Marine Heat Waves: New Zealand’s Hauraki Gulf Region Experiences Extreme Temperatures Since 1967

Marine heat waves have struck the Hauraki Gulf region with prolonged and record-breaking extreme temperatures, according to a new study led by researchers from the University of Auckland in New Zealand. The findings suggest long-term warming and unprecedented heat have been recorded in the Hauraki Gulf in Northern New Zealand starting in 1967 and 2012.

A marine heat wave, unlike a terrestrial heat wave, can last for many weeks or months cover larger areas, and may even warm some parts of the deep ocean, according to the United Kingdom's National Oceanography Centre (NOC). Based on previous research, this extreme weather event is tied to climate change and global warming, elements that are also linked to other natural disasters.

Hauraki Gulf Marine Heat Wave

The research team from the University of Auckland, the University of Waikato, and the National Institute of Water and Atmospheric Research found that marine heat waves occurred for decades from 1967 and another starting in 2012. The findings of the study on the Hauraki Gulf marine heat wave were published in the journal New Zealand Journal of Marine and Freshwater Research.

The team determined these findings by daily measurements of sea surface temperature since 1967 at the Leigh Marine Laboratory in the Hauraki Gulf. By analyzing anomalies of increasing marine temperatures and heat waves from 1967 to 2023, the scientists found there is unprecedented warming events during the autumn and winter seasons, instead of summer and spring.

By continuing to examine the anomaly over the past decade, the researcher detected that 2022 has been the warmest year in the region within 57 years and has the highest recorded temperatures for six months. The results of the research paper show that there is a decades-long uptick of ocean warming, likely caused by the anthropogenic climate crisis, in the Hauraki Gulf.

Marine Heat Waves

Marine heat waves pose an immediate threat to the coastal marine environment not only in the Hauraki Gulf but also in other parts of the world. In recent years, scientists have warned that ocean warming and heatwaves pose a significant ecological threat, including both on aquatic prey and predators. These extreme events can also damage marine animals' habitats and can lead to their death.

According to the National Oceanic and Atmospheric Administration (NOAA), marine heat waves can cause significant impacts to ocean life such as fishery collapse and coral death. From 2013 to 2017, the NOAA reported that a marine heat wave, called "The Blob" struck the West Coast of North America. The impact ranged from the Gulf of Alaska to the province of Baja California in Mexico.

Marine heat waves have been recorded in all parts of the world, including the Atlantic Ocean, Pacific Ocean, and Indian Ocean, resulting in mass fish deaths and even the forced migration of some species away from their local habitats.