Assessing the relationships between marine protected areas and invasive species

Informations

Funding country

France

Acronym

PAVIS

URL

-

Start date

3/1/2016

End date

-

Budget

365,335 EUR

Fundings

Abstract

Humans depend on marine ecosystems for valuable services, such as food provision and climate regulation, but at the same time ecosystems are threatened by multiple human stressors. Marine protected areas (MPAs), areas of the ocean designated to enhance conservation of marine resources, have emerged as a prominent management tool for threat mitigation and recovery of marine communities. Under the European Union Marine Strategy Framework Directive, member states are committed to developing strategies, including the establishment of new MPAs, to achieve ‘‘Good Environmental Status (GES)’’ by 2020. One descriptor determining GES dictates that alien species introduced by human activities should be at levels that do not adversely alter ecosystems. Through competition, predation, and habitat alteration, invasive aliens can radically change the biodiversity, functioning of native ecosystems, and consequently services provided to humans. At the same time, global warming of the oceans has triggered the range expansion of thermophilic native species (called range-expanding), some of which may severely impact the recipient ecosystem, in a similar way to invasive alien species. Currently, the role of MPAs in controlling invasive species populations is generally unknown. At the same time, assessments of impacts of invasive species on marine ecosystems within and outside MPAs are scanty. This project will aim to investigate the following hypotheses: 1) whether MPAs influence the expansion of alien/range-expanding species and mitigate their effects on native assemblages, 2) whether the ecological effects of such species could alter, reduce, or nullify ecosystem responses to protection in MPAs (e.g., ecosystem-wide recovery), and 3) whether local economic activities, such as artisanal fisheries and recreational diving, performed within MPAs and in adjacent areas, have been impacted by the presence of alien/range-expanding species (e.g., impoverishment or enhancement of fisheries catch). The study will focus on alien/range-expanding fish species that have been characterized as invasive species or are considered to impact ecosystems in a similar way (regardless of their origin) in the Mediterranean Sea. During the first year of the project, a broad-scale observation of species distribution patterns will be conducted. Non-destructive observation methods will be used in 8 MPAs and fished adjacent sites, following a replicated sampling design over multiple spatial scales. Data on fish and benthic assemblages will be collected along biogeographic gradients, and along a gradient of impact by alien/range-expanding species, contrasting MPAs and adjacent fished areas to assess potential effects of MPAs on alien/range-expanding species distribution and estimate impacts of such species on native communities. At the same time data on fishing catches will be collected through questionnaires administered to key actors (e.g., fishers). During the second year we will investigate the specific processes which explain the patterns observed by conducting a series of experiments in a subset of sites within the study region. Fish tethering experiments will be performed in 3 MPAs and adjacent sites to examine the effects of alien/range-expanding large predators on native fishes, as well as the effects of large native predators on alien/range-expanding fish species. During the third year of the project the results of the first two years will be synthesized with the aim to: 1) provide a better understanding of the relationships between invasive species and MPAs, and 2) inform spatial planning by forming site-specific guidelines on additional actions and strategies to be implemented to mitigate the impacts of invasive species. The output of the project will assist decision-makers in France and the EU to achieve the desired “Good Environmental Status” and develop marine spatial plans in a changing world.