Constantine Alexander's blog

NOAA sets fishing quotas for bluefin tuna

School of bluefin tuna. Credit: NOAA Fisheries Service

NOAA today announced quotas and other measures for bluefin tuna that underscore the nation’s commitment to sustainable science-based management of this vital fish stock. The allocations divide the available 2011 U.S. bluefin tuna quota of 957 metric tons among commercial and recreational fishing sectors for the fishing season that began on June 1.

“The best way to ensure the long-term sustainability of bluefin tuna is through international cooperation and strong domestic fishery management,” said Eric Schwaab, assistant NOAA administrator for NOAA’s Fisheries Service. “Today’s domestic quotas provide allocations to U.S. commercial and recreational fishermen who target bluefin tuna. At the same time, the quotas ensure that longline fishermen can continue to operate while they will take additional steps to minimize their unintended catch of bluefin.”

In addition, NOAA’s Fisheries Service announced it would begin a review of domestic bluefin tuna management to address allocation issues, discards of dead bluefin tuna and the best ways to reduce unintended catch of bluefin tuna.

The total U.S. quota was set by the International Commission for the Conservation of Atlantic Tunas in November, the international body made up of 47 nations and the European Union that manages this highly migratory species. Each of the member nations divides its national quota among its domestic users. The U.S. has been a leader at ICCAT in promoting quotas based on science and in urging the adoption of strong measures to help with the recovery of bluefin tuna and other fisheries.

The General category, which includes commercial fishermen who use rod and reel, will receive 435 metric tons, nearly half the 2011 U.S. quota. Allocations for the other categories are as follows: Angling category (which includes recreational fishermen), 182 metric tons; purse seine fishermen, 171.8 metric tons; longline fishermen, 61 metric tons; harpoon fishermen, 36 metric tons; trap fishermen, 0.9 metric tons; and a reserve of 70.6 metric tons. The reserve is set aside for scientific research and to account for landings and dead discards.

The allocations account for potential discards of unintentionally caught bluefin tuna. Bluefin tuna are primarily discarded by longline fishermen who are targeting swordfish and other tunas. Although fishermen attempt to release fish alive, many discarded fish do not survive. The longline fishery was the only sector to receive reductions in its base quota to account for dead discards in advance of them actually being caught. Data from the 2010 fishing season was used to estimate the discard amount.

“We are working closely with longline fishermen to reduce the amount of bluefin tuna that they catch unintentionally,” said Schwaab. “This spring, we began requiring longline fishermen in the Gulf of Mexico to use weak hooks to reduce the unintended bluefin catch while still allowing them to catch swordfish and yellowfin tuna.”

The weak hook, a circular hook constructed of thin gauge wire, is designed to straighten when a large fish such as bluefin tuna is hooked, releasing it but holding on to smaller, lighter fish.

After extensive scientific review, NOAA announced on May 27 that the Atlantic bluefin tuna currently do not warrant species protection under the Endangered Species Act. NOAA also committed to revisit this decision by early 2013, when more scientific information will be available. NOAA has also formally designated Atlantic bluefin tuna as a “species of concern” under the Endangered Species Act, placing the species on a watchlist for concerns about its status and threats to the species.

More information on bluefin tuna is available online. NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources.

 

Denmark can triple its biomass production and improve the environment

University of Copenhagen

The industry is interested in establishing a biorefinery sector in Denmark that can replace oil-based products with biofriendly materials, chemicals, energy and fuel. But this requires a larger biomass production than we are currently achieving. Scientists from University of Copenhagen and Aarhus University have published an extensive report that shows how we can increase the production of biomass by more than 200% in an environmentally friendly way.

The report called "The ten-million-tonne plan" shows how we can increase the Danish production of biomass from agriculture and forestry by 10 million tonnes per year without affecting the current production of feed and food.

The plan also shows how we can substantially reduce the environmental impact compared with current levels.

"It sounds too good to be true, but it is quite realistic. By concentrating on a number of areas we can in practice double plant production and improve the utilisation of existing resources so there is enough both for food and feed production and for an additional 10 million tonnes of biomass in 2020," says Morten Gylling, senior advisor at the Faculty of Science, University of Copenhagen.

The report contains a number of specific subelements that combined provide a solution for how we can use sustainable biology and technology to get an additional 10 million tonnes of biomass a year by 2020 without incorporating more agricultural land.

"One of the options is to double crop yield per hectare in selected areas. This can be done by converting to cropping systems with improved perennial crops and break crops to extend the growing season and thus more fully exploit the solar radiation. This will be sufficient to meet the requirements for both feed and food production and for the biomass production for a number of biofriendly products," explains Uffe Jørgensen, senior scientist at Aarhus University.

The increased production of biomass means that it would be possible to establish a biorefinery sector in Denmark – a sector that is crucial for the establishment of a green growth economy in Denmark.

"A future Danish biorefinery sector would create around new 20,000 jobs in production and industry, primarily in the provinces," says professor Claus Felby from University of Copenhagen and continues:

"10 million tonnes of biomass actually corresponds to 20 percent of our current consumption of natural gas and to 30-50 percent of our consumption of petroleum and diesel. To this should be added a significantly higher feed production that to a large extent will be able to replace what we currently import from countries such as South America," says Claus Felby.

The results of the report also show that the aquatic environment will improve with a focus on biomass: The loss of nitrogen from farmland can be reduced by more than 20,000 tones:

"A focus on biomass production alone will help meet our obligations in the EU Water Framework Directive, which is one of the most important tasks of Natur og Landbrugskommissionen (Agriculture and Nature Council) at the moment. It is particularly a better utilisation of animal manure that will help us to significantly reduce nitrate leaching," emphasizes Morten Gylling.

Biodiversity in Denmark will also be enhanced:

"We can increase biodiversity by harvesting the grass from approx. 70,000 ha of lowland meadows so they do not become smothered in nettles and willow as a result of nutrient overloads. Another option is to increase the area with natural woodland by 47,000 ha, and it is also possible to cut and remove the biomass and nutrients from approx. 7,000 ha of road verges to increase floral diversity," adds Uffe Jørgensen.

In order to realise the biomass potential, a massive investment in research and development will be needed in future years, particularly within agriculture and forestry, but also within the biological and chemical conversion of biomass.

The project is part of the collaboration between University of Copenhagen, Aarhus University and DONG set up in December 2011 to help launch special initiatives within research and education in green energy.

Contact: Morten Gylling
gylling@foi.ku.dk
(45) 27-24-34-84
University of Copenhagen

Mass extinctions reset the long-term pace of evolution

		The fossil mollusks in this Maryland outcrop lived approximately 15 million years ago. UChicago paleontologists Andrew Z. Krug and David Jablonski analyzed the fossil record of mollusks for the last 200 million years, finding that mass extinctions don't just remove evolutionary lineages, they exert a long-term influence on evolutionary rates among the survivors. Credit: Susan Kidwell

A new study indicates that mass extinctions affect the pace of evolution, not just in the immediate aftermath of catastrophe, but for millions of years to follow. The study's authors, University of Chicago's Andrew Z. Krug and David Jablonski, will publish their findings in the August issue of the journal Geology.

Scientists expected to see an evolutionary explosion immediately following a mass extinction, but Krug and Jablonski's findings go far beyond that.

"There's some general sense that the event happens, there's some aftermath and then things return to normal," said Krug, a research scientist in geophysical sciences at UChicago. But in reality, Krug said, "Things don't return to what they were before. They operate at a different pace, sometimes more rapidly, other times more slowly. Evolutionary rates shift, and that shift is permanent until the next mass extinction."

Krug and Jablonski's suggestion that the potential for rapid speciation and expansion of survivors and new groups of organisms in the "emptier" world following a mass extinction "is a reasonable possibility as one source of rate change," said paleontologist Richard Bambach of the Smithsonian Museum of Natural History, who was not directly involved in the UChicago study.

The long-term evolutionary patterns of species diversification following mass extinctions are poorly understood. Paleontologists have extensively debated whether diversity has increased over the last 251 million years, which followed the most devastating mass extinction in Earth history, Bambach said

Inconsistent classifications

Scientists have been putting Latin names on fossils since 1758, often inconsistently. Methods and tools have changed with the times, but old names often remain. The UChicago paleontologists have combed through seemingly endless volumes of research papers and countless museum drawers in an ongoing attempt to standardize these classifications.

