Dangers for whales and dolphins
DANGERS FOR WHALES AND DOLPHINS IN OUR MODERN SOCIETY
Apart from whaling cetaceans nowadays face a number of other dangers produced by mankind. Many whales and dolphins are killed, injured or disturbed by shipping, chemical and noise pollution, entanglement in fishing gear, oil and gas exploration and climate change.
(1) Marine Litter
In the spring of 2013 a sperm whale was washed up onto an Andalusian beach. It had swallowed 59 different plastic items, weighing a total of 17kg. A large amount of it consisted of the thick plastic sheets used in southern Spain to build greenhouses to grow vegetables for the European market. In addition, nine meters of rope, two small flower pots and many plastic shopping bags had blocked its digestive system and led to its death. Unfortunately, thousands of cetaceans die and are injured as a result of the millions of tons of plastic debris that we dump in our oceans. 80% of marine litter consists of plastic.
Ocean currents caused by wind and wave action form zones in which plastic accumulates, known as Garbage Patches. Today there six of them, the majority consist of micro plastic, which can be considered as highly dangerous, because it enters the food chain and exceeds the amount of plankton up to six times.
According to WWF reporting in 2011, entanglement in fishing gear kills about 300.000 cetaceans per year. Being accidently caught is not the only danger from the fishing industry, abandoned drift-nets which can be hundreds of meters long will move as a vertical wall, still catching and harming animals.
(3) Chemical and Heavy Metal Pollution
Chemicals and heavy metals are a danger, because once consumed they accumulate in the blubber (layer of fat) of the whale and so can weaken their immune system and cause fatal diseases.
In the Mediterranean one case is known, in which seven sperm whales were driven to shallows water, probably my military sonar. There they could not find squid, so the starving bodies started to break down fat and therefore all the accumulated heavy metals were released and poisoned the animals; weakened they stranded themselves together on the shore.
Ship Accidents are on top of the danger list. In some parts of the world collisions with ships happen so frequently that they endanger the survival of already threatened species. Some animals receive life-threatening injuries but many are killed instantly (a study shows that 68% of 292 large ship strikes were fatal). Some species seem to be more at risk than others; they don’t seem to be aware of approaching ships and do not avoid them, at high risk are fin whales and sperm whales.
(5) Climate Change
Climate change is happening so fast, that some populations may well not adapt in time. Changes in temperatures, water freshening due to melting ice and increased rain water, loss of icy polar habitats and changes in prey availability are only a few of the consequences.
(6) Ocean Acidification
For 300 million years, the ocean has been slightly alkaline. Now it is rapidly becoming more acidic and this has a direct effect on plankton and other species that make up the diets of marine mammals. Studies show that the decline of plankton reaches about 40%.
(7) Habitat Loss
Habitat loss happens due to pollution, building, landfills, harbours, aquaculture, ship traffic, noise etc ...
(8) Manmade Noise
Whales use sounds for different reasons: communication, navigation, making contact with members of their own species, to find a mate and to search for prey. Some manmade noises can damage their ear-structure. The noise in our oceans makes life hard for cetaceans. Blue Whales are nowadays only able to hear up to 160km away, compared to the 1.600 km range they had in 1940.
WHAT CAN I DO TO HELP?
• Reduce – the waste
• Reuse - products
• Recycle – in a proper way
• Participate in Beach-Clean-Ups
• Buy sustainably caught fish
• Drink from glass bottles
• Avoid straws
• Bring your own reusable shopping bag
• Use matches instead of lighters
• Be respectful to nature and all creatures living in it
• Inform yourself and pass on your knowledge to family, friends
• Don’t throw rubbish into the toilet
• Don’t waste energy