Sofia Wikström

Sofia Wikström

AN UNCERTAIN INVESTMENT

Restoration – an uncertain investment

Restoration – an uncertain investment

Restoration of underwater habitats is becoming an increasingly common tool for improving the marine environment. But with existing knowledge, it is difficult to predict the chances of success.

Over the past 20 years, many researchers and managers have begun to show an interest in the possibility of restoring coastal ecosystems. Now there is growing interest in Sweden, too. The new Swedish program of measures for improving the  marine environment includes restoration as an important measure.

Many ongoing restoration projects in Sweden

And there are many actors who are interested in coastal restoration:

  • On the west coast the project (ZORRO), run by the University of Gothenburg, has developed methods to restore eelgrass meadows in Swedish waters.
  • Recently the County Administrative Board in Kalmar and Linnaeus University received SEK 3.2 million from the Swedish Agency for Marine and Water Management for a five-year project to restore eelgrass meadows along the coast of Kalmar and Blekinge counties.
  • In several areas along the Baltic Sea, coastal wetlands are being restored to provide spawning habitats for pike.
  • In the Stockholm archipelago, attempts are underway to restore an entire eutrophied bay.

Investments in restoration can never replace measures to avoid further destruction of habitats.

One important reason is of course that the coastal and underwater nature has been degraded or lost to a large extent and that this has consequences for marine life as well as for us humans. When nursery grounds for fish are degraded due to eutrophication or exploitation, there will be fewer fish for us to catch. And the loss of underwater vegetation such as seagrass can lead to increased coastal lead to emissions of carbon dioxide that would otherwise have been stored in the plants and their root systems. 

We are already working in many ways to reduce our negative impact on the sea. The question is whether this is enough? Can we get nature to recover faster and more completely if we help to restore it – either by restoring the physical environment or by helping species that have disappeared to re-establish?

Actually, we do not know.

Active restoration can lead to recovery of species and habitats. But just as often the restoration attempts fail to restore the habitat or the functions we wish to regain. This could be because the conditions are not right, or because nature is complex and unpredictable.

A recently-published study that summarises the results from attempts to restore seagrass meadows in different parts of the world comes to that conclusion. Even with good knowledge of an ecosystem, it is difficult to predict whether or not restoration will succeed. 

This does not mean that we should not try. In cases where there is much to be gained by restoring nature, it may be worth an investment – despite the risk of failure. But then the measures should be planned properly, followed up and evaluated scientifically, so that also failed attempts provide knowledge that increases the chances of success next time.

As with all other measures, it is also important to weigh the costs against the potential gains.

Investments in restoration of underwater ecosystems involve substantial costs and large uncertainty. They should thus never replace measures to avoid further destruction of habitats.

The best and most secure investment for the future is to protect the nature we already have, so that it never has to be restored.

Sofia Wikström

Sofia Wikström

Marine biologist
sofia.wikstrom@su.se