ELEPHANT SEAL COMMUTES 18,000 MILES

Southern elephant seal. Credit: Butterfly voyages�Serge Ouach�e via Wikimedia Commons.

 
A southern elephant seal has been tracked swimming an astonishing 18,000 miles/29,000 kilometers between December 2010 and November 2011.

That's the equivalent of a roundtrip between New York and Sydney.

Jackson's amazing travels. Via Our Amazing Planet.

  
The Wildlife Conservation Society (WCS) fitted a male seal named Jackson with a small satellite transmitter on the beach of Admiralty Sound in Tierra del Fuego in southern Chile. 

From there he swam:

• 1,000 miles/1,610 km north
• 400 miles/644 km west 
• 100 miles/160 km south

Along the way, Jackson meandered inshore through fjords and ventured offshore beyond the continental shelf.

Patagonia fjords. Credit: � Julia Whitty.

  
All this in search of the fuel that drove his travels: fish and squid. From the IUCN Red List description of the species:

Foraging elephant seals combine exceptionally deep diving with long-distance traveling, covering millions of square kilometers while traversing a wide range of oceanographic regions during periods of up to seven months at sea. The seals spend most of their at-sea time in particular water masses that include frontal systems, currents and shifting marginal ice-edge zones. Studies of foraging locations suggest that seals are sensitive to fine-scale variation in bathymetry and ocean surface properties (sea-ice concentration, sea surface temperature).

In the course of his travels, Jackson was also diving deep�a skill at which elephant seals excel.

Different satellite tracking studies (pdf) have shown that during the seven months they're living offshore southern elephant seals typically spend only a few minutes breathing hard at the surface before making repeated dives of 20-minutes or more duration to depths of 1,300-3,300 feet/400-1,000 meters.


  
Some female elephant seals have been recorded making 2-hour-long dives. And some have made dives to more than 4,600 feet/1,400 meters. From the Red List:

Southern elephant seals are prodigious divers and routinely reach the same depths as their northern counterparts. Dive depth and duration vary during the year and between the sexes, but normally range from 300 to 500 m deep and from 20 to just over 30 minutes in duration. A maximum depth of 1430 m was recorded for a female, following her return to sea after the moult. Another post-moult female dove for an astonishing 120 minutes, which is by far the longest dive ever recorded for a pinniped.

Southern elephant seals. Credit: B.navez via Wikimedia Commons.

   
At the end of his peregrinations, Jackson returned to the same beach he'd left from on Admiralty Sound. His satellite tag should continue to transmit until early next year when it will cease transmitting and fall off.

The WCS research is part of their ambitious goals in the region:

The information WCS gathers will serve as a foundation for a new model of private-public, terrestrial-marine conservation of the Admiralty Sound, Karukinka Natural Park (a WCS private protected area), and Alberto de Agostini National Park. It will help build a broader vision for bolstering conservation efforts across the Patagonian Sea and coast.

FIRST FISHERS

Beach at Tutuala, East Timor. Credit: doug.deep Doug Anderson via Flickr.

 

A new paper in Science reports on 42,000-year-old fish bones found in Jerimalai cave on the island of East Timor, just north of Australia. 

This is the oldest evidence yet of human fishing activity. Even more interesting, about half the 38,000 bones were of fast-swimming pelagic species�tuna and shark�implying the ancient fishers worked offshore from vessels.

Credit: Froschmann : ?????? H Aoki via Flickr.

  

We know that people were seafaring 50,000 years ago. And seafaring and fishing are inextricably linked. But until now hard evidence of pelagic fishing was lacking. From Science Now:

Although modern humans were exploiting near-shore resources, such as mussels and abalone, by 165,000 years ago, only a few controversial sites suggest that our early ancestors fished deep waters by 45,000 years ago. The earliest sure sites are only about 12,000 years old.

 

What's not known is exactly how these first fishers in East Timor caught open-water species. The researchers speculate they went to sea on boats or rafts equipped with nets or hooks-and-lines.

  

A broken shell fishhook found in East Timor. Scale is in millimeters. Credit: Sue O�Connor, et al. Science. DOI: 10.1126/science.1207703. 

  

At Jerimalai the archaeologists also found the earliest known fish hooks�including one from a mollusk shell dating to 23,000 years ago. These hooks were too small to catch the pelagic species, so were likely used inshore. 

