Rebuilding Mediterranean fisheries: a new paradigm for ecological sustainability

Abstract

In Mediterranean European countries, 85% of the assessed stocks are currently overfished compared to a maximum sustainable yield reference value (MSY) while populations of many commercial species are characterized by truncated size‐ and age‐structures. Rebuilding the size‐ and age‐structure of exploited populations is a management objective that combines single species targets such as MSY with specific goals of the ecosystem approach to fisheries management (EAF), preserving community size‐structure and the ecological role of different species. Here, we show that under the current fishing regime, stock productivity and fleet profitability are generally impaired by a combination of high fishing mortality and inadequate selectivity patterns. For most of the stocks analysed, a simple reduction in the current fishing mortality (Fcur) towards an MSY reference value (FMSY), without any change in the fishing selectivity, will allow neither stock biomass nor fisheries yield and revenue to be maximized. On the contrary, management targets can be achieved only through a radical change in fisheries selectivity. Shifting the size of first capture towards the size at which fish cohorts achieve their maximum biomass, the so‐called optimal length, would produce on average between two and three times higher economic yields and much higher biomass at sea for the exploited stocks. Moreover, it would contribute to restore marine ecosystem structure and resilience to enhance ecosystem services such as reservoirs of biodiversity and functioning food webs.

Mediterranean Sea: A Failure of the European Fisheries Management System

“…In fact, notwithstanding that the scientific advice (i.e., TAC advice) has been provided by STECF since 2008, it has rarely been followed or implemented, with realized catches being much larger than the scientific advice (178%; this paper). Even the realized reductions in (Colloca et al, 2013). Moreover, another key difference between North East Atlantic and Mediterranean is the low level of compliance and enforcement in the Mediterranean compared to the North East Atlantic (Vasilakopoulos et al, 2014).…”

“…Here we showed that up to 2014, the average exploitation rate for the main demersal and small pelagic stocks of the Mediterranean Sea is around three times the estimated level of F MSY , with a general similar pattern across species and area, which confirms analyses recently conducted (STECF, 2015c). Moreover, as we have mostly only a snapshot of the last decade for Mediterranean stocks (i.e., generally from the beginning of the 2000s to today), and, as F has been estimated to be very high since the beginning of the time series (Colloca et al, 2013;Vasilakopoulos et al, 2014), the decline in stock biomass might have started much before and being more pronounced than described by current assessment models. This has been demonstrated by those assessments with a longer time series, as small pelagics in the Adriatic Sea (time series: 1975GFCM, 2015b) and common sole in the Northern Adriatic Sea (time series: 1970GFCM, 2015a;STECF, 2016).…”

“…In recent years European fisheries managers have witnessed the success of the European CFP in the north (i.e., North East Atlantic, Cardinale et al, 2012;Fernandes and Cook, 2013) and at the same time, its failure in the south (i.e., Mediterranean Sea, Colloca et al, 2013;Vasilakopoulos et al, 2014). Thus, despite the fact that both areas are managed under the same broad fishery policy (i.e., European CFP), a large discrepancy in management performance still occur between the North East Atlantic and the Mediterranean Sea.…”

“…After 8 years from the adoption of WSSD and the enforcement of MSFD with the definition of GES and targets in each Member State (MS), and the concurrent application of the CFP, Europe has made great progress toward MSY for stocks inhabiting the North East Atlantic (e.g., Cardinale, 2011;Cardinale et al, 2012;Fernandes and Cook, 2013) but it is still far from achieving its objectives for the Mediterranean Sea marine resources (e.g., Colloca et al, 2013;Vasilakopoulos et al, 2014). Notwithstanding the enforcement of the EU Data Collection Regulation (EU, 2000) in the early 2000s by all EU MSs, and the rapid increase in the number of assessed stocks by the General Fisheries Commission for the Mediterranean (GFCM) and the European Scientific, Technical and Economic Committee for Fisheries (STECF), Mediterranean Sea marine resources are still exploited above the levels that deliver the maximum sustainable yield and no signs of recovery are evident (Vasilakopoulos et al, 2014).…”

Harvest Strategies for an Ecosystem Approach to Fisheries Management in Western Mediterranean Demersal Fisheries

“…This would not imply stopping the fishing activity, but a sort of diversification of the fishing exploitation to focus on healthier stocks until the recovery of the most impacted ones. (B) Improved gear selectivity According to recent studies (Colloca et al, 2013;Vasilakopoulos et al, 2014), improvements in the fisheries selectivity would be more effective than reducing the fishing effort in order to manage Mediterranean BTFs. Although the recent change in mesh geometry (Council Regulation No.…”