Advice on Toxoplasmosis Hector and Maui Dolphins

To: Hon Kiritapu Allan, Minister of Conservation and Hon David Parker, Minister for Oceans and Fisheries
Date: 12 November 2021

The New Zealand Conservation Authority (Authority) has recently received a report on the Hector and Maui Dolphin Threat Management Plan. We wish to express our concerns with the threat of toxoplasmosis to both Hector and Maui dolphins, particularly the latter. The failure to address the threat of toxoplasmosis is very likely to lead to the extinction of Hector and Maui dolphins, hence we bring this matter to the urgent attention of you both.

To provide some context, toxoplasmosis is a parasite that can infect all warm-blooded animals, including humans. In more recent times the disease has become the primary cause of death for Hector and Maui dolphins and has previously been known to infect other endangered wildlife such as kiwi, kereru, kaka and kakariki. Toxoplasmosis is known to sexually reproduce in cats and gets spread through the depositing of faeces, that becomes run-off leading into rivers and streams, which end up in the ocean. This parasite only reproduces in cats, is very durable and can be present in the environment for long periods of time.

The Authority was presented with a report on toxoplasmosis at their October 2021 meeting and was surprised by the statistics provided in the report. In a comparison between the mean annual deaths of Hector and Maui dolphins, the combined deaths by commercial set nets and inshore trawls for Maui dolphins is 0.12 per year and Hector’s dolphins is 58 per year. These numbers are well exceeded by toxoplasmosis related deaths, with Maui being 1.9 deaths per year and Hector’s being 334 deaths per year. These numbers alone illustrate the seriousness of the matter and justifies the Authority’s stance in addressing the topic.

Based on these statistics, the Authority would like to share their opinion on what steps should be taken in dealing with the toxoplasmosis matter:

• The Authority is of the view that, given the urgency of the matter, the 5-year Hector and Maui dolphin research plan needs to be amended to reflect more immediate goals to be achieved in shorter timeframes.
  
  
• In order to be effective, the Hector and Maui Dolphin Threat Management Plan needs to be properly funded and resourced. A decision is being made now as to whether these species survive extinction.
  
  
• The Authority suggests considering a cat control programme within the context of Te Mana o te Taiao. This urgently needs to be socialised with the wider public, so it can be initiated by 2025. It has long been recognised that cat controls would have wider benefits for other terrestrial native species as well.

The Authority wishes to remain involved in dealing with toxoplasmosis, whilst also providing advice and guidance to both of you as Ministers for Conservation and Oceans and Fisheries. Authority members are extremely concerned about this road to possible extinction could happen on their watch.

No reira

E noho ora mai

Edward Ellison ONZM
Chairperson NZCA