An estimate of the total catch in the Spanish Mediterranean Sea and Gulf of Cadiz regions (1950-2010)

The underestimation of fisheries removals is a global issue that spans countries from different continents and different socio-economic situations. Underestimation of catches is especially important in countries where fishing fleets are highly diversified, the enforcement of fishing management is low, data availability is poor, and there is high demand for fish products in local markets. This is the case for Mediterranean countries. Here, we estimated total removals of marine resources by Spain from 1950 to 2010 for the Spanish Mediterranean Sea and Gulf of Cadiz regions following a catch-reconstruction approach. We first collected information from scientific publications, grey literature and secondary sources of information (i.e., personal communications, interviews with managers and fishers) to complement officially reported catch data, which are publicly available from FAO databases and from national and regional statistics. A literature search and fishers interviews provided assessments of missing catch sectors that are time-point estimates. These were used as anchor points of reliable data upon which we then estimated total catch using interpolation to fill in the periods for which quantitative data were missing. Overall, the reconstructed catch was 70% larger than the nationally reported data for the same time period. Results illustrated that unreported removals and discards represent important portions of total removals in the study area. Unreported landings and discards accounted for, on average, 42% of total removals between 1950s and 2010, and were composed of black market sales, subsistence fishing, artisanal fishing, recreational fishing and illegal catch, in addition to discarding. By the late 2000s, recreational fishing was the most important sector for unreported landings (~36%), followed by black market sales (~32%), subsistence fishing (~17%), unreported artisanal fishing (~12%) and illegal catch (~2%). While FAO landings data showed an increase of landings from 1950 to the mid-1960s and a decline from the mid-1970s to 2010, a different trend emerged after accounting for all fisheries removals. Reconstructed total catches revealed an earlier maximum of total removals in the late 1950s, a plateau being reached during the 1960s and 1970s, and a decline from the early 1980s to 2010. Our estimates of total fisheries catches represent an improvement over official catch data, and suggest a different historical trend of marine resource use

Knowing the past to improve the future: Estimating historical fishing catches to improve fisheries management in the Western Mediterranean Sea

We developed for the first time the commercial fishing catches reconstruction of the Balearic Islands (Western Mediterranean) between 1950 and 2010, by adding non-reported components, including unreported landings and discards, to the official reported landing data. To back‑estimate historical unreported landings and discards, collaboration and information acquired from fishermen were essential, as gathered through interviews and observer programs of the Spanish Oceanographic Institute (IEO) on board commercial bottom trawling fleet. We estimated a total catch of 511,500 t over the period 1950‑2010, of which official landings represented 49% (around 248,000 t), followed by unreported catches (32%) and discards (20%). A decrease in unreported catches was observed during the period 1950-2010 (from 58% to 38%) due to a reduction of unreported landings, but substantial efforts are still required to improve the recordings of actual fishing catches. This work contributes to the global assessment of fisheries removals led by the Sea Around Us and aims to provide the basis for an improved management of the Balearic Islands and Mediterranean Sea fisheries

Closer to reality : reconstructing total removals in mixed fisheries from Southern Europe

Underestimation of catches is especially important in countries where fishing fleets are highly diversified, the enforcement of fishery management is low, data availability is poor, and there is high demand for fish products in local markets. This is the case for southern European and Mediterranean regions. Adapting a catch-reconstruction approach, we estimated the total removals of marine resources by Spain for the Spanish Mediterranean Sea and Gulf of Cadiz regions from 1950 to 2010. We collected available information from scientific publications, the grey literature and secondary sources of information to complement officially reported catch data. We assessed missing catch sectors as time-point estimates, used as anchor points of reliable data upon which we then estimated total catch using interpolation to fill in the periods for which quantitative data were missing. Unreported removals and discards represented important portions of total removals in the study area. They accounted for, on average, 43% of total removals between 1950s and 2010, and were composed of black market sales, subsistence fishing, artisanal fishing, recreational fishing and illegal catch, in addition to discarding. By the late 2000s, recreational fishing was the most important sector for unreported landings (similar to 36%), followed by black market sales (similar to 32%), subsistence fishing (similar to 17%), unreported artisanal fishing (similar to 12%) and illegal catch (similar to 2%). The overall catch trend differed from the official trend highlighting that the depletion of marine resources in the region started earlier than previously observed. The catch composition changed with time, with a higher diversification of species in fish markets with time. These results indicate an earlier trend towards expansion of fisheries and depletion of marine resources

Estimates of total fisheries removal for the Balearic Islands (1950-2010)

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