Rising carbon dioxide levels are threatening ocean life in myriad ways, but traditional knowledge and tech offer solutions.
Hundreds of ocean experts from around the world will meet at The Ocean in a High-CO₂ World conference in Wellington to discuss how climate change is affecting the seas, and what to do about it.
The SMC asked experts to comment.
Dr Pete Russell, oceanographer with Coastal People Southern Skies Centre of Research Excellence at the University of Otago, comments:
“After tropical storms, it’s not uncommon to see massive blooms of plankton in the ocean. We still know very little about them.
“I personally think these are one of nature’s great events, just on the scale of them – for example, the size of Otago. Where does all this green stuff go? Does it go on to feed tropical marine food chains?
“I am developing a global catalogue of these events and aiming to build awareness of them in the wider scientific community.
“The long term objective is, if this stuff ends up on the ocean floor as marine snow, it might be buried there as a distinct layer representing that big storm. If we drill deep enough into the seafloor to find sediments from the last warm interglacial period, we may then be able to use these marine snow layers to see what cyclone activity was like – and could be like in the future – in a world where ocean temperatures are 2 degrees warmer than today.”
Note: Dr Russell’s talk, “One of natures’ great events rises from the ashes of an extinguished tropical cyclone,” is at 4 pm on Thu 15 October.
Conflict of interest statement: “Nil.”
Dr Christopher Cornwall, marine biologist, Victoria University of Wellington, comments:
“Ocean acidification and marine climate change are major threats for Aotearoa’s marine ecosystems. Ocean acidification makes it difficult for marine organisms with calcium carbonate shells and skeletons to grow. Extra CO₂ can also help some opportunistic seaweeds, possibly degrading ecosystems.
“Ocean acidification does not occur in isolation, but rather hand in hand with local and global ocean changes. Ocean warming brings about more extreme marine heatwaves that kill off corals and kelp. Ocean deoxygenation also occurs as waters warm, reducing the oxygen for marine invertebrates and fishes. Coastal darkening brings about periods of increased low light that can stop seaweeds and corals from growing.
“These future changes will all occur at the same time, and in conjunction with local stressors such as pollution, sewage spills, coastal development, and increased run off of sediments from development or land use changes that can cause widespread ecosystem harm.
“However, there are some solutions to marine global change. Ocean solutions of the future will need to involve collaboration with mana whenua in Aotearoa, and other indigenous people across the globe. Our symposium will highlight some of these solutions, such as the use of Mātauranga to improve ecosystem management, marine carbon dioxide removal, and restoration.”
Note: Dr Cornwall is the conference chair.
Conflict of interest statement: No statement received.
Dr Nathan Kenny (Te Ātiawa, Ngāi Tahu), Department of Biochemistry, University of Otago, comments:
“I work with Māori communities, scientists and the aquaculture industry to help protect Aotearoa’s kaimoana as our oceans change.
“I study the instructions – genes – that mussels and other shellfish use to find out why some are better at surviving warmer, more acidic seas. For example, we are studying regional and family-level differences in Kuku – Green-lipped mussels – from across the country, to see why some individuals can cope with warming conditions better than others.
“By finding these natural strengths and weaknesses, this research can help communities understand how their taonga might be affected in the future, and allow communities, policy makers and the industry choose which animals to protect, breed or monitor over time.
“Genomics gives kaitiaki (guardians) a tool for making active, informed choices about how best to care for their kaimoana, and our goal is to ensure continued access to healthy seafood and treasured species for future generations.”
Note: Dr Kenny’s keynote talk “Safeguarding Taonga in a Changing World,” is at 9:50 am on Tue 13 October.
Conflict of interest statement: “None.”