Killer Whales Sonar Confused with Navy Call

Navy sonar could be confusing whales and dolphins, causing them to flee and become stranded.

It appears that the frequency used by navy sonar, which is lower than that of merchant ships, is similar to the attack frequency used by killer whales.

A research vessel near the Bahamas, with a team of scientist from the Sea Mammal Research Unit has been studying the effects of sounds on deep diving whales. One of the theories is that the similarity in sonar frequency between the killer whale attack sonar and that of navy ships is confusing these sea mammals and causing a strong response, which for some ends in being stranded on beaches.

In 2007 the same research team played a recording of sounds made by killer whales near a Blainville’s whale who surfaced and left the area. They repeated the experiment but with sonar sound from a navy ship, with the similar results.

Back in the sixties when the first reporting of stranded dolphins began to appear, the navy was suspected.

The results of these reports will probably be rejected in certain quarters and accepted at others. Probably more experiments and research will take place.

But suppose navy sonar is responsible for these strandings, and who knows what other effects underwater noise pollution is having, and suppose it is accepted as fact. And suppose also that there is a will to do something about it.

And after supposing all these things, what a come down to know that the costs involved, to design, find and then change all the navy’s sonar devices, will make it highly unlightly.

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Endangered Species

The IUCN red list of endangered species for 2008 has just been published.

It is obviously a very lengthy report covering the list of endangered species, from extinct and extinct in the wild to those that fall under the classification of not enough data.

A selective look of some of the results:
- 20% of reptiles are struggling to survive
- 20% + of mammals, including marine mammals, are also threatened with extinction
Of the nearly 50,000 species listed (fauna and flora) over 35% are threatened.

But there are a few other things I want to highlight.

The first is that people typically look at the extremes, for example those species that are extinct or critically endangered. Bad news sell newspapers as they say. And the more shocking the more they sell.

For endangered species this is a disservice as those species that may today be classified as least concerned can later on become critically endangered.

The list (and it is a very extensive list covering vertebrates, invertebrates, plants, mushrooms, and so on) does present species whose potential survival has deteriorated but also for those that have improved.

The overall message we should take from this, apart from recognizing the efforts of the IUCN, is that all species deserve our care, and this care is really reflected by respect and looking after the environment.

Anyone interested in living natural must take the environment seriously.

We have to be aware that species in the world are at risk due to many factors, in fact to many human created factors.

Amongst these are:
- habitat loss due to human settlement, agricultural expansion;
- hunting and poaching for skins and meat;
- depletion of food sources;
- habitat degradation coming from overgrazing;
- climate change;
- many others.

And now for some good news.

-Walia Ibex has shown an improvement in classification, moving from Critically Endangered (CR) to Endangered (EN)
- Przewalski’s Gazelle from CR to EN
- Pohnpei Flying Fox from CR to EN
- Black Lion Tamarin from CR to EN

The number of mammal species that showed an improvement is 37.

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