“For the Florida Keys’ reefs, overall, the live coral cover has diminished by 50 to 80 percent in the past 10 years,” says Margaret Miller, a coral reef researcher at the National marine Fisheries Service. According to Miller, the destruction is the result of several contributing factors, such as pollution, climate change, over-fishing, and coastal developments.

“Corals are very susceptible to warming temperatures, because their lethal temperature [temperature at which they die] and their happy, normal temperature are very close, only separated by a couple of degrees,” Miller explains.

The reef building corals are not the only creatures in trouble in Florida; the situation looks dire for many reef associated species as well.

University of Miami marine professor Jerry Ault has studied marine life in the region for more than a decade.
“The research has discovered that about 70 percent of all the snapper and grouper in the Florida keys reef system are at population levels below those considered to be sustainable,” he said. “Everybody loves Florida because of the marine environment. Folks come here to fish and to dive and to take advantage of it, but we are loving it to death.”

During recent years, massive jellyfish congregations have appeared along the Northeast U.S. coast, in the Gulf of Mexico, in the Mediterranean, in the Black and Caspian Seas, and in South-East Asian coastal waters.

“Dense jellyfish aggregations can be a natural feature of healthy ocean ecosystems, says Dr Anthony Richardson of the University of Queensland, but a clear picture is now emerging of more severe and frequent jellyfish outbreaks worldwide.”

A new study by Richardson and his colleagues at the University of Miami, Swansea University and the University of the Western Cape, presents convincing evidence that these massive jellyfish populations are supported by the release of excess nutrients from fertilisers and sewage, and that fish populations depleted by over-fishing no longer are capable of keeping them in check.

“Fish normally keep jellyfish in check through competition and predation but overfishing can destroy that balance,” Dr Richardson says. “For example, off Namibia intense fishing has decimated sardine stocks and jellyfish have replaced them as the dominant species. Mounting evidence suggests that open-ocean ecosystems can flip from being dominated by fish, to being dominated by jellyfish. This would have lasting ecological, economic and social consequences.”

In addition to this, the distribution of many jellyfish species may extend as a response to global warming and an increased water temperature could also favour certain species by augmenting the availability of flagellates in surface waters.

The study, which was lead by CSIRO Climate Adaptation Flagship, has been published in the journal Trends in Ecology and Evolution.

You can find more information about CSIRO Climate Adaptation Flagship here:

450 pound blobs filling up the Sea of Japan

The changing ecosystems affect a long row of different jellyfish species, but some of the most spectacular jellyfish congregations observed during recent years have involved the Nomura jellyfish (Nemopilema nomurai) living in the Sea of Japan (Also known as the East Sea). This colossal species, which can reach a size of 2 metres* across and weigh up to 220 kg**, is also present in the Yellow Sea as well as in the rest of the East China Sea.

After becoming a major problem in the region, the Nomura jellyfish population is now combated by a special committee formed by the Japanese government. Killing jellyfish or ensnaring them in nets will however only prompt these animals to release billions of sperm or eggs; aggrevating the problem rather than reducing it. Coastal communities in Japan have started to harvest jellyfish and sell them as a dried and salted snack, and students in Obama, Fukui have started making jellyfish cookies and jellyfish-based tofu.

* circa 6 feet 7 inches

** circa 450 pounds

While conducting magnetic experiments in 2006, the company SharkDefense Technologies discovered how certain metal alloys would keep sharks away by affecting the shark’s electric sense.

After extensive testing on several different shark species, SharkDefense Technologies and HEFA Rare Earth Canada, Co. Ltd are now finally ready to put their product on the market: metal alloy thingamajigs that keep sharks away from fishing gear by generating a small voltage as soon as the product is placed in saltwater.

Unlike popular food fishes like tuna and swordfish, sharks are equipped with an electric sense organ and will therefore stay clear of this type of voltage generating alloys. By placing a small piece of metal alloy near the bait at each hook, you cause sharks to shun your fishing equipment like the plague. This is a win-win situation for fishermen and sharks, since the fishermen will able to focus on more expensive target species and the sharks will avoid getting entangled in fishing gear and die.

Continuously submerged in seawater, the metal alloys continue to emit electricity for up to 48 hours.

Scientists are unaware of the state of nearly two-thirds of Europe’s fish stocks and do not have enough information to assess the exact scale of the crisis the European fishing industry is facing, says the European Commission.

This is naturally alarming, since the commission last month admitted that nothing short of a completely new fisheries management system based on scientific evidence could stop the downward spiral of years of dangerously depleted fish stocks and get the struggling European fishing industry back on its feet.

Europe

The European Commission is now proposing smaller annual EU fish catch quotas and have given governments and industry representatives until the end of July to submit their views.

“The contribution of EU fisheries to the European economy and food supply is far smaller today than it was in the past. Even more worryingly, the status of some 59 per cent of stocks is unknown to scientists, largely due to inaccurate catch reporting,” the European Commission says in an official statement.

The policy has not been reformed since 2002 and the European Commission admits there has been “slow progress” in stock recovery, since quotas consistently have been set at unsustainably high levels.

Commercial, recreational and party/charter boat fishermen from Maine to North Carolina have all rallied together to deal with an out-of-balance population of predatory spiny dogfish sharks that threatens the recovery of New England groundfish and several others fish stocks living along the U.S. East Coast.

The newly formed Fishermen Organized for Rational Dogfish Management (FORDM) has requested the assistance of Dr. Jane Lubchenco, newly appointed National Oceanic and Atmospheric Administration head, in dealing with the predator.

Spiny dogfish

The disproportionate abundance of dogfish is not a new problem; as early as 1992 Dr. Steven Murawski, now chief scientist of the National Marine Fisheries Service’s, wrote “Given the current high abundance of skates and dogfish, it may not be possible to increase gadoid (cod and haddock) and flounder abundance without ‘extracting’ some of the current standing stock.”

That was over 15 years ago and the situation has not improved. On the contrary, the amount of dogfish now exceeds that of skates, and dogfish comprises over half of all fish taken in the annual trawl surveys carried out by the Northeast Fisheries Science Center.

The spiny dogfish can exceed 150 cm in length and preys on virtually all species of fish smaller than itself. Dogfishes can also create a problem for other species by competing with them for prey fish.

This remarkable abundance of dogfish is most likely the result of countless years of ever increasing over-fishing. Spiny dogfish is not an appreciated food fish and the depletion of other species seems to have favoured it greatly in these waters.