The “discard problem” in Mediterranean fisheries, in the face of the European Union landing obligation: the case of bottom trawl fishery and implications for management

Abstract

Since the first introduction of the landing obligation (a.k.a. Discard ban) in 2015, the EU Mediterranean fisheries are facing some unforeseen challenges. The demersal bottom trawl fisheries, being the most significant contributors to the so-called 'discard problem', are confronted with the greatest challenges. Data from the Italian and the Greek fleet, spanning over two decades (1995–2015), were analysed with the intention of revealing the diversity and heterogeneity of the discard problem, especially for regulated species. Species composition of discards, as well as discarding rates, were shown to be irregular, fluctuating among areas, depth strata, seasons and years. Although fish dominated the discarded gross catch in weight, benthic invertebrates (other than commercial cephalopods and crustaceans) were the taxa discarded almost exclusively. The established minimum conservation reference size was largely ignored by fishers. From a management point of view, the present investigation suggests that the recently established Discard Management Plans lack scientific evidence (given the high intrinsic variability of the parameters and confusion regarding the rules) and provide exemptions from the landing obligation that will in practice allow the average Mediterranean bottom trawl vessel to continue business as usual. Moreover, detecting if these rules are actually respected is an almost impossible task for the Mediterranean control and enforcement authorities. Incentivizing the adoption of fishing technologies and practices that reduce pre-harvest mortality and post-harvest discards, while avoiding damage to sensitive marine species and habitats, seems the only way to move forward, rather than dealing with the problem after it has occurred.

Identifying Persistent Hot Spot Areas of Undersized Fish and Crustaceans in Southern European Waters: Implication for Fishery Management Under the Discard Ban Regulation

“…Under the current trawl net selectivity patterns used in southern European fisheries, undersized individuals of some important commercial species, such as European hake (Merluccius merluccius) and Atlantic horse mackerel (Trachurus trachurus), predominate in the discard (Milisenda et al, 2017b;Damalas et al, 2018;Despoti et al, 2020), especially during the recruitment period (FAO, 2016). The combined provisions of art.…”

Marine spatial closures as a supplementary tool to reduce discards in bottom trawl fisheries: Examples from southern European waters

“…In the Mediterranean bottom trawl fishery, either due to national legislation or local market demand, species subjected to MCRS are often discarded independent of their size (Machias et al, 2004;Tsagarakis et al, 2017). The most valuable species (e.g., European hake, Merluccius merluccius; red mullet, Mullus barbatus) are discarded mainly if they are smaller than the MCRS (Damalas et al, 2018). Whereas, species with low commercial value (e.g., horse mackerels, Trachurus spp.)…”

Monitoring the Environmental, Social and Economic Dimensions of the Landing Obligation Policy

“…Some changes are expected to be negative in the short term, such as the anticipated reduction in commercial landings, which is not expected to be compensated by the sale of UWC for industrial purposes (Christou et al, 2019), but some mid to long term ecosystem benefits could be expected if the implementation of the LO leads to more selective fishing practices (Guillen et al, 2018). Where discards are in high densities (Catchpole et al, 2006) or discarding patterns exhibit high spatio-temporal heterogeneity (Maina et al, 2018), the LO regulation effects cannot be accurately estimated (Damalas et al, 2018). Therefore, while the LO is an important step for fisheries conservation in European waters, to monitor the implementation of the LO is expected to be challenging due to the diversity of issues that must be taken into account for proper monitoring, the limited control and surveillance capabilities of fisheries management agencies and the reluctance of the industry to comply with the LO (Fauconnet et al, 2019;Villasante et al, 2019).…”