Fondo E.N., Chaloupka M., Heymans J.J., Skilleter G.A.
School of Biological Sciences, University of Queensland, B0risbane, QLD, Australia; Kenya Marine and Fisheries Research Institute, Mombasa, Kenya; Scottish Association for Marine Science, Oban, United Kingdom
Fondo, E.N., School of Biological Sciences, University of Queensland, B0risbane, QLD, Australia, Kenya Marine and Fisheries Research Institute, Mombasa, Kenya; Chaloupka, M., School of Biological Sciences, University of Queensland, B0risbane, QLD, Australia; Heymans, J.J., Scottish Association for Marine Science, Oban, United Kingdom; Skilleter, G.A., School of Biological Sciences, University of Queensland, B0risbane, QLD, Australia
Food subsidies have the potential to modify ecosystems and affect the provision of goods and services. Predictable Anthropogenic Food Subsidies (PAFS) modify ecosystems by altering ecological processes and food webs. The global concern over the effects of PAFS in ecosystems has led to development of environmental policies aimed at curbing the production or ultimately banning of PAFS. However, the effects of reducing or banning PAFS are not known. We explore the consequences of PAFS removal in a marine ecosystem under two scenarios: 1) gradual reduction, or 2) an abrupt ban, using a mass balance model to test these hypotheses The reduction or loss of PAFS will: i) modify trophic levels and food webs through effects on foraging by opportunistic species, ii) increase the resilience of opportunistic species to food shortages, and iii) modify predatorprey interactions through shifts in prey consumption. We found that PAFS lower the trophic levels of opportunistic scavengers and increase their food pathways. Scavengers are able to switch prey when PAFS are reduced gradually but they decline when PAFS are abruptly banned. PAFS reduction to a certain minimal level causes a drop in the ecosystems stability. We recommend gradual reduction of PAFS to a minimal level that would maintain the ecosystems stability and allow species exploiting PAFS to habituate to the food subsidy reduction. © 2015 Fondo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.