NZ Dolphin Cat Sh*t Theory
Despite reports from Seafood NZ and NIWA that there is now “a revised understanding” around NZ Dolphin deaths an International Expert Panel warned Fisheries NZ and DOC last year they were concerned results from the cat sh*t (toxoplasmosis) model could be seriously misleading and advised them to ….” ‘back off’ from forcing the model to produce conclusions which are supportable only when a series of questionable assumptions are made and which even then, are highly uncertain”.
The eighteen month long study conducted by NIWA’s Dr Roberts referenced findings from 2013 which looked at toxoplasmosis as a potential cause of death in 7/28 (25%) of the dolphins in their study (2/3 Maui’s and 5/25 Hector’s) from the years 2007-2011. Again the Expert Panel advised such a small sample size taken as the representative profile of total mortality for the species as a “questionable decision”.
The Expert Panel further concluded: “If the effects of disease are as large as the MPI estimates, NZ dolphin would be “in rapid free-fall towards extinction.”
Michael Lawry Sea Shepherd NZ Director states: “The revised understanding strangely does not take into account areas such as Banks Peninsula where toxoplasma has been identified as present but there has been increased protection from commercial fisheries (gillnetting and trawling) since 1988. The survival rate of Hector’s dolphins in this area has increased by over 5% since protection measures were introduced and is now almost stable. This doesn’t appear to support the theory that toxoplasma is an important source of mortality for NZ dolphins, as fisheries regulations resulted in a large increase in survival rate while nothing has been done to reduce disease."
Sea Shepherd is calling for a complete ban on set nets and no trawling within the 100 metre depth contour. Currently trawling is only prohibited in about five per cent of Maui habitat.
The International marine conservation organisation has petitioned the US government for a trade ban on fish caught in Maui habitat. It will shortly file a case with the US Court of International Trade.
For further information regarding the Expert Panel’s comments: