Ms Catalina Musrri1,2,3, Professor Alistair Poore2, Professor Fadia Tala3,6,7, Mr Oscar Pino-Olivares3, Mr Nicolás Riquelme-Pérez3, Professor Martin Thiel3,4,5
1School of Life and Environmental Sciences, The University Of Sydney, Camperdown, Australia, 2School of Biological, Earth and Environmental Sciences,The University of New South Wales , Kensington, Australia, 3Departamento de Biología Marina, Universidad Católica del Norte, Coquimbo, Chile, 4Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile, 5Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile, 6Centro de Investigación y Desarrollo Tecnológico en Algas y Otros Recursos Biológicos (CIDTA), Universidad Católica del Norte, Coquimbo, Chile, 7Instituto Milenio en Socio-Ecología Costera (SECOS), Coquimbo, Chile
Both physical and biotic factors affect large-scale patterns in the strength of trophic interactions and contribute to latitudinal gradients in diversity and community structure. While temperature frequently predicts the strength of consumption, local environmental conditions may also affect consumption rates and result in complex relationships between temperature and consumption. This study assessed the relative effect of environmental variables and local consumer communities on predation and herbivory along more than 20 degrees of latitude (2,500 km) of the Chilean coast. Consumption assays with animal prey (porcellanid crabs and squidpops) and the kelp Lessonia spp. were used to estimate predation (2 and 24 h) and herbivory (24 h) at sites where a range of environmental variables was measured (including water quality measurements, habitat features and consumer community characteristics). For each prey item, the explanatory variables that best explained variation in consumption were determined using a model selection approach. Temperature was the variable that best predicted variation in predation after 24 h and explained the latitudinal patterns observed. Predation on squidpops and crabs after 2 hours, however, was also included predicted by local habitat variables that modify foraging behaviour. Rates of herbivory were relatively low, likely due to habitat characteristics (high understorey algae cover) and the palatability of the selected bait. While drivers for large-scale patterns in herbivory remain unclear, we confirm temperature as one of the main drivers for variation in predation across large spatial scales. With future climate change, these patterns of consumption will be altered, with additional effects on local scales due to direct impacts on consumer communities (such as overfishing).
Biography:
Catalina is a Marine Biologist from Chile. She has worked on coastal ecology and is now doing a PhD on crayweed future-proofing restoration at the University of Sydney. This work is part of a chilean FONDECYT project in which she was working as a research assistant before travelling to Australia.
