Flotsam & Jetsam

Another Bad Outcome of Climate Change. The sex of turtles is determined by the temperatures of the eggs buried in the sand. Rising seasonal temperatures along Australia's Great Barrier Reef are causing more and more turtles to hatch as females. NOAA's Dr. Michael Jensen says that their findings are "a bit alarming." Northern GBR green turtle rookeries have been producing primarily females for more than two decades, and the complete future feminization of this population is possible -- with obvious results!

Disappointing News for Hammerheads. Costa Rica has had 10 tons or more of hammerhead shark fins in storage at Punta Arenas since 2015, when its government banned their export as part of its CITES obligations. Since then it has granted Costa Rican fisheries authority to undertake its own study, and surprise, surprise, it recommends that fin exports (and fishing) be resumed. That's despite two panels composed of the country's best scientists indicating that the activity cannot be done sustainably.

Citation Correction. The citation for '75 Hours Afloat and Survived' (Undercurrent March) should have read: Massey H, Leach J, Davis FM, Vertongan V. Lost at sea: the medical, physiological and psychological factors of prolonged immersion. Diving and Hyperbaric Medicine. 2017 December; 47(4):239-247. doi10.28920/dhm47.4.239-247

Lake Michigan Sanctuary Proposal Scuttled. Wisconsin Gov. Scott Walker has rescinded a nomination to implement a National Marine Sanctuary in Lake Michigan that would have given Federal protection to dozens of offshore shipwrecks. While the proposal had widespread support, he apparently gave in to a few people who don't like the idea of federal government intruding in local affairs. So, the wrecks will remain unprotected.

In Case You Were Wondering. Tiger sharks are at their most active in water around 72°F (22°C). It's their niche temperature, scientists have recently learned. Better take a warm wetsuit if you're going to Tiger Beach in the Bahamas!

Old Tank Alert! Aluminum cylinders made before 1996 are under scrutiny by a British government agency, which reports the catastrophic failures of several made using aluminum alloys HE30/AA6082 and AA6351. The cylinders were manufactured by Water Kidde in the U.S., Luxfer & Reynolds in the UK and CIG in Australia.

Florida's Manatees Dying in Record Numbers. The unusually cold weather in Florida has resulted in record manatee fatalities -- 35 during the first three weeks in January -- and we are "one more big freeze away from an ecological disaster," according to the executive director of the Public Employees of Environmental Responsibility, Jeff Ruch. Luckily, increased regulations have allowed the population to double in the last 20 years to roughly 6,000 animals.

U.S. Travel Warnings. After incidents including one bomb detonation and the discovery of a second pipe bomb on the Barcos Caribe ferry, the U.S. has given the all-clear for U.S. government personnel to use the other ferry services running between Playa del Carmen and Cozumel.

The Marine Apocalypse in 2048. That's when the world's oceans will be virtually empty of fish, predicts an international team of ecologists and economists led by Boris Worm of Dalhousie University in Halifax, Nova Scotia. The cause: the disappearance of species due to overfishing, pollution, habitat loss, and climate change. Already, 29 percent of edible fish and seafood species have declined by 90 percent -- a drop that means the collapse of these fisheries. But the issue isn't just about having seafood on our plates. Ocean species filter toxins from the water. They protect shorelines. And they reduce the risks of algae blooms such as the red tide.

Midnight Emergency. Three dozen Thai divers were rescued by the crew of diveboat Scubanet in the small hours of March 25 after their own dive boat Choltara caught fire and sank in the Andaman Sea between Lanta and Phi Phi islands en route to Phuket. There were no casualties.

The Ultimate Risk of Breath Holding! Gabriel Crowther, 39, died on March 24 after he lost consciousness practicing breath-holding in a swimming pool in Salt Lake City. Apparently he was wearing scuba gear, but whether he suffered a separate unexpected medical issue is being investigated. Serious practitioners have an observer close by to watch for underwater blackout or other problems. Crowther was practicing alone.