Science Recorder

Two major studies seem to be rewriting the rules of evolution.

According to new research on the evolution of the human hip bone, the process of change from the simple hips of a fish to the complex, weight-bearing hips of homo sapiens was far less complicated than previously thought. This study, along with those comparing genetic distances between human and other species, underscores just how closely related all living creatures are to one another.

Four-legged animals, or tetrapods, ventured onto land for the first time about 395 million years ago. One important evolutionary change that made this possible was the development of strong hipbones connected by an ilium. The ilium is the largest, most uppermost bone of the pelvic and is present in birds, mammals, and all reptiles except snakes–but not in fish.

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CNS News

The Department of Interior is providing $472,150 grant funding to increase the survival of two endangered fish species by “training” them to “recognize and avoid predators.”

“The objective of the proposed project is to determine if training increases Bonytail and Razorback Sucker survival when exposed to predators,” the grant abstract states. “This proposal builds upon the 2012 Bureau of Reclamation assistance agreement with the Arizona Game and Fish Department (AZGFD) tasked with investigating the potential for training Bonytail and Razorback Suckers to recognize and avoid predators.

“One of the early conclusions of the prior work is that the schooling behavior of Bonytail may allow untrained fish to show improved survival because they recognize predator avoidance behaviors exhibited by trained individuals,” the abstract states.

The funds, announced on Grants.gov on May 9, 2013 and set for a June 22, 2013 activation, will be given to the Bureau of Reclamation, Lower Colorado Region. The two species – Bonytail minnow and Razorback Sucker – are found in the Colorado River.

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Science Codex

The impact of industrial fishing on coastal ecosystems has been studied for many years. But how it affects food webs in the open ocean―a vast region that covers almost half of the Earth’s surface―has not been very clear. So a team of Smithsonian and Michigan State University scientists and their colleagues looked to the ancient bones of seabirds for answers, revealing some of the dramatic changes that have happened within open-ocean food webs since the onset of industrial fishing. The team’s research is published this week in the Proceedings of the National Academy of Sciences.

Few records of species that live in the open ocean date back more than 60 years, and the sheer size of open-ocean regions makes their food webs difficult to study. The Hawaiian petrel (Pterodroma sandwichensis), a crow-sized oceanic bird, offered the team a solution. These birds range widely over the northeast Pacific, and their diets integrate food webs from that vast area.

What the petrels have eaten is recorded in the chemistry of their bones. By extracting protein from bones and feathers and studying stable isotopes of carbon and nitrogen in the protein, the scientists were able to assess the birds’ diet and how it changed over centuries. What they found from bones 100 to 4,000 years old were nitrogen isotope ratios that were consistently high, indicating a diet of relatively large prey. Those less than a century old, after industrial fishing started, had low ratios, revealing a shift to smaller fish, squid and other prey.

“The question is, have the effects of open-ocean fishing gone beyond targeted species, like tuna,” said Anne Wiley, lead author, Smithsonian postdoctoral researcher and former MSU doctoral student. “Our study is among the very first to show that it has, and because Hawaiian petrels eat such a wide variety of prey over a large area, our results suggest that fishery influence may be widespread and profound in the Pacific. Understanding the influence of fisheries on open-ocean food webs has been one of the great mysteries of biological oceanography.”

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The Hindu

The Central Marine Fisheries Research Institute (CMFRI) headquartered in Kochi is seeking its place in the sun betting on its efforts to develop a chlorophyll-based, remote-sensing-assisted fisheries forecasting system, currently the holy grail of marine fisheries research.

“This is CMFRI’s flagship project in the 12th Plan period,” said the director of the institute, G. Syda Rao. CMFRI, under the Indian Council of Agricultural Research (ICAR), has been in the vanguard of marine fisheries research in the country. It ventured into measuring chlorophyll in Indian seas way back in the 1970s and 1980s using remote sensing technology.

Chlorophyll is the basic food for all sea animals. The presence of large amounts of chlorophyll in the water could be used as an indicator of areas of fish stock congregations and migration. Every 1.2 gram of chlorophyll is equivalent to roughly 100 kg of fish in 18 months, says Dr. Rao putting things in layman’s language, but masking the enormity of the task of evolving an accurate system that can predict fish availability. The project’s success will evolve into a whole package of recommendations for fisheries management, which is at the core of CMFRI mandate.

From fleet management to marketing, chlorophyll-based, fisheries forecasting system promises to be a game-changer. “Nobody has done it before. But we will do it,” says Dr. Rao.

