERT: unless you live within 100 miles of the reactor, radiation from the Fukushima Disaster is still not harmful. This post was meant to be a guide to understanding radiation in the ocean. It ended up being one of most shared posts ever and the one we received death threats over.

2014

The Ever Increasing Size of Godzilla: Implications for Sexual Selection and Urine Production

Beth: Where Craig discusses the body size characteristics of godzilla over time, and the logical implications this would have on the millions of gallons of urine that massive godzilla would generate. This post has the thing that makes me love DSN – using scientific reasoning to explain a totally ridiculous thing. And it features Craig’s weird obsession with the size of things.

Runner up:

Sex, snails,sustenance…and rock and roll 

Where Craig uses great metaphors to explain some cool scientific studies on how snails reproduce based on food availability, featuring inappropriate references to rock stars and sex, and with a bonus soundtrack!

2015 

Ten Simple Rules for Effective Online Outreach

Alex: It’s like we all wrote a blog post… together. And then published it for realsies.

2016 

On Being Scared.

Alex: In which Craig verbalizes the place we have all been. I love and admire the vulnerability in this post and that he ended it so positively… that even when shit hits the proverbial sea fan, we get to choose how we respond. We get to choose how we show up.

Runner up:

The Twelve Days of Christmas: NASA Earth Science Edition

Alex: When you get retweeted by NASA… you get a spot on the list.

(Runner up #2)

The worst ocean environments to catch them all

Rebecca: When you love Pokémon but hate crushing barometric pressure.

The post A Decade of Deep Sea Decadence first appeared on Deep Sea News.

Edward Forbes spent his life championing a hypothesis whose evidence was flawed and extrapolations unjustified. The idea of a lifeless deep-sea held sway in a society mystified by the unknown and afraid of what it would hold. Forbes was the scientist-manifestation of this fear and never would concede the Azoic Hypothesis, even in the face of historical and tangible evidence. He was not the villain or the Benedict Arnold of deep-sea biology, but more like the conflicted tragic who could not achieve the historical greatness he so much desired. As Tony Koslow describes in The Silent Deep (1): “Forbes stands in the history of science as one of those enigmatic figures who, through an excess of antiquated intellectual baggage, comes close yet fails to grasp greatness.”

The evidence for life in the depths of the sea was firmly established by the early part of the 19th century, nearly 40 years before Forbes would set sail and drop dredge in the Aegean Sea. Many of the reports were coming in from naval officers and ship captains, not scientists. These reports were either not well-known or were not valued as rigorous evidence among the scientific circles. Indeed, these two issues are as pervasive today and they were nearly 200 years ago. Many modern marine scientists are unaware of government reports or choose to ignore their findings as they have not been vetted in the manner appropriate for scientific rigor.

Some of the earliest observations of the British Arctic exploration expedition commanded by Captain John Ross in 1818 aboard HMS Isabella and Alexander. While exploring the northwestern Atlantic for a fabled Northwest Passage under the charge of the Royal Admiralty, he was instructed to collect specimens along the way. His dredges routinely made fall between 850 and 2000 meters depths and contained many crustaceans, corals, worms and other fauna that we would today consider typical deep Atlantic species like the Medusa’s Head basket star (left). Captain John Ross’ nephew, Sir James Clark Ross, wrote 20 years later,

“Although contrary to the general belief of naturalists, I have no doubt that from however great a depth we may be enabled to bring up the mud and stones of the bed of the ocean, we shall find them teaming with animal life; the extreme pressure at the greatest depth does not appear to affect these creatures…”

Ironically, though neither Ross published their results in scientific papers, Forbes did examine the collections of James Clark Ross.

Expeditions were continuing to report a vibrant expanse of life in the Northern Atlantic even after Forbes wrote his account on the fauna of the Aegean Sea and proposed the Azoic Hypothesis (2). From 1850 and into the 1860s, Norwegian marine biologist Michael Sars was routinely discovering an enormous variety of new sea life between 300-800 meters. These findings though were criticized by not being deep enough to disprove the Azoic Hypothesis. In 1860, sailing aboard the HMS Bulldog, G.C. Wallich recovered 13 brittle stars from a sounding line reaching over 2300 meters. Fascinated by these findings, Charles Darwin wrote to Wallich,

“What a wonderful fact about the Ophiurae, & what a capitol proof of the Foraminerifera having been alive in their stomachs […]

P.S. Is it not a most curious fact that the Water at such pround depths, & under such a vast pressure, should retain Oxygen for the respiration of the animals mentioned by you?”

Forbes passed away in 1852 at the very young age of 39 just days after the onset of an illness. While he wasn’t around to witness the results pour in from Sars’ and Wallich’s expeditions, there was opportunity to revise his ideas based on the collections, reports and notes of both Ross expeditions. But it should be noted that Forbes was not only a marine biologist. He made significant research advance on land molluscs, botany, geology and paleontology. He was on the quick rise up, being elected to the President’s Chair of the Geological Society just a year before his death, and well-liked and respected among colleagues. Prominent scientist Thomas H. Huxley wrote of his impact in a lengthy obituary,

“It is not because he was so gifted that the veterans of science one and all affirm his loss to be irreparable; and the aspirants know that they may succeed, but cannot replace him. Our affections cling to character and not to intellect; and rare as was the genius of Edward Forbes, his character was rarer still. The petty vanities and heart-burnings which are the besetting sins of men of science and of men of letters, had no hold upon his large and generous nature–he did not even understand them in others.”

Many scientists make mistakes in their career and are cautious to admit any error on their parts. His folly was not a setback to the science at the time, in my opinion because it set up a null hypothesis that can easily be tested. One person’s legacy should not be constrained by a single event when there was no harm done. Given what Huxley and others appear to think of Edward Forbes, had he lived long enough he may very well have re-evaluated his position. But the greater lesson I think we can learn, one still relevant today, is to not ignore evidence, opinions and observations from non-traditional sources. Scientists frequently turn a smug nose to those outside of their circles (even to other scientists with expertise in other areas). But scientists time and again can gain valuable insight by merely listening to the people, and acknowledging the world, around them. That is, in essence, how science proceeds.

References:

The post Deep Sea 101: Forbes’ Folly – Evidence of Deep Sea Life Ignored first appeared on Deep Sea News.

