Before–after control–impact (BACI) assessment of the effects of a deep-water no-take fishery reserve to recover Norway lobster (Nephrops norvegicus) overfished populations and coexisting megafauna

Abstract

One of the main drivers of marine ecosystem change is fishing activity, bottom trawling being the most intensive fishing practice affecting benthic ecosystems worldwide. In the western Mediterranean Sea, Norway lobster stocks present signs of overexploitation due to trawling pressure, as their biomass and abundance have decreased abruptly during the last few years. No-take fishery reserves, a type of marine protected area where fishing is prohibited, could be efficient management measures to recover Norway lobster overexploited populations and coexisting demersal megafauna. Adopting a BACI (before–after control–impact) approach, we performed experimental fishing surveys before and after 4 years of the implementation of a deep-sea no-take reserve in the northwestern Mediterranean. After 4 years of closure, the Norway lobster population increased in abundance, biomass, body size, and trophic level in the no-take reserve. Our approach also revealed an increase in Norway lobster biomass beyond its boundaries, suggesting a spillover effect. Other demersal fish species also increased in biomass and abundance in the no-take reserve. Based on the results of this study, we suggest that no-take reserves might be an effective measure for recovering the Norway lobster stock and some species present in the same habitat.

Limited spatiotemporal larval mixing of the Norway lobster from no‐take marine protected areas in the northwestern Mediterranean Sea

“…MPAs have been proven impactful for the recovery and protection of the lobster populations in European waters (Knutsen et al, 2022;Vigo, Navarro, et al, 2023). As a species of commercial importance and under fishing quotas management in European water, the sustainability of the fisheries would benefit from no-take MPA implementations within other regions of Europe (Letschert et al, 2021).…”

“…In fact, highlighting the sites of high abundance of mixed larvae would suggest hotspot sites for MPA implementation. For that, future modelling studies should include the key factors that influenced the abundance: the fecundity, greatly improved with bigger specimens found within MPAs (Nichols et al, 1987;Vigo, Navarro, et al, 2023), and the larval mortality (Nichols et al, 1987). Overall, the presence of mixed larvae is a token of population persistence and resilience to disturbance (Cecino & Treml, 2021).…”

“…Along the Catalan coast of the northwestern Mediterranean in the Balearic Sea, four no-take deep-sea MPAs were implemented with a focus on the recovery and protection of Norway lobster Nephrops norvegicus (Linnaeus, 1758) fishing stock by permanently preventing any fishing activities. The four MPAs are distributed over the continental slope, between 300 and 400 m depth since early 2022 (Aguzzi et al, 2003;BOE, 2022;Vigo et al, 2024Vigo et al, , 2023. Two areas are located in a region with the presence of indented large submarine canyons impacting the demersal community (Company et al, 2012).…”

“…The others areas are located near the widening continental slope before the Ebro delta's shelf, a region frequently exposed to gyres (Font et al, 1995). Progressive recovery of population density and biomass has already been observed (Vigo et al, 2021;Vigo, Navarro, et al, 2023), but knowledge of connectivity is still lacking.…”

Size at Sexual Maturity of Deep-Sea Unexploited Caribbean Metanephrops binghami (Boone, 1927) and Overexploited Mediterranean Nephrops norvegicus (Linnaeus, 1758) Using Morphometric and Gonadal Staging Approaches

“…Morphologically, both species are relatively small compared to other Nephropids such as Homarus spp. The mean cephalothorax length (CL) of M. binghami is approximately 34 mm [5], while that of N. norvegicus is around 30 mm [6]. Both lobsters show a very similar ecological niche and inhabit areas of soft sediments within self-made burrows, around which strong territorial behavior is associated [5,7].…”