29 November 2011

I LONG TO BE ONCE AGAIN IN THE SEA


dagdraumar from Allan Wilson on Vimeo.

OZ MARINE PARK: BIGGEST, BEST, OR BUST?

Part of the Coral Sea off the Queensland coast of Australia. Credit: NASA.
 
The Australian government announced last week a proposal to create the world's largest marine protected area in the phenomenally biodiverse richness of the Coral Sea.

Too bad no one's happy with it.

Of course, it's in the nature of protected areas to make people unhappy for a good long while before there's any hope of making them happy.

Bison, Yellowstone National Park. Credit: Daniel Mayer via Wikimedia Commons

Yellowstone, the world's first national park, might have triggered part 2 of the Civil War if there had been more people living in the West at the time. Here's what Senator Cornelius Cole of California had to say about it during legislative debate:

I have grave doubts about the propriety of passing this bill. The natural curiosities there cannot be interfered with by anything that man can do.... I cannot see how [they] can be interfered with if settlers are allowed to appropriate them....  I do not see the reason or propriety of setting apart a large tract of land of that kind in the Territories of the United States for a public park. There is abundance of public park ground in the Rocky Mountains that will never be occupied. It is all one great park, and never can be anything else.... There are some places, perhaps this is one, where persons can and would go and settle and improve and cultivate the grounds, if there be ground fit for cultivation.

Australia's Coral Sea draft marine reserve covers 989,842 square kilometers (382,180 square miles). Courtesy Commonwealth of Australia.

In Australia, some fishers are mad as hell about the proposed new park. For brevity in reporting, nothing beats this article, in its entirety, from the Queensland ABC:

Commercial fishers in the Coral Sea claim they are being made scapegoats despite a long history of sustainable fishing. Rob Louden is a licence and quota holder in the Coral Sea and East Coast sea cucumber fishery. He says the proposed Commonwealth marine park will put valuable and productive fishing grounds off limits for no apparent ecological or biological reason.

Man, sea cucumber. Credit: Fritz Geller-Grimm via Wikimedia Commons.

Scientists and conservationists are equally unhappy with the Coral Sea proposal. From Nature News:

Hugh Possingham, director of the Australian Research Council (ARC) Centre of Excellence for Environmental Decisions at the University of Queensland, points out that little more than half... of the Coral Sea reserve is proposed as a 'no take' area, in which all fishing would be banned. The world’s largest existing marine reserve, established last year by the British government around the Chagos Islands in the Indian Ocean, spans 544,000 [square kilometers] and is a no-take zone throughout. An alliance of campaigning conservation groups, including the WWF and the Pew Environment Group, argues that more of the Coral Sea should receive this level of protection.

Blue starfish (Linckia laevigata) resting on Acropora coral, Lighthouse, Ribbon Reefs, Australia. Credit: Richard Ling via Wikimedia Commons.

The fight is fierce—and important. Australia is struggling to create meaningful protection for much of its waters. 

But its weak draft proposal last May for a southwestern Australian marine park prompted 173 scientists to write an open letter to the government in protest. One of the co-signers, CJA Bradshaw, wrote at his blog Conservation Bites:

Basically, the proposed parks are merely a settlement between government and industry where nothing of importance is really being protected. The parks are just the leftovers industry doesn’t want. No way to ensure the long-term viability of our seas.

Barry Wrasse is a stakeholder too. Here's what he has to say.


25 November 2011

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 : かえるおとこ 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

22 November 2011

HAPPIEST FEET: OILED PENGUINS GO FREE

Little blue penguin. Credit: Noodle snacks via Wikimedia Commons.

Forty-nine of 343 little blue penguins rescued from the oil spill off the New Zealand coast were released back into the ocean yesterday—with more to come in the next few weeks, says Maritime New Zealand.

At least 2,008 birds died.

When Rena grounded on 5 October 2011 it contained 1,712 tons of oil. About 360 tons spilled into the ocean. The last of the 1,319 tons remaining were removed by salvors working under really tough conditions by 13 November. Kudos to them.


