Monday, December 10, 2012

Thar’ she blows!!

Here’s a bit of a catchup on my whale investigations.  I’ve started looking at whales and whaling in Southland for a booklet coming out in about twelve months.  The most recent stranding in Southland is a humpback, at least the fourth in ten years.  These big guys don’t get stranded alive; they die at sea and drift ashore.  If the bodies get stuck in the inter-tidal zone they break down quite rapidly.  One which washed up on 1 November at Mason Bay on Stewart Island had largely disintegrated by 9 December with each tide bringing a new wave of crustaceans to nibble the flesh and wash away the loosed debris to expose more meat for the tearing gulls.  If it had been cast up above high tide by an exceptional tide, then it’s the flies that break it down and that process takes years. 

Pictures show the remains of a Humpback in November 2012
and the same animal six weeks later.

 Humpbacks were hammered by the shore whalers and it was this species that kept the last of the whalers – the Tory Channel ones – going until the early 1960s.  There had been an extensive humpback fishery on the Northland east coast until then.  The whales were trapped by huge nets across the mouths of bays, harpooned and dragged ashore for flensing.

Some of the vertebrae and other bones had separated from this carcass.  The back of the skull was detached and showed a severe growth of cancerous bone which may have contributed to the whale’s death.  Sea mammals suffer the human diseases of old age as they are amongst the few animals to actually reach advanced years.  For other species, advancing weakness or illness makes them vulnerable to predation and they are quickly killed and eaten.  Whale bones often show arthritis and osteoporosis.
The whale’s radius and ulna were protruding from the carcass.  These are the longest radius and ulna of any sea creature that ever lived - longer than the equivalent bones on the Blue whale and exceeding those of any of the giant marine reptiles.

Pilot whales stranded in February 2011 photographed three months later.

Further south along Mason Bay the last remains of the Pilot whales that stranded in February 2011 are slipping from view.  Here and there you see a rib or vertebra on the beach and there are still a dozen skulls, much battered after this time.
It was on this spot that Pilot whales, or Blackfish, as they were known, were herded ashore by Stewart Island fishermen.   The iron pots were brought around from Oban and the carcasses were boiled for their oil. 

From time to time the suggestion comes up for using stranded whales and dolphins for food – a cultural issue rather than one of necessity.  There is plenty of historical precedent for eating whales and dolphins and whale meat is available in Japan, Norway and other countries.  In wartime Britain canned whale meat from the Antarctic whale fishery supplemented beef and mutton although it was eaten unenthusiastically.  There is a big difference between the meat of baleen whales and toothed whales with the Sperm whale in particular giving a dark, oily meat with noted laxative powers, while the meat of the rorquals – Blue, Fin, Minke and Sei and Bryde’s whales – is milder, paler and better flavoured.

Whale meat is low in cholesterol and calories and high in Omega-3 oils but the prospect for the harvest of meat from stranded cetaceans is bleak for several reasons.

1)  The insulating layer of blubber on a large whale effectively prevents the carcass from cooling after death and the temperature rises rather than falls.  Decomposition begins rapidly in the hot lifeless tissues and the meat is inedible after a few hours.  Commercially harvested whale meat is removed from the body and chilled quickly aboard a factory ship.

2)  As the cause of death is usually not obvious, the whale may have died from a disease that may be transmissible to humans or may render the meat toxic.

3)  Being top carnivores, marine mammals accumulate natural and man-made toxins which remain in the food chain.  Pesticides, such as DDT, and heavy metals, especially mercury, can be at a dangerously high levels, as can the natural level of vitamin A in seal livers.

So there goes the case for eating meat from stranded carcasses.  They can provide other useful bits though.  Although whales dead and alive are protected, it is lawful to remove bones and teeth that have separated naturally from the carcass.  Bone, especially the jaw of the Sperm whale, is much prized by carvers, as are the teeth.  Baleen, formerly removed from Right whales to make corset stays, umbrella ribs and the springy bottoms of chairs, can be used for carving, and the large vertebrae are used for garden seats.  By the way, we don’t know why it is called the Right whale.  It was clearly the wrong whale to hunt as its oil was inferior and it was regarded with distain by the whalers, for whom the ‘right whale’ was the Sperm whale.