Prior to these findings, the oldest fish hooks dated to the beginning of agriculture, or about 5,500 years ago in Southeast Asia. 

Fisher, East Timor. Credit: United Nations Photo via Flickr.

  

The paper:

• Sue O�Connor, Rintaro Ono, Chris Clarkson. Pelagic Fishing at 42,000 Years Before the Present and the Maritime Skills of Modern Humans. Science. 2011. DOI: 10.1126/science.1207703

KILLER WHALES V. SALMON

Credit: Robert Pittman, NOAA.

What happens when we 'manage' two species in the wild with different�and conflicting�objectives? 

And what happens when one eats the other�and so do we?

That's the question raised in an interesting new paper in PLoS ONE. The authors investigated how many endangered chinook salmon are needed by endangered killer whales to recover their numbers in the northeastern Pacific.

Salish Sea, comprising the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound, surrounding Vancouver Island and Washington state. Credit: SeaWiFS Project,NASA/Goddard Space Flight Center, and ORBIMAGE.

The question gets even more intriguing when you have two countries�Canada and the US�managing the fate of the two species that blithely cross international boundaries as if, you know, they weren't there.

The killer whales in the middle of the conflicted question are known as the southern resident killer whales (SRKW), who summer in the Salish Sea. They eat only fish, and are so dependent on chinook salmon that when they can't get them more adult whales die and fewer calves are born. 

• Current population of southern resident killer whales: 87 individuals
• Current chinook salmon stock: 36% of historical run in Canada, 8% in US

Chinook salmon. Credit: Josh Larios via Wikimedia Commons.

The stated objective of US management is to grow the dwindling killer whale population by 2.3% per year over 28 years. 

The authors assessed what the minimum basic caloric requirements were likely to be to make that come true�based on food requirements of captive killer whales, and body lengths of wild whales.

Estimated prey requirements of wild killer whales, based on two plausible values for calorie content of a typical, 4-year-old Chinook salmon. Credit: Rob Williems, et al. PLoS ONE. DOI:10.1371/journal.pone.0026738.

What they found suggests that the chinook salmon can't support both a growing killer whale population and human fisheries at current levels.

What's a fish-eating primate to do? The authors' suggest:

When one protected species relies almost exclusively on another protected species, it can be difficult to develop management frameworks that meet the needs of both species. This can lead to a perception that the needs of the more charismatic species will unfairly trump those of the prey species. In our experience, genuine conservation conflicts often result in management inaction in the absence of a framework in which to assess likely impacts... It is faster to reduce takes of salmon than to increase salmon production, and it is faster to increase salmon production than promote population growth in killer whales. The efficacy of salmon habitat restoration actions can often be measured within a decade, whereas similar measurements will take decades in studies of long-lived species like killer whales.

In other words, maybe we should let the whales get the fish for a while.

There's a lot more interesting stuff going on in this forward-looking paper and luckily it's open access. So you can freely read deeper.

The paper:

• Williams R, Krko�ek M, Ashe E, Branch TA, Clark S, et al. 2011Competing Conservation Objectives for Predators and Prey: Estimating Killer Whale Prey Requirements for Chinook Salmon.PLoS ONE 6(11):e26738. DOI:10.1371/journal.pone.0026738

HAIR O' THE SEAL

Antarctic fur seal (right), Weddell seal (left), Penguin Island, South Shetland Islands, Antarctica. Credit: � Julia Whitty.

   

How do you assess the health of a marine invertebrate�namely Antarctic krill�when there's no historical baseline to measure it against? 

In an intriguing piece of detective work reported in PLoS ONE a team of researchers from China and the US turned to analyzing old seal hairs to determine changes in abundance of krill in the past century.

Antarctic krill. Credit: Uwe Kils via Wikimedia Commons.

Antarctic krill, Euphausia superba, is a keystone species in the Southern Ocean and the primary consumer in a foodweb supporting fish, penguins, seabirds, seals, and whales. 

They school in swarms of up to of 30,000 individuals per cubic meter and are perhaps the most abundant animal on Earth, with a total biomass estimated at ~379 million metric tons.

In the video below (starting at 00:01), you can see humpback whales bubble feeding on krill in Antarctic waters.

 

There's evidence of a decline in krill biomass in parts of Antarctica in the past 30 years�but when did it begin?

To look deeper into history, the authors analyzed core samples from lake sediments near an Antarctic fur seal colony on King George Island in the South Shetland Islands off the Antarctic Peninsula.They dated the fur in the cores via stable carbon (d¹³C) in the samples. They inferred the abundance of krill in the seals' diet via the nitrogen (d¹⁵N) isotopes in the fur. From the paper:

Since Antarctic fur seals feed preferentially on krill, the variation of [nitrogen] in seal hair indicates a change in the proportion of krill in the seal's diets and thus the krill availability in local seawater.

  

Antarctic krill grazing on algae living on the underside of sea ice. Credit: Uwe Kils via Wikimedia Commons.

  
Their results indicate that krill began to decline in the diet of fur seals in this part of Antarctica nearly a century ago. That time frame correlates with increasing sea surface temperatures and dwindling sea ice. (See my post Life Inside the Sea Ice more about the relationship between krill and sea ice.) 

From the PLoS ONE paper:

In this region for the past decades, the sea ice shows a decline trend, and this is in coincidence with the decline trend in krill populations. Like the seal [nitrogen] values, the sea surface temperature anomaly in Southern Ocean (50�S) also shows an obvious increasing trend for the 20th century, and the significant correlation between them... suggests that the inferred decreasing krill population is linked with warming ocean and declining sea ice extent.

 

The paper: 

• Huang T, Sun L, Stark J, Wang Y, Cheng Z, et al.Relative Changes in Krill Abundance Inferred from Antarctic Fur Seal.PLoS ONE. 2011.DOI:10.1371/journal.pone.0027331.

THE SECRET LIFE OF TSUNAMI DEBRIS

Portions of houses and an overturned boat afloat in the Pacific after the 11 Mar 2011 earthquake and tsunami off Japan. Credit: US Navy/ Specialist 3rd Class Alexander Tidd.

The International Pacific Research Center (IPRC) in Hawaii reports that somewhere between 5 and 20 million tons of tsunami debris from the March earthquake and tsunami in Japan is migrating quickly across the Pacific Ocean.

Crew from the Russian tall ship STS Pallada spotted furniture, appliances, and a fishing boat with the home port 'Fukushima' painted on it after passing the Midway islands�part of the Hawaiian Islands Archipelago�last month. That's 2,000 miles from the epicenter of the quake. 

This is the first confirmed sighting since shortly after the disaster, when the massive floating remnants of coastal Japanese towns�more than 200,000 buildings�simply disappeared from view.

The image above shows the likely path of tsunami debris as of 25 Oct 2011.

The IPRC research suggests this path based on 678,305 tracers released from the northeast coast of Japan beginning 11 March 2011�the same day as the quake. 

You can watch an animation of the full dispersal here. The fluid dynamics are beautiful.

  
This video shows the IPRC prediction of the long-term�5-year-plus�travels of the tsunami debris. The original animation for the statistical model is here.

As you can see from the video, the debris, after bouncing off the west coast of North America, is likely to get trapped in the North Pacific Gyre�along with all the other garbage collecting there. The plastics will last close to forever. 

As an interesting aside, monstrously huge rafts of tsunami debris may well be one of the mechanisms by which life originally dispersed to the Hawaiian Islands. 

Pallus' rosefinch, Carpodacus roseus, native to China, Japan, the Korean Peninsula, Kazakhstan, Mongolia, and Russia. Credit: M. Nishimura via Wikimedia Commons.

  
A new analysis of the genome of Hawaiian honeycreepers reveals they're not descended, as thought, from the honeycreepers of the Americas, but are instead a sister taxon to the Eurasian rosefinches of the genus Carpodacus.

Based on a genetic analysis, the precursors of Hawaiian honeycreepers probably arrived on Kauai and Niihau about 5.7 million years ago and continued to diverge into different species after Oahu emerged from the sea.

?I?iwi, or scarlet Hawaiian honeycreeper, Vestiaria coccinea. Credit: Paul Banko, NPS.

 
It's possible that huge floating mats of tsunami debris�perhaps from Japan�brought the ancestors of Hawaii's present-day honeycreepers to the islands.

Those of you who've spent time at sea know how land birds get blown off course and will rest on any platform on the water�ship, boat, raft, the backs of sleeping whales�as they fight to stay alive.

Maybe the current tsunami debris will transport some newcomers to the Hawaiian Islands.

