29 March 2011

DEEPWATER HORIZON'S UNCOUNTED VICTIMS


(Killer whales. Photo by Pittman, courtesy NOAA, via Wikimedia Commons.)

A new paper in Conservation Letters calculates that the numbers of whales and dolphins killed in BP's Deepwater Horizon disaster could be 50 times higher than the number of carcasses found. 

The authors—a high-powered list of renowned cetacean researchers from Canada, the US, Australia, and Scotland (including Scott Krause, who I filmed years ago for a documentary about North Atlantic right whales)—write of a general misperception of the Deepwater Horizon impact:

Many media reports have suggested that the spill caused only modest environmental impacts, in part because of a low number of observed wildlife mortalities, especially marine mammals.
























(Atlantic spotted dolphins. Photo by Bmatulis, via Wikimedia Commons.)

Compared to the 1989 Exxon Valdez, with its iconic oiled otters and high body counts, the Deepwater Horizon seems, well, not so bad.

The authors point out that "only" 101 dead cetaceans (whales, dolphins, and porpoises) were found in the Northern Gulf of Mexico as of 7 November 2010. The number's misleading though.

The issue arises when policymakers, legislators, or biologists treat these carcass-recovery counts as though they were complete counts or parameters estimated from some representative sample, when in fact, they are opportunistic observations. Our study suggests that these opportunistic observations should be taken to estimate only the bare minimum number of human-caused mortalities.


(Humpback whale. Photo by Whit Welles Wwelles14, via Wikimedia Commons.)

So how many more whales, dolphins, and porpoises actually died? That problem is tough to figure to begin with and is compounded by a dearth of data in the Gulf—a fact that will work greatly in BP's favor when the time comes to levy fines.

The Gulf of Mexico is a semi-enclosed subtropical sea that forms essentially one ecosystem with many demographically independent cetacean populations. Some of these cetacean populations, such as killer whales (Orcinus orca), false killer whales (Pseudorca crassidens), melonheaded whales (Peponocephala electra), and several beaked whale species, appear to be quite small, are poorly studied, or are found in the pelagic realm where they could have been exposed to oil and yet never strand. Small, genetically isolated populations of bottlenose dolphins (Tursiops truncatus) could have experienced substantial losses either inshore or offshore.
























(Mother and calf bottlenose dolphins. Photo by M. Herko, courtesy NOAA, via Wikimedia Commons.) 

Two methods of extrapolation could shed light on how many cetaceans BP's disaster killed:

  1. Compare abundance before the disaster to abundance after—but since we don't know the population size of whale and dolphins species in the Gulf before hand we're unlikely to notice anything short of "the most catastrophic decline" and maybe not even that.
  2. Count the number of carcasses recovered—knowing that many will evade our count, having sunk, decayed, been scavenged, or drifted away. So adjust the counts upward to estimate total mortality. This approach is used to estimate bird deaths at power lines, where, in at least one instance, we now know that bird body counts underestimate total actual deaths by a whopping 32 percent.

The authors worked the two methods as best they could and added something more.

Given the magnitude of the spill and complexity of the response, quantifying the ecological impacts will take a long time. To contribute to this effort, we examined historical data from the Northern Gulf of Mexico to evaluate whether cetacean carcass counts in this region have previously been reliable indicators of mortality, and may therefore accurately represent deaths caused by the Deepwater Horizon/BP event.

(Sperm whale. Photo courtesy NOAA, via Wikimedia Commons.) 

Their methods and analysis suggest that an average of 4,474 cetaceans died in the northern Gulf every year between 2003 and 2007 from all causes, human and natural. Yet since an average of only 17 bodies were found in those years, the body count represented only ~0.4 percent of total deaths.
 
Consider, for example, one sperm whale being detected as a carcass, and a necropsy identified oiling as a contributing factor in the whale’s death. If the carcass-detection rate for sperm whales is 3.4%, then it is plausible that 29 sperm whale deaths represents the best estimate of total mortality, given no additional information. If, for example, 101 cetacean carcasses were recovered overall, and all deaths were attributed to oiling, the average-recovery rate (2%) would translate to 5,050 carcasses, given the 101 carcasses detected.

Those are chilling numbers. Period. But also in light of the relatively tiny populations of cetaceans in the Gulf. Especially since most if not all cetaceans are highly social, and since oil and chemical dispersants likely injured, sickened, or killed entire clusters, schools, pods, matrilines, or groups at the same time—and may still be doing so.