Early on, Osedax was only found on whale bones from carcasses that sank into the abyss. It wasn’t long before researchers started a long and productive string of experiments placing whale bones (and the entire carcass of stranded whales) out in the deep sea to study the evolution of the community supported entirely on dead whale.

Footage of whale fall succession in the deep sea produced by the lab of Dr. Craig Smith, University of Hawaii.

Immediately, and with good reason, it was thought that Osedax was clearly a whale-fall specialist. The core of whale bones consists of a matrix rich in lipids – up to 60 percent! – an organic manna from the sunlit heavens. University of Hawai’i researcher Dr. Craig Smith estimates that a 40 ton whale carcass sinking to the deep sea contains about 2 million grams of organic carbon in its tissues and bones (Smith & Baco 2003). For each square meter of the seafloor that the carcass affects, it supplies the equivalent of over 100 years of carbon from the rain of marine snow that falls to the seafloor from dead surface plankton!

Recently, other researchers challenged this conventional wisdom. To characterize the extent of what these strange worms can live on, they started deploying other substrata than whale bones in the deep sea. Initially, Osedax was found living on cow bones (Jones et al. 2008), but the argument was proposed that this was an unnatural environment in the deep-sea and would therefore be of a minscule contribution to Osedax habitat and nutrition. Only a few months later Vrijenhoek and colleagues (2008) replied with a report of Osedax on ungulate bones that were likely galley waste thrown over from fishing or shipping vessels, suggesting:

“With numerous fishing, commercial transport, passenger and military vessels sailing the world’s oceans, we wonder how frequently bones from galley waste might reach the ocean floor. We do not suggest that such bones provide a more bountiful and temporally stable resource for Osedax than large cetacean carcasses, but every food fall may help these bone-eating worms continue to flourish in a world that now has fewer large whales.”

But cows are ungulates… and ungulates – like whales – are mammals. Mammalian vertebrae are generally rich in lipids. A real smoking gun for the specialization of wHaLe BoNe-DeVoUrInG zOmBiE wOrM fRoM TEH ABYSS!!1!! would be to find it happily perched upon the bones of non-mammalian taxa, for instance marine reptiles or fish. Previous studies of fish falls in the deep sea were carried out on time scales likely too short for Osedax to colonize or be detected with imagery. Nonetheless, Glover and colleagues suggested that for most fish or small carcass remains

“… the likelihood of many of the small bones being scavenged or settling into the sediment, suggests that there would be little available bone material left after three to four weeks.”

So like any good scientist out there to prove their instinct correct, Drs. Greg Rouse, Robert Vrijenhoek and colleagues went out to collect data deploying an experimental array of fish bones and calcified shark cartilage into the depths of Monterey Canyon. 157 days later, the array was recovered and lo and behold Osedax had colonized the largest bones! Not only do they appear to colonize any bones and suck them dry of their precious, juicy lipids, but they do it pretty swiftly.

The real kicker is that these fishy Osedax were colonized by 3 different species (2 undescribed, nicknamed “yellow patch” and “nude palp E” <-scandalous!). One specimen of Osedax roseus had already started spawning eggs suggesting that they grow, mature and spawn rapidly after settling on a bone – in less than 7 months. This last point is of particular interest because previous genetic studies have found that Osedax populations are very diverse with high effective population sizes. What this means for the species is that there must be many breeding individuals down in the deep sea.

This finding helps to solve a paradox in Osedax research. How can the worm persist in huge numbers on a resource (whale falls) that is so highly variable in time and space? They would either need a massive reproductive output or the whale-fall habitat would need to be very common. This is complicated by Osedax‘s life-history variables, some known and some not: it must acquire it’s symbiont, grow, recruit dwarf males, mature, convert bone lipids into egg mass and spawn – all while this resource persists. Whale bones may be optimal habitat, but we know from decades of ecological study that animals have trade-offs. Fish bones may be less rich in lipids and persistence of Osedax habitat, but it certainly be preferable to starving to death in the freezing cold, dark, lonely depths!

By colonizing a wider variety of bone types, Osedax opens up many more habitat possibilities and may help explain how in the vast expanse of the planet’s largest (and some might say grandest) environment such an unusual lifestyle could evolve and persist.

References:

Glover AG, Kemp KM, Smith CR, & Dahlgren TG (2008). On the role of bone-eating worms in the degradation of marine vertebrate remains. Proceedings. Biological sciences / The Royal Society, 275 (1646), 1959-1961 PMID: 18505721

Jones WJ, Johnson SB, Rouse GW, & Vrijenhoek RC (2008). Marine worms (genus Osedax) colonize cow bones. Proceedings. Biological sciences / The Royal Society, 275 (1633), 387-391 PMID: 18077256

Rouse GW, Goffredi SK, Johnson SB, & Vrijenhoek RC (2011). Not whale-fall specialists, Osedax worms also consume fishbones. Biology letters PMID: 21490008

Smith CR, Baco AR (2003). Ecology of whale falls at the deep-sea floor. Oceanography and Marine Biology: An Annual Review 41:311-354.

Vrijenhoek, R., Collins, P., & Van Dover, C. (2008). Bone-eating marine worms: habitat specialists or generalists? Proceedings of the Royal Society B: Biological Sciences, 275 (1646), 1963-1964 DOI: 10.1098/rspb.2008.0350

The post Whale Bone-Devouring Worm Into More Than Just Whales first appeared on Deep Sea News.

While the Census of Marine Life may be the most recent call to survey the ocean, deep-sea exploration has a rich, paradigm-shifting history. It has all the makings of a Hollywood blockbuster: colorful characters, high seas action, the drama of antagonistic actions between “men of honor”, you name it! Probably has a bit of romance in there too, but that tends to get left out of the scientific literature. Examining the history of deep-sea exploration is an excellent case study in how technological advances continue to yield new insights and increase our ability to ask better questions. This section of Deep Sea 101 will be composed of 4 parts.

Nearly 2400 years ago Socrates (via Plato) posited of the deep sea:

“… everything is corroded by the brine, and there is no vegetation worth mentioning, and scarcely any degree of perfect formation, but only caverns and sand and measureless mud, and tracts of slime wherever there is earth as well, and nothing is in the worthy to be judged beautiful by our standards.”

Such a damning indictment from such a classical thinker indeed! Curiously, the Greeks and other civilizations during this time were in no position to make such bold statements having an inability to visit and sample past a mere tens of a meters.

