Ever heard of forensic limnology? Neither had I, until I had a random conversation during a coffee break.

The police find a body in the water. How did it get there? How did this person actually die? Was this a tragic accident, or perhaps something more malicious?

The fateful anecdote, the one that enticed me to write about this topic, goes something like this: A mob informant suddenly turns up dead. At first glance, the death doesn’t look suspicious – he was surely drunk when he fell off that balcony. But something’s not quite right. The bleeding appears to be postmortem, the autopsy shows water in the lungs. It’s well known that the local mob wanted this man dead. But how do prosecutors build a case?

To solve this mystery, we have to rely on diatoms. I’m talking about tiny, single-celled species of algae with “shells” made of silica (sidenote: this shell is actually a cell wall called a frustule, which is by far the awesomest anatomical term in marine biology!!). Diatoms under the microscope look something like a kaleidoscope, and I probably wouldn’t try to study them if you’re on LSD:

Diatoms live EVERYWHERE where there is water: oceans, lakes, rivers (and even soil). They are used to monitor and assess water quality. Diatoms are also probably in your cat litter and toothpaste. In fact diatoms are damn useful for many many things, even for determining the age of rock and sediment layers – diatom cell walls are so well preserved in the fossil record and have been so extensively studied by scientists, that we know almost exactly when different species appear and disappear in geologic time.

Where else are diatoms well preserved? IN DECOMPOSING BODIES!!!!

Back to our case – diatoms provide key evidence for forensic investigations of suspected drowning deaths. As a person drowns, they inhale water into the lungs. This water, along with any microscopic animals floating around, gets taken up by the bloodstream and circulated around to the internal organs. Following drowning, Diatoms are known to aggregate in the bone marrow (especially the long bones such as the femur). These microscopic creatures are particularly critical in autopsies, because, well…

For the decomposed corpses and skeletonised body [sic] found in water…the diagnosis of drowning is rather difficult because those ‘‘drowning signs’’ were destroyed. Here [the] diatom test stands as the only direct screening test for drowning [1]. (Vinayak et al. 2013)

The collection of diatoms in a victim’s bone marrow represents a microbial “fingerprint” of the time and place where drowning occurred. Each lake, river, estuary and ocean contains a unique community of diatoms. The mix of species found in any given location also fluctuates over time, and varies according to season. So upon finding a body, a medical examiner can deduce whether a person drowned in freshwater or saltwater — or if death didn’t occur by drowning at all. On the other hand, if a person was forcibly drowned in a bath (and then maybe their body transported out to sea), their body tissues wouldn’t show any evidence of diatoms, since only filtered, diatom-free tap water would have been ingested at the time of death (before the heart stops beating). Diatoms have even been used to convict criminals in attempted drownings, where the species assemblages on the perps’ sneakers were shown to be pretty much identical to the species found in the “crime scene pond”.

In the case of our fallen mob informant, the courts would need to build up a solid body of evidence to prove that the accident was staged. A forensic investigator would perform an autopsy to remove bits of the brain, liver and bone marrow. “Femers are longitudinally sectioned using a clean band saw…” (Verma, 2013) – and then dissolved in acid.  The gooey mix of liquified tissue is centrifuged and purified, and the slurry that remains is examined under the microscope to look for diatoms and identify the species present. The police can go even further and collect swabs of dirt from suspects’ shoes and homes. Since diatom communities can fluctuate quite a bit over space and time, guilt could be easy to prove if the “fingerprint” of diatom species shows an exact match between the suspect’s shoes and the victim’s bones. But one thing is certain – our man drowned. The biology don’t lie!

Case. CLOSED!

References:

Cox, E. J. (2012) Diatoms and Forensic Science, in Forensic Ecology Handbook: From Crime Scene to Court (eds N. Márquez-Grant and J. Roberts), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9781118374016.ch9

Vinayak V, Mishra V, Goyal MK (2013) Diatom Fingerprinting to Ascertain Death in Drowning Cases. J Forensic Res 4: 207. doi:10.4172/2157-7145.1000207

Pollanen, M. S., C. Cheung, and D. A. Chiasson. “The diagnostic value of the diatom test for drowning, I. Utility: a retrospective analysis of 771 cases of drowning in Ontario, Canada.” Journal of forensic sciences 42.2 (1997): 281-285.