The authors describe the near-lethal affect of the Exxon Valdez disaster on one well-known and well-studied pod of killer whales in Alaska.

In the first year after the 1989 Exxon Valdez spill, the AT1 group of "transient" killer whales experienced a 41% loss; there has been no reproduction since the spill. Although the cause of the apparent sterility is unknown, the lesson serves as an important reminder that immediate death is not the only factor that can lead to long-term loss of population viability.
























(Pilot whale mother and calf. Photo by Clark Anderson via Wikimedia Commons.)

The paper:

ResearchBlogging.org

Rob Williams, Shane Gero, Lars Bejder, John Calambokidis, Scott D. Kraus, David Lusseau, Andrew J. Read, & Jooke Robbins (2011). Underestimating the damage: interpreting cetacean carcass recoveries in the context of the Deepwater Horizon/BP incident Conservation Letters : 10.1111/j.1755-263X.2011.00168.x

28 March 2011

THE RADIOACTIVE OCEAN: A PRIMER


(The "Baker" explosion at Bikini Atoll, Micronesia, on 25 July 1946. Credit: US Navy, via Wikimedia Commons.)

The compass of news the past few days has swung to a new North—to the rising measurements of radioactivity in the waters off Japan's Fukushima nuclear power plant. What does it mean?

You can see in the illustration below the  transmission of radionuclides—in this case from deep-sea dump sites—through the physical and biological webs of ocean and atmosphere. 

Clearly, the process is dynamic and far-reaching, with the contamination carried by waves and winds and life itself.











Radioactive pollution in the ocean is nothing new. We've been loosing the stuff offshore since 1944. Here's how.

1) Nuclear weapons tests:
  • For example, at Bikini Atoll between 1946 and 1958, the US detonated 23 atmospheric nuclear bomb tests, including the first hydrogen bomb, which exploded far more violently than predicted and contaminated a swath of ocean 100 miles/160 kilometers away from the epicenter. The fallout affected inhabited islands, fishing boats and fishers at sea, and, obviously, a lot of marine life.



(Points X marks where contaminated fish were caught, or where the sea was found to be excessively radioactive, after the 1955 hydrogen bomb test at Bikini. B=original "danger zone" announced by the US government. W="danger zone" extended later. xF=position of the Lucky Dragon fishing boat, whose crewmen were sickened by fallout, one of whom died. NE, EC, and SE are equatorial currents. Credit: Y. Nishiwaki, 1955, for the government of Japan, via Wikimedia Commons.)

  • France exploded ~193 nuclear tests in the atmosphere and in the waters of French Polynesia between 1966 and 1996. The tests began after the 1963 Partial Test Ban Treaty outlawing detonations in the air. I wrote about this in my book THE FRAGILE EDGE:

The [first] bomb was exploded aboard a barge in the [Moruroa's] lagoon, sucking water into the air and raining dead fish, corals, cephalopods, crustaceans, mollusks, and all the once living components of the reef onto Moruroa’s motu [islands], where their radioactive forms decayed for weeks. Confounded by this result, the French hastily arranged to explode their second bomb seventeen days later from an air plane 45,000 feet above the featureless South Pacific, some 60 miles south of Moruroa. Without people or equipment to witness, record, or analyze this distant blast, virtually no data was collected, making its detonation more an act of pique than science. Two days later, as described by the Bulletin of the Atomic Scientists:

An untriggered bomb on the ground [at Moruroa] was exposed to a "security test." While it did not explode, the bomb’s case cracked and its plutonium contents spilled over the reef. The contaminated area was "sealed" by covering it with a layer of asphalt.


(Top: Moruroa Atoll. Bottom: Fangataufa Atoll. Both atolls are part of French Polynesia, site of French nuclear tests. CORRECTION: The medium-dark blue waters marking the center of the lagoon of Fangataufa Atoll mark the deep crater created by bomb explosions. Credit: NASA, via Wikimedia Commons.)

2) Sinking of nuclear-powered submarines:
  • So far, eight nuclear-powered submarines have sunk or been scuttled: two American, four Soviet, two Russian.
  • Four sank in the North Atlantic, three in the Barents Sea, one in the Kara Sea north of Siberia.
  • Another accident in 1968 sank a diesel-electric Soviet sub carrying nuclear ballistic missiles in the North Pacific 1,796 miles / 2,890 kilometers northwest of the Hawaiian island of Oahu.

(Salvaged wreck of the Russian nuclear submarine K-141 Kursk, via Wikimedia Commons.)

