Science In The Hutt: Impacts Of Climate Change On NZ’s Kelp

Chris Cornwall (Victoria University Wellington) on ocean warming and acidification threatening New Zealand’s iconic kelp forest ecosystems. Ocean warming will cause profound shifts in species distributions and growth rates. Ocean acidification will inhibit the ability of calcifying species to form new skeletons and could shifts ecosystems away from calcifying species and towards opportunistic seaweeds.

Science in the Hutt are monthly science talks are organised by the Lower Hutt Café Scientifique crew. Come and enjoy a range of science and technology speakers in a relaxed, friendly environment. Talks are aimed at non-scientists so that everyone can explore and learn more about new scientific ideas.

More information: Anthropogenic CO2 emissions threaten New Zealand's iconic kelp forest ecosystems. Ocean warming and associated marine heatwaves have devastated kelp forests ecosystems in Australia, resulting in phase shifts to tropicalised ecosystems in the north and sea urchin barrens in the south.

These same processes, and more subtle shifts in species distributions and growth both threaten New Zealand's kelp forests. Ocean acidification is the increases absorption of CO2 by the surface seawaters and has been dubbed the 'evil twin of ocean warming' and will also cause profound changes to ecosystem dynamics. Species with calcium carbonate skeletons are a particular risk. This includes our Taonga species, kina and pāua, but also less well-known species such as coralline algae. Coralline algae provide a nursery for kina and pāua larvae, and also act to bind together reefs of various substrates.

Ocean acidification also may benefit some seaweeds, shifting ecosystems from calcifying species towards more opportunistic and structurally less complex organisms.