KEY POINTS:
The Government has recently released its Threat Management Plan for the protection of Hector's dolphins. Among other things it suggests setting up Marine Mammal Sanctuaries in some stretches of water and has prompted the immediate call from green lobby groups that set netting also be banned as "the most serious threat" to Hector's.
It seems to me the most serious threat to these precious mammals would be to take very public and drastic action that actually does nothing to protect them, because it is based on questionable evidence that is being presented as fact. Heck, it has to be said.
The Government is being carried along by a wave of slick and intense lobbying from Forest and Bird and others that appeals to everyone's emotions, but has no creditable evidence. Should we be surprised? It's probably less than a year out from an election.
We can all appreciate that discussions around the protection of endangered species like Hector's and Maui's dolphins will be intense and emotional. But those discussions should also be balanced, and the public should have an opportunity to form their own opinions based on real and quantifiable information.
There is the constant claim, for example, that set-netting presents the most significant threat to Hector's and Maui's dolphins. There is simply no evidence to back this claim up.
Here are the facts:
* Between 1988 and 2003 there were two Maui's dolphin deaths attributed to net entanglement out of a total of 17 notified deaths.
* Since 2003, when a ban was established for one nautical mile off the west coast of the North Island, there have been no reported net entanglements.
* Since 1992 there have been 123 confirmed deaths of Hector's dolphins and only 29 attributed to commercial set netting.
Forest and Bird have widely distributed and published in their own magazine the statistic that nearly 70 per cent of Hector's dolphin deaths were caused by set nets.
This is an entirely mischievous statistic - that's 70 per cent of deaths where the cause of death is identified.
Of all dolphin deaths, the commercial fishing sector is held responsible for just 4 per cent. Quite a different picture, isn't it?
Then there are the conservationists' claims that "hundreds" of Hector's are being killed every year.
Significantly, the basis for these claims seems to be a belief - or rather, a guess - that there were around 26,000 Hector's dolphins in New Zealand waters in the 1970s.
The fact is that the number 26,000 is based on an estimated set net entanglement rate from a year-long observation programme, carried out in the Pegasus Bay set net fishery in 1997-98. During that survey a total of eight Hector's dolphins were observed caught in set nets, of which two were released alive.
Using this observer data from Canterbury only, a total by-catch of 18 Hector's dolphins was estimated for the east coast South Island 1997-98 set net fisheries. It's worth noting that the 1997 catch rate caused the fishing industry to take measures to stop or reduce bycatch, including codes of practice and closed areas.
This number has been used to extrapolate a 1970s dolphin population of 26,000.
It's interesting to note that this number keeps mysteriously growing, having been quoted at 27,000, 28,000, and even 30,000 in some publications. It's worrying that measures that could have a serious economic impact on fishing communities are being made on the basis of so little evidence.
I know dozens of people who fish who've never caught a dolphin, and would be devastated if they did. But they want to know that any decisions around the protection of the Hector's are being made on the basis of reason and sound scientific evidence.
