Bahrain Team Pindar - Earthwatch update on wildlife at sea

On Day 84, Brian Thompson is lying in 6th place, on board his Open 60 yacht ‘Bahrain Team Pindar’, in the non-stop round the world yacht race, the Vendée Globe.

Below is an update from Debbie Winton at Earthwatch, the leading international environmental charity and partner to Bahrain Team Pindar, who has been monitoring the wildlife Brian has encountered at sea. 

Vendée Globe Sightings blog
Written by Debbie Winton, January 27th 2009

Sightings Brian has blogged so far:
5 dolphins
Whales
- pilot whale groups - one of three; a pod of 30; and lately a pair
- 2 unidentified whales
Storm petrels
Black petrels (species unknown)
6 unidentified snow white birds (possibly egrets?)
1 gannet
2 Arctic terns
Albatrosses
Prions
Shoal of garfish
Flying fish
Krill
Squid (ink!)
A few clumps of kelp
As Brian mentioned in one of his blogs back in December, krill (Euphausia superba) are becoming an important commercial fishery, but this is not the only threat facing the base of the food web that supports the entire southern ocean ecosystem.  Climatic changes such as sea surface temperature, salinity and pH balance of the water all affect the rate of survival of krill populations.  Research by the British Antarctic survey* found that krill numbers had declined by 80% since the 1970s due to a decrease in sea ice, which is a vital feeding ground and acts as a nursery for krill.  Couple this with competition with humans for the resource and the result is that the many predators that rely on krill, such as baleen whales, seals and penguins will find they do not have enough food.  Baleen whales include species such as the blue, right and humpback whales.  You may remember a baleen whale featuring in the film Finding Nemo, helping Nemo and Dory in Sydney Harbour!  They have baleen plates made of keratin, rather than teeth, to filter their food from the water.  A blue whale will eat up to 4 tonnes of krill a day. 

Other whales, like the pilot whales Brian has regularly seen belong to the toothed whales.  The latest two he saw would have been long finned pilot whales because the waters of the Southern Ocean are too cold for the short finned species.  The diet of toothed whales ranges from krill to larger morsels, such as fish and squid.  They are smaller than the baleen whales, include the sperm and beaked whales and are closely related to dolphins and porpoises.  Brian has seen a few dolphins in the Southern Ocean, which are likely to be the less commonly known species, such the southern right whale dolphin, striped, Commerson’s, Risso’s, dusky or hourglass dolphin, which inhabit the cold Southern Ocean.  He is likely to have seen even more as he passed Tierra del Fuego.

The Auckland Islands, which Brian passed south of at the end of December, are renowned for their diversity and abundance of seabirds.  Breeding colonies of albatross, penguin and petrels are found there, including rare and endangered species such as the yellow-eyed penguin, the endemic Auckland shag and the sooty shearwater. It is a shame Brian did not come across any of these, I expect they were resting and protecting their nests from predators during the night.  His lack of seabird sightings in the far south of the Pacific is not unusual, for exactly the reason that Brian described – a lack of islands or other land for the seabirds to nest on and no migratory routes in the area, which gives them no reason to be there.  The albatrosses are still present though as they can cover great distances with little exertion, using techniques called dynamic soaring and slope soaring.  They are a long-distance forager, and disperse widely after breeding, often undertaking circumpolar trips.

A few weeks ago Brian found squid ink on his deck, illustrating a squid in distress had been onboard.  Squirting black ink is their defence mechanism for confusing and escaping predators and is a last resort to accomplish survival in dangerous situations.  Unfortunately for the squid, the chances are that it became a seabird’s dinner, as they are a source of food for petrel, albatross, tropicbird, boobie, gannet and cormorant species.

Brian is now sailing back up the Atlantic and the surrounding marine life will consist of warm water species again. 

Let’s hope he sees something exciting!  Good luck for the last 3000 nm!

* Atkinson, A., Siegel, V., Pakhomov, E. & Rothery, P. (2004) Long-term decline in krill stock and increase in salps within the Southern Ocean.  Nature 432:100-103.