Whale poo could help oceans absorb CO2-scientists

SYDNEY, April 23 (Reuters Life!) - Whale droppings have emerged as a natural ocean fertiliser which could help combat global warming by allowing the Southern Ocean to absorb more carbon dioxide, Australian scientists have have found.

New research from the Australian Antarctic Division suggests whales naturally fertilise surface waters with iron-rich whale excrement, allowing the whole eco-system to send more carbon down into deep waters.

"The plants love it and it actually becomes a way of taking carbon out of the atmosphere," Antarctic scientist Steve Nicol told Reuters, adding the droppings appear as a plume of solids and liquids.

A larger population of baleen whales and krill would boost the productivity of the whole Southern Ocean ecosystem and could improve the absorption of carbon dioxide, blamed for global warming.

Iron is a limited micronutrient in the Southern Ocean, but recent experiments have found that adding soluble iron to surface waters helps promote much-needed phytoplankton algal blooms.

Iron is contained in algae in the surface waters where plants grow, but there is a constant rain of iron-rich particles falling into deep waters.

When krill eat the algae, and whales eat the krill, the iron ends up in whale poo, and the iron levels are kept up in surface waters where it is most needed.

"We reckon whale poo is probably 10 million times more concentrated with iron than sea water," Nicol said.

"The system operates at a high level when you have this interaction between the krill, the whales and the algae and they maintain the system at a very high level of production. So it's a self sustaining system."

Nicol said the idea to research whale droppings came from a casual pub chat among Antarctic scientists in Australia's island state of Tasmania.

He said it was not yet known how much poo it would take have a significant impact on the Southern Ocean.

Whaling worsens carbon release, scientists warn

A century of whaling may have released more than 100 million tonnes - or a large forest's worth - of carbon into the atmosphere, scientists say.

Whales store carbon within their huge bodies and when they are killed, much of this carbon can be released.

US scientists revealed their estimate of carbon released by whaling at a major ocean sciences meeting in the US.

Dr Andrew Pershing from the University of Maine described whales as the "forests of the ocean".

Dr Pershing and his colleagues from the Gulf of Maine Research Institute calculated the annual carbon-storing capacity of whales as they grew.

"Whales, like any animal or plant on the planet, are made out of a lot of carbon," he said.

"And when you kill and remove a whale from the ocean, that's removing carbon from this storage system and possibly sending it into the atmosphere."

He pointed out that, particularly in the early days of whaling, the animals were a source of lamp oil, which was burned, releasing the carbon directly into the air.

"And this marine system is unique because when whales die [naturally], their bodies sink, so they take that carbon down to the bottom of the ocean.

"If they die where it's deep enough, it will be [stored] out of the atmosphere perhaps for hundreds of years."

Ocean trees

In their initial calculations, the team worked out that 100 years of whaling had released an amount of carbon equivalent to burning 130,000 sq km of temperate forests, or to driving 128,000 Humvees continuously for 100 years.

The idea would be to do a full accounting of how much carbon you could store in a fully populated stock of fish or whales

Dr Pershing stressed that this was still a relatively tiny amount when compared to the billions of tonnes produced by human activity every year.

But he said that whales played an important role in storing and transporting carbon in the marine ecosystem.

Simply leaving large groups of whales to grow, he said, could "sequester" the greenhouse gas, in amounts that were comparable to some of the reforestation schemes that earn and sell carbon credits.

He suggested that a similar system of carbon credits could be applied to whales in order to protect and rebuild their stocks.

"The idea would be to do a full accounting of how much carbon you could store in a fully populated stock of fish or whales, and allow countries to sell their fish quota as carbon credits," he explained.

"You could use those credits as an incentive to reduce the fishing pressure or to promote the conservation of some of these species."

Is bigger better?

Other scientists said that he had raised an exciting and interesting problem.

Professor Daniel Costa, a marine animal researcher from the University of California, Santa Cruz, told BBC News: "So many more groups are looking at the importance of these large animals in the carbon cycle.

"And it's one of those things that, when you look at it, you think: ' This is so obvious, why didn't we think of this before?'."

Dr Pershing pointed out that whales, with their huge size, were more efficient than smaller animals at storing carbon.

He used the analogy of a small dog compared to a large dog.

"My wife's 6lb (2.7kg) toy poodle eats one cup of food per day and my dog - a 60lb standard poodle - eats five cups of food per day," he said.

"That's only five times as much food but my dog weighs ten times as much."

He said that the marine carbon credit idea could be applied to other very large marine animals, including endangered bluefin tuna and white sharks.

Dr Pershing said: "These are huge and they are top predators, so unless they're fished they would be likely to take their biomass to the bottom of the ocean [when they die]."

The American Geophysical Union's Ocean Sciences meeting has been taking place this week in Portland, Oregon.

Two killer whale types found in UK Waters

Scientists have revealed for the first time there is not one but two types of killer whale living in UK waters.

Each differs in its appearance and diet, with males of one type being almost two meters larger than the other.

The killer whales could be at an early stage of becoming two separate species, the researchers say.

The international group of scientists has published its results in the journal Molecular Ecology.

"It's exciting to think about two very different types of killer whale in the waters around Britain," says Dr Andy Foote from the University of Aberdeen, UK, who undertook the study.

"Killer whales aren't really a species that we think of as being a regular visitor to Britain, but in fact we have two forms of these killer whales in our waters," he told the BBC.

Scientists have found different forms of killer whales that occupy particular niches in the Pacific and the Antarctic, but this is the first time that they have been described in the North Atlantic.

Dr Andy Foote undertook the study along with colleagues from universities and museums in Denmark and the UK.

Killer whales (Orcinus orca), otherwise called orcas, live in family groups called pods.

As the largest member of the dolphin family, killer whales are known for their intelligence and range of hunting behaviours.

Tooth work

There was very little prior to this study to suggest that different types of killer whale would be found in the North Atlantic.

However, Dr Foote and colleagues studied teeth from remains of killer whales stranded over the past 200 years and found a difference in tooth wear.

Differences in tooth wear: Type 1 (top) and type 2 (below)

"We found that one form, which we call 'type 1' had severely worn teeth in all adult specimens," explains Dr Foote.

"The other form, 'type 2', had virtually no tooth wear even in the largest adults."

In the wild, killer whales that "suck up" herring and mackerel display this tooth wear.

Knowing this, the researchers suspected a difference in diet and ecological niche between the two groups.

Dolphin predator

Using stable isotope analysis that gives clues to the orcas' diet, the scientists found that type 1 is a generalist feeder, consuming fish and seals.

Type 2, on the other hand, is a specialist feeder that scientists suspect exclusively feeds on marine mammals such as small dolphins and whales.

This specialisation for alternate ecological niches has also resulted in a difference in shape and appearance.

"The two types also differed in length, with type 2 adult males being almost two metres larger than types 1 males," Dr Foote says.

The researchers also found that colour, pattern and number of teeth vary between the groups.

Dr Foote says the fish feeding type 1 killer whales are found across the North East Atlantic and around Britain.

The cetacean hunting type 2 killer whales are regularly seen off the west coast of Scotland and Ireland.

New species

Genetic analysis indicates the two types belong to two different populations.

"Type 1 specimens were from closely related populations, but the type 2 whales were more closely related to a group of Antarctic killer whales," Dr Foote explains.

Comparing the findings with studies on killer whales around the world shows that killer whales have radiated to fill different ecological niches.

"It's similar to how Darwin's finches have adapted to different ecological roles in the Galapagos, but on a larger scale," Dr Foote notes.

He suggests this could be an important discovery for the future of the animals.

"They seem to have occupied completely different ecological niches and have started to diverge morphologically. This divergence may eventually lead to the two types becoming different species."

He also recommends the two types be considered "evolutionary significant units" and monitored separately in order to more effectively conserve one of the oceans most charismatic animals.

Ancient whale sucked mud for food

Mammalodon probably lived by sucking small animals up from the seafloor

An ancient "dwarf" whale appears to have fed by sucking small animals out of the seafloor mud with its short snout and tongue, experts say.

Researchers say the 25 million-year-old fossil is related to today's blue whales - the largest animals on Earth.

The ancient animal's mud slurping may have been a precursor to the filter feeding seen in modern baleen whales.

These whales strain huge quantities of tiny marine animals through specialised "combs" which take the place of teeth.

The research is published in the Zoological Journal of the Linnean Society.

The fossilised remains of the primitive baleen whale Mammalodon colliveri were discovered near Torquay, in Victoria, Australia.

Clearly the seas off southern Australia were a cradle for the evolution of a variety of tiny, weird whales that seem to have lived nowhere else Dr Erich Fitzgerald, Museum Victoria

This animal still had teeth; it had not yet evolved the baleen plates - used for filter-feeding - which characterise present-day baleen whales.

Although Mammalodon was discovered in 1932 and named in 1939, it has not been widely studied, according to Museum Victoria, which holds specimens of this group.

The study's author, Dr Erich Fitzgerald from Museum Victoria, said that his study of the fossil led him to the conclusion that Mammalodon was a bottom-feeding mud-sucker.

Splinter group

The idea would support Charles Darwin's observation about whale evolution in his seminal book On the Origin of Species.

In it, Darwin speculated that some of the earliest baleen whales may have been suction feeders - and that this served as a precursor to the filter feeding of today's giants of the deep.

Mammalodon probably evolved from much bigger ancestors

Mammalodon had a total body length of about 3m. But it appears to have been a bizarre evolutionary "splinter group" from the evolutionary lineage which later led to the 30m-long blue whale.

It was effectively a dwarf whale; the research suggests that Mammalodon may have evolved into a relatively tiny form from larger ancestors.

Mammalodon belongs to the same family as Janjucetus hunderi, fossils of which were also found in 25 million-year-old Oligocene rocks near Torquay in Victoria. This family appears to be unique to south-east Australia.

"Clearly the seas off southern Australia were a cradle for the evolution of a variety of tiny, weird whales that seem to have lived nowhere else," said Dr Fitzgerald.

The baleen plates which allow today's baleen whales to filter their food from water, distinguish this group from the toothed whales - a group which includes beaked whales and dolphins.

Baleen whales are a taxonomical group which includes not only the majestic blue whale, but also the right whales, fin whales and humpbacks, to name but a few.