Why Whales are so large .

Why Whales are so large
Andre Willers
12 Aug 2011

Synopsis :
Vertical migration in the ocean between each breath recycles nutrients into the sunlit layers of the ocean , stimulating phytoplankton-krill-whale positive feedback cycle . The bigger the whale , the more krill , the more whales , etc

Discussion :
See "Givers of Life" by Steve Nicol in NewScientist 9 Jul 2011 p36 .
This is an excellent overview by an actual researcher .

Critical points :
1.Nutrients tend to sink after concentration into plant cells . Small animal faeces like krill sink by 100 – 1000 metres a day . The thermocline acts as a trapdoor , excacerbating the effect in summer or global warmaing .

2.Mammals have to breathe at the surface . This forces a vertical migration with each breath , mixing things up in at least three ways :

2.1 Wake turbulence and Coanda Effect (Google it) . Large volumes of water are transported up and down . It is part of whale's reduction to water-flow resistance . The bigger the whale , the better .

2.2 Nutrient scavenging from the depths and faeces plumes at surface . Size helps .

2.3 Floating reservoirs of nutrients in krill are eaten and excreted as faeces plumes in the sunlit zones , preventing loss of vital nutrients like iron . This stimulates phytoplankton , which stimulates krill , which stimulates whales . The bigger the whales , and the more of them , the better .


Social effect and mini-ecology :
A pod of whales use their sonar calls to coordinate their vertical migrations to create a nutrient rich mini-ecology around the pod . They farm the sea .
Other species benefit . Fishing is good .

Note that the minimum survival size is a pod , and the techniques are learned .
Think of the pod as a farming village in 3-dimensional oceanic terms .

A lonely whale is a hungry whale

The feedback effect here would be as the cube of the number of whales and their size . A very strong effect , leading quickly to large numbers and maximum possible sizes .

This was indeed the case as late as 17th century Whale , fish and wild bird populations were about 100 times larger than at present . Google it .

The Fly-by effect :
Whale pod ecologies moving past a coast would have significant effects on local crustaceans and inshore fishing .
The same is applicable for coral reefs . Blanching is be ameliorated by temperature-layer mixing .
The Australian Great Barrier reef can be saved through whale pods doing a fly-by
Coral atolls the same .

Without them there would be a desert .

Whales seems to have been the key-stone eco species .

The Bad News :
This seems bad , since humans reduced whale numbers so drastically .

The Good News :
1.The feedback effect is very strong (cubed effect) and can be applied per pod .
2.Pod-package : similar to human civilization package .
Symbiotic and commensal species of fish , phytoplankton , krill , dolphins , orcas , can be used to accelerate repopulation , under strict human protection .
3.Commercial Demand :
Whale Pods and their symbiotic humans can negotiate their own terms for ecological beneficiation for coral islands , fisheries , barrier reefs , etc .
In a warming world , the Whale Union will be a powerful force .

Whales and Dinosaurs :
Whales are the largest animals that ever lived .
Sea dinosaurs did not need to breathe air . Hence no vertical migration .
Hence no feedback effect for size .

Hippo's
Hippo's are a branch of whales (from long ago) . They also create a mini-ecology in their pool by stirring things up . Especially in the dry season . The pools are stagnant . The only thing stirring up nutrients are hippo's . The other species depend on them . The eco-system collapses without them .
Which is why humans put up with bad-tempered hippo's in Africa . They were essential to a functioning ecosystem .
(Or , to put it more elegantly , the tribe that killed them perished .)

Which makes me wonder why they were not domesticated .
Maybe an attempt was made around the Makgadigadi Sea , and what we have are the descendants of the untamable ones . Similar to buffalo and kwagga .
See http://andreswhy.blogspot.com "Makgadigadi Sea" Aug 2009

The Human-Whale interaction .
There is fairly good evidence that a crucial human bottle-neck experience took place about 190 000 to 200 000 years ago on the Agulhas plains during an ice-age .The only thing enabling them to survive was the annual whale pods flying by , fertilizing the Agulhas Banks .

This survives to this day . The locals are fanatical in protecting the whales . No large scale whaling has ever taken place . They have long forgotten the reasons for it , but like any good religious proscription , it persists .

Whale watching is a major industry today .
Local South Africans and others gather to watch the phallic plumes of whale-breath spume new life into the banks .

Every time the whale pods go by , the poor over-fished abalone , crayfish and other fisheries are invigorated and struggle on .

Having a whale of a time .

Andre