It was not until Aristotle we could really call anyone a marine biologist. He dedicated much of his life to describing the life on the Aegean coasts, describing 180 marine species nearly 1700 years before Linneaus. Aristotle was the first person to study form, function, ecology and behavior and developed a classification system based on multiple traits. He is perhaps most famous for describing the mouth parts of sea urchins, which is named in his honor (called Aristotle’s Lantern, at right).

But his enthusiasm for the ocean did not catch on in the ancient period and an attitude of complacency persisted all the way towards the Victorian Era when deep-sea exploration really took off, chiefly out of economic and imperial interests. Echoing the contented ignorance of the time, or perhaps a fear of the unknown, noted historian Pliny the Elder wrote in 40 AD:

“By Hercules, in the sea and in the ocean, vast as it is, there exists nothing that is unknown to us, and a truly marvelous fact, it is with those things that that has concealed in the deep that we are best acquainted!”

It took until the 17th century, during the tail end of the Renaissance, for these unfounded assertions to be even questioned, and by none other than Robert Hooke who stated:

“Animals and Vegetables cannot be rationally supposed to live and grow under so great a Pressure, so great a Cold, and at so great a Distance from the Air, as many Parts at the Bottom of very deep Seas are liable and subject to…

We have had instances enough of the Fallaciousness of such immature and hasty Conclusions…” (emphasis mine)

What Hooke has done was twofold. He first provided a set of testable hypotheses for absence of life in the deep sea disguised as common sense. Then, he made a statement hinting that perhaps we ought to actually test this because if past experience shows, common sense might not always be correct.

For the next 100-200 years the deep sea was considered lifeless based on 4 criteria: temperature, light, pressure and stagnancy of the environment (i.e. it was all uniform). The first three of these criteria were well-reasoned, though no one knew what the true depths of the deep sea were. But it was well-known that light was refracted by water and the visible spectrum gets filtered out, the deeper you go the more pressure an organism must bear – this is easily calculated estimating forces, and without the energy from the sun’s rays warming the deep waters it could be reasoned that it must be cold down there. In fact, some early scientists thought the bottom of the sea must be ice.

The last criteria of stagnancy is an interesting one that I am not entirely sure how it came about since they had no direct knowledge of deep-sea life until the mid-1800s. It may have been derived from calculation of the current speeds. Surface currents are wind-driven and any given body of water tends to be stratified, or composed of different layers. The top layer of the water moves at a given speed but experiences drag from rubbing against the layer of water below it. This causes the lower layer to move with the upper layer but at a slower speed because there is energy loss from friction against the seafloor (see figure at right). Because of this, water currents near the seafloor are typically much slower than surface currents. Therefore one can posit that at some depth water speed eventually just stops. This has important implications because animals down there would need fresh, constant input of dissolved nutrients (nitrogen, oxygen, etc.). Stop the flow, there’s no grow!

During the golden age of deep-sea exploration in the 1800s the Azoic Hypothesis of the deep-sea was largely championed by Edward Forbes and was based on his observations in the Aegean Sea, between Greece and modern-day Turkey (map below). I’ll refer to the Azoic Hypothesis as tied specifically to Forbes, but recognize that it had much earlier roots. Forbes was merely the first to study it scientifically. As I’ll go on to explain though, the Azoic Hypothesis was largely the result of common sense thinking, an unfortunate study area, inadequate sampling gear and ignoring previous results.

Though not known at the time, the Aegean Sea was a poor choice for a study site. First of all, it is not very deep and we now know it is not a very productive area away from coastal areas. The map above (at right) shows the concentration of chlorophyll – the pigment used by phytoplankton to capture solar energy to use in photosynthesis – in the Aegean Sea based on satellite measurements. Green to red signify higher concentrations of phytoplankton, and hence higher amounts of surface primary production. Blue is low productivity and you’ll notice that in the center of the Aegean Sea where the deep water is it’s mostly blue, or unproductive. Oligotrophic waters (meaning with few nutrients) are defined as containing less that 80 grams of carbon per square meter. The central Aegean Sea has about 30 grams of carbon per square meter. With very few plankton at the surface, there is very little food that falls down to support the denizens of the deep.

Had Forbes actually been in a productive area he still might not have found much life in the deep because he was using a dredge that was modified from ones used by oystermen. It was inadequately designed to sample the muddy deep seafloor. The mouth of the dredge was narrow and the bag was small. Note the design of the canvas bag (below, at right), there are vents only in middle of the sides. The dredge would immediately fill up with mud and thereafter become a wrecking ball let loose upon the seafloor until it was brought up. Curiously though, and deceptively, Forbes made an illustration of sea creatures all-too-happy to enter into his dredge for his book Natural History of the European Seas (his initials are under the dredge). But the difference between the dredge he used versus this idealized dredge that he illustrated is actually quite important. The illustrated dredge would have been ideal to use since it has a wide mouth and plenty of vents to discharge mud.

Throughout his sampling, he failed to document life in the deep, but did document very thoroughly patterns of animal abundance with depth. In general, the deeper his dredge dove the fewer organisms he found. He wrote in 1859, the same year as Darwin published On the Origin of Species:

“As we descend deeper and deeper in this region, its inhabitants become more and more modified, and fewer and fewer, indicating our approach towards an abyss where life is either extinguished, or exhibits but a few sparks to mark its lingering presence.”

By means of extrapolation he asserted that life ceased to exist beyond 550 meters. Which probably seemed pretty reasonable to Forbes’ contemporaries. Forbes had went out to sea, carried out an extensive sampling program and had based his conclusions on data. In hindsight we can say that Edward Forbes was ill-prepared to adequately sample the deep sea and had a poor choice of study area, but was his extrapolation just the result of bad luck, or is there more to the story?

Find out in the next installment of Deep Sea 101 as we continue to examine the early evidence for life in the depths during Forbes’ time and enter whom I refer to as the father of modern oceanography, Sir Wyville Thomson!

The post Deep Sea 101: Early Paradigms and Exploration first appeared on Deep Sea News.

As part of Darwin Day on Friday, I gave a brief talk at Duke Marine Lab during happy hour about Darwin and his beloved barnacles. I was going to post the slides but didn’t think they did the 201 year legacy of Darwin much justice out of the talk’s context so I decided to write up the talk as a post. Happy Darwin Day!

