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To rigorously compare the search for the MH370 black box to searching for a needle in a haystack we need to do a little bit of mathematics of proportions.  Not much, so don’t be put off.  There’re some assumptions too, so feel free to tear those apart in the comments section.

To start with, how big is this black box?  Well, I don’t have exact measurements, but based on what they’ve shown on the news, a maximum linear dimension of about 2 feet seems about right.  OK, how big is a needle?  Let’s assume it’s not a giant knitting needle, but a mattress or darning needle, let’s say 3 inches long.   The needle and the black box have quite different shapes, but maximum linear dimension is a good proxy for overall size of differently shaped objects, so we’ll use that.  So, a needle is about 1/8th the maximum linear dimension of the black box.   To be a useful analogy then, the haystack needs to be equal or more than about an eighth the size of the search area because the needle is about an eighth the size of the black box.

So, how big is a haystack?  I haven’t the foggiest, I’m not a farmer.  But for a starting point, let’s assume that the haystack fits inside a barn.  There are several standard size barns, but let’s go with 20’x30’.  Nah, let’s go bigger, 36’x60’, and let’s assume the entire footprint of the barn is filled with hay.

Now, since the black box is likely on the bottom at this point, let’s make this about the area, not the volume of the haystack.  In other words, the needle is UNDER rather than embedded IN the haystack some non-zero distance off the floor.  This is really important , because if we assume volume instead and we’re searching the entire water column, then it’s all over bar the shouting; as WaPo elegantly shows in this infographic, the ocean is deep, Deep, DEEP.  That would be one hell of a tall haystack (EDIT: about 1,850 feet tall, proportionally speaking, or 500ft taller than the empire state building).  Let’s also assume that the batteries have run out (they will soon if they haven’t already) so the black box is not going to help us find it, the same way a needle won’t help you find it either.

Our haystack is 36’x60′, so that would be 2,160ft² to search under for a 3 inch (0.25ft) object.  This is a size ratio of 1.16 x 10^-4 (or 0.000157).  The cumulative search area for the black box has been 2.96 million square miles (source: BBC), or 8.25 x 10¹³ square feet to search for a 2ft object.  That’s a search ratio of 2.42 x 10^-13, or 9 orders of magnitude difference.  Even if you take the most recent focus area of about 30,000 square miles, that’s still 8.36 x 10¹¹ square feet, or ten million times the ratio of the haystack to the needle.  It is not an exaggeration, then, to say that the search for MH370 – the black box at least – is not just like finding a needle in a haystack, it’s a billion times harder than that.  

Add in the depth factor (go to that WaPo infographic to remind yourself) and you get a feel for the magnitude of the task at hand.  If they find anything, it will be a triumph of science, engineering and human determination.  I truly hope they do for the sake of the families involved, but we should have some realistic expectations.

The post MH370 and the proverbial haystack. first appeared on Deep Sea News.

Sea squirts, aka tunicates, in shallow water are more like, “Hey look at me! Food is everywhere.  I’m just gonna sit her on my fat tunicate ass, play GTA5, and filter that yummy food out of the water.”

The atrial siphon is located on D. antirrhinum’s top.  Stare closely and long enough and you will see my favorite Hanna-Barbera cartoon character from the 80’s—a Snork.  Of course a big mouth is no good without some muscles to back it up.  And o’ do muscles flourish! Circular muscles surround the lips, longitudinal muscles run both along the top and bottom of the mouth, and set of oblique muscles link the corners of the lips right the digestive system. Tiny crustaceans are not leaving this tunicate trap.

Impressed yet? Well, consider that the name antirrhinum is homage to the genus of flowers Antirrhinum.  You know the flowers better as snap dragons so called because the flowers resemble the face of a dragon that opens and closes its mouth when laterally squeezed.

