Tuesday 17 July 2012

Octopus V Dolphin


Dolphin lunch
A dolphin caught in the process of eating an octopus in Jervis Bay. Picture: Greg Maloney, Dolphin Watch Cruises Source: Supplied
BEING the world's smartest mollusc wasn't enough to save this octopus from the jaws of a dolphin.
The mature bottlenose dolphin found its brainy but unlucky lunch while hunting in reefs near Huskisson on Jervis Bay on the NSW south coast.
"We'd been watching a group of between 20 and 30 dolphins when this one surfaced with the occy in its mouth,'' Dolphin Watch Cruises skipper Greg Maloney said.
"It was bashing it on the surface of the water for a good 10 minutes trying to stun the occy so it could start eating.
"Dolphins have great gripping teeth, but the teeth are not very good at tearing up their food so they need to stun the occy before starting to eat it or the occy can get away.
"Sometimes the octopus does win, and escape, but this one didn't.''
Octopus's large complex brains are seen as compensating for losing the hard shell that protects other mollusks like snails and clams.
It's just that dolphins are smarter. When Animal Planet listed the top ten smartest animals on the planet, dolphins were at Number 2 (behind chimps) and octopuses came in at Number 9.
Mr Maloney took the photo about two weeks ago and said dolphins were a common sight in and around Jervis Bay.

Thursday 12 July 2012

CETACEAN ACOUSTICS: HOW TO DO WHALES AND WAVELETS

CETACEAN ACOUSTICS: HOW TO DO WHALES AND WAVELETS
Mark Fischer

If you want to know the science, you kind of need to begin with basic Calculus and introductory physics, especially the physics of waves. For a good online introduction to acoustics in the ocean, check out Acoustic Ecology's page here.
Second, to explore the world of cetacean sound, it helps to understand the physics of sound in the ocean. There are significant differences between sound in the ocean and the sounds we hear in the air. For example, the ocean conducts sound at 5 times the speed it travels in air, and has a beautiful 'lensing' property that is a function of depth and temperature [specifically, sound travels faster at the top and bottom of the ocean, slower in the middle], thus creating what is known as the 'deep sound channel'. To study up on these things I would recommend "Marine Mammals and Noise" as a good place to start. From ATOC and HIFT (also described in MM&N) we know that a sound as loud as a Blue whalewww.whalesongart.com makes can span half the world's oceans, which means two (well, probably three as noisy as the oceans are today ) whales could send a signal around the globe in just over 7 hours. Like, you know, if they wanted to.
Third, you have to consider the science of wavelets. My best recommendation for a place to start is Ms. Amara Graps' page, here.
To actually perform the analysis you need to know a little programming. This could be done in C/C++, or you could use a variety of mathematical software tools, such as Mathematica or Matlab.
So, what we do is to take a sound clip, transform it using wavelets, then display the product of this operation using some algorithm that maps the resulting matrix to a range of colors to make a kind of 'paint by numbers' picture; exactly as children would fill in a coloring book. What you are seeing is a picture of how well a particular sound correlates to a particular base function- that is, how much one shape looks like another. That's kind of all there is to it.

Mark Fischer (USA) is a cetacean acoustics specialist. 1961 born, Pittsburgh, Pennsylvania.
1979-1983 US Army, stationed in Amberg, Germany;
1983-1987 Earned BS in electronics and computer engineering from George Mason University
1988-1998 Software development in defense and telecommunications
1999-2002 Walkabout, Baja California
Since then - independent research in cetacean acoustics using wavelets, exploring both the science and the art of the way they use sound.

http://aguasonic.com

South Korea announces plans to hunt minke whales


Jul 5, 2012
whale finSouth Korea has announced plans to begin hunting minke whales for scientific purposes at the annual meeting of the International Whaling Commission (IWC).
WSPA, along with governments from around the world, condemned the announcement.
Claire Bass, Oceans Campaign Leader for WSPA said: “This is extremely bad news. We believe there's absolutely no need to kill whales in the name of science and that all we need to find out about whales can be done using non lethal means. This is a big step backwards for the IWC that another country has decided to start doing this wholly unnecessary and cruel practice.”
WSPA has been at the forefront of efforts to promote the protection of whales from the cruel, unnecessary and outdated practice of hunting.

A step backwards

This bad news follows the recent announcement that a move to create a South Atlantic whale sanctuary had been rejected by the IWC.
Despite 65% of member countries voting in favour of creating a sanctuary, the move needed the backing of 75% of members in order to pass. The sanctuary was put forward by a group of Latin American countries, but was strongly opposed by pro-whaling nations including Japan and Norway.
Currently there are two whale sanctuaries created under the IWC: the Indian Ocean and the Southern Ocean. Japan disregards the Southern Ocean Sanctuary and conducts a so-called ‘scientific’ whale hunt there, with the meat sold commercially.
Claire Bass added: “The opposition to this sanctuary from three commercial whaling countries and their allies is outrageous and unjustified. The rejection of the proposal for this sanctuary denies protection for the 54 species of cetaceans in this region.”
WSPA will continue to report back from its work at this year’s IWC meeting in Panama City.