Interspecies relationships in the Hauraki Gulf are changing and things are ‘not how they are meant to be’ an expert says.
At the Hauraki Gulf Forum on August 22, University of Auckland biological sciences professor Rochelle Constantine presented about her latest work on marine megafauna in the Hauraki Gulf Marine Park.
The Hauraki Gulf is “an important area. I know that, mana whenua know that, I do not think a lot of people in the region know that,” Constantine said.
Constantine’s work looks at the relationships between species when feeding with some focus on Bryde whales.
A video played during the presentation where dolphins were rounding up fish before a whale came to steal their meal, showing how species can interact during feeding.
“The region is getting warmer and there are consequences for that,” Constantine said.
“Plankton do not like warm waters so they move, then the fish move, the dolphins move, the whales move.”
Bryde whales were leaning further toward a zooplankton-based diet and Constantine said “we don’t see the big schools of fish these whales need to live on… There are changes. This is not how it is meant to be.”
The shift towards plankton also meant Bryde whales had gained a greater feeding association with seabirds she said.
While warming temperatures were noted to be a big contributing factor to changing dynamics in the Gulf, Constantine also said the soundscape of the gulf impacted marine life.
“Humans are very noisey… when all the boats are on the water it masks the biological sound.”
Marine animals in the Gulf were unable to communicate if a predator is near, indicate when they are ready to mate or during a hunt because of the noise she said.
“Noise pollution is a loss of mauri… the social fabric of these species are changing.”