Artisanal Harvest of Shellfish in the Northeastern Atlantic: The Example of Limpet and Topshell Fisheries in the Archipelago of Madeira

Abstract

The harvesting of littoral benthic shellfish in the archipelago of Madeira dates back to the fifteenth century when the Portuguese discovered and colonized the archipelago. The consumption of littoral shellfish is part of the gastronomic cultural heritage of this region, appreciated by the local population and tourists, and has a high social and economic importance. Therefore, harvesting pressure on these resources is one of the greatest concerns, and as such, a sustainable exploitation based on proper regulation, considering the biological and ecological specificities of these species in their particular habitat, is crucial to promote the preservation of species and habitats at medium and long terms. This study presents the current harvesting management regime for gastropods in the archipelago of Madeira and characterizes the artisanal harvest through a period of 27 years providing new insights for future research in these topics. This artisanal harvesting operates mostly by small vessels (<10 m), with low tonnage and capacity, in nearby areas preferentially in the North coast of Madeira and around Desertas Islands. During the studied period, management actions resulted in the reduction of 50% of the vessels operating in the harvesting of limpets and in slight recovery of the stocks of limpets. The economic impact of limpets gradually increased over the years, representing in 2017 96% of the economic value landed for molluscs and 2% of the total landings in this region. The present characterization provides a comprehensive outlook of the evolution of the marine gastropod harvest in the archipelago of Madeira and allows future comparisons with other regions where gastropods are commercially exploited.

Fecundity, an overlooked life-history trait for coastal management of commercial molluscs?

“…For this study, 158 specimens of Patella ordinaria (49.34 ± 6.86 mm total shell length, SL) and 70 P. aspera (45.65 ± 6.83 mm SL), two species that coexist in the lower intertidal to the subtidal from 0 to 6 m deep (Corte-Real et al, 1996;Sousa et al, 2017;Sousa et al, 2020b), were randomly collected between October 2021 and June 2022 in four coastal settlements in the Madeira archipelago, two on the North coast (Porto Moniz and São Vicente) and two on the South coast (Funchal and Porto Santo) (Table 1; Figure 1). Due to the fact that these species are winter breeders (Henriques et al, 2012;Sousa et al, 2017), there were some limitations in the monthly (e.g., December) and site (as the North coast of Porto Santo Island) sampling of the reproductive stock, mainly due to the sea adverse conditions, particularly on the north coast of the archipelago (Castejoń et al, 2022;Vasconcelos et al, 2023).…”

“…In harvested molluscs, such as intertidal and shallow subtidal limpets, several reproductive parameters have been used as a proxy to establish the exploitation status of their populations (Riera et al, 2016;Sousa et al, 2019a). The impact of harvesting on littoral limpets from Madeira has been extensively studied in recent years (e.g., Sousa et al, 2019a;Sousa et al, 2019b;Sousa et al, 2020a;Sousa et al, 2020b). Reproductive parameters, including size and age at first maturity, have traditionally been used to assess the level of exploitation of P. ordinaria and P. aspera in this region.…”

Shellfish consumption preferences in an oceanic archipelago

“…The accessibility to rocky shores and coastal settlement prompted the exploitation of these resources along the coast over the years (Henriques et al, 2017). This activity is of high importance for the region's small-scale fisheries, directly benefitting coastal communities and indirectly providing for the whole community (Sousa et al, 2020). The economic impact of harvesting limpets has gradually increased over the years, marked by annual catches of up to 88 tonnes and yielding a first value of ca.…”

Shell shape, morphometrics and relative growth of four sympatric limpet species from the Algarve coast (southern Portugal)

“…For instance, in the Iberian Peninsula, true limpets (patellogastropods) have been traditional seafood since prehistoric times (Middle Palaeolithic) (Bicho & Haws, 2008;Fa et al, 2016;Verdún-Castelló & Casabó i Bernad, 2020). Nowadays, various limpet species are collected for seafood by both professional fishermen and recreational harvesters, under exploitation levels that depend on the geographic location, ease of access to intertidal areas and species abundance, and that reflect local/regional heritage, cultural legacy and gastronomic tradition (Sousa et al, 2020a). In Portugal, limpets are professionally and/or recreationally harvested in some scattered locations sporadically exploited along the mainland (Vasconcelos et al, 2019), whereas these activities are ancestral, popular, widespread and intense in the archipelagos of Madeira (Henriques et al, 2012;Sousa et al, 2019aSousa et al, , 2019bSousa et al, , 2020aSousa et al, , 2020bSousa et al, , 2020cCañizares et al, 2021) and Azores (Santos et al, 1995;Côrte-Real et al, 1996;Martins et al, 2011Martins et al, , 2017Diogo et al, 2016).…”