Ocean Currents » rays http://blog.oceanconservancy.org News, opinions, photos and facts from Ocean Conservancy Fri, 03 Jul 2015 18:30:11 +0000 en-US hourly 1 http://wordpress.org/?v=3.4.2 What’s Lurking in the Ocean’s Depths? http://blog.oceanconservancy.org/2014/10/29/whats-lurking-in-the-oceans-depths/ http://blog.oceanconservancy.org/2014/10/29/whats-lurking-in-the-oceans-depths/#comments Wed, 29 Oct 2014 17:00:53 +0000 Brett Nolan http://blog.oceanconservancy.org/?p=9419

Trick or treating in the ocean can be a matter of life or death. Meet four ocean creatures who might just surprise you!

Vampire Squid

You’ve no doubt heard of the famous vampire bat, but did you know that there’s a vampire squid? Don’t worry. It won’t fly out of the ocean to suck your blood. These cephalopods don’t even spray ink like other squids. They produce a bioluminescent mucus cloud that can glow for up to 10 minutes. They were given their names due to their blood red eyes, which can also look blue depending the lighting. Their bodies definitely reflect the gothic nature of vampires by being black or red. A web like material connects their tentacles. They can even envelop their bodies in their tentacles and webbing to shield themselves from predators.

Vampire squids live in really cold depths of the ocean with very little oxygen. This makes them far less threatening to humans than their name suggests. In order to conserve energy, they simply drift along the ocean currents and only eat dead plankton and fecal matter. Instead of fangs, vampire squids eat with their beaks.

Goblin Shark

The goblin shark is an incredibly amazing and terrifying shark. Males can grow up to 8 feet long and females can be up to 11 feet in length. They’re often a pale white color with blue fins. Their most distinctive feature is their jaws. Unlike your jaws that move up and down, their jaws can project from their mouths like the movie Alien! Goblin sharks locate their prey by using electroreceptors in the nose. Because these sharks inhabit the dark ocean depths, fishermen can sleep well at night, knowing that only a few have ever been caught.

Their range is suspected to be very wide. These bottom dwellers have been documented in the Atlantic, Pacific, and Indian oceans.

Smallspine Spookfish

The smallspine spookfish, lives in the deep ocean. As their name suggests, they’re pale white like ghosts and have an elongated snout, which can track prey with sensory nerve endings. In fact, they sort of resemble the ghost dog from the Nightmare Before Christmas! Not many have been seen or documented because they live in extreme depths, like more than a mile below the ocean’s surface. As if they weren’t scary cool already, they also have a venomous spine. Unfortunately not much else is known about them, so they’re a regular fish of mystery.

Giant Devil Ray

The devil ray isn’t as scary as it sounds. They’re not actually named for their devilish behavior, but rather from the fins on top of their heads that resemble devil horns. The only way they might scare you is if you see a large dark shape in the water before you realize what it is! They often sport dark colors on the top of their bodies and are typically white on the bottom half. They swim using their pectoral fins, flapping them almost like wings. Giant devil rays are really gentle giants. They only feed on plankton and small fishes.

The only truly devilish thing about them is that they’re endangered. By-catch is a major threat to this species. Since they spend a lot of time close to the surface, ocean traffic and oil spills also pose serious threats to these gentle giants.

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Western Australia Shark Cull http://blog.oceanconservancy.org/2014/02/13/western-australia-shark-cull/ http://blog.oceanconservancy.org/2014/02/13/western-australia-shark-cull/#comments Thu, 13 Feb 2014 16:08:06 +0000 Claudia Friess http://blog.oceanconservancy.org/?p=7517

Tiger shark photo: Matthew Potenski, 2011 photo contest

Many species of sharks and rays around the world are in trouble, and current events in Australia remind us of that. The government of Western Australia is presently implementing a controversial “shark cull” policy in response to recent highly publicized shark attacks near Western Australian beaches. The policy consists of deploying baited hooks about a mile off of various Western Australian beaches, aimed specifically at catching large sharks. Any shark larger than 10 feet is viewed as a threat to public safety and is to be “humanely” killed; the main targets of the cull are tiger sharks, bull sharks and great white sharks. Great white sharks are a protected species in Australia, and state authorities were given a special exemption from Australia’s Environment Protection and Biodiversity Conservation Act to be able to kill them. The shark cull is a pilot program. If it were to continue after the April 30 trial period ends, there would have to be a full environmental act assessment.


The public outcry in Australia and around the world about the shark culling policy is indicative of the sea change in public attitudes toward sharks that has been occurring over the past decade. People around the world are growing increasingly concerned about that status of sharks and rays and are opposing what is viewed as senseless killing of an important ecosystem component. Unfortunately, the major threats to sharks and rays around the world are much less publicized than the high-visibility Australian shark cull, which has a comparatively small impact on global populations.

A scientific study published this month in the journal eLife concludes that about a quarter of the world’s sharks and rays are threatened with extinction, according to the International Union for Conservation of Nature Red List criteria. While the study identifies habitat loss, persecution (such as the Australian cull) and climate change as threats to sharks, the No. 1 threat remains overfishing. Some sharks are being directly targeted by fishing fleets while others are caught incidentally as bycatch in other fisheries. The global shark fin trade is a major driver for shark fisheries, but so is the demand for meat and liver oil. Most catches of sharks and rays are unregulated and unmonitored, and the shark fin market is also largely unregulated. In the United States, Ocean Conservancy supported California’s ban on shark fins in order to help curb the global demand for fins, which is fueling the trade.

Sharks and rays are more vulnerable to overexploitation than most fish in the ocean. They are slow-growing and long-lived, mature late in life, and have few young. The species most vulnerable to the fishery are the larger-bodied sharks and rays that inhabit shallow waters easily accessible to the fishery. Many of the biodiversity hot spots for sharks occur in areas where the threats are highest, for example in the Indo-Pacific and the Mediterranean Sea where population declines are most severe. Scientists are not aware of any global extinctions of sharks and rays, but there have been regional extinctions and a few species have not been seen in decades. One species that has experienced local extinctions is the smalltooth sawfish, the first marine fish to be listed in the United States under the Endangered Species Act, with the help of Ocean Conservancy and other groups in 2003.

Effective shark conservation requires attention to all of the major threats that sharks and rays face. It requires monitoring international catches and trade, assessments of the status of local populations, and implementation and enforcement of effective regulations to prevent further population declines and allow recovery of overfished populations. This is challenging in many of the poor countries where the problems are most severe due to lack of effective governance mechanisms and funding for conservation and management. Australia, in spite of the heavy criticism it has drawn for the current shark cull, is one of the few nations in the world with a relatively effective monitoring, assessment and management system in place, for sharks and other fisheries. Given the condition of the world’s shark and ray populations and their important role in ocean ecosystems, it’s important that policies protect and conserve these vital species.

 

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