Assessing the risk of vulnerable species exposure to deepwater trawl fisheries: the case of orange roughyHoplostethus atlanticusto the west of Ireland and Britain

Abstract

-With slow growth rates, late maturity and a high maximum age of 100 years or more, orange roughy can be classified as a vulnerable deepwater fish species that can only sustain low rates of exploitation. Historical patterns of exploitation associated with this species suggest that it is currently not possible to manage its fisheries in the Northeast Atlantic sustainably, and the total allowable catch for orange roughy has been gradually reduced to zero for European fisheries since 2010. Orange roughy to the west of Ireland and Britain occurs on distinct bathymetric features (seamounts, hills and canyons) as well as on flat ground along the continental slope. Productivity-susceptibility analysis (PSA) was performed to evaluate the biological vulnerability of orange roughy in relation to other deepwater species and the risk that recent and current fisheries pose to its populations in the study area. Time-dependant PSA, based on the spatial overlap between orange roughy distribution and recent and current deepwater fisheries demonstrated a strong reduction in risk over time when fisheries stopped directed targeting practices and continued with mixed deepwater trawl fisheries. Some spatial overlap between the species and current fisheries remains, and while the method can show relative risk reduction, it cannot provide information on whether the risk is low enough to allow the recovery of depleted populations.

A Scientific Basis for Regulating Deep-Sea Fishing by Depth

“…This is clearly relevant to the EC's Marine Strategy Framework Directive, which requires fishing activity to be managed to meet conservation objectives, one of which is ''the maintenance of biodiversity.'' Even though a recent study in the northeast Atlantic suggested that there has been no detectable impact of deep-sea fishing on fish diversity [2], there have been significant declines in abundances of some commercially important species [6,8], leading to commercial extinction in some cases [7]. When interpreting the lack of effect of deep-sea fishing on biodiversity [2,8,22], caution should be taken, as it may take a longer time period (decades) for the effects of fishing to become fully apparent.…”

“…eries in the deep sea have a track record of being unsustainable [5,6]. In the northeast Atlantic, there has been a decline in the abundance of commercial fish species since deep-sea fishing commenced in the 1970s [7,8]. Current management is by effort restrictions and total allowable catch (TAC), but there remain problems with compliance [9] and high levels of bycatch of vulnerable species such as sharks [10].…”

Kerentanan Spesies Non Target (Retain) Dalam Perikanan Tuna Longline Berbasis Data Produktivitas Dan Susceptabilitas

“…Penentuan indek kerentanan menjadi langkah awal dalam menilai potensi risiko dan penurunan serta degradasi stok akibat penangkapan maupun perubahan iklim (Bell et al, 2011). Stok yang terus menurun menjadi potensial karena produktivitas rendah (Dransfeld et al, 2013) et al, 2011).…”

Harvest control rules for a sustainable orange roughy fishery

“…In the northeast Atlantic, the orange roughy catch quota was set to zero from 2010, and although fishing effort has declined the current status of the stocks is unknown (Dransfield et al, 2013). Off Chile, the orange roughy fishery has been closed since 2006 (Nitlitschek et al, 2010).…”