Otago Marine Science

Maui dolphin declines below 50 individuals - Making Waves

Sep 26, 2021

The chances of Maui dolphin avoiding extinction have just got even worse. It was bad enough already, but the latest population estimate shows that there are now fewer than 50 Maui dolphins left in the World. Meanwhile, the Ministry for Primary Industries has just increased the quotas for gillnet and trawl fisheries in Maui dolphin habitat and New Zealand is continuing to ignore the recommendation by the IUCN to fully protect both Hector’s and Maui dolphins. The IUCN has urged New Zealand to “urgently extend dolphin protection” by “banning gill net and trawl net use from the shoreline to the 100 meter depth contour in all areas where Hector’s and Maui’s dolphins are found, including harbours”. At this year’s IUCN Congress, which finished a couple of weeks ago, we heard from the Director General that the vast majority … Read More

New Zealand research shows what a fat, healthy right whale looks like! - Making Waves

Jul 29, 2020

Professor Steve Dawson Scientists from the University of Otago, working with colleagues from around the world, have found that New Zealand right whales are doing much better than right whales in other parts of the world. The research was published as the feature article in the journal Marine Ecology Progress Series. Southern right whales are starting to bounce back from the impact of whaling. They are still not exactly common, numbering 10,000–15,000 individuals. But each individual whale is fat and healthy! Mothers in poor condition tend to have much skinnier calves By contrast, the North Atlantic right whale is teetering on the brink of extinction, with about 410 individuals remaining off the east coast of North America. Shipping and fishing continue to kill these whales through collisions with vessels and whale entanglement in fishing gear … Read More

Alarming decrease in calves increases fears for endangered Hector’s dolphin - Unsorted

Mar 31, 2020

Prof Elisabeth Slooten, Prof Steve Dawson This has been a terrible summer for Hector’s dolphins. The first indication was very low numbers of dolphin sightings during late spring and early summer. The Otago University Marine Mammal Research Team has carried out routine dolphin surveys at Banks Peninsula for more than 30 years. In all that time, we have never seen such low dolphin numbers during summer. Hector’s dolphins change their distribution with the seasons. During winter, they are found almost evenly distributed throughout waters less than 100 metres deep. In summer, they become much more concentrated close inshore and are routinely found inside harbours like Akaroa Harbour, Manukau Harbour, Otanerito Lagoon and other large bays and harbours. Seasonal changes in dolphin distribution These seasonal movements are driven by the distribution of their food; the fish and squid … Read More

The options for Hector’s and Māui dolphins - Making Waves

Sep 01, 2019

Professor Liz Slooten and Professor Steve Dawson, University of Otago The recently released Threat Management Plan for Hector’s and Maui dolphins presents government’s proposals for better protection from entanglement in fishing nets and other threats. Better options than any in the Threat Management Plan have been recommended by New Zealand and international experts. Worse options have been proposed by the fishing industry. It is now up to the Ministers of Fisheries and Conservation to choose among the “good, the bad and the ugly”. Government options The Threat Management Plan proposes four options for Maui dolphins and three options for Hector’s dolphins. In addition to some serious problems with the science the options are based on, they are also very complex. Depending on where you are, the offshore boundary for protected areas would be 2, 4 … Read More

Dolphin researchers say NZ’s proposed protection plan is flawed and misleading - Making Waves

Jul 01, 2019

Elisabeth Slooten and Steve Dawson The New Zealand government recently proposed a plan to manage what it considers to be threats to Hector’s dolphins, an endemic species found only in coastal waters. This includes the North Island subspecies Māui dolphin. Māui dolphins are critically endangered and Hector’s dolphins are endangered. With only an estimated 57 Māui dolphins left, they are literally teetering on the edge of extinction. The population of Hector’s dolphins has declined from 30,000-50,000 to 10,000-15,000 over the past four decades. The Ministry for Primary Industries (MPI) and the Department of Conservation (DOC) released a discussion document which includes a complex range of options aimed at improving protection. But the proposals reveal two important issues – flawed science and management. Flawed science Several problems combine to overestimate the importance of disease and underestimate … Read More

How endangered are New Zealand dolphins and sea lions? - Making Waves

Jun 05, 2019

Professor Steve Dawson, Professor Liz Slooten, Associate Professor Bruce Robertson The Department of Conservation (DOC) has downgraded the threat status of the New Zealand sea lion and New Zealand (Hector’s) dolphin. NZ sea lion has changed from “Nationally Critical” (the same category as the kākāpō) to “Nationally Vulnerable” based on “actual improvement”. The problem is, the available data do not support any actual improvement in sea lion numbers. Indeed, the graph in DOC’s publication (Baker et al. 2019) shows the decline is ongoing. Plus, across all breeding locations in 2019, there was a decline in the number of sea lion pups born, which is not what one would expect for a species showing “actual improvement”. The question must be asked then, how a species’ threat classification can improve when the data shows the opposite. New Zealand sea … Read More