3) Spacecraft and satellite failures, including:

  • The launch failure in 1964 of an American navigation satellite with an onboard radioisotope thermoelectric generator (RTG)—an electrical generator fueled by radioactive decay. This fell into the ocean near Madagascar and deposited a quantity of plutonium-238 equal to half the amount of plutonium-238 naturally present in the entire World Ocean.
      • The failed Apollo 13 mission (1970) jettisoned its Lunar Module Aquarius with the intention that it would crash into the sea and plummet into the Pacific's Tonga Trench—one of the deepest places on our planet—since it was still carrying its RTG with plutonium dioxide fuel. So far no plutonium-238 has been recorded in nearby atmospheric and seawater sampling, suggesting the cask is currently intact on the seabed. 
      • At least four other RTG-powered spacecraft have fallen back to Earth, including one into the waters of the Santa Barbara Channel off California in 1968.
      • Between 1973 and 1993, at least five Soviet/Russian RORSAT satellites failed to eject their nuclear reactor cores prior to falling back to Earth. One fell into the Pacific north of Japan (1973), another over Canada's Northwest Territories (1978), another in the South Atlantic (1983). The successfully ejected cores are in decaying orbits, destined to plummet back to Earth someday.


      (The Apollo 13 Lunar Module, Aquarius, just after jettisoning on 17 April 1970. Credit: NASA, via Wikimedia Commons.)

      4) Discharges from nuclear reprocessing and power plants, including:

      • Britain's Sellafield (aka Windscale), a nuclear storage site, an erstwhile nuclear weapons production plant, nuclear reprocessing center, and nuclear power plant, currently in the process of decommissioning [CORRECTION]. Due to accidents, chronic emissions, and overflows at Sellafield, the nearby Irish Sea is deemed the most radioactive sea on Earth.
      • The Hanford Site in Washington—home to the world's first plutonium production reactor—purposely released radionuclides down the Columbia River from the 1940s to the 1970s. The contamination travelled hundreds of miles into the Pacific Ocean. Today the radionuclides are used as markers by oceanographers tracking sediment movements on the continental shelf.


      (Salmon spawning in the Hanford Reach of the Columbia River, at the site of 30 years of radioactive releases. Credit: US Department of Energy, via Wikimedia Commons.)

      5) Ocean dumps:

      • Dump sites for radioactive waste were created in the northeast Atlantic (1 site), off Europe (3), off the US eastern seaboard (1), and off the US Pacific coast (1).
      • Between 1946 and 1970, the US dumped ~107,000 drums of radioactive wastes at its two sites, including some 47,800 in the ocean west of San Francisco, supposedly at three designated sites. However drums actually litter an area of at least 1,400 square kilometers/540 square miles, known as the Farallon Island Radioactive Waste Dump, which now falls almost entirely within the boundaries of the Gulf of the Farallones National Marine Sanctuary. The exact location of most drums is unknown. At least some are corroding.


      (A drum of radioactive waste dumped off San Francisco. Credit: USGS.)

      A 1996 paper in Health Physics described some of the radionuclides found in the tissues of deep-sea bottom-feeding fishes—Dover sole, sablefish, and thornyheads—plus intertidal mussels in the waters around the Farallon Islands:

      Concentrations of both [plutonium-238] and [Americium-241] in fish tissues were notably higher than those reported in literature from any other sites world-wide, including potentially contaminated sites. These results show approximately 10 times higher concentrations of [plutonium-238+240] and approximately 40-50 times higher concentrations of [plutonium-238] than those values reported for identical fish species from 1977 collections at the [Farallon Islands Nuclear Waste Dump Site] . 


      (Bottom-feeding Dover sole, Microstomus pacificus, a species living within the Farallon Islands Nuclear Waste Dump Site. Credit:Linda Snook / MBNMS, via Wikimedia Commons.)

      Of course the fallen satellites, the sunken submarines, the leftovers from nuclear bomb tests, and the dumped drums of waste are all subject to saltwater corrosion and the same destructive tectonic forces that triggered the March 11th Sendai earthquake and tsunami.

      In an upcoming post, I'll take a look at what might lie ahead for Japan's troubled waters and beyond.

      27 March 2011

      SUNDAY POETRY: "YOU SEA!"


      YOU SEA!
      Fragment: SONG OF MYSELF
      by Walt Whitman

      You sea! I resign myself to you also—I guess what you mean,
      I behold from the beach your crooked fingers,
      I believe you refuse to go back without feeling of me,
      We must have a turn together, I undress, hurry me out of sight of the land,
      Cushion me soft, rock me in billowy drowse,
      Dash me with amorous wet, I can repay you.