Verma, Kapil. “Role of diatoms in the world of forensic science.” J Forensic Res 4.181 (2013): 2.

The post Diagnosing Death with Diatoms first appeared on Deep Sea News.

The post The Biological Pump: A short film in construction paper first appeared on Deep Sea News.

Recently we at Deep-Sea News have tried to combat misinformation about the presence of high levels of Fukushima radiation and its impact on marine organisms on the west coast of the United States.  After doing thorough research, reading the scientific literature, and consulting with experts and colleagues, we have found no evidence of either.  In the comments of those posts and on Twitter, readers have asked us about the “evidence” of dead marine life covering 98% of ocean floor in the Pacific as directly attributed to Fukushima radiation.  After some searching I found the main “news” article that is referenced.

The Pacific Ocean appears to be dying, according to a new study recently published in the journal Proceedings of the National Academy of Sciences. Scientists from the Monterey Bay Aquarium Research Institute (MBARI) in California recently discovered that the number of dead sea creatures blanketing the floor of the Pacific is higher than it has ever been in the 24 years that monitoring has taken place, a phenomenon that the data suggests is a direct consequence of nuclear fallout from Fukushima.

Before I discuss this “evidence” further, I want to provide a little background.  I am a deep-sea biologist and over the last several years my research has focused on the biodiversity of deep-sea communities off the California coast.  Like many others, I am also working toward understanding how deep-sea life will respond to increased anthropogenic impacts particularly climate change.  This resulted in a high profile publication in the Proceedings of the National Academy of Science.  I mention this background because 1. It explains why I view myself as an expert to comment on this and 2. it explains why I was confounded for a moment when I thought I had missed a paper in a journal I have published in, on a geographic region I study, and on a topic close to my own research.  And to boot from researchers at institution (MBARI) I was formerly employed with.

The reason I am unfamiliar with a study providing evidence of  “Dead sea creatures cover 98 percent of ocean floor off California coast; up from 1 percent before Fukushima” is because no such study exists.  Here are the details of the actual study.

Ken Smith’s group at MBARI has monitored a deep-sea abyssal site called Station M off the California coast continuously since 1989 (24 years).  Their work has lead to many major findings.  A majority of deep-sea animals are completely reliant on the sinking of food from the surface, i.e. marine snow. One of the most important findings from Smith and colleagues’ work is that rhythm of deep-sea life is intrinsically linked to the production of phytoplankton at the oceans surface. Thus El Nino/La Nina cycles and other such meteorological/oceanic events leave a deep-sea signature.  Ken’s research has been paradigm shifting for deep-sea research.  We have moved from a belief of a stable and climate-buffered view of the deep sea to one of a dynamic system intimately related to seasonal, annual, and decadal changes in surface production and ocean currents.

This group’s newest paper

Smith, K. L., H. A. Ruhl, M. Kahru, C. L. Huffard, and A. D. Sherman. (2013). Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean. Proceedings of the National Academy of Sciences, www.pnas.org/cgi/doi/10.1073/pnas.1315447110.

reports findings that large and episodic pulses of marine snow occur.  These large blizzards are met by hungry deep-sea animals that quickly gobble the meal.  The amount of food these blizzards deliver are huge equaling years, if not decades, of normal marine snow.  But the amounts and frequency of both normal marine snow and the blizzards are changing.

From 2003 to 2012 the amount of phytoplankton production, fodder for marine snow, was higher than years prior.  After 2006, the frequency of spikes in marine snow, i.e. blizzards, also increased.   In the summer of 2011, the first of three dramatic blizzards occurred.  During this event a large number of diatoms bloomed at the surface and sank rapidly to the seafloor.  The second event in the spring/early summer of 2012, was triggered by a major bloom of gelatinous salps. As mentioned in the press release of the paper, “These salps became so abundant that they blocked the seawater intake of the Diablo Canyon nuclear power plant, located on the California coast east of Station M.”  When these salps died, as they do after a bloom, they carpeted the seafloor.  In September 2012 another plankton bloom occurred and this combined with fecal pellets from salps (who hungrily munched on the algae) again carpeted the floor with marine snow.  In addition the greatest amounts of marine snow and consumption by deep-sea life (as measured by respiration rates) occurred in the last two years of the time series.

