Oyster reefs are part of a sustainable green transition in Europe
The ongoing climate and biodiversity crises put substantial pressure on coastal ecosystems, and the researchers behind the study emphasize that nature restoration is key for sustainable development under future changing climates.
“Biodiversity is essential for supporting climate resilient natural ecosystems, and genetic diversity within species, the intra-specific genetic diversity, serves important buffering functions for the species through potential adaptation to local environmental conditions,” says Homère J. Alves Monteiro, the lead author of the scientific paper and former PhD student at DTU Aqua.
So, preserving and restoring the ecosystem services provided by functional oyster reefs is an important component of sustainable green transition in Europe.
An unprecedented level of detail
In the new study, the researchers have used genome sequencing technology to map the biodiversity in the native European flat oyster populations.
The study identified genetic diversity with a high level of spatial resolution, and by doing so the researchers have obtained an unprecedented level of detail in the genetic analyses.
The results have direct implications for restoration initiatives which need to source material for the restoration of existing or the establishment of new oyster reefs.
They can be used by restoration practitioners to identify suitable regions for sourcing material for new restoration projects while taking the natural biodiversity of the species into account. For example, several very distinct local populations were identified over short geographical distances in Scandinavia.
Nature restoration in the big picture including human activities
With an increasing focus on coupled biodiversity/climate nature restoration using habitat forming species, such as eelgrass, seaweed and shellfish, nature restoration will - according to the new study - benefit from detailed knowledge about the distribution of natural biodiversity within species to support climate resilient restoration.
“The European flat oyster has been subject to intense translocation and aquaculture production activities for centuries, which may have resulted in negative impacts on biodiversity in natural populations,” says Jakob Hemmer-Hansen.
The study found traces of past translocations of non-native oysters in the genomes of contemporary oyster populations.
These results show that human activities may impact natural genetic biodiversity. And the researchers behind the study strongly suggest that restoration projects should carefully consider procedures for limiting adverse negative effects on natural biodiversity.
Implementation of more efficient restoration procedures
Jakob Hemmer-Hansen explains that such procedures should include using sufficiently large numbers of local wild broodstock animals in hatcheries to limit loss of genetic diversity and avoiding crossing natural genetic barriers, for example by moving individuals between Sweden and Ireland, which belong to two different genetic populations in the species.
Also, an effort to monitor the broodstock animals taken into the hatchery is recommended to trace how many of them actually contribute to offspring used in restoration.
In this way, genetically informed restoration practices can help practitioners to avoid unintended negative consequences related to loss of diversity – and to save time and money through the implementation of more efficient restoration procedures.
In addition, they will be useful for monitoring biodiversity effects and the success of restoration projects in nature and could play an important role in the coming years with increasing nature restoration activity.