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Barnacles held an immense fascination for Darwin. It was through some rather chance events that he ended up being the world’s expert on this fascinating group. He created 4 volumes of masterpieces devoted to all available living and fossil barnacles worldwide. I hope to show that indeed his work with the barnacle did indeed contribute to solidifying his thoughts on transmutation and improving his understanding of what will eventually become his greatest contribution to science. Before we get started though let’s sit back, learn the barnacle basics and set the mood for this post!

Charles Darwin’s grandfather Erasmus (left) was an eccentric physician noted for racey poetry and author of Zoonomia in 1794, a text that presaged the evolutionary works of even Lamarck. Erasmus’ eccentricism appeared to permeate his whole life. Ex omnia conchis – all from shells – was transcribed everywhere according to Rebecca Stott, author of Darwin and the Barnacle. Curiously, the crest of the Darwin-Wedgewood family (right) bears 3 shells. Erasmus’ inspiration must have stemmed from a family history of love for the natural environment. Though Charles Darwin never would have known his grandfather – Erasmus died in 1802, seven years before Charles was born – the family crest and ex omnia conchis surely foreshadowed his legacy.

Darwin started speculating on species during the Beagle voyage, but many of his ideas were solidified after the expedition and after consultation with taxonomic experts. He was very close to publishing his theory of evolution by the 1840s and was keenly aware of the abuse given to Lamarck’s theories. In 1844, Robert Chambers anonymously published a book titled Vestiges of the Natural History of Creation which was written in style and priced for the lay person. It became very popular and laid his own theory for evolution built upon Lamarckian ideas. Vestiges purported a linear chain of transmutation culminating in man, more specifically white English man.

While popular with the laity, the academics and clergy who mentored Charles and whose approval he often sought were up in arms about the book and its rampant attacks against Natural Theology, the prevailing modus operandi in natural history of the time. It was because of the that his friend and confidant botanist John Hooker wrote Darwin after reading a draft of his “big species paper”:

“Do not think I meant to insinuate that you could not be a judge from not having worked out species, for your having collected with judgement is working out species: what I meant I still maintain, that to be able to handle the subject at all, one must have handled hundreds of species with a view to distinguishing them & that over a great part,—or brought from a great many parts,—of the globe.” – Hooker in a letter to Darwin 14 September, 1845

This frightened Charles, as he was not inclined to disappoint or scientifically alienate himself from his beloved colleagues. While it is arguable that Hooker’s letter set back Darwin’s publication of his ideas, it encouraged him to intimately study several larger aspects of morphology that would inevitably aide him in cementing his theory of evolution by natural selection.

Darwin had been working on a problematic barnacle collected during the Beagle voyage since 1835 he  called “Mr. Arthrobalanus” (left, now referred to as a Cryptophialus). He noticed “[t]he thick shell of some of the individuals of the Concholepas Peruviana [sic] is completely drilled by the cavities formed by this animal” (Zoology Notes). In essence, Charles discovered the first burrowing barnacle! A rare find indeed and one that would intoxicate him with crustaceous ecstasy. He intended to describe this small, parasitic barnacle rather quickly, but “was led, for the sake of comparison, to examine the internal parts of as many genera as I could procure.” Beginning in 1846 barnacles would consume his family’s life for the following 8 years resulting in 4 volumes of living and fossil barnacles of all known types around the world during that time. Charles’ son Francis would famously ask of another child, “where does you father do his barnacles?”

It was not until 1830 that it was realized that barnacle were crustaceans. Since they were shelled creatures, naturalists had considered them mollusks akin to mussels and limpets. John Thompson followed the embryology and metamorphosis of barnacles and determined by their developmental characteristics that they were actually closely aligned to the crustaceans. Mollusks weren’t considered a metamorphosing species to Victorian naturalists.

The basic concept that Darwin wrapped around his barnacle synthesis, and even more so later in his Origin, was Richard Owen’s homology, meaning that characters were derived from shared ancestry. Owen was a powerful colleague and former mentor of sort to Charles. Darwin had much respect for him and tried to work within Owen’s archetype framework, which was initially developed with vertebrates in mind. The archetype was a theoretical ancestor, a blueprint in the mind of the ‘creator’. Owen did not necessarily believe it existed but nonetheless thought it was a useful construct from which to understand his homology framework. Darwin, working within the archetype framework for barnacles, was able to systematically classify everything and place Cirripedia correctly as a subclass of the Crustacea, confirming Thompson’s embryological observations.

One of the more interesting challenges to Darwin’s classification of barnacles was the issue of small “complimentary males”, as he called them. Not only did these dwarf males attach to the female, but some species had hermaphrodites with attached dwarf males as well! Because Charles was working within Owen’s homology paradigm, he viewed hermaphroditism as a major character in his barnacle classification and made some interesting, though erroneous, inferences. In his Victorian worldview, Darwin naturally saw the condition of having separate sexes as the most highly evolved, while rampant hermaphroditism must surely be the basal condition. But these curious parasitic dwarf males must be a transitional state between a hermaphroditic ancestor and the more ‘dignified’ separation of sexes.

“These parasites, I now can show, are supplemental males, the male organs in the hermaphrodite being unusually small, though perfect & containing zoosperms: so we have almost a polygamous animal, simple females alone being wanting. I never sh^d. have made this out, had not my species theory convinced me, that an hermaphrodite species must pass into a bisexual species by insensibly small stages, & here we have it, for the male organs in the hermaphrodite are beginning to fail, & independent males ready formed.” – Letter to J.D. Hooker May 10, 1848

Hooker was absolutely correct in suggesting to Darwin that he become an expert of species prior to speculating on the subject out in the open. His eight years of focused in depth taxonomic study made keenly aware of the variation out in nature. The choice of taxa enabled him to view strange morphology and reproductive strategies that might have been potentially as obvious as it was in the barnacles. More importantly, his approach using homology helped to formulate three central components to his Origin: 1) shared ancestry of parts in related organisms, 2) loss of useless organs (i.e. abdominal segments and swimmerets in barnacles) and 3) transformation in function of homologous organs (i.e. thoracic limbs for walking into cirri for feeding).

Though Charles, like systemacists even today, had difficulty drawing the line between what is and what is not a species he was one of the first taxonomists to recognize the role of variation in studying species. Eight years spent studying variation and homology did indeed make him an expert in the “species question”. It confirmed his transmutationist views, gave him credibility in the face of Vestiges and the much contested views of Lamarck, and resulted in an award from his colleagues at the British Association for his extensive monographic work. These elements were important in securing the “political capital” needed once he was ready to unveil his tome on the origin of species by natural selection.