What caused these recent changes in marine snow?

From the paper,

The abyssal area surrounding Station M is influenced by the California Current, which is experiencing increased wind stress, resulting in increased upwelling of nutrient-rich subsurface waters, contributing to increased primary production. With increasing primary production there has been a corresponding increase in POC flux and detrital aggregate accumulation on the sea floor over the past several years.

And from the press release,

The researchers note that deep-sea feasts may be increasing in frequency off the Central California coast, as well as at some other deep-sea study sites around the world. Over the last decade, the waters off Central California have seen stronger winds, which bring more nutrients, such as nitrate, to the ocean surface. These nutrients act like fertilizer, triggering blooms of algae, which, in turn, sometimes feed blooms of salps. The fallout from all of this increased productivity eventually ends up on the seafloor.

Nowhere does the paper or the press release mention radiation or Fukushima. Nilch, negatory, nadda, never.

But this is not good enough for staff writer Ethan Hunt and others outlets that continue to recycle this story.

Though the researchers involved with the work have been reluctant to pin Fukushima as a potential cause — National Geographic, which covered the study recently, did not even mention Fukushima — the timing of the discovery suggests that Fukushima is, perhaps, the cause.

MBARI today also issued a press release addressing the “several misleading stories [that] have been in circulation on the internet.”  The press release points out the obvious.

1. MBARI research actually showed evidence that there were MORE algae and salps living in California surface waters during 2011 and 2012 than during the previous 20 years.
2. Salps are small gelatinous animals that eat single-celled algae. They are known to experience large blooms in their populations. Large populations of salps have been periodically documented in California waters since at least the 1950s.
3. Blooms of gelatinous animals (including salps) and single-celled algae are a common occurrence off the California Coast. They come and go, running their course when they use up their food and nutrients.
4. Animals and algae that live in the surface waters eventually die. If they are not eaten in surface waters then they sink to the deep sea. This is the main food source for deep-sea animal and microbe communities.
5. Soon after the salp bloom and die-off at the surface in 2012, the deep seafloor at the researchers’ study site was littered with dead salps. This was observed at one location, and salps were the only dead animals observed in large numbers.
6. There is no indication that any of the events in this study were associated with the Fukushima nuclear accident.

I will also note the Fukushima disaster occurred in March 2011, five years after the researches begin to see changes in surface production.   To reiterate the statements points, there is evidence of more life recently in California waters. The supposed “die off” is a common feature of any bloom of short-lived invertebrates. The “die off” was experienced at one location and with one species.  The entire Pacific seafloor is not littered with dying organisms.  I would also point out that these massive food falls of marine invertebrates are a common occurrence. For example, in 2002 a massive deposition of jellyfish was seen in the deep Arabian Sea.

As I write this post on this cold Saturday morning, my attitude matches.  I have wanted to write about this paper for a while here at DSN.  And I’m sorry I did not.  I shoudn’t be defending great science against propaganda and poor journalism.  I should be writing about how this paper answers a major question about the deep sea.  Previous studies have noted that the energy requirements of deep-sea animals could not be met by normal and minimal marine snow.  Research over the last decade or so set out to determine how this deficit is made up.  Smith and colleagues’ work solves this riddle.  Deep-sea animals simply wait for a sporadic feast.  Smith’s work suggests this is likely linked to climatic events.

If anything the paper is a cautionary tale of climate change not radiation.

The post Is the sea floor littered with dead animals due to radiation? No. first appeared on Deep Sea News.

