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Sea lion pup and mother on Campbell Island. Photo: Kyle Morrison/NIWA.

  Here are some inconvenient facts about endangered sea lions.

  Inconvenient, that is, for those whose agenda is to close down Southern Ocean commercial fishing by any means.

  NIWA fisheries scientist Dr Jim Roberts is so concerned by biased environmental and activist academic claims that he has spoken out.

  He says recent public comments about the species are out of touch and are based on claims for which there is weak scientific evidence.

  MPI and DOC have developed a threat management plan for sea lions and released a consultation paper for public comment, which closes today.

   Despite the fact not one fishing-related sea lion death was recorded in this year’s Auckland Island squid season (with near 100 percent observer coverage)  and that the management plan identifies disease as a bigger threat than fishing, the usual naysayers – Forest & Bird, the Greens, Otago University academics – lined up against the industry.

   Their contribution to a number of media articles “containing myths and misinformation”, according to Dr Roberts, “are counter-productive to the conservation of the species”.

   He has studied sea lions population modelling, diet and reproductive biology for the past five years.

   His research shows the claim sea lions mainly eat squid (and are therefore in direct competition with squid trawlers) is wrong.

   Southern arrow squid make up less than one fifth of their diet. Survival and breeding rates of sea lions at the Auckland Islands were poor during a period of high squid abundance. 

   There is evidence of nutritional stress but the ultimate causes are not clear. 

   Sea Lion Exclusions Devices (SLEDs) were introduced to squid trawls a decade ago to allow escape from the nets. This has led to a major reduction in trawl mortality.

  Opponents claim the sea lions are instead  being killed by the SLEDs, labelled cryptic mortalities, and these are being ignored.

  This, too, is untrue, according to Dr Roberts.

  Modelling of collision with SLEDs suggests the risk of trauma or concussion is around three percent, according to the threat management plan.

  Dr Roberts said even the most pessimistic SLED-related scenario does not explain the whole of the sea lion population decline.

  “The Auckland Islands population has been dealing with something much bigger than trawl mortality and we urgently need to know what it is,” he says.

  It is known that the bacterial disease klebsiella pneumoniae, first noticed killing sea lion pups in 1998, has since become endemic.

  It is the main killer of pups during the summer field season, Dr Roberts says. “The duration of this endemic is unusual for a seal species and coincides with a protracted period of low pup survival.”

  While the main Auckland Island population is in trouble, Stewart Island and the New Zealand mainland have been recolonised by sea lions in the past 20 years and the Campbell Island population, where a third of all pups are now born, is on the rise.

  The myths, if not deliberate misinformation, that Dr Roberts has been moved to tackle are harmful in his view “because they distort the science and may divert resources into ineffective conservation measures.

  “Misinformation is a genuine threat to the conservation of New Zealand sea lions.”

- Tim Pankhurst