Townsend's warbler rests on a boat. Credit: Andrew Revkin via Flickr.

  
If so, would we recognize them as naturally-delivered refugees? 

Or would we try to exterminate them as human-introduced aliens?

The papers:

• Nikolai Maximenko and Jan Hafner. Marine Debris. pdf.
• Heather R.L. Lerner, Matthias Meyer, Helen F. James, Michael Hofreiter, and Robert C. Fleischer. Multilocus Resolution of Phylogeny and Timescale in the Extant Adaptive Radiation of Hawaiian Honeycreepers. DOI:10.1016/j.cub.2011.09.039.

CANADIAN SEABIRDS WALLOPED BY BP'S OIL

Northern gannet. Credit: Alan D. Wilson via Wikimedia Commons.

  
A new paper in early view in Biology Letters�a journal of the Royal Society�finds that Canadian migrant seabirds suffered disproportionately the lethal effects of BP's oil catastrophe in the Gulf of Mexico last year.

Northern gannets (Morus bassanus) suffered the highest oiling among beach-wrecked birds recovered last year.

These are the largest seabirds in the Atlantic, who migrate from their Canadian breeding colonies to overwinter in the Gulf of Mexico. Adults return to the breeding colonies by about March�earlier than immature birds.

Winter positions of northern gannets from 4 of 6 North American colonies, where adults and chicks were banded and adults and juveniles tracked. Mean winter (Jan�Feb) positions from adults carrying GLS (2004�2010) and final positions from 18 juveniles with PTTs (2008�2010). Deepwater Horizon site (star) and associated slicks (grey) indicated. Credit: William Montevecchi, et al. Biology Letters. DOI: 10.1098/rsbl.2011.0880.

  
Due to these migration timetables, most of the northern gannets killed in the Gulf last year were likely immature birds.

Which means the real impact of their deaths will not show up until those birds would have reached sexual maturity�at about 5 or 6 years old�or betwen now and far beyond. Gannets can live at least 21 years.

From the paper:

Most adult gannets had returned to Canadian colonies by 20 April 2010, although more than 50,000 immature gannets were in the Gulf at the time and suffered oil-related mortality. Hence, two probable outcomes are (i) a lagged (likely difficult to detect) population decrease or (ii) mortality will be buffered by age-related life-history processes.  

A bonded pair of northern gannets. Credit: Al Wilson via Wikimedia Commons.

  
The authors found the story grew even more ominous when they compared numbers on how many gannets were overwintering in the Gulf of Mexico�numbers that differed hugely depending on the technology used:

• Old-fashioned technology: recovery of banded birds
• Modern technology: bird-borne global location sensors (GLS) and satellite tags (Platform Terminal Transmitters, PTTs)

The newer technologies revealed more than twice as many gannets overwintering in the Gulf. From the paper:

Extrapolation from band recoveries indicates that 13,318 adult gannets winter in the Gulf of Mexico, much less than the 66,124 estimate based on GLS data... PTT positions suggest an estimated population of 52,509 immature gannets in the Gulf compared with 41,587 extrapolated from banding recoveries. Extrapolating tracking data for all gannet age classes more than doubles the estimated number of birds using the Gulf, from 54,905 to 118,633 birds. 

Oiled gannet washed ashore on Cape Cod. Credit: Dennis Minsky at SeaNet.

  
Add to that the fact that dead or oiled birds found ashore represent only a fraction of the birds dead or dying at sea. From the paper:

Seabirds are among the most obvious and immediate indicators of wildlife and environmental damage during marine pollution events. In these circumstances, seabird mortality has been assessed by counting dead and dying animals along coasts. These assessments are biased towards animals that die near accessible well-populated coastlines, and as offshore winds and currents can reduce coastal-deposition of carcasses that sink after a few days, mortality is inevitably underestimated.

The authors note that gannets may be shifting their winter range to the Gulf in response to overfishing of menhaden�their primary winter prey�in Atlantic waters.

Northern gannet in flight. Credit: Andreas Trepte via Wikimedia Commons.

 
And the authors noted possible signs of oil fouling on birds returning to their Canadian breeding colonies:

In April 2011, at their southernmost colony, Cape St. Mary's Newfoundland, gannets on inaccessible cliff-sites were observed and photographed with dark soiled plumage that looked like oil, but this could not be verified by chemical analysis. Tracking, survival and physiological measurements at gannet colonies during 2011 are evaluating other potential repercussions and informing management about conservation concerns.