A. Mecho, J. Aguzzi, J.B. Company, M. Canals, G. Lastras, X. Turon (2013)  First in situ observations of the deep-sea carnivorous ascidian Dicopia antirrhinum Monniot C., 1972 in the Western Mediterranean Sea. Deep-Sea Research, Pt. 1 http://dx.doi.org/10.1016/j.dsr.2013.09.007

BONUS: In quality only USA and Hanna-Barbera in the 80’s could deliver here is the opening to the Snorks.

The post This Deep-Sea Predator is the Love Child of a Macaron and a Snork first appeared on Deep Sea News.

Flagellum and ingesting puppies, metaphorically speaking, is the norm for most sponges.  However, in the dark depths of oceans and in the black caverns of the marine caves, lurks Earth’s strangest creatures—the carnivorous sponges.

Most sponges are composed of spicules, little shards of silica, that provide structure.  In the carnivorous sponges, Cladorhizidae, some spicules are shaped like hooks.  Unsuspecting tiny crustaceans or other animals near the sponge are often caught in the sheets of hooks that line the surface of the Cladorhizid sponges, much schmutz in Velcro.  In some Cladorhizids copepods may be caught by an adhesive surface.  Once a crustacean is caught, the cells surrounding mobilize, cover, and create a temporary cavity around the crustacean.  Within this cavity the crustacean is digested.  It’s the equivalent of mosquito being caught in your arm hairs , the skins cells then form a layer of skin over it, and finally you digest the mosquito just below the surface of the skin.

The first species of Cladorhizid was described only recently in 1995 from submarine caves in the Mediterranean.  In approximately the last 20 years, 33 species have been discovered and described, with several more in the works. Even though new to humans, Cladorhizids have dwelled on Earth since at least the Pleistocene, 2 million years ago.  Fossils from this period are easily identifiable as the bizarre sponges.  However, 200 million year old spicules do bear a striking resemblance to those from the carnivorous sponges of the modern oceans.

Even more unusual is the bewildering shapes that Cladorhizids take, from the pipe cleaner structure of Abestopluma, to the ping pong tree structure of Chondrocladia lampadiglobus, to the beautiful harp shape of Chondrocladia lyra. The evolutionary reasons for this vast variety of shapes among species remains a major unknown, as is most of the biology of the fascinating group. Despite our lack of knowledge a carnivorous sponge is deserving of rightful place as a top 10 species.

Les Watling (2007). Predation on copepods by an Alaskan cladorhizid sponge. Journal of the Marine Biological Association of the United Kingdom, pp 1721-1726. doi:10.1017/S0025315407058560.

Vacelet, Jean & Boury-Esnault, N. (1995): Carnivorous sponges. Nature 373 (6512): 333–335. doi:10.1038/373333a0

Lee, W. L., Reiswig, H. M., Austin, W. C. and Lundsten, L. (2012), An extraordinary new carnivorous sponge, Chondrocladia lyra, in the new subgenus Symmetrocladia (Demospongiae, Cladorhizidae), from off of northern California, USA. Invertebrate Biology. doi: 10.1111/ivb.12001

The post Flesh Eating Sponges? first appeared on Deep Sea News.

Unfortunately  what we know of deep-sea diversity is based on bigger life like worms like snails, crustaceans, and echinoderms. Little is known about microbial diversity of the muddy ooze that characterize the immense deep-sea floor.  That is until now.  Microbial diversity on the abyssal plains is higher than we thought and dominated by the rare biosphere.

A new study in PNAS by Scheckenbach et al. documents the biodiversity of microbes across the South Atlantic.  Nearly 400 “operational taxonomic units,” shorthand for genetically distinctive organisms, were discovered.  For 73% of these organisms, no closely genetically related organisms are currently known.  Like many other deep-sea organisms, microbial communities are dominated by rare species represented by single to few individuals. And like other deep-sea species found over large areas of the seafloor, in this case over 1000’s of kilometers.

