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April 2013 Issue

Red Tide Causes Manatee Deaths in Florida
Red tide has killed 149 manatees in Florida within two and a half months this year, NBC News reported. The state will likely pass the record of 151 manatee deaths, set in 1996.

The algae bloom currently covers a 70-mile stretch of the west coast of Florida, from Sarasota to Fort Myers. Manatees, which are endangered mammals, congregate there for winter.

The algae contain a toxin that disrupts the manatees’ breathing process when they ingest it.

“They’re basically paralyzed, and they’re comatose,” Virginia Edmonds, animal care manager of Florida mammals for the Lowry Park Zoo in Tampa, Florida, told the Tampa Bay Times. “They could drown in 2 inches of water.”

The toxin gets absorbed by seagrass, which the manatees also eat.

The deaths will likely continue for two more months after the red tide breaks up.

So far this year, 11 manatees have been rescued and taken to the zoo for treatment, where workers take three-hour shifts holding a manatee’s head above water inside a tank so it can breathe until it recovers and regains the ability to breathe on its own again.

Red tide develops when water temperature, salt content and nutrients interact in a particular combination, turning the water reddish-brown. Red tide has been linked to global warming because algae thrive in warmer water, according to some scientists.

There are an estimated 4,000 to 5,000 manatees in Florida.

The most common cause of death for manatees is collisions with boats, the Florida Fish and Wildlife Conservation Commission said.

Shark Deaths by Fishing Outpace Reproduction Rates
Up to 100 million sharks or more are killed each year by fishing, which jeopardizes their future, according to a study published in Marine Policy.

Dalhousie researchers teamed with scientists from the University of Windsor, Stony Brook University, Florida International University and the University of Miami to calculate total shark mortality worldwide using available data.

Because adequate data of shark catches is lacking for most of the world, the range of possible mortality is based on available data of shark deaths and calculated projections for unreported, discarded and illegal catches.

The researchers estimated an average exploitation rate for sharks of between 6.4 and 7.9 percent. That means that of the estimated number of sharks in the ocean, 100 million of them or more are killed each year. Based on available data for 62 different shark species, sharks have an average rebound rate of 4.9 percent each year. This means there are more sharks dying than being born.

While total shark deaths were estimated at 100 million in 2000 and 97 million in 2010, the total possible range of mortality could be between 63 and 273 million annually.

Sharks are similar to whales and humans in that they mature late in life and have few offspring. Because of this, they cannot sustain much additional mortality.

The study shows that about one in 15 sharks gets killed by fisheries every year. With an increasing demand for their fins, sharks are more vulnerable today than ever before due to a global boom in shark fishing.

While some sharks are receiving protection through national and international agreements, the researchers suggested that legislation should be expanded to a greater number of species. Another solution they suggested is a tax on the export and import of shark fins to curb demand and generate income for domestic shark fisheries management.

Privatizing Florida’s Coral Reefs As Conservation Solution
Florida’s coral reefs are on the verge of collapse, according to the Property and Environment Research Center (PERC). On average, southeast Florida reefs contain 2 to 3 percent live hard coral cover. This decline is due to the impact of effluent discharges from municipal storm and wastewater treatment facilities along the coast and the physical destruction caused by boat groundings, fishing equipment and recreational divers.

PERC’s report “Closing the Coral Commons to Support Reef Restoration in Florida” explores the viability of a framework for managing Florida’s coral reefs based on property rights. Rather than relying on the political process to determine the optimal level of reef protection, such property rights would allow voluntary trades to occur between competing reef users, namely, divers, anglers, boat captains, conservation organizations and coastal communities.

Conservation entrepreneurs have already developed methods for growing imperiled coral species in nurseries and replanting them on reefs. A market-based management approach that rewards this kind of innovative stewardship—and creates accountability for reef deterioration—has greater potential to enhance Florida’s coral resources than the government policies currently under consideration, according to the report.

Pod Deployed Off Eday to Test Effect of Turbines on Wildlife
A team from the European Marine Energy Centre has deployed an environmental monitoring pod, which has started to collect data to assess the potential effects tidal turbines may have on wildlife, such as mammals, at its tidal test site at the Fall of Warness off the island of Eday, north of the Scottish mainland. The key aim of the Energy Technologies Institute’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project is to boost public, industry and regulatory confidence in tidal turbine technology deployment.

The pod features a variety of specialist monitoring and measuring equipment to capture physical and environmental interactions with tidal turbines. These include hydrophones and an active sonar system, which is produced by Greenford, England-based Ultra Electronics, as well as more standard equipment that measures the temperature, speed and density of the tidal flow.

The project also involves Plymouth Marine Laboratory testing of marine coating systems to prevent biofouling, and resist scour and abrasion.


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