For their Geology study, Krug and Jablonski analyzed contemporary groups of organisms from the end of the Pleistocene Epoch, which ended approximately 10,000 years ago, to the Jurassic Period, which began approximately 200 million years ago. The availability of globally abundant data on bivalves, a group that includes clams, oysters and scallops, set the study's time boundaries.

"With some groups, like sea urchins or corals, you just couldn't do it because the numbers aren't big enough," said Jablonski, the William R. Kenan Jr. Distinguished Service Professor in Geophysical Sciences. When he and Krug statistically plotted the origination rate of new bivalve species at 50 million-year intervals, they found that all the species evolved at a fairly steady rate for millions of years. Then the bivalve groups show a sudden increase or decrease in the rates at which new species evolved. These sudden shifts marked the occurrence of a mass extinction. "They settle back down to a different rate from what was before, and they do it multiple times, corresponding to each mass extinction," Jablonski said.

Theoretically, the origination rates of the organisms might have "been all over the map," with evolutionary rates varying in a random or chaotic style, but they didn't. "It's surprising how organized the pattern is," he said.

Krug and Jablonski's perspective of the data is somewhat different from Bambach's. These perspectives are "not contradictory, but complementary, ways of looking at the data," Bambach said. "One of the valuable things about their work is that they record the pattern and pattern change during intervals that I lump together."

Bambach bases his work on older data compilations that include the animal kingdom as a whole, while Krug and Jablonski use their new, carefully vetted data from bivalve mollusks.

Setting a new pace

"There's been a lot of talk about the evolutionary role of mass extinctions, but it's like the weather. Everyone talks about it, but no one does much about it," Jablonski joked.

"No one has really thought about it in terms of these downstream dynamics, once the smoke has cleared and ecosystems have found a new equilibrium, for want of a better word. But the wonderful thing is that when they find a new equilibrium, it's a different evolutionary pace from the one that prevailed for the preceding 50 million years. The survivors of the mass extinction, or the world they inherited, is so different from what went before that the rate of evolution is permanently changed."

Krug and Jablonski's research builds upon the work of UChicago's David Raup, the Sewell L. Avery Distinguished Service Professor Emeritus in Geophysical Sciences, and Michael Foote, professor in Geophysical Sciences.

In 1978, Raup published a method for determining the extinction rate of organisms. His method involved monitoring the survivorship of a group of organisms that had all originated during a specific time period and quantifying when they disappeared. It would be like collecting census data for all individuals born on Jan. 1, 1899, tracking their longevity, then finding that the 1918 influenza epidemic had produced a spike in this group's mortality.

Foote followed up in 2001, showing that Raup's method worked equally well for determining origination rates as it did for extinction rates. One simply needed to use the method in reverse, tracking the time since origination of a group of co-occurring lineages as opposed to the time until extinction. Now comes Krug and Jablonski's latest study, finding that the evolutionary "birth rate" was also reset at major catastrophes. "It's very Chicago-esque," Jablonski said.

Citation: Andrew Z. Krug and David Jablonski, "Long-term origination rates are re-set only at mass extinctions," Geology, posted online June 29, 2012.

Contact: Steve Koppes
skoppes@uchicago.edu
773-702-8366
University of Chicago

Acid-wielding worms drill through bones at the bottom of the sea

		These "bone-devouring worms, " known to both eat and inhabit dead whale skeletons and other bones on the sea floor, have a unique ability to release bone-melting acid. Credit: Greg Rouse

Tiny 'bone-devouring worms', known to both eat and inhabit dead whale skeletons and other bones on the sea floor, have a unique ability to release bone-melting acid, scientists at Scripps Institution of Oceanography, University of California, San Diego have recently discovered. The work is being presented at the Society for Experimental Biology's 2012 meeting in Salzburg, Austria.

Dr Sigrid Katz, a postdoctoral researcher working with Greg Rouse and Martin Tresguerres, said: "These worms are unique in using bone as a habitat and nutrient source. We have learned a lot about these worms in the past 10 years, but one of the most intriguing questions has been how they penetrate bone and take up nutrients."

