Return of the blue whale?

Teile:
16.11.2015 07:30
Kategorie: News

Reports of sightings in European waters

Fluke of a Blue Whale - © A.u.W. Steffen (Archiv Taucher.Net)

For several years, blue whales are more frequently being sighted in European waters, be it off the coast of England, in the Azores or the Canaries Island. Before the early 20th century, this species had been almost hunted to extinction in these waters. Today, they are listed as an endangered species by the International Union for Conservation of Nature.

Currently, there are only about 12,000 blue whales worldwide. Information about populations in specific regions is largely unknown. The Whales and Dolphin Conservation Organisation (WDC) works on various projects globally, geared towards the protection of this massive animal.


What makes the blue whale so special?

- The blue whale grows up to 33 metres. It is the largest mammal that has ever lived on the earth.
- Blue whales can weigh up to 200 tons. That’s about as much as 45 elephants, 225 cows or 2,500 people. On land, the weight of their own skeleton would crush them; whereas in the ocean, they are virtually weightless.
- Despite their enormous mass, they can reach speeds of more than 30 km/hr, its powerful blas can reach up to 10 metres high.
- The heart of a blue whale is the size of a small car. In its main artery a child could float.
- The blue whale’s stomach can hold approximately two tons of food. It requires about 1.5 million calories. - Every mouthful it takes in can be as much as 80,000 litres of water (including krill); this translates to 90 times as much energy as what is consumed during a dive.
- The tongue of a blue whale weighs more than four tons, about as much as a full-grown elephant.
- A baby blue whale is breastfed till it is seven months old, and drinks several hundred litres of milk daily. At birth, it weighs two to three tons and is seven metres long.
- The profound and far-reaching calls of the blue whale can reach 188 decibels, surpassing the volume of a jet plane. In this way, they can keep in contact with other blue whales which may be hundreds or thousands of kilometres away.

Gigantic Blow of a Blue Whale - © Fred Benko, NOAA
Gigantic Blow of a Blue Whale - Fred Benko, NOAA

The main threats to blue whales today are noise in the ocean, collisions with ships, pollution and climate change. Due to increasing shipping traffic, seismic surveys, as well as military sonars and their associated noise, it is increasingly difficult for the whales to communicate and orient. Since blue whales have never learnt how to deal with fast-moving ships, many blue whales have perished after colliding with them. Trash in the sea and environmental toxins are additional burdens, while climate change causes their main food source (krill and small fish) to distribute differently and causes their populations to shrink.

How can we save the blue whale from extinction?
In 2014, Chile designated marine reserve measuring over 70,000 hectares as a sanctuary for whales. Every spring, several hundred blue whales gather in these waters to feed on the krill population here. This is a positive move in the right direction, allowing these large animals to have such a large space dedicated to them, where they can feed, give birth and raise their young in safety.

Hence, it is important to establish more of such protected areas where protective measures like the prohibition of seismic testing and military exercises are in place. Such areas must also be free from fishing so that a healthy and productive ecosystem can develop. In addition to these measures, a global strategy that limits the pollution and littering in the oceans must also be established.

What does the WDC do for blue whales?
Over the years, the WDC has established protected marine areas worldwide, for example, the Costa Rica Dome in the Pacific. In addition, the organisation is campaigning against noise in the oceans by participating in multi-group projects, seeking expert opinions and political support as well as extensive education of the public.

For many years, it has been working with an organisation in Sri Lanka to offer regular training workshops about responsible whale watching for providers of whale-watching tours. This is essential as more and more of such tours are being organised, so it is important that the providers observe the proper protocol, such as keeping a minimum distance from the blue whales. Such workshops have been well received.

How we deal with the blue whale’s situation affects the state of our oceans. If we do manage to save them from extinction and preserve their vast habitat, we would at the same time be safeguarding our own future on this planet (www.whales.org).

WWF also offers a good overview of the research and conservation efforts of the blue whales: www.wwf.de/hoffnung-fuer-blauwale.


WWF Video – Activity in Chile