Fortunately, Jim Acker of NASA Earth Observatory Goddard Earth Science Data and Information Services Center [apologies! -MG] was on the case. His analysis of satellite data, using the Giovanni information system, is so interesting that I am coming out of my dissertation-writing hole specifically to highlight it. First, to prove that there’s a iron-related phytoplankton (microscopic ocean plant) bloom, you have to show that there wasn’t a bloom there to start with. This satellite image, taken July 19-26 2012, shows the chlorophyll-a concentrations in the surface ocean – warm colors mean more chlorophyll, which means more phytoplankton, and cool colors mean less. You’ll see in the image below that there’s more phytoplankton near the coast, which is normal for this area of the world, but that offshore there is far less. (The white means no data, since there were clouds in the way of the satellite’s sensors.)

The iron was purportedly dumped in the beginning of August, but clouds mostly blocked the satellites around that time. The next good image was taken between August 20-27, and clearly show a bloom (large orange blotch) offshore .

On August 29, the clouds almost entirely disappeared, allowing a really clear view of the area. This is a pseudo-true color image from the MODIS satellite, courtesy of Rob Simmon – if you were looking down from space, this is what you might have seen. The light-colored swirl is likely a coccolithophore bloom – a type of phytoplankton with a calcium carbonate shell. If you look carefully, you’re see blackish water both above and below the light swirl – that dark color means that there’s some other kind of phytoplankton bloom (not coccolithophores) there too. The water is dark because all the phytoplankton is sucking up light.

By September 5-12, the iron fertilization bloom was mostly gone. The area where it used to be is no longer a big orange blotch, but mostly green and yellow, with a few areas of orange.

I’ve highlighted just a few of the wonderful and informative Giovanni visualizations – there’s a lot more over at their website. I encourage you to check them out. But in short, did Russ George’s iron dumping actually cause a plankton bloom? It does seem that it did.

UPDATE 19 Oct 2012 10:20 AM PDT: Jim also looked at the chlorophyll anomaly over 10 years of MODIS Aqua data with Giovanni. The area of the purported iron fertilization is 2-5 mg per m3 higher.

The post Satellite imagery of the rogue Canadian iron dumping experiment first appeared on Deep Sea News.

The post Blue whales in a red tide first appeared on Deep Sea News.

This is a guest post modified from two emails by professor of biological oceanography Peter Franks, reprinted here with his permission. Peter is a phytoplankton ecologist who studies how the physical processes in the ocean influence the growth and distribution patterns of phytoplankton, so he’s often the go-to guy on red tides. I have edited the emails slightly for clarity and context.

We’ve got a pretty spectacular red tide going in the waters off San Diego (and farther north and south). The organism is Lingulodinium polyedrum, my favorite dinoflagellate. Why favorite? Because it’s intensely bioluminescent. When jostled, each organism will give off a flash of blue light created by a chemical reaction within the cell. When billions and billions of cells are jostled – say, by a breaking wave – you get a seriously spectacular flash of light.

And the best part? The moon is in its “new” phase. That means that the bioluminescence will not be dimmed by moonlight for the next few days.

So please take the opportunity to go down to the beach tonight or tomorrow night to see one of nature’s most impressive light shows.

Or, if you’re like me (too lazy to get up after the sun goes down) get a clear drink bottle, get a friendly neighborhood surfer to fill it for you (knee-deep water is fine), and take it home. Put it in a cool, dark place – a closet or a bathroom without windows. Then, after the sun goes down go in there and let your eyes adjust to the darkness. Then give the bottle a shake – you’ll see blue sparks from the dinoflagellate’s bioluminescence. Then start experimenting: try your electric toothbrush. Or pour some on your arm, or on the countertop. Let some get sucked up into a towel. Or (this is the best) try adding vinegar. The acid makes the dinoflagellates release their bioluminescence chemicals all at once, giving a show similar to the finale of a 4th of July fireworks display. Unfortunately, like the 4th of July fireworks display, it’s terminal. That’ll be the end of the fun. Until you go and get some more red-tide water…

I’ve received a number of inquiries about the red tide. Frequently Asked Question #1 is (in a nutshell): will it [this red tide] kill me?

The answer?

No.

I know, I know. I’m as disappointed as you are. This species of dinoflagellate is not toxic. If it were, I’d have a lot more funding. It’s possible that it contains low levels of a toxin called “yessotoxin“, but this toxin is not one that’s tested for in the US (as far as I know), and there’s no records of it having any detrimental effects.

