ChemTrail – Sensory enrichment to augment fish community development on degraded coral reefs

• Applicant: Dr. Gerrit Nanninga, Ph.D.
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Oceanography
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544382465

Coral reefs worldwide are being degraded at unprecedented rates through anthropogenic impacts. To save these important ecosystems, decision makers are increasingly turning towards active coral restoration (e.g., coral gardening). However, current restoration approaches are costly and limited in scale. Here we propose the use of chemosensory enrichment to enhance the development of coral reef fish communities at degraded reefs. Fishes perform a range of functional roles on the reef that are vital for habitat recovery and resilience. Local abundance of fishes is governed by recruitment of pelagic larvae that use olfactory cues emitted by the reef community to navigate towards settlement habitat. However, degraded reefs smell less favourable than healthy reefs, and therefore receive less recruitment. This negative feedback-loop hampers reef recovery. By mimicking the chemosensory signal of a healthy reef habitat, we can attract fish (and potentially coral) larvae to degraded reefs or restoration sites, thereby enhancing natural reef recovery. Specifically, we aim to: (1) assess the chemosensory signature of natural reef communities; (2) experimentally test which (mixes of) compounds identified in step one are most attractive to fish larvae; (3) develop a method to achieve sustained release of the relevant compounds in situ; (4) test and refine chemosensory enrichment to enhance fish recruitment in field experiments. In the long run, we aim to establish this approach as a cheap and effective new tool to support coral reef restoration worldwide.

• DFG Programme: Research Grants
• International Connection: Italy
• Co-Investigators: Professorin Dr. Olivia Monika Merkel; Professor Dr. Gert Wörheide
• Cooperation Partner: Professor Dr. Davide Seveso