Saving Seafood

Oil impairs ability of coral reef fish to find homes and evade predators

July 18, 2017 — Just as one too many cocktails can lead a person to make bad choices, a few drops of oil can cause coral reef fish to make poor decisions, according to a paper published today in Nature Ecology & Evolution. A team of fisheries biologists led by Jacob Johansen and Andrew Esbaugh of The University of Texas Marine Science Institute have discovered that oil impacts the higher-order thinking of coral reef fish in a way that could prove dangerous for them—and for the coral reefs where they make their home.

Examining six different species of , Johansen and the team found that exposure to oil consistently affected behavior in ways that put the  at risk.

During several weeks when coral  fish go through their juvenile stages of development, they are especially vulnerable. Even in healthy populations of reef fish, typically less than 10 percent of embryos and larvae reach adulthood. Those who survive must learn to identify friend from foe and adopt protective behaviors, such as traveling in groups, minimizing movement in open waters and swimming away quickly from danger.

In experiments, the scientists found that juvenile fish exposed to oil struggled on all these counts.

“In several different experiments, the fish exposed to oil exhibited very risky behavior, even in the presence of a predator,” said Esbaugh, an assistant professor of .

The scientists also found that oil exposure negatively affected the fishes’ growth, survival and settlement behaviors (their ability to find a suitable habitat).

Oil concentrations are found in oceans worldwide, but until now little has been known about the impact of oil exposure on coral reef fish. Earlier research that explored how oil affects the physiology of fishes has demonstrated developmental heart deformities and associated cardiac functions, but this is the first study to demonstrate that oil exposure affects behavior in a way that increases predation and reduces settlement success.

Read the full story at Phys.org

Noisy tests offshore scaring fish away from reefs

January 31, 2017 — The sonic tests used to map the ocean floor in order to explore for oil and gas is scaring fish away from reefs, according to a first-of-its-kind study released by a University of North Carolina at Chapel Hill researcher.

Avery Paxton, a marine ecologist with UNC’s Institute for Marine Sciences, has for two years been studying the effects of loud manmade noises on fish in the ocean.

“These noises, on the reef, they’re repetitive,” Paxton said. “The sound levels on the reef that were heard by these fishes were loud enough that, in laboratory experiments, fish did have physiological damage.”

Read the full story at WRAL.com

Why the death of coral reefs could be devastating for millions of humans

November 10th, 2016 — Coral reefs around the globe already are facing unprecedented damage because of warmer and more acidic oceans. It’s hardly a problem affecting just the marine life that depends on them or deep-sea divers who visit them.

If carbon dioxide emissions continue to fuel the planet’s rising temperature, the widespread loss of coral reefs by 2050 could have devastating consequences for tens of millions of people, according to new research published Wednesday in the scientific journal PLOS.

 To better understand where those losses would hit hardest, an international group of researchers mapped places where people most need reefs for their livelihoods, particularly for fishing and tourism, as well as for shoreline protection. The researchers combined those maps with others showing where coral reefs are most under stress from warming seas and ocean acidification.

Countries in Southeast Asia such as Indonesia, Thailand and Philippines would bear the brunt of the damage, the scientists found. So would coastal communities in western Mexico and parts of Australia, Japan and Saudi Arabia. The problem would affect countries as massive as China and as small as the tiny island nation of Nauru in the South Pacific.

Read the full story at The Washington Post

Researchers find abundant life in Hawaii’s twilight zone

October 5, 2016 — HONOLULU — Coral reefs in Hawaii’s oceanic twilight zone, where light still penetrates and photosynthesis occurs, are abundant and host a wide variety of life, a new study shows.

A paper published Tuesday in the journal PeerJ revealed that some of these ecosystems off the Hawaiian archipelago, particularly an area off Maui, are the most extensive deep-water reefs ever recorded.

The ecosystems, found in waters from 100 to 500 feet deep, host more than twice the amount of unique Hawaiian fish species as their shallow-water counterparts, and they are much more extensive than previously known.

“What is unique about this study is how vast and dense the coral cover is,” Richard Pyle, a Bishop Museum researcher and lead author of the publication, told The Associated Press.

Read the full story from the Associated Press at KSL

Stopping the world’s most rapacious invasive species, one fillet at a time

August 18, 2016 — Since Pacific lionfish were first detected off the coast of Florida three decades ago, they have spread around the Caribbean, gobbling up everything that fits in their mouths and reproducing at a phenomenal rate. Scientists have shown that soon after they descend upon a reef, there is a sharp fall in the number of small fish, notably the herbivores on which coral depends for survival.

“They’re eating their way through the reefs like a plague of locusts,” said Mark Hixon, a lionfish specialist at the University of Hawaii.

It is by far the most destructive invasive species ever recorded at sea, and the blight is believed to have started with aquarium fish released off the Florida Atlantic coast in the mid-1980s.

However, in the last few months, a set of unrelated trends has resulted in two U.S. supermarket chains, Whole Foods and Wegmans, offering Florida lionfish, which has a white, delicate flesh, to consumers with much fanfare. Early signs suggest that the state’s fishery might just be big enough to protect the native denizens of at least some reefs from being decimated.