The freed penguins were released back into the Bay of Plenty with hopes they'll make their way to their breeding rookery on Rabbit Island.

Bonne chance, little dudes.

18 November 2011

A HISTORY OF THE SKY



TIDEPOOL CURIOSITIES

Keyhole limpet. Credit: skome via Flickr.
Bubbles left at tidepools after waves retreat. Credit: Mila Zinkova via Wikimedia Commons.

Sparring sea anemones, white tentacles are fighting tentacles. Credit: Mila Zinkova via Wikimedia Commons.

The curio cabinet of a tidepool, with starfish, anemones, sea urchins, marine algae, barnacles, and hermit crabs. Credit: summersumz via Flickr.

Tidepool architecture. Credit: 4johnny5 via Flickr.

Artificial tidepool. Credit: Johnny Grim via Flickr.

Natural tidepool. Credit: bikehikedive (nugun) via Flickr.

Sea star growing new legs. Credit: Mila Zinkova via Wikimedia Commons.

Sea anemone, Anthopleura sola, eating a by-the-wind-sailor, Velella velella, carried to shore on spring winds. Credit: Mila Zinkova via Wikimedia Commons.

Octopus in tidepool. Credit: Mila Zinkova via Wikimedia Commons.

Microcosmos. Credit: Avenue via Wikimedia Commons.

Highrises. Credit: Glen Bowman via Wikimedia Commons.

Sea star eating a mussel. Credit: Mila Zinkova via Wikimedia Commons.

Brooding sea anemone, Epiactis prolifera. Numerous young in different stages of development are visible on the pedal disk. The brooding anemone is a colonial hermaphrodite that fertilizes and incubates its eggs in its own digestive cavity. After hatching, the larvae swim out of the mouth and migrate to the disk, installing themselves on the outside until they're big enough to move on and feed themselves. Credit: Mila Zinkova via Wikimedia Commons.

Nudibranch, Acanthodoris lutea, laying eggs in tidepool. Credit: Mila Zinkova via Wikimedia Commons.

Psychedelic nature: flame-lined chiton. Credit: Mila Zinkova via Wikimedia Commons.

Ocean vegetables. Credit: bastasia via Flickr.

Curiosities observed. Credit: nashworld via Flickr.

14 November 2011

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, Krkošek M, Ashe E, Branch TA, Clark S, et al. 2011 Competing 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

08 November 2011

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 (δ13C) in the samples. They inferred the abundance of krill in the seals' diet via the nitrogen (δ15N) 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.

04 November 2011

OCCUPY VERTEBRATES!

Credit: Kara Treibergs and Laurel Hiebert for the Oregon Institute of Marine Biology, via Pharyngula.

OCCUPY EAGLE!

Herring gull mobbing a white-tailed eagle. Credit: Markus Varesvuo/naturepl.com.

  
The situation: The breeding season, a mad-as-hell gull defending eggs or chicks, a gigantic maurading scavenger.

BIRDS OVER WATER



02 November 2011

ANTARCTICA EMERGES

1657. Jan Janssonius. Dutch. Showing hints of southern coastlines labelled 'Terra Australis Incognita.'

1714. French. Guillaume de L'Isle. Antarctica empty.

1739. Philippe Buache. French. Showing two Antarctic land masses, New Zealand connected to Antarctica, and Australia connected to New Guinea.

1777. Thomas Bowen. British. Showing the 'Track of his Majesty's Sloop
Resolution in Search of a Southern Continent.'

1818. John Pinkerton. US. Antarctica missing again.

1855. J. H. Colton. US. Showing partially sketched details of the 'Southern Regions.'

1894. Scottish. Real features getting named, including ocean currents.

1912. German. From Stielers Handatlas. Suddenly, details.

1920s. Showing 'unexplored regions,' focus on expedition routes.

1922. John Bartholomew. UK. Limited but exquisite detail.

1934. US. Focusing on the Byrd Expedition.

1972. H.C. Berann. US. Showing Antarctica in context with the seafloor.

2006. UK. Showing Antarctica without the ice.

2006. Dave Pape. Stitched satellite view.