Ecology: Human-made structures could help threatened corals flourish

Anthropogenic structures in the ocean - such as oil and gas rigs, shipwrecks or renewable energy devices - could connect populations of species under threat from human pressure and climate change, thereby increasing their chances of survival, according to a modelling study in Scientific Reports.

The increasing spread of human-made structures in the world’s oceans could negatively impact marine ecosystems in many ways, including by facilitating the spread of invasive species. However, whether these structures also have the potential to help conservation by providing threatened species with new habitats and feeding sites and expanding their geographical range is less clear.

Lea-Anne Henry and colleagues used a computer algorithm to model how a protected species of coral - Lophelia pertusa - might disperse in the North Sea if its larvae were released into the ocean around installations such as oil and gas rigs. The model predicted that the larvae would travel between coral populations that have colonized individual structures and even reach natural populations located at great distances. There the larvae could supplement the existing population or recolonize damaged reefs.

The findings suggest that anthropogenic structures in the North Sea form a network of densely connected clusters of coral ecosystems that spans hundreds of kilometers and crosses international borders. These structures could act as stepping stones, holding coral networks together and increasing their resilience at times of low ocean circulation, which could become increasingly important as ocean currents weaken due to climate change in coming decades.