The paper:

• William Montevecchi, David Fifield, Chantelle Burke, Stefan Garthe, April Hedd, Jean-Fran�ois Rail, Gregory Robertson. Tracking long-distance migration to assess marine pollution impact. Biology Letters. 2011. DOI: 10.1098/rsbl.2011.088.

THE X-RAY ORIGAMI OF TAKAYUKI HORI

   

Takayuki Hori's unique work won first place in the 2010 Mitsubishi Chemical Junior Designer Competition. Using a process called Oritsunagumono�defined as 'things folded and connected'�he portrayed eight endangered Japanese species. The only color in Hori's pieces comes from the ubiquitous marine garbage swallowed by his wild origami birds and reptiles.

Via designboom and monogocoro.

MODELLING THE HISTORY OF THE UNIVERSE

Galaxies in Real and Simulated Universes from Risa Wechsler on Vimeo.

Seriously cool stuff. From the Vimeo page:

We see galaxies in the sky, but cannot see the dark matter clumps surrounding them. However, we can simulate them as they form in a model Universe. In this video we show how good the agreement is between the observed distribution of galaxies in the SDSS sky survey, and the predicted distribution of model galaxies associated with dark matter halos in the Bolshoi simulation. It's hard to tell them apart!  

OCEAN OBSERVED

Compound eye of an Antarctic krill. Credit: Gerd Alberti and Uwe Kils, via Wikimedia Commons.

Scales on a 3-day old zebrafish. Credit: Carla Stehr, NOAA.

     Coccolithophore, Gephyrocapsa oceanica. Credit: NEON_ja via Wikimeda Commons.    

Diatoms. Credit: Carla Stehr, NOAA.

Gills of a mudskipper, Periophthalmus argentilineatus. Credit: G. Kruitwagen and H.P.M. Geurts, Radboud University Nijmegen.

Gills of a mudskipper, Periophthalmus argentilineatus. Credit: G. Kruitwagen and H.P.M. Geurts, Radboud University Nijmegen.

Suckers on a newly hatched east Pacific red octopus, Octopus rubescens. Credit: Carla Stehr, NOAA.

Dinoflagellate. Credit: Carla Stehr, NOAA.

All these images were taken with a scanning electron microscope. If you're wondering how that works, this video explains.

HAECKEL'S OCEAN

Actiniae [sea anemones]

Prosobranchia [archaic: snails]

Acsidiae [sea squirts]

Cyrtoidea [archaic: radiolarians]

Chaetopoda [archaic: segmented worms]

Hexacoralla [corals & allies]

Gamochonia [archaic: cephalopods]

Decapoda [crustacean]

Ostraciontes [boxfishes & allies]

Diatomea [diatoms]

Discomedusae [archaic: jellyfish]

Ophiodea [brittle stars]

Cubomedusae [archaic: box jellyfish]

Excerpted from Wikipedia:

Ernst Heinrich Philipp August Haeckel (16 February 1834-9 August 191) was an eminent German biologist, naturalist, philosopher, physician, professor, and artist who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology, including anthropogeny, ecology, phylum, phylogeny, stem cell, and the kingdom Protista. Haeckel promoted and popularized Charles Darwin's work in Germany and developed the controversial recapitulation theory ("ontogeny recapitulates phylogeny") claiming that an individual organism's biological development, or ontogeny, parallels and summarizes its species' evolutionary development, or phylogeny.

The published artwork of Haeckel includes over 100 detailed, multi-colour illustrations of animals and sea creatures (see: Kunstformen der Natur, "Art Forms of Nature"). As a philosopher, Ernst Haeckel wrote Die Weltr�tsel (1895�1899, in English, The Riddle of the Universe, 1901), the genesis for the term "world riddle" (Weltr�tsel); and Freedom in Science and Teaching to support teaching evolution.

In the United States, Mount Haeckel, a 13,418 ft/4,090 m summit in the Eastern Sierra Nevada, overlooking the Evolution Basin, is named in his honor, as is another Mount Haeckel, a 2,941 m/9,649 ft summit in New Zealand; and the asteroid 12323 Haeckel.

All plates from Ernst Haeckel's Kunstformen der Natur, courtesy of Wikimedia Commons.