You’ve probably heard of various forms of toxic shellfish poisoning. Typically what happens is that shellfish such as mussels (which filter a “pant load” (technical term) of water each day) will concentrate the phytoplankton toxins in their tissues. When you eat the shellfish you get an extraordinarily magnified dose of the toxin, and bad things may ensue.

(Useful party fact: phytoplankton kill ten times more people globally than sharks each year.)

Frequently asked question number 2: Why do the dinoflagellates bioluminescence?

As far as we know (which is surprisingly not very far) the bioluminescence both deters grazers of the dinoflagellates (who likes eating food that flashes in your mouth?), and also attracts the predators of the grazers which are mostly visually oriented organisms such as fish (the so-called “burglar hypothesis”).

Frequently asked question number 3: When I surf in a red tide I get sick (ear aches, sinus infections, etc.). Why?

My usual answer is that you should bathe more. Or at least check to see whether you get sick when there isn’t a red tide.

However … a student of mine (Meg Rippy – please give her a postdoc) has some evidence that red tides can decrease the mortality of human pathogenic bacteria that get into the nearshore waters. These bacteria normally die pretty quickly; they may die slower during a red tide, perhaps due to the increased amounts of organic material in the water. So perhaps your ear infection is because of other bacteria that are present in higher concentrations in a red tide than they would normally be. (Please give us funding to pursue this.)

That covers most of the FAQ. If you have other questions, please keep them coming, and I’ll do my best to answer.

The post The San Diego red tide: FAQ from Scripps professor Dr. Peter Franks first appeared on Deep Sea News.

]]> https://deepseanews.com/2011/09/the-san-diego-red-tide-faq-from-scripps-professor-dr-peter-franks/feed/ 101 https://deepseanews.com/2011/05/fools-gold-from-hydrothermal-vents-to-plankton/ Sun, 15 May 2011 23:06:04 +0000 https://www.deepseanews.com/?p=14030 A nice little paper in Nature Geoscience that helps reconcile iron budgets for the word’s oceans.  The hot, mineral rich water that spews from hydrothermal…

The post Fool’s Gold from Hydrothermal Vents to Plankton first appeared on Deep Sea News.

]]> A nice little paper in Nature Geoscience that helps reconcile iron budgets for the word’s oceans.  The hot, mineral rich water that spews from hydrothermal vents contains a significant amount of fool’s gold, or iron pyrite.  Because iron pyrite is more resistant to rusting than basic iron and much of the iron pyrite venting is nanoparticles, they are though to disperse great distances before sinking and dissolving.  What makes this finding more important is that iron is often a limiting factor for phytoplankton growth in the oceans.  Thus, hydrothermal vents may an indirect but major role in carbon production in the world’s oceans.

The post Fool’s Gold from Hydrothermal Vents to Plankton first appeared on Deep Sea News.

]]> https://deepseanews.com/2011/02/marine-biology-fail/ https://deepseanews.com/2011/02/marine-biology-fail/#comments Mon, 07 Feb 2011 20:47:26 +0000 https://www.deepseanews.com/?p=12758 Zazzle, are you saying that all phytoplankton look the SAME to you?! Thanks, R.A.!

The post Marine Biology FAIL first appeared on Deep Sea News.

]]>

Zazzle, are you saying that all phytoplankton look the SAME to you?!

Thanks, R.A.!

The post Marine Biology FAIL first appeared on Deep Sea News.

]]> https://deepseanews.com/2011/02/marine-biology-fail/feed/ 11 https://deepseanews.com/2011/01/scientist-in-residence-danny-richter-on-the-to-humble-diatom/ Sat, 15 Jan 2011 17:15:10 +0000 https://www.deepseanews.com/?p=12241 Dear Diatoms, You are pretty, and I like you. Haeckel liked you too, so did Gaudi. Obviously, they appreciated the little things in life. While…

The post Scientist In Residence: Danny Richter on the To Humble Diatom first appeared on Deep Sea News.

]]> Dear Diatoms,

You are pretty, and I like you. Haeckel liked you too, so did Gaudi. Obviously, they appreciated the little things in life. While you still make appearances now and again in modern life, let’s face it: being microscopic and aquatic, recognition is an up-current battle, and you can’t swim.

