Patterns of predation on native and invasive alien fish in Mediterranean protected and unprotected areas

• Published in: Marine environmental research Vol. 150; p. 104792
• Main Authors: Giakoumi, Sylvaine, Pey, Alexis, Thiriet, Pierre, Francour, Patrice, Guidetti, Paolo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2019; Elsevier BV; Elsevier science
• Subjects: Adaptive control; Animals; Conservation of Natural Resources; Control; Ecosystem; Fish; Fish behavior; Fish populations; Fishes; Fishing; Interspecific relationships; Introduced Species; Invasive fish; Invasive species; Life Sciences; Marine fishes; Marine parks; Marine protected areas; Mediterranean; No-take marine reserves; Overexploitation; Population Dynamics; Predation; Predators; Predatory Behavior; Prey; Protected areas; Protective coatings; Restoration; Sardina pilchardus; Tethering; Tethering experiment; Threatened species; Time Factors; Mediterranean; Tethering experiment; Predators; Marine protected areas; Invasive fish; No-take marine reserves; predators; no-take marine reserves; marine protected areas; invasive fish; tethering experiment
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2019.104792

Worldwide, the loss of predatory fish due to overexploitation has altered the structure of native communities and caused ecosystem shifts. Ecosystems deprived of high-level predators may be more vulnerable to invasive alien species as the latter are subject to reduced predation control. Marine protected areas (MPAs), and particularly no-take reserves where fishing is banned, can be effective tools for the restoration of predatory relationships within their boundaries. We explored whether the restoration of high-level predatory fish populations within Mediterranean MPAs can exert top-down control on alien fish. Fish tethering experiments, including native (Sardina pilchardus, Boops boops) and alien (Siganus rivulatus) dead specimens, were conducted to quantify predation within the no-take zones of three MPAs and in unprotected areas, and to assess potential differences in predation rates and prey type preferences. A subsample of experimental units was filmed to document predation events and related fish behaviour. More high-level predators interacted with the tethered fish inside the MPAs than in unprotected areas. Yet we did not find significant differences in the consumption of alien or native fishes between MPAs and unprotected areas. The native S. pilchardus was consumed more in comparison to the other tethered fishes, regardless of protection status and location. Interestingly, the alien S. rivulatus was consumed by native predators in the western Mediterranean locations where this alien fish is not established. Despite its limitations, our study provides evidence on the ability of some native predators to feed on and potentially control certain alien species without requiring ‘adaptive’ time-lag periods. •More high-level predators interacted with the tethered fish inside MPAs.•Native and alien fish consumption did not differ between MPAs and unprotected areas.•The alien rabbitfish was consumed by native predators.•Some native predators can feed on and potentially control certain alien species.