      Sea of stretch'd ground-swells,
      Sea breathing broad and convulsive breaths,
      Sea of the brine of life and of unshovell'd yet always-ready graves,
      Howler and scooper of storms, capricious and dainty sea,
      I am integral with you, I too am of one phase and of all phases. 


      I think the photo might also be by Jason Wingrove. Found it here.

      You might remember another lovely Jason Wingrove shorted I posted a while back, called Sea Pool.

      The song in the video: "The Swimming Song" by Loudon Wainwright III.

      21 March 2011

      OCEAN BIRDS

      American white pelican, Pelecanus erythrorhynchos. Photo by Manjith Kainickara via Wikimedia Commons.


      Northern gannet, Morus bassanus. Photo by Andreas Trepte via Wikimedia Commons.

      Great crested tern, Thalasseus bergii. Photo by Martin Pot (en:User:Martybugs) via Wikimedia Commons.

      Atlantic Puffin, Fratercula arctica. Photo by Thomas O'Neil via Wikimedia Commons.

      Blue-footed booby, Sula nebouxii. Photo by Rileypie via Wikimedia Commons.


      Rockhopper penguin, Eudyptes chrysocome. Photo by Ben Tubby via Wikimedia Commons.


      Spectacled eider, Somateria fischeri. Photo by Laura Whitehouse, courtesy USFWS, via Wikimedia Commons.

      Long-tailed duck, Clangula hyemalis. Photo by Wolfgang Wander via Wikimedia Commons.


      Penguin, via.


      Unknown, via unknown (saltwater or fresh?).

      Red phalarope, Phalaropus fulicarius. Photo by Andrei Taranchenko via Wikimedia Commons.

      Smew, Mergellus albellus. Photo by Thermos via Wikimedia Commons.

      White-faced storm-petrel, Pelagodroma marina. Photo by Aviceda via Wikimedia Commons.


      Sanderlings, Calidris alba. Photo by Mbz1 via Wikimedia Commons.

      Australasian gannets, Morus serrator, on the nest. Photo by Follash via Wikimedia Commons.

      Common murres, Uria aalge, colony. Photo by Duncan Wright via Wikimedia Commons.

      Ivory gull, Pagophila eburnea. Photo by jomilo75 via Wikimedia Commons.

      Far eastern curlew, Numenius madagascariensis. Photo by 
      Duncan Wright courtesy USFWS, via Wikimedia Commons.

      17 March 2011

      IRELAND FROM ABOVE
























      (From the Earth Observatory. Credit: NASA, courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center.)

      Ireland on a rare cloud-free day, seen here in true color.

      The Atlantic Ocean makes the clouds and the North Atlantic Drift funnels the warm waters across the ocean. Together they produce between 750 and 2000 millimeters / 29 and 78 inches of rain a year for lovely Éire.

      HOW TO CROSS A FROZEN OCEAN

      UPDATE: WISDOM SURVIVED!

      (Photo from Wild Encounters. Many other beauties here of albatross and the ever-lovely fairy terns. Well worth a visit.)

      Many thanks to friends and readers who pointed out this BBC article reporting that Wisdom, a 60-year-old Laysan albatross mother, survived the tsunami that killed many thousands of birds on Midway Atoll. 

      I'm guessing that Wisdom's part of the atoll wasn't submerged...? I'm hoping her chick survived too...?

      Seems to me the world could use more Wisdom DNA.

      16 March 2011

      DID THE TSUNAMI KILL "WISDOM?"


      (Laysan albatross Wisdom, seen here with her chick at Midway Atoll, March 2011, before the tsunami. Credit: John Klavitter/U. S. Fish and Wildlife Service, via Wikimedia Commons.)

      I've tweeted a few times of late about the remarkable Laysan albatross named Wisdom. She's at least 60 years old—the oldest-known wild bird in the US. 

      A few months ago she returned to Midway Atoll in the northwestern Hawaiian Archipelago, found her mate, laid an egg, and recently hatched a chick. 

      Now the Honolulu Star-Advertiser reports that tsunami waves from Japan's massive quake devastated Midway's seabird breeding rookeries, completely washing over one of the islands and partially submerging the other two. Tens of thousands of albatrosses died, adults and chicks. 

      (Calculated wave height of the 2011 tsunami originating near Sendai, Japan.  Credit: NOAA.)

