Disentangling interactions between seagrasses and small-scale fisheries using scientific and local traditional knowledge

Seagrass meadows deliver key ecosystem services in coastal environments worldwide by hosting early and adult life stages of many fish stocks, improving water quality, capturing carbon dioxide (mitigating the effects of global warming), protecting against adverse events and providing leisure opportunities. Shellfishing is often carried out in seagrass meadows, causing alterations derived from harvesting and/or culture processes. While the negative impacts of shellfisheries on seagrass meadows have been well established, the effects of the meadows on shellfishing have not yet been explored. In this study we analyzed the two-way interactions between shellfishing and Zostera spp. beds in north-west Spain and identified gaps in the governance system related to seagrass management. We conducted interviews (with 154 shellfishers) and held workshops (involving 61 shellfishers) to collect and validate information on the perceptions of shellfishers regarding the ecosystem services supplied by seagrass meadows, the interactions with shellfishing activity and how to improve the management of the activity in these key habitats. In general, shellfishers viewed the presence of seagrass negatively because greater physical effort is needed to extract the shellfish from among the plants. The shellfishers also recognized that the plants are easily damaged during their work. Temporal trends were also perceived negatively, as catches have been decreasing over time, while the area occupied by seagrass meadows has increased. However, experienced shellfishers recognized the benefits of the meadows for coastal ecosystems and fisheries (including those that they exploited), such as increased recruitment of the target species, to the extent that they were open to the allocation of areas to seagrass conservation. The compatibility of traditional shellfishing and management of seagrass meadows should be fostered by developing seagrass monitoring programs to develop adaptive fisheries management strategies and ensure conservation of these complex social-ecological systems.