Global patterns of cleaning interactions in the ocean of tomorrow

Chair: Victoria Cole

José Ricardo Paula (1)*, Joana Boavida-Portugal (1,2), Alexandra S. Grutter (3), Miguel B. Araújo (3,4), Rui Rosa (1)

1 MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal
2 CIBIO/InBio, Universidade de Évora, Largo dos Colegiais, 7000 Évora, Portugal
3 School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
4 Imperial College London, Silwood Park, Buckhurst Road, Ascot SL5 7PY, Berkshire, United Kingdom

Background
Cleaning mutualisms are key ecological components in marine ecosystems and drivers of biodiversity and abundance. Nonetheless, until now, there is no knowledge on future climate change-driven changes in the global patterns of these cleaning interactions. Cleaner organisms remove ectoparasites from their so-called “clients” (usually larger reef fish) in complex interactions between multiple species. Climate change scenarios have predicted a significant sea surface temperature rise and a decrease in sea water pH by 2100 and marine species are expected to respond to this warming and acidification by shifting their latitudinal range and depth.

Methods
We used species distribution modelling to explore the potential impact of climate change, namely temperature, salinity, pH, O2 and primary productivity, on the habitat suitability of cleaner fishes. Using an ensemble forecast approach, we applied 6 different statistical models to project the potential distribution of 91 species cleaner fishes by 2100, under the Intergovernmental Panel for Climate Change (IPCC) AR5 RCP2.6 and RCP8.5 scenarios, implemented with an ensemble of 19 different Earth System Models.

Findings
When analysed without cleaning dependency we found significant losses in species suitability area around 70% and species richness per area around 60%. Facultative cleaners loss 70% of suitable area and species richness per area around 60%. We also observed a significant loss in obligatory cleaners suitable area (63%) and species richness (21%).

Conclusions
This is the first study to model habitat suitability of a crucial interspecific interaction may be affected by future climate change scenarios. As cleaner fish absence has been described as a main driver of biodiversity and abundance loss, these findings unravel a higher problem to communities as predicted shifts of cleaners presence might affect essential ecosystem stability around the globe.