Warmer seas around Waiheke are leading to sharks, whales and little blue penguins changing their habits – and creating ideal conditions for infestations of jellyfish.
Niwa meteorologist Ben Noll says satellites are used to measure ocean temperatures across the Auckland region, including the Hauraki Gulf around Waiheke.
“Sea temperatures warmed to 20 and 21 degrees around Waiheke Island during early January. Overall, it’s about a degree above average for the time of year,” says Ben.
“January 2021 is warmer than it was in 2020 and, overall, it is fairly similar to 2019 but not as warm as the extreme summer of 2017-18.”
As with air temperatures, ocean temperatures are continuing to rise. Across the four oceanic regions (Chatham Rise, Tasman Sea, subtropical, and subantarctic waters), sea-surface temperatures increased between 0.1 and 0.2 degrees Celsius per decade between 1981 and 2018.
Last winter, sea surface temperatures surrounding the country were warmer than average, most notably during August. In December, Niwa forecasters identified a marine heatwave in waters to the north of the North Island and they’re currently keeping a close eye on ocean temperatures around the country, which have all been above average since October.
• Sophie Boladeras