Read the full story at the Alaska Dispatch News

Biodiversity makes reef fish more resilient in the face of climate change, research confirms

May 17, 2016 — New research confirms that biodiversity can help reef fish weather the impacts of global warming.

Reef systems with greater numbers of fish species are not just more productive but also more resilient to rising sea-surface temperatures and the temperature swings associated with climate change, according to a new study led by researchers with the Smithsonian’s Tennenbaum Marine Observatories Network.

After analyzing data from more than 4,500 fish surveys of reefs around the world to compare the effects of biodiversity and other environmental factors on global reef fish biomass, the authors of the study found that biodiversity, measured by the number of species (species diversity) and the variety of functional traits (functional diversity) within a reef system, was one of the strongest predictors of fish biomass, second only to mean sea-surface temperature.

A direct impact of the carbon emissions that continue to concentrate in Earth’s atmosphere is warmer, more acidic ocean waters, which has contributed to the bleaching of reefs around the world. Just last month, scientists announced that 99 percent of coral reefs surveyed in Australia’s Great Barrier Reef have been hit by the global bleaching event that has already taken a toll on reefs at the Pacific islands of Hawaii, Vanuatu, American Samoa, and Fiji, as well as parts of the Caribbean, the Florida Keys, and the Indian Ocean.

Read the full story at Mongabay

More acidic seawater now dissolving bit of Florida Keys reef

May 4, 2016 — Seawater — increasingly acidic due to global warming — is eating away the limestone framework for the coral reef of the upper Florida Keys, according to a new study. It’s something that scientists had expected, but not so soon.

This is one of the first times scientists have documented long-term effects of ocean acidification on the foundation of the reefs, said study author Chris Langdon, a biological oceanographer at the University of Miami.

“This is what I would call a leading indicator; it’s telling us about something happening early on before it’s a crisis,” Langdon said. “By the time you observe the corals actually crumbling, disappearing, things have pretty much gone to hell by that point.”

The northern part of the Florida Keys reef has lost about 12 pounds per square yard (6.5 kilograms per square meter) of limestone over the past six years, according to the study published in the journal Global Biogeochemical Cycles. Over the length of the reef, that’s more than 6 million tons. The water eats away at the nooks and crannies of the limestone foundation, making them more porous and weaker, Langdon said.

Read the full story at the New Jersey Herald

China’s Island Building Hurts Environment, U.S. Report Says

April 13, 2016 — China’s reclamation work in the South China Sea may have destroyed coral reefs, damaged fisheries in a region heavily dependent on seafood and breached international law on protecting the environment, according to a report to U.S. Congress.

“The scale and speed of China’s activities in the South China Sea, the biodiversity of the area, and the significance of the Spratly Islands to the ecology of the region make China’s actions of particular concern,” an April 12 report prepared for the U.S.-China Economic and Security Review Commission said.

China reclaimed about 3,000 acres of land on seven features it occupies in the Spratly islands of the South China Sea between December 2013 and October 2015, the report said. Vietnam has reclaimed about 80 acres, Malaysia 70 acres, the Philippines 14 acres and Taiwan eight acres, according to the U.S. Department of Defense.

See the full story at Bloomberg

Is global warming causing marine diseases to spread?

March 29, 2016 — PORTLAND, Maine –Global climate change is altering the world’s oceans in many ways. Some impacts have received wide coverage, such as shrinking Arctic sea ice, rising sea levels and ocean warming. However, as the oceans warm, marine scientists are observing other forms of damage.

My research focuses on diseases in marine ecosystems. Humans, animals and plants are all susceptible to diseases caused by bacteria, viruses, parasites and fungi. Marine diseases, however, are an emerging field.

Infectious agents have the potential to alter ocean life in many ways. Some threaten our food security by attacking important commercial species, such as salmon. Others, such as bacteria in oysters, may directly harm human health. Still others damage valuable marine ecosystems – most notably coral reefs.

To anticipate these potential problems, we need a better understanding of marine diseases and how climate change affects their emergence and spread.

Read the full article at the Portland Press Herald

Acidic Ocean Leads to Warped Skeletons for Young Coral

February 19, 2016 — Rising emissions of carbon dioxide create twin threats for coral in oceans around the world: warmer temperatures, which can cause mass bleachings, and ocean acidification, which can hinder the animals’ ability to build reefs.

But a new study published on Friday in the journal Science Advances suggests that ocean acidification may be the bigger worry in some waters.

Studying a chain of remote Australian islands in the Indian Ocean, researchers found that more acidic waters (those that have absorbed more atmospheric carbon dioxide) cause serious skeletal deformities in juvenile coral in subtropical waters.

Using 3-D imaging techniques, they saw that young coral from the Houtman Abrolhos islands developed skeletons that were missing sections or had very porous and fragile surfaces.

Other studies have shown similar effects of ocean acidification, but the researchers also discovered something that had not been seen in earlier studies of tropical coral development — higher temperatures didn’t have a negative effect on coral skeleton formation.

Read the full story at the New York Times