The worms, whose official genus name is Osedax, are up to 3-4 cm long and were discovered on a whale carcass in 2002. They come from a family of worms living in unexpected locations, with their relatives inhabiting the extremely hot and acidic hydrothermal vents in the sea.

		The pinkish "bone-devouring worms " shown here on a piece of whale bone, eat and inhabit dead whale skeletons and other bones on the sea floor. A recent study has shown they have a unique ability to release bone-melting acid. Credit: MBARI

Like all worms in their family, Osedax have no mouth, anus, or gut. Their digestion of the nutritious bone is made possible by their partnership with bacteria.

While it had been clear that the worms and their bacteria rely on nutrients such as collagen or fat from the bones they inhabit, until now it was a mystery how the worms penetrated the bones and access their nutrients. Their bodies consist of a worm-like portion and 'roots' that house the bacteria and penetrate the bones, but they have no body parts mechanically able to drill through bone.

The researchers looked instead for signs of a chemical drilling strategy, testing for the presence of acid-secreting enzymes in different tissues of the worm. One of the enzymes, a proton pump, was abundant in the roots, the part of the worm that penetrates the bone. The results indicate that the worm secretes acid to demineralize the bones.

As Katz explained, "The discovery of Osedax shows that nutrition is even more diverse than we imagined, and our results are a step further in understanding the special relationship between the worm and its bacteria."

The findings of this study pertain to the females only. The males never grow beyond their larval size (about 1 mm) and they live inside the gelatinous tube that surrounds each female. Each female will have hundreds of males living in her tube.

Contact: Catie Lichten
leitac@gmail.com
44-777-279-5646
Society for Experimental Biology

 

Native plant restoration not enough to maintain tropical dry forests in Hawaii

The Hawaiian Islands

Protecting Hawaiian dry forests from invasive species and the risk of wildfire is an on-going challenge for land managers and scientists conducting research on the Island of Hawaii. It is commonly thought that removing the invasive species and planting native species will restore the land to its original state. However, in a recent paper published in Biological Invasions, Dr. Susan Cordell, USDA Forest Service Pacific Southwest Research Station, Institute of Pacific Islands Forestry; Dr. Erin Questad, Cal-Poly Pomona; and Dr. Jarrod Thaxton, University of Puerto Rico found that it is not quite that simple.

The research team has been working at the Kaupulehu dry forest reserve on the Island of Hawaii for the past decade. The largest current threat to this highly unique and endangered ecosystem is the spread of non-native fire-promoting grasses, in particular, fountain grass or Pennisetum setaceum.

To test characteristics of ecosystem resilience in this dry tropical forest, the researchers allowed natural rates of re-invasion of non-native species into an existing restoration project and looked at how effective restoration projects were at enhancing invasion resistance. They paid particular attention to the relationship between invasibility and native plant diversity.

Key findings from the research include:

• Higher invasion rates occurred in plots that supported the most native species, suggesting that similar mechanisms may regulate the distribution of both native and invasive species.
• Fountain grass was associated with native plant mortality and declines in native diversity, particularly in areas with harsh environmental conditions (i.e. steep slopes, little soil, exposed terrain).
• Native woody plant restoration alone was not an effective tool for weed control in this community, and continuing invasion may result in declines in native diversity in the long term.

"We have spent a considerable amount of time understanding the role of restoration on non-native plant invasion," says Dr. Cordell. "In the short term, restoration of native species serves to improve invasion resistance —but results from this study also indicate that long-term sustainability of restoration projects will require continued non-native species management."

These findings suggest the need for consideration of long-term sustainability measures in restoration plans for tropical dry forest ecosystems in Hawaii.

Headquartered in Albany, Calif., the Pacific Southwest Research Station develops and communicates science needed to sustain forest ecosystems and other benefits to society. It has research facilities in California, Hawaii and the U.S.–affiliated Pacific Islands. PSW's Institute of Pacific Islands Forestry, located in Hilo, Hawaii, is a leading research institution addressing many critical natural resource-related issues in the Pacific. 

Contact: Sherri Eng
sleng@fs.fed.us
510-559-6327
USDA Forest Service - Pacific Southwest Research Station