Source: Department of Conservation
Climate change effects are considered the top threats to marine ecosystems according to a 2012 study. These effects will disrupt ocean currents, food webs, species distribution, and intertidal habitats.
The likely impacts from climate change on some of our marine species and ecosystems are relatively easy to predict and understand, but others require a bit more investigation. Some of the processes that will change the ocean dynamics include: increased sea-surface temperature, sea level rise, ocean acidification, and extreme weather events (heat waves, storms etc).
Marine Climate Change Project Team
Our Marine Climate Change Project Team was formed in early 2019, with staff from our Mountains to Sea, Marine Species, and Marine Ecosystems teams. The purpose of the team is to prioritise work, support action and report on work relating to marine climate change mitigation and adaptation.
The team is working to increase the resilience of native species and ecosystems so they have a better chance to adapt to climate change. As well as working on adaptation solutions we are focusing effort on marine mitigation opportunities.
The team is also helping with DOC’s Climate Change Adaptation Action Plan which will set out actions we can take to reduce the impacts of climate change across all aspects of our business.
The Marine Climate Change Project Team are focussing on five specific areas: coastal wetlands and blue carbon, marine protected areas, seabirds, marine mammals, and coastal adaptation for nature .
Coastal wetlands and blue carbon
There is a lot of focus on ‘One Billion Trees’, but we are keen to add marine opportunities into the toolbox. Marine ecosystems are a great opportunity for mitigation! This so called “blue carbon” may be a new idea for New Zealand but the concept already has much traction overseas and in some countries people are getting paid to grow coastal wetlands! Salty wetlands can store 10-40 times more carbon, per unit area, compared with terrestrial forests.
This project supports the restoration of coastal wetlands (one rich form of blue carbon) as a tool for carbon sequestration to help mitigate climate change.
A coastal wetlands and blue carbon central government hui was held in November to start an ongoing programme, throughout the country, to get timely action on healthy estuaries to restore carbon.
Coastal adaptation for nature
Many of our coastal marine ecosystems – shallow surf zones, dunes, intertidal areas of open beaches and estuaries, coastal wetlands, coastal sequences – are at risk from sea level rise induced “coastal squeeze”.
How should we be managing our coasts against sea level rise and increased storm events? Seawalls and hard structures, or a managed retreat? What can we do to help our coastal species adapt – particularly those that rely on our shorelines for rest, reproduction, and feeding, e.g. NZ sea lions, yellow-eyed penguins.
Seabirds are a key indicator of the impact of climate change, as they are an apex predator that traverse the world’s oceans.
Seabirds rely on both the land and the sea throughout their lives and will therefore be affected by both land-based and sea-based risks. There will be some direct measures we can take to help seabirds at their breeding colonies adapt to increased storm frequency, sea level rise, and predator eruptions. Indirect effects on food webs at sea will be harder to manage.
The challenge will be prioritising the species or populations most at risk.
Some adaptation projects have been identified that we could focus on e.g. coastal nesting gulls and terns, protection of surface nesting seabirds from extreme heat events, and identification of future risks to seabirds from climate change.