Image analysis of settlement plates for monitoring marine benthic communities of the Kerguelen Islands, a preliminary study

Aurélien, Louis Calas

Kerguelen Islands are likely to be strongly affected by climate change due to particular oceanographic settings. Local benthic communities of the coastal areas are expected to be significantly impacted as many species have relatively low resilience ability. The program PROTEKER aims at monitoring benthic communities of the Kerguelen Islands through a multi-disciplinary approach. The objective of this preliminary study is to determine to which extent, photo quadrat analysis of settlement plates allow a satisfying assessment of colonization dynamics of benthic communities in the Morbihan bay (Kerguelen Islands). Ecological successions at the monitored sites have been analyzed through univariate and multivariate diversity analyses and a typical and simplified succession model was proposed. We could assess a simplified local succession model and polychaetes, ascidians and bryozoan seem to play a key role in the early stages of the colonization dynamics in the Morbihan Bay. Further researches coupled with photo quadrat analysis are needed such as molecular analyses and deeper studies on abiotic factors potentially influencing colonization dynamics, to result in a more efficient benthic community survey assessment. Pristine benthic ecosystems of the Kerguelen Islands are considered as climate change sentinels, their colonization dynamics throughout a long-term monitoring program should therefore provide the obtention of crucial scientific criteria for management and conservation purposes.