KEY POINTS:
New Zealand is falling behind international responses to the effects of climate change on coastal habitats, a scientist with the National Institute of Water and Atmospheric Research has warned.
Dr Simon Thrush, science leader coastal ecosystems, said there was now strong evidence that climate change was real and
in action on the coast, as measured by rising sea levels and increasingly intense storms.
"But in New Zealand we are really dragging the chain regards our responses on the coast and estuaries ... there is no focused programme of research like overseas."
Dr Thrush, who is speaking at a New Zealand Marine Sciences Society conference on Hamilton today, said estuaries would be one of the natural environments most profoundly affected by changes in climate.
He said there was an urgent need to develop ways of identifying ecological threats and responses to them.
Apart from in the Auckland region there was no commitment to long-term monitoring of coastal environments in New Zealand.
"There are no national initiatives for qualitative data to show the status of the coast and estuaries' ecological condition. That makes it difficult to measure changes which means they will be prone to debate."
Dr Thrush said it was now known there would be more storms and some areas of New Zealand would be drier or wetter.
"But we don't understand how various factors associated with climate change are going to impact with natural ecosystems in any particular region."
He said the increased frequency and intensity of storms and their disturbance on the coastline would have the most impact.
"They can rip animals out of the sea floor and move them on to beaches." In estuaries such storms and rain run-off from the land carrying nutrients and contaminants could restrict shellfish beds in their abundance or change their distribution.
"In Northland the floods and storms have led to muddy water in estuaries ... deposits which smother and can suffocate communities that live within them."
Dr Thrush said although it was known such things would happen it was not known by how much.
"We need to build models to make predictions on how ecological systems respond - we are lacking insight and understanding of how to make a reasonable assessment."
A concerted effort was needed to investigate how ecosystem processes would interact.
"We now need to shift gear and start considering the impact on our coasts and estuaries, particularly ecological life and why we should care about it."
Such ecosystems had many benefits and values, he said.
They included fisheries, aquaculture, shoreline protection provided by mangroves and seagrass meadows, and coastal invertebrates and microbes which filtered nutrients.
Dr Thrush said that better identifying what was likely to happen as a result of climate change would mean New Zealand's coastal planning could be improved.
"Where biodiversity might increase or decrease could affect decisions for new aquaculture and marine protected areas."
He said there was also potential for carbon sequestration in coastal waters where some marine animals made shells out of of calcium carbonate.
"They are effectively sucking carbon out of the sea water and turning it into rock, so are locking up carbon ... there could be potential for managing our carbon footprint providing a further argument to protect the marine environment."
Mitigation of the extra stresses of climate change could include reducing existing stresses due to sediment, stormwater and drain run-offs, nutrient inputs and fishing.
Planners to rescue of threatened reefs
The United States' coral reef taskforce this week announced in American Samoa the formation of a climate change working group and an action plan for the International Year of the Reef 2008.
The group is to develop practices to help minimise the impact of climate-induced stresses such as coral bleaching. Response plans were requested from areas with reefs to establish how much expertise was available.
Task Force co-chairman and spokesman Timothy Keeney said the aim was to recognise and address the vulnerability of island and coastal communities to changes in shoreline protection, fisheries and tourism because of climate change.
Discussions would continue next week as 30 experts from the US and Pacific countries shared strategies to predict where coral bleaching would occur, measure coral reef resilience, and assess the socioeconomic impacts of climate damage.