For more about Darwin and the barnacle years I highly recommend Rebecca Stott’s Darwin and the Barnacle. Darwin’s Study of the Cirripedia by Marsha Richmond was an invaluable resource for preparing for this talk and post.

Richard Grant has some images of Darwin’s Barnacles from the Whipple Museum in Cambridge.

The post Darwin Day Repost – Ex Omnia Conchis: Darwin And His Beloved Barnacles first appeared on Deep Sea News.

One of the common criticisms that travels around the science journalism/PR circles is that scientists can’t communicate with nonscientists. But I would like to suggest that communication isn’t the problem, but that scientists might not know how to judge the best communication strategy for their audiences. Journalists and writers are trained in this, and if they do it well can turn a single story into 4 pieces with different angles to different magazines written for separate audiences. Scientists might take a lesson in audience detection from the science writers in this respect. But, at the risk of turning this into communications royal rumble between journalists, scientists, PR people and science writers – no one horse in this race has the singular answer. This might be because we talk to people in different ways, but we don’t talk to different people in different ways.

Scientists tend to, not always though, communicate AT people. That is, tell them things in a non-engaging way. This is not always a bad thing. People of walks of life have a thirst for knowledge and want to hear the minute details of every grain of deep sea sediment we collect. But other audiences demand a good story. Science writers and journalists are often very good at communicating TO people. This entails putting the science in a context that is understandable to a “general public”? It might mean framing the results around a story with characters, structure, plots, and a moral or lesson. It could mean just describing recent research results in downgraded terminology. Here though, it is still a non-engagement with the audience (though it certainly doesn’t always have to be).

What has not been done very well by all the involved parties is communicating WITH people. In the last few years, with the advent of science blogging, the conversation has widened. Or at least we think so. Speaking from our experience at Deep Sea News, we have an extremely diverse readership of nonspecialists to tenured marine biology professors and everywhere in between. We are very appreciative of our audience and learn a great deal from the variety of backgrounds represented in our comments and the emails you send us. But without blogs and social media there is very little opportunity for people to connect with scientists. Building social connections undoubtedly makes people more receptive to new ideas, or at least lend a sympathetic ear.

This was the topic of a fantastic TED talk by Steven Johnson (embedded below) who asks, where do good ideas come from? He argues rather nicely, in my opinion, that good ideas derive from “coffee house” type environments. We use the combined intellect of our peers to bounce ideas off of and filter out good ideas for further exploration. Blogs are much like online coffee houses. Anyone can walk in, join a conversation and leave as they wish. Having people from all walks of life gives us scientists more diverse walls to bounce ideas off of, making us better communicators and helping us in our own research. The direct outcome of interacting with a variety of backgrounds is an improvement in how science as a process, and scientists as people, are appreciated in society. The indirect outcome is hopefully an improved climate for scientists to work in, e.g. more funding, jobs, etc.

Communicating with people involves a two way conversation. Its a give and take, a recognition that the party you are communicating with has a contribution to the discussion. Scientists may be mediocre communicators at best because it is in our nature to be the only one that understands what we do. We teach and lecture, communicating AT students or TO an institution’s press office. Some media training involves teaching scientists to drive home their main points during interviews with journalists. This has the unsatisfactory result of appearing elitist and ignoring the conversation that the interviewer is trying to set the tone of. If people are not part of the conversation, they are not invested in the discussion and may end up losing interest and fail to reach the conclusions you were trying to lead them to.

It disturbs me a little bit when I hear people say that what they do on blogs or elsewhere is communicating to the “common people”. Who are these common people? Does it include scientists or specialists in or outside your immediate research academic vicinity? Does it include teachers with or without an in-depth scientific training? Does it include maintenance people with a child-like fascination of their natural environment? Does it include school children and their parents? The truth is we never know who our audience is and we are lying to ourselves if we believe audiences are homogeneous. So I would like to propose that away from communicating AT or TO “common people” or the “general public” and move closer towards engaging people in a conversation about science.

I understand there are lots of criticisms to what I am talking about here. There is an institution of pure research that fights hard to maintain the scientist as a fixture of knowledge-elitism in society. This institution shuts away scientists from the “coffee houses”, virtual or otherwise, and encourages seclusion into a world of like-mindedness and long hours for high ranking publications and overhead money. This institution prevents creativity by trying to provide an false environment that fosters creativity

I won’t pretend to know how to be a better communicator and I don’t think we should dumb down content and resort to merely “shock and awing” our audience entirely. We do need to stop appearing elitist and give audiences a benefit of a doubt that they want to know something for the sake of knowing something. A blog post should be a starting point, not the final product. The ability to comment is a right that we as citizens on this planet should all utilize more often and exercise responsibly. We also need to take a pluralist approach, something I’ve recommended before and will continue to hammer. Pluralism, using multiple concepts or tools to tailor science outreach to different audiences, extends our reach and hopefully grasps into that most high of goals: to increase representation of minorities in science, in particular marine science as the case is here, because diversity is a good thing.

Scientists are not an authority that should be feared, but a resource to improve our civilization’s state of knowledge, to advance new ideas and technologies that improve our lives and more generally that of life on our planet. Thanks for entertaining my opinions.

The post From the Editor’s Desk: Communicating At, To Or With People? first appeared on Deep Sea News.

Last week we kicked off our online class with an introduction to the deep sea environment. Before we continue on to spend a bit of time talking about the history of deep-sea exploration, I want to discuss the current state of marine biology. An exciting and huge initiative to catalog the diversity of our oceans just concluded last Fall called the Census of Marine Life. When we discuss what explorers and scientists were doing in the Victorian era, keep this knowledge in the back of your mind and cross-reference it occasionally. You’ll find that while our methods have remained very similar throughout 200 years, our technology has allowed us to peer further and deeper with each passing year. Part of the key is identifying those areas to explore which will give us the greatest discoveries. You will see very quickly that we are not running out questions to ask or places to explore, despite the success of initiative like the Census, or great explorations like the Challenger expeditions in the late 1800s.

