March 18, 2026

#regional: Hauraki Gulf seabirds struggle to raise chicks as climate pressures intensify

Matthew Tukaki Posted On March 18, 2026

New research from the University of Auckland is raising alarm over the state of seabird populations in the Hauraki Gulf, with scientists reporting unusually low chick survival rates linked to changing ocean conditions.

Researchers monitoring diving petrels and fluttering shearwaters across the gulf this summer have found clear signs that food shortages are impacting breeding success, with climate-driven changes to marine ecosystems emerging as a key factor.

Fieldwork carried out since October shows significant disruption to normal breeding patterns. At Tāwharanui, north of Auckland, around half of the monitored fluttering shearwater nests failed, a rate well above what is typically observed. Several adult birds abandoned nests altogether, behaviour associated with an inability to find sufficient food.

Scientists tracking the birds say their foraging patterns have changed dramatically. Where seabirds once returned daily, some were now travelling distances of more than 200 kilometres, reaching as far as North Cape in search of food. These extended trips left eggs unattended for long periods, slowing development and delaying hatching.

The timing of breeding has also shifted. Fluttering shearwater chicks, which usually hatch between late October and November, were hatching much later this season, with some eggs still being incubated into mid-December. Similar patterns were observed among diving petrels on Tiritiri Matangi Island, where chicks hatched later than normal and were significantly underweight.

Researchers say the reduced weight of chicks is particularly concerning, as it lowers their chances of survival once they leave the nest. In one case, a rescued chick weighed far below the expected level, highlighting the severity of the food shortage.

The findings point to broader environmental changes in the Hauraki Gulf. Marine heatwaves and rising ocean temperatures are affecting the availability of key food sources such as zooplankton and small fish, which form the base of the food chain for seabirds.

Scientists describe seabirds as early indicators of ecosystem health, warning that the impacts being observed are likely to extend to other marine species. The Hauraki Gulf is considered a global hotspot for seabirds, supporting around 70 species, including several found nowhere else in the world.

There are growing calls for stronger marine protections to help improve food availability. Suggestions include reducing fishing pressure, particularly methods that remove large volumes of fish, and introducing more adaptive, seasonal protections that follow migratory species.

Researchers say restoring the natural balance of the gulf will be critical to improving resilience, but acknowledge that climate change is already reshaping the marine environment. With global temperatures continuing to rise, the outlook for seabirds and the wider ecosystem remains uncertain.

The study highlights the urgency of addressing both climate impacts and local pressures such as overfishing, pollution, and sedimentation, as the Hauraki Gulf transitions into a new environmental reality.