Freshwater conservation and climate change

It is still largely unknown how climate change will influence freshwater ecosystems in New Zealand.

DOC, as lead conservation agency, has an important role in understanding how freshwater biodiversity will respond to climate change and how to manage important ecosystems and species into the future.

Climate change and biodiversity provides more information on DOC's role in protecting New Zealand's native species and ecosystems form climate change.

Inaugural New Zealand workshop

A national workshop was seen as an effective way to bring together an interdisciplinary group of researchers, policy advisers and people involved in freshwater management to identify key issues with respect to climate change and freshwater conservation.

DOC organised a two day inter-agency meeting in Wellington, 10-11 December 2013. There were 24 participants who covered specialist fields of freshwater ecology, conservation, climate change, policy and Mātauranga Māori. The programme focused on 'what are the issues?' on day 1 and 'what can we do?' on day 2.

Proceedings from the workshop

Freshwater conservation under a changing climate (PDF, 2,687K)
September 2016

Preliminary messages from the workshop

Climate projections and current policy

• Warming of the climate is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia (IPCC Fifth Assessment Report, 2014).
• In New Zealand, changes in the hydrological dynamics of watersheds, sea-level rise, increased water temperature and altered land use patterns are projected to occur. For example, eastern regions are likely to experience more droughts and low flows.
• The RMA (Section 7) and National Policy Statement for Freshwater Management have provisions for climate change that can be applied to support the conservation of freshwater biodiversity.

Vulnerability of freshwater ecosystems due to climate change

• Workshop participants noted that many rivers, lakes, estuaries and wetlands may be affected by climate change, and biodiversity values are likely to change as well. Without action, local extinctions of freshwater species and shifts in distribution may occur.
• The degree of impact will depend on geographic location (exposure) and the type of freshwater ecosystem (sensitivity).
• Sea level rise will result in saltwater intruding further up coastal rivers and could alter whitebait spawning areas.
• A number of New Zealand's Ramsar sites (wetlands of international importance) are susceptible to changes in ecological function and species composition due to the consequences of climate change.
• No national assessment on the vulnerability of freshwater conservation values due to climate change has occurred.

Adapting management and policy for freshwater conservation

• DOC and other agencies are applying strategic approaches to freshwater conservation management, but few programmes appear to specifically consider climate change.
• Investment decisions need to be informed by the expected changes in freshwater ecosystems as a result of climate change. For example, some lowland freshwater lagoons are expected to transition to brackish estuaries that may require different approaches to management.
• Greater effort to reduce sediment and nutrient inflows, control invasive species and provide for ecological flows may be needed at sites that are sensitive to climate change.
• Adapting our network of freshwater protected areas is likely to help vulnerable ecosystems and species respond to climate change.

Science needs: informing a climate change response

• There exists sufficient scientific consensus on the impacts of climate change to implement a precautionary approach to freshwater conservation.
• Key knowledge gaps also remain - such as predictions of likely changes in wind events and subsequent impacts on the health of New Zealand lakes.
• Integration of climate projections, species response models, Mātauranga Māori and conservation management scenarios is recommended.
• Stronger partnerships are required between science, policy and managers to ensure the most up to date information is used. For instance, to ensure management decisions to protect freshwater biodiversity and conservation values are based on future climate scenarios.
• New Zealand application of tools developed by other countries will limit duplication of effort.

Feedback

Participants were from a range of government agencies and research institutions. Following the workshop they commented on the importance of the meeting in addressing a significant gap in freshwater conservation.

Other comments (from feedback forms) were "very informative and positive", "good to get cross-sectorial knowledge in the aquatic area" and a "milestone workshop".

Next steps

• Improve linkages between natural resource management agencies and science institutions.
• Implement a collaborative programme to fill key knowledge gaps (e.g. map of ecosystems vulnerable to climate change).
• Revise our approach to ecosystem management, and priority setting, to consider the effects of climate change on freshwater conservation.