February 6, 2002
Diving Through Debris
This is Genevieve Johnson of the Ocean Alliance speaking to you from the southern coast of Australia the home of the Australian Fur Seal.
Seals and sea lions, collectively known as Pinnipeds, are familiar animals to most people, though there isn't just one kind, rather there are thirty-three species around the world divided into three groups.
Some species such as these California sea lions are at home living in cities close to humans. Other species, like the subantarctic fur seal and the Elephant seal, live part or all of their lives in the freezing polar regions of the globe. While still others like Galapagos Sea Lions, spend their lives in the warm equatorial waters of the tropics.
All Pinnipeds are marine mammals and are superbly adapted to life in an aquatic environment. Although they vary in size and shape, their bodies are noticeably sleek. This streamlined profile means these animals are able to move through the water with minimal resistance, however on land there are noticeable differences. The hind limbs of some pinniped species have no supporting function on shore, these animals need to heave themselves forward. Other species are quite agile on land and can move their fore flippers alternately, while bringing their hind flippers up underneath their bodies.
The heads of all Pinnipeds are equipped with sense organs that allow them to gather information about their environment. Long tactile whiskers that sense vibration and large eyes, assist in navigation and the detection of prey below the surface.
Sadly, marine debris is causing much suffering to seals and sea lions around the world, together with whales and dolphins, and countless millions of seabirds, fish and reptiles. All are facing an uncertain future at the hands of humans.
Today we went to visit our friends at the Royal Melbourne Zoo where we were taken behind the scenes of the fur seal exhibit with one of their Keepers Adrian Howard. Adrian gave us a greater insight into the lives of these amazing marine mammals and the threats they face.
Adrian Howard - Marine Mammal Keeper, Royal Melbourne Zoo:
G'day, my name is Adrian Howard. I'm a seal keeper here at the Melbourne Zoo. Come and join us and we'll go and have a look at Silver.
The Melbourne Zoo concentrates on the prevention of marine pollution through public education.
Silver is an Australian Fur Seal and is one of the few lucky survivors of an encounter with discarded fishing gear, as a result she is now heavily scarred.
Today, Silver has become an ambassador for her species, doing her part to educate visitors about the dangers of marine debris and how many animals suffer as a result of our actions. Silver demonstrates the effects of the entanglement process, highlighting the fate of marine animals caught in debris.
Silver came to us in 1998, at that time she was around eight months old. She was found on a beach outside Melbourne known as Sorrento and she was entangled in fishing net. We managed to capture her at that stage, bring her in, remove that net and start the rehabilitation process. She had become so used to humans that she was pretty much an un-releasable animal, or, not appropriate for release.
On average, the Melbourne Zoo rehabilitates eight fur seals annually, some are stranded or injured, and others like Silver are victims of entanglement.
The keepers at the zoo use Silver to demonstrate the speed and agility of these animals as she porpoises through the water. She then re-enacts her own entangled, demonstrating how the synthetic material caught around her body restrict her movements.
Pinniped rely very heavily on all of their specific adaptations and any kind of compromise to any of these adaptations can really reduce their likelihood of surviving in the wild. Silver is a great example of that. We can see quite obviously that she has a very heavy scar around her neck as a result of being entangled in plastic pollution, specifically fishing net, and that has severely reduced her ability to glide through the water.
In the wild, the increased drag means the animal tires quickly, finds it difficult to capture prey and often starves. Others die a slow painful death as the netting or synthetic fibre cuts into the animal's hide as it grows.
Litter on land and marine debris discarded by humans is wreaking unimaginable havoc on the creatures that live in the oceans and seas of the world. Plastic rubbish is often mistaken for food and ingested, while inquisitive seals and sea lions, often young animals, become entangled, such debris can ensnare, choke, trap, drown and maim.
Adrian Howard and Silver work together to educate the public
about the dangers of marine debris.
Photo: Chris Johnson
Unfortunately pollution found in the ocean has a number of different sources, not only is it discarded directly into the sea, but it also comes from storm water drains, drains within cities, all eventually empty out into the oceans. So what we do here in cities can often affect animals out in the open ocean.
One of the things that happens with Australian fur seals and seals in general is that they're very inquisitive animals. Young animals in particular have a habit of trying to put their noses into plastic debris in the ocean and they get entangled. Unfortunately, flippers aren't very well designed to remove debris and they can end up in a lot of trouble, if not die.
With the introduction of synthetic fibres, the life of debris, including plastic bags and fishing gear, has become greatly extended. Plastics are strong, flexible and long lasting which has made them prevalent in the marine environment, and as they float they continue to catch and entangle marine organisms.
Unfortunately escape from an entanglement in a plastic bag or fishing net is often impossible, once it is tightly wrapped around an animal, their flippers don't provide the tools necessary to remove it and in actual fact the fur on a seal all points backwards so it actually hooks that debris onto their neck for example and it's there to stay.
It is believed that such debris has become a significant threat and is directly responsible for the deaths of over one million sea birds and as many as one hundred thousand marine mammals every year.
There are a number of things people can do to help reduce marine pollution. The first is to be very thoughtful in the way you dispose of plastic products in particular, put them into recycling bins, and make sure that they don't end up in our waterways
Individuals can make a difference and help save the incredible array of animals that live in our oceans by making their world safer.
Log by Genevieve Johnson
Special Thanks to all of the staff of the Royal Melbourne Zoo for making this video report possible.