The Census of Marine Life was designed to look at the diversity, abundance and distribution of marine, from the tiniest microbes to the largest whale, at a global scale. In addition to the species information, the Census created an Ocean Biogeographic Information System (OBIS) that everyone – students, policy makers and scientists alike – can use, making this a highly valuable educational and research tool. No other initiative has been so ambitious and while the full success of the Census will be hashed out through the next 10s of years, the current success of the initiative is massive! A quick look at the participants’ statistics is at best an early indicator of what  is to come as the Census wraps up.

A DECADE OF DISCOVERY
2,700 scientists
80+ nations
540 expeditions
US$ 650 million
2,600+ scientific publications
6,000+ potential new species
28 million distribution records and counting

Though my part was minuscule compared to the overall scale of the Census, I am proud to have been associated with it for my small part in describing 5 of those species in 2 publications with colleagues from 3 countries. Below is the map of the Census’ project areas. There are 13 regional projects and 4 additional informatics and analysis projects. Most of the oceans were covered, yet so much remains to be discovered.

The initial results from the Census are being published as a collection in the freely available, open access journal PLOS One (a great opportunity for you see how scientists write up results from exploration!). In particular, one of the overview articles by Costello and colleagues describes the current knowledge state of marine biodiversity research. In it they examine the number of specialists per taxonomic group per region (below, left). What is striking is the emphasis on only a few different geographic regions. For instance, we know so little about basic marine ecology of the African continent! This is a new way of looking at our  effort as a community of marine biologists. Some of you may be joining this community and become my colleagues. Think about where the historical efforts have been placed and think very hard about where you might make a contribution.

In the Census’ 2010 Highlights of a Decade of Discovery Report (read it here for yourself!) they highlighted some of the data assembled on new species resulting from the Census efforts between 2000 and 2006 (above, right). In addition to pointing out the bias in geographic region found by Costello and colleagues, the Census Report highlights further a taxonomic bias, from our already limited expert pool, in marine crustaceans and molluscs. Between 2006 and 2010 the number of newly described species nearly doubled, and the Census Report estimates that there are potential up to 6000 new species resulting from the 10 year effort. The most species these appear to be the rare ones, emphasizing the ocean as a hot spot for speciation.

Species discovery wasn’t the only goal of the Census though and there were many basic science questions that were asked about how animals use the ocean, where they travel, how are their abundances distributed, how have human pressure exerted a selective force on fisheries populations, etc. To give you an idea of how enormous an effort this was, nearly 30 million new observations were added to the database greatly expanding our knowledge about animals distributions at a fine-scale, as well as all over the world’s oceans. Below is a Census video that does a very nice job of summarizing the initiative.

While there are many fantastic results coming out of the Census as we speak, and I could devote multiple lectures to them, I want to just highlight 2 results in particular that I hope you’ll find as fascinating as I do. The first result was obtained by studying how animals utilize their habitat. Researchers tracked Antarctic seals – the crabeater and southern elephant seals – using tags that record the location, time and depth of the seal (read about how to tag an elephant seal!). This data was recently published by Costa and colleagues and showed how these two seal species had very different ecologies (see figure to right). Crabeater seals stayed inshore and rarely dove deep, an average dive depth of 61 meters. On the other hand, elephant seals moved out into pelagic waters to forage and dove much deeper, an average of 345 meters (maximum depth recorded was 2388 meters). Interestingly, despite these huge differences in movement and habitat partitioning, both species maintained similar traveling speeds at 22.2 meters per second. By tracking seals over several years and tracking oceanographic conditions like current direction and speed, Costa and colleagues were able to show how seal movement patterns reflected the local oceanography. In fact, the seals and many other species out there like tuna, seabirds, whales, sharks, and sea turtles have become invaluable animal oceanographers.

The second result I would like to highlight was the thorough characterization of historical ecology of marine fisheries. A team of researchers were assembled which dove through historical records from not just the published literature but fisheries records and any historical observations from the last 1000 years or so to track temporal changes in marine populations. This project, dubbed Historical Marine Animal Populations (HMAP), for instance documented a drastic decline in body size of swordfish caught by harpoon or long line. In 1860 the average weight of a swordfish was 270kg (see graphic on left). By 1930 the fisheries records indicate that the average weight had dropped to near 100kg. A 63% decrease in average weight of swordfish landings over 60 years!

The researchers at HMAP sifted through thousand of records for all landings they could uncover. Over 100 HMAP researchers analyzed marine population data before and after human impacts on the ocean became significant. They documented a wide range of declines in marine animal populations that were commercially important in the past or currently are at the present. Some of these records were not necessarily targeted by the industry but were the result of bycatch in fishing practices, such as sea turtles, or from other non-fisheries sources, such as some coastal birds. This window into past helps understand what steps are needed in the future to better inform people, from fishermen to policy makers to scientists, about how to manage these species . Additionally, understanding the biological and sociological dimensions that brought us to our present enables us to make finer resolution predictions about how any action affects the system as a whole

What I hope you have gained from this small peephole into the Census of Marine Life is an appreciation of where we at now. There is still so much more to know in ocean science. We haven’t even scratched the surface and it is likely we never will. Our understanding of the ocean has proceeded in leaps and bounds, punctuated by pioneering enterprises much like the Census. In our first section we will look at the history of deep-sea exploration and examine how it has rapidly evolved due to leaps and bounds in technology and sampling ability. Our ever-increasingly ability to resolve finer scales in deep-sea science has allowed us to shift paradigms, which enables us to ask new and more interesting questions with a broader reach.

Costello, M., Coll, M., Danovaro, R., Halpin, P., Ojaveer, H., & Miloslavich, P. (2010). A Census of Marine Biodiversity Knowledge, Resources, and Future Challenges PLoS ONE, 5 (8) DOI: 10.1371/journal.pone.0012110

Costa, D., Huckstadt, L., Crocker, D., McDonald, B., Goebel, M., & Fedak, M. (2010). Approaches to Studying Climatic Change and its Role on the Habitat Selection of Antarctic Pinnipeds Integrative and Comparative Biology, 50 (6), 1018-1030 DOI: 10.1093/icb/icq054

The post Deep Sea 101: Lessons from the Census of Marine Life first appeared on Deep Sea News.

