Marine Protected Areas (MPAs) have spread across the Mediterranean to protect its rich biodiversity and manage human activities for a more sustainable coastal development. Within MPAs, traditional artisanal fisheries are competing for space and resources with increasing recreational fishing, likely leading to interacting ecological effects.
This study developed an Ecopath and EcoTroph trophic model for the case study (Portofino MPA, Italy) to 1) identify keystone species and assess fishing impact on them; 2) analyse the interacting impact of artisanal and recreational fishing on ecosystem biomass and trophic structure; and 3) assess the impact of recreational fishing on artisanal fishing catches.
The obtained results for the Portofino MPA example show that the modelling approach allowed identifying species that play important keystone roles in the food web, while highlighting that some of these species are also subject to strong fishing impact. The authors propose these species groups as sentinels of the condition of the food web and to be targeted as a priority in MPA monitoring. The authors state that in the studied example recreational fishing had the widest impact on the food web, strongly impacting keystone species groups (high trophic level predators, HTLP). The model shows that forbidding recreational fishing in this case study allowed a 24% increase in HTLP biomass and benefited artisanal fishing by increased availability of HTLP catches. It is highlighted that in Portofino artisanal fishing alone could instead be maintained with a moderate impact on the food web.
It is concluded that it is essential that coastal Mediterranean MPAs develop long-term monitoring programs on key species and on extractive artisanal and recreational activities. Only by increasing ecological and fisheries data, it will be possible to develop robust food web models and enhance their potential as management tools.
Prato G, Barrier C, Francour P, Cappanera V, Markantonatou V, Guidetti P, Mangialajo L, Cattaneo-Vietti R, Gascuel D (2016) Assessing interacting impacts of artisanal and recreational fisheries in a small Marine Protected Area (Portofino, NW Mediterranean Sea). Ecosphere 7:e01601-e01n/a