We gauge how well we have sampled an area by viewing a sampling curve, a plot of sampling effort versus the number of new species.  This allows us to determine whether we are likely to find more new species with increased sampling effort.  We hope these curves are “saturated” and that the answer to the previous question is no.  However, this is rarely the case with deep-sea studies and sampling curves rarely reach saturation.  The Scheckenbach et al. microbial study is no different and future sampling is likely to uncover hundreds of new species.

Overall this study challenges the idea of depauperate deep sea.  It will also shape how we strive to understand biodiversity of the deep sea, as hypotheses explaining these biodiversity patterns will have to account for both metazoans and microbes.
Scheckenbach, F., Hausmann, K., Wylezich, C., Weitere, M., & Arndt, H. (2009). Large-scale patterns in biodiversity of microbial eukaryotes from the abyssal sea floor Proceedings of the National Academy of Sciences, 107 (1), 115-120 DOI: 10.1073/pnas.0908816106

The post Great Abyssal Diversity Among the Microscopic first appeared on Deep Sea News.

The project is completed by 2010, a little less than a month away. In the last ten years, The Sloan Foundation funded well over 100 million dollars for the CoML project. With a cadre of biologist, a huge budget, 14 field projects, and 210 expeditions, 17,650 new species were found and described. “The abyssal fauna is so rich in species diversity and so poorly described that collecting a known species is an anomaly,” says Dr. Billett. “Describing for the first time all the different species in any coffee cup-sized sample of deep-sea sediment is a daunting challenge.”

Five of the Census’ 14 field projects focus on the habitats below 200m – the continental margins (COMARGE: Continental Margins Ecosystems), the mid-Atlantic Ridge (MAR-ECO: Mid-Atlantic Ridge Ecosystem Project), the submerged mountains (CenSeam: Global Census of Marine Life on Seamounts), the muddy abyssal plains (CeDAMar: Census of Diversity of Abyssal Marine Life), and and chemically-driven ecosystems (ChEss:Biogeography of Deep-Water Chemosynthetic Systems).  I’m involved with and received funding (yeah!) both under CenSeam and CeDAMar.  As part of CeDAMar, I worked with a group developing a synthesis of abyssal diversity.

“There is both a great lack of information about the ‘abyss’ and substantial misinformation,” says Dr. Carney. “Many species live there. However, the abyss has long been viewed as a desert. Worse, it was viewed as a wasteland where few to no environmental impacts could be of any concern. ‘Mine it, drill it, dispose into it, or fish it – what could possibly be impacted? And, if there is an impact, the abyss is vast and best yet, hidden from sight.’ “Census of Marine Life deep realm scientists see and are concerned.

The post Cataloging Life On the Deep-Sea Floor first appeared on Deep Sea News.

In the last 130 years, our view of the deep oceans radically changed.  No longer is the largest environment on earth considered a dark homogenous wasteland, unchanging through time, buffered against climatic fluctuation, and devoid of biodiversity.  The modern view of the deep-sea realizes a varied landscape comprised of reducing habitats such hydrothermal vents, methane seeps; mid-oceanic ridge systems and geologic hotspots that produce topographic complexity and new volcanic substrates; large food falls in the form of wood and whales that provide oases of food in a low productivity system; intricate canyon and slope systems presenting radical environmental shifts; and oxygen minimum zones intercepting continental margins.  Even the expansive mud bottom that serves as the backdrop for these multiple habitats is considered a spatially and temporally dynamic system characterized by episodic benthic storms, internal tides, downslope debris and sediment flows, patchy carbon input across multiple scales, rich with biogenic disturbance and structure, and intrinsically linked to ocean surface processes.   The hypothesis of a biological desert is but a ghost of science past put to rest by findings of spectacularly high biodiversity. But what of the notion of deep-sea species unbound by dispersal barriers able to distribute across to the farthest extents of ocean basins?  What is the biogeography of the deep sea?

In a multipart series I will examine the biogeography (defined very well by Jim Lemiere as the patterns of the geographic distribution of biodiversity – where organisms are, where they ain’t, and who lives with or without whom) of the deep.  I do this in conjunction with an invited review on the same project, authored by myself and two accomplished deep-sea biologists that I have longed admired and possess a deep respect for. My plan is to use DSN as sounding board for this project.