      If you click on the image above you'll see the larger version, with the main Hawaiian Islands located in the center-right. The Hawaiian Archipelago tracks west-northwest from there, with Midway just visible near the far end of the island chain, embedded in the high-wave tsunami zone marked in red.

      The albatross chicks on Midway were killed by the waves because none have fledged this early in the season. Laysan albatrosses have extremely long dependency periods—64 days of incubation, followed by 165 flightless days before they fledge and leave the island.


      (Laysan albatross chicks with a few embedded adults, Midway Atoll. Credit: Mass Communication Specialist 2nd Class Mark Logico, US Navy, via Wikimedia Commons.) 

      The adults were likely killed because they don't readily abandon their young.

      Plus these are big birds of the open ocean. It takes them a long time to lumber across the water or the beach to get airborne. Midway's old runways turn out to be extremely useful for this purpose.

      In the absence of wind, they can't takeoff or land. The Birds of North America Online describes their flight like this:

      Depending on wind strength, take-off may be difficult, requiring a long run with the head outstretched, the bird flapping its wings and literally running. Take off from water is similar, requiring furious paddling with the webbed feet. Landings can be equally difficult, especially in birds that have been at sea for months, or in light winds. In the absence of the braking effort of a strong wind, landing birds may occasionally tumble on landing.




      Midway is home to about 450,000 of the world's 590,926 breeding pairs of Laysan albatross. The IUCN Red List deems the species Near Threatened.

      Some 25,300 black-footed albatrosses also live on Midway Atoll and presumably took some tsunami losses too.

      (Black-footed albatross, Midway Atoll. Credit: Forest & Kim Starr, via Wikimedia Commons.)

      Plus one pair of short-tailed albatrosses arrived this year. This species breeds on islands off Japan and China and is deemed Vulnerable by the IUCN Red List—with a total global population of only 2,364 individuals. 

      A few months ago I tweeted the exciting news that this pair had appeared on Midway—an encouraging sign the species' range might be expanding.

      Now, in the wake of the tsunami waves, US Fish and Wildlife officials have found one short-tailed albatross chick, returned it to a nesting area, and installed a remote-controlled camera to monitor it. But they haven't found the parents. 


      (Short-tailed albatross. Credit: US Fish and Wildlife Service, via Wikimedia Commons.)

      No word yet that I've heard on Wisdom's fate. This late in the breeding season few if any birds will try to lay another egg and start the long cycle again.

      15 March 2011

      THE TSUNAMI MASTER


      (The Great Wave at Kanagawa. 1823-1829. Katsushika Hokusai.) 

      The Great Wave at Kanagawa, or simply, The Great Wave, a woodblock created by Japanese printmaster Katsushika Hokusai between 1823 and 1829, is widely seen as a depiction of a tsunami—though it might be an okinami, a "wave of the open sea."

      Whatever Hokusai's original intent, the image has since become a Japanese icon, copied and emulated many times.



      (Modern copy of The Great Wave off Kanagawa. c. 1930. Unknown.)

      The recut above, made 100 years after Hokusai's original, is probably the better-known version today.


      (Die Woge. 2006. Tobia Stengel. Via Wikimedia Commons.)

      The German city of Dresden installed a sculptural version of The Great Wave by Tobias Stengel, called Die Woge, commemorating the epic flooding on the Elbe River in 2002.


      (The Great Wave Off Of Louisiana. Via.)

      Hokusai's image can be powerfully repurposed for current calamities—in this case, for BP's Gulf oil catastrophe last year.

      I couldn't find anything more on this dark wave, such as: who made it. Can anyone help?


      (Illustration to The Tale of Tsar Saltan, 1905, by Ivan Yakovlevich Bilibin.)

      Hokusai's wave was adapted by the Russian Ivan Yakovlevich Bilibin, who created many lovely images to illustrate Slavic fairy tales.

      Sadly, Bilibin was overwhelmed by the tsunami of World War II, and died in 1942 during the Siege of Leningrad, alongside 642,000 other civilians, many of whom starved to death.

























      This is the original cover to the sheet music for Claude Debussy's 1905 La Mer ("The Sea"), as moody and shifting an impression of the ocean as was ever written.


      (Via.)

      Hokusai's image is metaphor friendly and travels well through time. As best I can tell, this homage, above, called The Wave of the Future, was made by an IBM users group.


      (The Great Wave at Iwanuma, 2011. Via.)

      The adaptation above was posted online on 11 March 2011.


      (Via.)

      As was this map, produced by NOAA/NWS/West Coast and Alaska Tsunami Warning Center on the day of Japan's Sendai Earthquake.