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NOAA News

Because rockfish (Sebastes spp.) are physoclystic, i.e. their gas bladders are closed off from the gut, they often suffer internal barotrauma injuries from rapid air expansion in their tissues when brought up from depth.  Many rockfish released at the surface do not survive, either because they cannot submerge due to excessive buoyancy or because of internal damage.  There is some evidence that recompression may greatly increase the survival of barotrauma-injured rockfish.  However, survival can be species-specific; therefore, it is important to gauge the impacts on each species of interest.  Research completed during 2010-12 demonstrated that rougheye rockfish (S. aleutianus), caught at depths from 500 to 900 ft and exhibiting barotrauma, can survive if recompressed after capture.  This result is noteworthy because it is the deepest known successful capture and recompression of any rockfish species, which suggests there is potential to conduct scientific tagging studies to track movements and behavior of deepwater rockfish species.

All fish brought to the surface exhibited some external signs of barotrauma including exophthalmia (“pop-eye”), an everted esophagus, and ocular emphysema (air bubble under the cornea).  In 2011 and 2012, we tagged and released 130 fish at approximately 200 ft, and 46 others were recompressed in portable pressure tanks and slowly brought back to surface pressure.  All but one fish were brought to surface pressure over approximately 48 hours.  Using a 48-hr schedule, no fish larger than 54 cm survived.  One large fish was given roughly 96 hours in the tanks and survived with the longer depressurization schedule.  After repressurization in the tanks, fish no longer had exophthalmia or an everted esophagus.  In many cases, ocular emphysema also disappeared.  Of the 46 fish, 23 survived long-term and were monitored in the laboratory through January 2013.

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Live Science

When fish fight over food, don’t count the little guy out. In hostile situations, a fish’s personality — including how aggressive it acts — may matter more than size, according to new research.

The researchers from the University of Exeter in the United Kingdom and Texas A&M University in College Station studied how small fish managed relative to their larger peers when it came time for feeding. They found that small fish that exhibited aggressive behavior fared well in the feeding contests, regardless of their smaller stature.

“We wondered if we were witnessing a form of Napoleon, or small man, syndrome,” Alastair Wilson, an evolutionary ecologist in the department of biosciences at the University of Exeter, said in a statement.

The findings, published in the April 2013 issue of the journal Behavioral Ecology and Sociobiology, indicate that the strength of a fish’s personality may be crucial when food is scarce.

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The Advocate

Fish embryos exposed to oiled sediment in a laboratory setting, even when the oil isn’t visible, take longer to hatch and those that do hatch have deformities like elongated hearts, according to an article in the peer-reviewed science journal Environmental Science and Technology.

In addition, the scientific article states that adult Gulf killifish collected in the wild also show differences based on whether they were in an oiled or unoiled area. The changes were measured by looking at the “turning on” of a gene in the bait fish indicating exposure to oil even a year after oil was no longer visible in an area.

The results could have implications for other fish species that breed or live in Louisiana’s coastal marshes such as red fish, snapper or shrimp, researchers said.

Andrew Whitehead, assistant professor of environmental toxicology for the University of California at Davis, said animals that share a common habitat with the Gulf killifish, a common small bait fish in coastal Louisiana, share a similar risk.

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UDaily

More than a century ago, an estimated 180,000 female Atlantic sturgeon arrived from the coast in the spring to spawn in the Delaware River and fishermen sought their caviar as a lucrative export to Europe. Overfishing contributed to steep population declines, however, and today numbers have dwindled to fewer than 300 adults.

Researchers at the University of Delaware and Delaware State University are using satellites, acoustic transmitters, an underwater robot and historical records to pinpoint the ocean conditions that the fish prefer during migrations — and potentially help fishermen avoid spots where they might unintentionally catch this endangered species.

“There are specific, observable waters in the ocean that we hypothesize are more associated with this species,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment.

Oliver and graduate student Matt Breece compared prior years’ satellite data on ocean temperature and chlorophyll levels with locations where sturgeon were previously tracked migrating along the Mid-Atlantic coast. Based on patterns they found between the datasets, they are now using current satellite information to make rough daily predictions on where the sturgeon are migrating.

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Nature World News

Spilled crude oil from the Deepwater Horizon oil spill in the Gulf of Mexico sickened Gulf fish species for more than a year after the disaster, according to new research.

Gulf killifish embryos exposed to sediments from oiled locations in 2010 and 2011 show developmental abnormalities, including heart defects, delayed hatching and reduced hatching success, the researchers report.

Killifish are abundant in coastal marsh habitats along the Gulf Coast. Because the fish are non-migratory, the researchers say killifish are ideal subjects for a study of the health of ocean life in the wake of the oil spill.

The researchers collected Gulf killifish from an oiled site at Isle Grande Terre, La., and monitored them for measures of exposure to crude oil. They also exposed killifish embryos in the lab to sediment collected from oiled sites at Isle Grande Terre within Barataria Bay in Louisiana.

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