Perhaps obscurity suits you? Trees, after all, are also beautiful, and we tend to cut them down. Perhaps your fame as a pool filterer is enough for you. Forgive me diatoms, but you can do better. You should do better.

Humans should know who to thank for producing 20% of their oxygen [Kroger and Poulsen, 2008]. Heck, without you and your heavy frustules to help bury carbon, there might never have been enough oxygen for placental mammals grow larger than shrews in the first place [Falkowski et al., 2005]! That’s right diatoms: no you, no us.

Being key to our past, you may also be key to our future. You see, we’re kind of sort of a little bit addicted to oil. Oil, as you know, comes from phytoplankton fat, and you are phytoplankton. Do your Bear Grylls-like survival skills in the face of toxicity (Brand et al., 1986), acidity (Warner, 1971), and unsurpassed ability for resource utilization (Boyd et al. 2007; Cullen 2006) make you the ultimate carbon-neutral source of oil? How will we know unless more people know enough about you to take an interest?

I like you diatoms, you are pretty. I have a lot to thank you for. You seem pretty happy with the fame you have, but I think it would help us out if you could try a little harder to get just a little bit more famous. Go on dancing with the stars, or Oprah. Something like that. Here, at least, is one person who would be very appreciative of your efforts.

Your admirer,
-Danny

For more reading see…

Kroger, N. and Poulsen, N. 2008. Diatoms—From Cell Wall Biogenesis to Nanotechnology. Annu. Rev. Genet. 2008. 42:83–107

Falkowski, P. F. et al., 2005. The Rise of Oxygen over the Past 205 Million Years and the Evolution of Large Placental Mammals. Science 309, 2202

Brand, L. E., W. G. Sunda, and R. R. L. Guillard. 1986. Reduction of Marine-Phytoplankton Reproduction Rates by Copper and Cadmium. Journal of Experimental Marine Biology and Ecology 96: 225-250.

Boyd, P. W. and others 2007. Mesoscale iron enrichment experiments 1993-2005: Synthesis and future directions. Science 315: 612-617.

Cullen, J. T. 2006. On the nonlinear relationship between dissolved cadmium and phosphate in the modern global ocean: Could chronic iron limitation of phytoplankton growth cause the kink? Limnology and Oceanography 51: 1369-1380.

Warner, R. W. 1971. Distribution of Biota in a Stream Polluted by Acid Mine-Drainage. The Ohio Journal of Science 71(4): 202.

The post Scientist In Residence: Danny Richter on the To Humble Diatom first appeared on Deep Sea News.

]]> https://deepseanews.com/2010/08/socal-sea-a-swim-with-scum-sharks/ https://deepseanews.com/2010/08/socal-sea-a-swim-with-scum-sharks/#comments Thu, 12 Aug 2010 23:52:13 +0000 https://www.deepseanews.com/?p=9518 It’s been an eventful week here in the Southern California Bight – the northwest-southeast slanting part of the coastline between Point Conception (north of Los…

The post SoCal sea a-swim with scum and sharks first appeared on Deep Sea News.

]]> It’s been an eventful week here in the Southern California Bight – the northwest-southeast slanting part of the coastline between Point Conception (north of Los Angeles) and Ensenada, Mexico. There’s a bright green algae bloom making the waves look like they’ve been highlighted with a fluorescent marker. The color is caused by an algae bloom dominated by Tetraselmis, a harmless single-celled flagellate. Before I knew about the bloom, I thought someone was dumping flourescein dye in the ocean as part of an experiment – it is unbelievably vibrant!

We’ve still got a few giant black nettle jellies floating around, but the big news this week has featured something much toothier. White sharks are relatively common off the southern California coast, but since chances of getting munched are vanishingly rare, I don’t worry about them while swimming & diving. Still, I must say that seeing a huge predator emerge out of the familiar Pacific murk on this video makes my stomach clench. This was filmed off San Onofre, about 50 miles north of San Diego.

Me my Shark and I from Chuck Patterson on Vimeo.

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