Saving Seafood

Does ocean acidification alter fish behavior? Fraud allegations create a sea of doubt

May 7, 2021 — When Philip Munday discussed his research on ocean acidification with more than 70 colleagues and students in a December 2020 Zoom meeting, he wasn’t just giving a confident overview of a decade’s worth of science. Munday, a marine ecologist at James Cook University (JCU), Townsville, was speaking to defend his scientific legacy.

Munday has co-authored more than 250 papers and drawn scores of aspiring scientists to Townsville, a mecca of marine biology on Australia’s northeastern coast. He is best known for pioneering work on the effects of the oceans’ changing chemistry on fish, part of it carried out with Danielle Dixson, a U.S. biologist who obtained her Ph.D. under Munday’s supervision in 2012 and has since become a successful lab head at the University of Delaware (UD), Lewes.

In 2009, Munday and Dixson began to publish evidence that ocean acidification—a knock-on effect of the rising carbon dioxide (CO2) level in Earth’s atmosphere—has a range of striking effects on fish behavior, such as making them bolder and steering them toward chemicals produced by their predators. As one journalist covering the research put it, “Ocean acidification can mess with a fish’s mind.” The findings, included in a 2014 report from the Intergovernmental Panel on Climate Change (IPCC), could ultimately have “profound consequences for marine diversity” and fisheries, Munday and Dixson warned.

But their work has come under attack. In January 2020, a group of seven young scientists, led by fish physiologist Timothy Clark of Deakin University in Geelong, Australia, published a Nature paper reporting that in a massive, 3-year study, they didn’t see these dramatic effects of acidification on fish behavior at all.

Read the full story at Science Magazine

Fisheries need to make gender inclusion a norm, not just ‘reach’ women, says Pacific study

January 13, 2021 — As a marine ecologist who has long worked at the intersection of gender equality, conservation and fisheries, Sangeeta Mangubhai knows the importance of getting the language right. She asks to see a draft of this article, anxious that words like “gender,” “empowering” and “fishers” are often used incorrectly.

“Gender means both men and women, and the relationships and power dynamics etc. between them,” Mangubhai told Mongabay in a recent video interview from Fiji, where she is director of the Wildlife Conservation Society’s Fiji country program. “It’s quite problematic when people think it’s just about women.”

This is a misunderstanding she frequently came across while carrying out research for her new study.

Co-authored by Sarah Lawless from the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Australia, the report is based on interviews with fisheries managers and practitioners working in the Pacific countries of Fiji, Solomon Islands and Vanuatu.

One government respondent from the Solomon Islands, quoted in the report, spoke for many when he said, “We don’t really understand what gender is. Particularly the technical side of this so that we can apply to our work with communities and [have it] guide us.”

Read the full story at Mongabay News

Leaving more big fish in the sea reduces CO2 emissions

October 29, 2020 — An international team of scientists has found leaving more big fish in the sea reduces the amount of carbon dioxide (CO2) released into the Earth’s atmosphere.

When a  dies in the ocean it sinks to the depths, sequestrating all the carbon it contains with it. This is a form of ‘blue carbon’—carbon captured and stored by the world’s ocean and coastal ecosystems.

“But when a fish is caught, the carbon it contains is partly emitted into the atmosphere as CO2 a few days or weeks after,” said Gaël Mariani, a Ph.D. student at the University of Montpellier in France.

Mr Mariani led a world-first study showing how ocean fisheries have released at least 730 million metric tons of CO2 into the atmosphere since 1950. An estimated 20.4 metric tons of CO2 was emitted in 2014—equivalent to the annual emissions of 4.5 million cars.

Read the full story at PHYS.org

Little Relief in the Deep for Heat-Stressed Corals

January 8, 2020 — The following was released by NOAA Fisheries:

A team of NOAA scientists recently examined more than a thousand hot water events on coral reefs across the Pacific Ocean. Combining on-site monitoring with satellite records, they found that corals in deeper waters are just as exposed to marine heatwaves as those in shallower waters. They published these findings in Nature Scientific Reports.

This is bad news for coral reefs. These unique ecosystems have already experienced the devastating effects of three global coral bleaching events from hotter-than-normal water. Climate models project that temperatures will continue to rise.

“Scientists primarily use satellite-derived sea surface temperatures to understand heat stress and predict coral bleaching,” said Dr. Scott Heron, an associate professor at James Cook University and partner of NOAA. “It’s immediately available, it’s convenient and it has global coverage. However, because the measurement is only at the very surface of the ocean, there is some uncertainty about how well it reflects what is actually happening on deeper reefs.” In fact, the data might be underestimating the stress caused by these higher temperatures.

Read the full release here

Large Sections of Australia’s Great Reef Are Now Dead, Scientists Find

March 16, 2017 — The Great Barrier Reef in Australia has long been one of the world’s most magnificent natural wonders, so enormous it can be seen from space, so beautiful it can move visitors to tears.

But the reef, and the profusion of sea creatures living near it, are in profound trouble.

Huge sections of the Great Barrier Reef, stretching across hundreds of miles of its most pristine northern sector, were recently found to be dead, killed last year by overheated seawater. More southerly sections around the middle of the reef that barely escaped then are bleaching now, a potential precursor to another die-off that could rob some of the reef’s most visited areas of color and life.

“We didn’t expect to see this level of destruction to the Great Barrier Reef for another 30 years,” said Terry P. Hughes, director of a government-funded center for coral reef studies at James Cook University in Australia and the lead author of a paper on the reef that is being published Thursday as the cover article of the journal Nature. “In the north, I saw hundreds of reefs — literally two-thirds of the reefs were dying and are now dead.”

Read the full story at the New York Times

One Fish Stands Watch While Another Eats

September 28, 2015 — Rabbitfish help one another in a way that had been observed only in mammals and highly social birds, according to a new study.

Pairs of these tropical fish will cooperate: While one has its head down feeding in the crevices of coral reefs, the other holds its head at an upward angle, apparently watching for predators.

The fish take turns between feeding and keeping a lookout, said Simon Brandl, a behavioral ecologist at James Cook University in Australia and one of the study’s authors.

He added that “when one is down, in 90 percent of cases, the other has its head up.” He and his colleagues reported their findings in the journal Nature Scientific Reports.

Read the full story at The New York Times