This series will be divided into 5 sections:

1. History of Deep-Sea Exploration and Changing Paradigms
2. Processed Operating at Ocean Scale Affecting the Deep
3. Adaptations and Patterns
4. Diversity of Deep Sea Habitats
5. The Human – Ocean Relationship

Throughout this series I hope the reader can develop a scientific appreciation for the ocean, understand the value of interdiscplinary science, demonstrate an understanding of the human – ocean interaction and get more comfortable with the scientific literature and how scientists present data. To guide your exploration of the Deep, we are using Tony Koslow’s The Silent Deep, selected chapters from Gage & Tyler’s Deep Sea Biology (1992), and papers from the popular and academic literature. You should enjoy Silent Deep, it is a very readable, nicely produced and illustrated book. It reads like a book, not a text is very affordable, a bargain for its price! (I plan on reviewing it from an instructor’s perspective at the end of the semester). We will also be using review articles from Oceanography, which provide typically well-laid out, well illustrated and readable topical issues written by scientists.

What is the deep sea? Opinions differ but the ramifications matter. Older definitions define the deep-sea as less than 200 or 400 meters, sometimes less than 1000 meters. Much of our affect on the deep-sea occurs within the first 1000 meters of the water column. But the average depth of the ocean just less than 4,000 meters so we are even barely aware of the extent of our impact.

Maybe to you the deep-sea means scary, sharp-teeth laden fish like the anglers or bioluminescent creatures and odd jellyfish. You may have heard about the real sexy habitats like hydrothermal vents or deep-sea coral reefs. But you will probably be most surprised to know that the seafloor looks like mud (see left). Occasionally there is a little stick of a sponge, lonely in the abyss. Perhaps a tripod fish moping about. Not much that appears to be going on. Just an endless expense of mud for as far as the walleye can see.

And you would be dead wrong. The muddy seafloor is alive with thousand strong armies of sea pigs on the march, millions of small worms burrowing about, or a wide variety of fish coming and going following ephemeral traces of food. The deep sea is the largest environment on the planet and is extremely variable in both time and space at any given point. The diversity and uniqueness of the deep sea fauna and the variety of deep-sea habitats rivals that of many terrestrial habitats, which we will touch on later in the series.

The ocean is characterized by distinct zones, the transitions of which are marked by thermal or pressure interfaces. In the diagram to the right you can see that the majority of the biomass in a water column occurs in the first 200 meters where the temperatures are still warmer and light penetrates through the water. But as light get filtered out, the temperatures shorten, very little biomass exists in the water column, an area referred to as the twilight zone. It is also one of the least explored and understand parts of our planet. As we approach the seafloor there is more biomass, but it appears to never accumulate so much to even begin to rival the amount of life at the surface. Part of this may be our lack of understanding of what happens in sediment communities. Traditionally we study the things we can see on top of the seafloor and have paid little attention to the infaunal community, those animals that lives among the sediment grains.

Our understanding of the deep sea is a case study in how technology allows us to peer even closer at every step. We are limited by our own imagination to conceive of devices that will carry us to the bottom of the ocean. Only once have humans gazed at the seafloor near the deepest point in the ocean – the Marianas Trench. A point known as Challenger Deep, in honor of the vessel that paved the way for large-scale, hypothesis-driven oceanographic science. Technology has allowed us to discard a paradigm of a uniform seafloor devoid of life, with few interesting topographic features or geologic history. Instead, with the onset of sonar technology and improved sampling techniques and devices, we’ve discovered an environment with a wide variety of seafloor features from submarine canyons and underwater mountain ranges to abyssal plains and deep trenches. The seafloor is littered with habitats (see left) and our pace of discovery in deep-sea shows no signs of slowing down.

NEXT WEEK: Lessons from the Census of Marine Life

The post Deep Sea 101: Introduction and What Is the Deep Sea? first appeared on Deep Sea News.

Commercial fisheries have worn the brunt of excess and experiments in regulations for several decades. Many fishing quotas are set using recent historical catch data and based on a maximum sustainable yield. The commercial fishing industry has much to be concerned about. Reduced yields will devastate livelihoods and jobs in areas where fishing is the only, or by far the largest, industry. Subsidence fishing, typical in impoverished areas, will be threatened and inhabitants will need to procure new sources of protein.

Much of the current research has focused on animals with carbonate skeletons. Acidic oceans will degrade molluscan shells, making them particularly susceptible as larvae and as adults to mortality. Corals provide habitat for many commercial stocks of finfish, with nearly 10% of worldwide landings coming from reefs (Carpenter et al. 2008). Deep-sea coral reefs in cold, dark waters support juvenile commercial finfish stocks, such as roughy and codling (Hall-Spencer et al. 2002, Rogers 1999). Furthermore, larval and adult fish and marine mammals who rely on planktonic food sources will be nutrient limited if their prey have difficulty adapting to changing pH.

One area that will need particular attention is the physiological effects on already overfished commercial stocks. Preliminary experiments in cod suggest they are able to adjust enzyme levels, with motor control unaffected, to cope with the 2000 ppm levels of carbon dioxide projected not too far into the future (Meizner et al. 2008). Larval fish are likely to be more susceptible to changes in pH as they are less protected from changes in the environment, expend lots of energy for physiological processes, and experience high natural mortality. Lower ocean pH makes acid-base regulation more difficult since diffusion plays a stronger role than in adults where active ion-transport accounts for the majority of physiology.

Much research is needed, particularly with larval fish and invertebrates, to understand what lower pH means to their physiology, growth and survival. Commercial fisheries and consumers will need to adjust their seafood-consumption lifestyles to accommodate lower sustainable yields. The socioeconomics of reduced fishing capacity needs to be addressed at a global scale. I fear that fisheries will be attacked synergistically by all these forces – climate and fishing pressure – and hope people smarter than I can come up with tenable solutions.

It is likely not all doom and gloom. We humans have a remarkable ability to adapt when the will is strong. The sooner we address the changes that need to take place, the better off the ecology of the oceans are, the better off fishermen and their livelihoods and culture are, and the better off seafood consumers are. My plea is not merely for more research in ocean acidification and its effects on fisheries, but an integrative approach that accounts for our consumptive lifestyle.

