The Hauraki Gulf / Tīkapa Moana / Te Moananui-ā-Toi hosts many visiting whales, including humpbacks and blues, but its most common year-round resident is the nationally critically endangered Bryde’s whale.
This is a special place for the Bryde’s whale as it is one of only three places in the world where these whales live in coastal waters, with around 135 Bryde’s whales using the Marine Park. Bryde’s whales are most frequently seen in the area between Kawau Island, Waiheke and Aotea (Great Barrier Island), where they spend around 90% of their time in surface waters resting and feeding on small schooling fish and zooplankton. They need to eat a lot (600–650 kg per day) to maintain their body size, making them vulnerable to declines in prey availability due to fishing, environmental degradation or climate change.
In the past, a key threat to Bryde’s whales was ship strike. The Marine Park is one of the busiest waterways in Aotearoa, with the Ports of Auckland handling around 1,400 ship calls per year. Bryde’s whales are particularly vulnerable to being hit by fast-moving ships because they spend most of their time in surface waters. Between 1989 and 2014, 17 whales were likely to have been killed by ship strike, three whales died from entanglement with fishing or aquaculture gear, and 25 whales died from unknown causes.
Since ships voluntarily slowed down in the Gulf from 2013 deaths from collisions seem to have been eliminated meaning about 25 whales that would have died from ship-strike should have featured in the new population estimate. Females can give birth to a calf every two years, so that also should have helped the population to expand.
However, marine heatwaves altering ecosystems in the Gulf may also now be pushing the whales into the less frequently monitored outer Gulf.
In 2021 an art campaign, (run in 2022 due to Covid 19) and run by the World Wide Fund New Zealand (WWF), brought awareness to the mammals’ plight and that of the oceans' health.
