All,
I was lucky enough to travel to the Antarctic this January. There were lectures on board ship regarding everything from explorers to geology to wildlife, and there was a very informative one about krill. The decline in krill probably has nothing whatsoever to do with predators. I am no scientist, but my understanding is that it is likely due to:
– decrease in ice in key areas due to climate change, although large areas of the Antarctic may be getting colder, with some increasing in temperature – the invasion of Salp – an animal which is numerous like krill and is gradually displacing it but has no known role in the upward food chain – ocean acidifcation due to fossil fuel absorbtion – even immediate cessation would take time to reverse the acidification – possible overharvesting by humans. Certain countries have signed on to a convention which limits krill harvesting to a very sustainable level but there is much which goes on illicitly. However, krill is difficult to process after harvest, so it is not hugely economically attractive and the amount of trade which goes on may not be sufficient to be having a serious effect.
These things may be right or wrong but certainly a fair bit seemed empirically and scientifically based.
I doubt those nasty whales have much to do with it given that there were a thousand times as many in the Antarctic a hundred years ago….
The seabird declines are also probably much more due to increasing human pressures (including the loss of krill) while we are carefully protecting whales (at least most countries are).
When all is said and done, whatever nature’s imbalances and competition for resources are, it all comes down to one species – homo sapiens.
Cheers
Tim
> Date: Wed, 13 Apr 2011 06:32:52 -0700 > From: nhaass@yahoo.com > To: birding@ozemail.com.au; l.knight@optusnet.com.au > CC: birding-aus@vicnet.net.au > Subject: Re: [Birding-Aus] Antarctic penguins losing to climate change through 80% krill decline > > Any details? Which “pelagic sea birds”? Which “whales”? Species? Numbers? Rather than a terribly superficial statement? > > —————- > Nikolas Haass > nhaass@yahoo.com > Sydney, NSW > > > ________________________________ > From: Ian May
===============================
To unsubscribe from this mailing list, send the message: unsubscribe (in the body of the message, with no Subject line) to: birding-aus-request@vicnet.net.au
http://birding-aus.org ===============================