References:
Carpenter KE, Abrar M, Aeby G, Aronson RB, Banks S, Bruckner A, Chiriboga A, Cortés J, Delbeek JC, Devantier L, Edgar GJ, Edwards AJ, Fenner D, Guzmán HM, Hoeksema BW, Hodgson G, Johan O, Licuanan WY, Livingstone SR, Lovell ER, Moore JA, Obura DO, Ochavillo D, Polidoro BA, Precht WF, Quibilan MC, Reboton C, Richards ZT, Rogers AD, Sanciangco J, Sheppard A, Sheppard C, Smith J, Stuart S, Turak E, Veron JE, Wallace C, Weil E, & Wood E (2008). One-third of reef-building corals face elevated extinction risk from climate change and local impacts. Science (New York, N.Y.), 321 (5888), 560-3 PMID: 18653892

Doney SC, Fabry VJ, Feely RA, & Kleypas JA (2009). Ocean acidification: the other CO2 problem. Annual review of marine science, 1, 169-92 PMID: 21141034

Hall-Spencer J, Allain V, & Fosså JH (2002). Trawling damage to Northeast Atlantic ancient coral reefs. Proceedings. Biological sciences / The Royal Society, 269 (1490), 507-11 PMID: 11886643

Le Treut H, Somerville R, Cubasch U, Ding Y, Mauritzen C, Mokssit A, Peterson T, Prather M (2007) Historical Overview of Climate Change. In: Solomon S, Qin D, Manning M, Chen Z, Maruis M, Averyt K, Tignor M, Miller H (eds) Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, pp 94-127.

Melzner F, Göbel S, Langenbuch M, Gutowska MA, Pörtner HO, & Lucassen M (2009). Swimming performance in Atlantic Cod (Gadus morhua) following long-term (4-12 months) acclimation to elevated seawater P(CO2). Aquatic toxicology, 92 (1), 30-7 PMID: 19223084

Revelle R, Suess HE (1957) Carbon Dioxide Exchange Between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO₂ during the Past Decades. Tellus 9:18-27.

Rogers A (1999) The biology of Lophelia pertusa (Linnaeus 1758) and other deep-water reef-forming corals and impacts from human activities. International Review of Hydrobiology 84:315-406.

Stanhill G (2001) The growth of climate change science: a scientometric study. Climatic Change 48:515-524.

The post From the Editor’s Desk: The Grand Challenge of Ocean Acidification and Fisheries first appeared on Deep Sea News.

Barnacle evolution was recently rewritten by a large effort of Perez-Losada and colleagues in 2008. Using a combination of genes and morphological traits they rejected some of the ideas that were foundational to barnacle biology and taxonomy, while giving new support for other ideas.

Though Linnaeus and his students described several barnacles, the real authority was none other than Charles Darwin. He spent over 8 years studying, describing in rich detail and monographing every barnacle he could get his hands on from every part of the world. The result was four epic tomes that are still referenced today. Darwin Online has the complete works freely available over the internet: Living Cirripedia Volumes 1 & 2 and Fossil Cirripedia of Great Britain Volumes 1 & 2.

Though he certainly studied whole anatomy, Darwin based much of his taxonomy on characteristics of the shell. The cirripede shell is formed by plates secreted by the cuticle. They are not molted, or shed, like in other arthropods but increase in size circumferentially. The number of shell plates were traditionally hypothesized to increase from an ancestor with 4 or 5 plates during the course of evolution. Other groups in the Thoracica (meaning “little body”) with more plates are thus more derived. It is uncertain to what the selective pressure was to develop different numbers of plates. Perhaps more smaller plates offer greater protection than fewer larger plates. What Perez-Losada et al. found out though was there were no clear patterns with plate enumeration. Clades with no plates are mixed in with clades with 5 plates, while a clade with more than 12 plates is sister to a clade with a last common ancestor that had no more than 7 plates.

The theory of shell plate evolution is clearly debunked in this analysis, though they can say with some degree of certainty that the last common ancestor to the Thoracica had no more than 4 plates. Another interesting point is that asymmetry (Verrucomorpha) has evolved independently at least twice in the thoracican lineage. I believe this highlights the plasticity in biomineral characters, such as shell characteristics. This is seen in many molluscan clades where general shell characteristics are misleading, sometimes due to external parameters (erosion) and sometimes due to phenotypic plasticity in the mechanisms that construct biomineral structures. Thus, the soft parts and larval characteristics are more important (though often more difficult to study and they leave no fossil trace).

On a systematic level they uncovered several polyphyletic clades, such as the Heterlepadomorpha (those that have no shell plates). This clade appears to have evolved at least twice, independently, and in both cases are more derived (within clades that have more than 5 plates) and a more recent radiation. The previously well established clades of the Verrucomorpha (“wart shaped”), Scalpellomorpha (“lancet, of knife, shaped”) and Sessilia (“sedentary” or “without a stalk”) are no more, while the Iblomorpha and Balanomorpha have gained unequivocal support. One grouping that caught my attention is the clade below (magnified from above).

Especially everything under and including the clade marked ‘Verrucomorpha (7s)’. All those barnacles – Neoverruca, Ashinkailepas, Vulcanolepas, Leucolepas and the aforementioned Neolepas are – are hydrothermal vent barnacles from the Pacific Ocean. I am very surprised to see this neat and well supported grouping. In particular, the stalked barnacle Vulcanolepas osheai is known to likely harbor chemoautotrophic bacteria on its cirri. The more vent scientists look, the more it seems that vent organisms tend to form clades despite geographic distance, barriers or classical taxonomic ranks. We are seeing similar grouping in anemones, caridean shrimp, bythograeid crabs, and of course all the chemoautotrophic taxa: siboglinid annelids, bathymodiolin mussels, and vesicomyid clams. The habitat appears to be a unifying factor, though in chemoautotrophic mussels there have been transitions between habitats, and reversals (see Jones et al. 2006).

This is a great study for many reasons, partly because it answers some questions, but mostly because it rearranges our thinking about the taxa in question and gives us more avenues to explore. I didn’t highlight all the major discoveries from this article, such as the fine-tuning of the tempo of evolution, but I hope to see future papers addressing the evolutionary ecology of barnacles in light of the new systematic rearrangement. Taxonomy is at the point now where substantial revolutions need to occur in order to progress from stagnancy. This study and others like it using ‘total evidence’ (i.e. combining morphological characters, life history traits, genetics, etc.) will pave the way to understanding animal evolution and give the field of systematics the credit it deserves, both financially and publicly.

Pérez-Losada M, Harp M, Høeg JT, Achituv Y, Jones D, Watanabe H, & Crandall KA (2008). The tempo and mode of barnacle evolution. Molecular phylogenetics and evolution, 46 (1), 328-46 PMID: 18032070

*Next post in this series will examine the evolution of dwarf males.

The post Barnacle Evolution I: Phylogeny Served Without Plates first appeared on Deep Sea News.