Now, the biogeography of deep-sea organisms is historically a black box characterized more by conjecture than data. Unsurprising given the remoteness of this environment and challenges to sampling it presents. Previously, many assumed, due to the lack of perceived environmental variability and geographic barriers, ranges of deep-sea species on the abyssal plains and continental margins were exceedingly large. New research utilizing higher-resolution sampling, molecular methods, and a ever-expanding amount of information in public databases are once again raising the question of how small marine invertebrates disperse across the vast distances of the ocean floor. Recent findings on unique seamount and chemosynthetic habits suggest high levels of endemism and challenge the broad applicability of single paradigm for all deep-sea environments.

Stay tuned for the first segment on the origins of deep-sea fauna.

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The post TGIF: Making of Abyss first appeared on Deep Sea News.

The 285  macrourid fishes, the rattails, whiptails, and grenadiers, are one of, if not the, most abundant fish in the deep.  You cannot throw…well anything…without hitting one.  What do all these fish eat?  In one scenario, macrourids feed on organisms living on the seafloor, that in turn originally feed on detritus, i.e. marine snow, raining from the surface.  Or these fish could cut out the middle man and feed directly on dead prey originally from surface. Or they could do both?

In simplified terms, phytodetritus is consumed by deposit feeders, which in turn are consumed by primary carnivores and so on to the top trophic positions including many fishes.  However, an alternative trophic pathway exists. Many deep-sea fishes are attracted to cameras baited with pelagic carrion and a few studies have noted carrion in their diets.  However, these observations have rarely been quantified. Scavenging on the sunken carcasses of epipelagic nekton bypasses the conventional benthic food web, although the beginning of each path shares primary production in surface waters. The relative importance of these 2 trophic pathways remains uncertain.

The question may seem trivial but the answer gets at nothing less than the pathway of carbon into the deep, and impacts how we understand carbon cycling and sequestration. A new study by Drazen et al. in Marine Ecology Progress Series examines the fatty acids of two macrourids and a whole host of their potential prey items.  All the samples were collected from the well-known Station M site (see map).

[googlemap lat=”34.9″ lng=”-123″ width=”500px” height=”500px” zoom=”7″ type=”G_HYBRID_MAP”]Station M[/googlemap]

What is generated from the data are the two plots below.  All you need to know is that the closer two points are on the graph the more similar the fatty acid content of their tissue.  The first plot is for macrourids and benthic prey and the second plot adds a few more pelagic prey.  Macrourids are black, echinoderms green, polychaetes, orange, anemones purple, crustaceans blue, and either living or dead on the seafloor, depending on the plot, pelagic species in red.

So it is obvious what is going on here , right?  Benthic crustaceans and pelagic-derived carrion taste good.  Echinoderms and polychaetes not so much.

So Number 1, as the press release for this paper states “This indicates that epipelagic populations constitute a significant part of the diet in abyssal fishes”, and thereby circumventing part of the food web.  And Number 2, no doubt making Chris Mah smile, and a bit of conundrum, is that they do not eat echinoderms.  As Chris Mah would quickly tell you, probably over cocktails at a party, echinoderms are one of the most dominant taxa in the deep.  You cannot throw a macrourid without hitting one.  Why do macrourids, obviously opportunistic scavengers/predators, not eat the most abundant food source in the deep?

Drazen, J., Phleger, C., Guest, M., & Nichols, P. (2009). Lipid composition and diet inferences of abyssal macrourids in the eastern North Pacific Marine Ecology Progress Series, 387, 1-14 DOI: 10.3354/meps08106

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Everything you ever wanted to know about sea pigs (Holothuroidea: Scotoplanes sp.) from the Echinoblog.  The best part is the gastropods parasites that love them a little too much.

The post Sea Pigs first appeared on Deep Sea News.