Amino Acid Fingerprinting to Distinguish Between Faecal Pellets of Fouling Fauna near an Offshore Wind Farm

Installation of OWFs have increased with the aim to combat climate change. They act as hard substrates which facilitates the growth of fouling fauna that are capable of enriching the sediments surrounding OWFs. Hence, biogeochemical changes occur and potentially creates a carbon sink, possibly demonstrating an unexpected positive effect of OWFs. Faecal pellets released by fouling fauna cannot be easily distinguished from other end-members of the OM pool (phytoplankton, zooplankton) and therefore this enrichment pathway has not been quantified yet. This study focused on optimising a CSIA-AA protocol for the novel use of amino acid fingerprinting of the FPs of dominant fouling fauna collected from an OWF in Belgium and investigate species-specific and season-stable patterns in AAs. Results suggested that the CSIA-AA protocol was successful in characterising the AAs in the FPs and were able to identify trophic AAs (increase in δ 15 N with trophic level) that were species- specific (alanine and isoleucine) and some that were stable across seasons (aspartic acid and leucine). Hence, future research can use CSIA-AA to accurately identify season-stable tracers that are specific to fouling fauna, characterise other end-members of the OM pool and estimate the contribution of each member to the carbon budget of an OWF.

Master thesis