If whales increase the ocean carbon sink (and I've got to read the fine print to be convinced), then the obvious geoengineering response is to breed more whales. And/or will whale harvesters now need to pay a carbon tax? Could partnering with ETC and Greenpeace on this be far behind? Greg
>________________________________ > From: Fred Zimmerman <[email protected]> >To: geoengineering <[email protected]> >Sent: Monday, August 19, 2013 9:49 AM >Subject: [geo] sperm whales and oif > > > >Reference: Proc Roy SocB http://dx.doi.org/10.1098/rspb.2010.0863 > >Sperm whale poo offsets carbon by fertilising the oceans with iron >By Ed Yong | June 16, 2010 8:00 am >While the world wrangles over ways of reducing carbon emissions, some >scientists are considering more radical approaches to mitigating the effects >of climate change. Dumping iron dust into the world’s oceans is one such >strategy. Theoretically, the iron should act as fertiliser, providing a key >nutrient that will spur the growth of photosynthetic plankton. These creatures >act as carbon dioxide pumps, removing the problematic gas from the air and >storing the carbon within their own tissues. When the plankton die, they sink, >trapping their carbon in the abyss for thousands of years. >It may seem like a fanciful idea, but as with much of our technology, nature >beat us to it long ago. Trish Lavery from Flinders University has found that >sperm whales fertilise the Southern Ocean in exactly this way, using their own >faeces. Their dung is loaded with iron and it stimulates the growth of >plankton just as well as iron dust does. >Sperm whales are prodigious divers, descending to great depths in search of >prey like squid. When they’re deeply submerged, they shut down all their >non-essential bodily functions. Excretion is one of these and the whales only >ever defecate when they reach the surface. By happy coincidence, that’s where >photosynthetic plankton (phytoplankton) make their home – in the shallow >column of water where sunlight still penetrates. So by eating iron-rich prey >at great depths and expelling the remains in the shallows, the whales act as >giant farmers, unwittingly seeding the surface waters with fertiliser. >There are approximately 12,000 sperm whales left in the Southern Ocean. By >modelling the amount of food they eat, the iron content of that food, and how >much iron they expel in their faeces, Lavery calculated that these whales >excrete around 50 tonnes of iron into the ocean every year. And based on the >results of our own iron fertilisation experiments, the duo calculated that >every year, this amount of iron traps over 400,000 tonnes of carbon in the >depths, within the bodies of sinking plankton. >Previously, scientists assumed that whales (and their carbon dioxide-rich >exhalations) would actually weaken the Southern Ocean’s ability to act as a >CO2 pump. But according to Lavery, this isn’t true. She worked out that the >whales pump out just 160,000 tonnes of carbon through their various orifices. >All of these figures are probably conservative underestimates but even so, >they suggest that sperm whales remove around 240,000 more tonnes of carbon >from the atmosphere than they add back in. They are giant, blubbery carbon >sinks. >However, their true potential will go largely unfulfilled thanks to our >harpoons. Many sperm whales have been killed by industrial whalers, and the >population in the Southern Ocean has declined by some 90%. On the bright side, >the Southern Ocean’s population represent just 3% of the global total, so this >species may have an even greater role as a warden for carbon than Lavery has >suggested. Other seagoing mammals probably have a part to play too, provided >that they feed at depth and excrete near the surface. Several other toothed >whales do this, and some filter-feeding ones may do too. >Reference: Proc Roy Soc B http://dx.doi.org/10.1098/rspb.2010.0863 >Image by Cianc > >--- >Fred Zimmerman > >Geoengineering IT! >Bringing together the worlds of geoengineering and information technology >GE NewsFilter: http://geoengineeringIT.net:8080 -- >You received this message because you are subscribed to the Google Groups >"geoengineering" group. >To unsubscribe from this group and stop receiving emails from it, send an >email to [email protected]. >To post to this group, send email to [email protected]. >Visit this group at http://groups.google.com/group/geoengineering. >For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
