Work

Spatial control of the blue crab Callinectes sapidus explosive invasion to preserve clam farming in the Po Delta lagoons, Italy

Year: 2026

Type: article

Abstract: The rapid expansion of the invasive Atlantic blue crab Callinectes sapidus in the northern Adriatic Sea has caused severe ecological and economic disruptions, particularly within the Manila clam Ruditapes philippinarum aquaculture sector in the Po Delta lagoons. In response, fishers and aquaculture cooperatives have spontaneously implemented spatial control measures, including perimeter fencing, predator-exclusion netting, and selective trapping, to mitigate predation and safeguard clam farming areas. This study documents these interventions and analyzes trends in blue crab and clam landings between 2022 and 2024 to provide a more comprehensive picture of recent dynamics. Although clam production remains far below pre-invasion levels, spatial containment and daily trapping have facilitated a partial recovery of clam farming activities. These farmer-led initiatives represent a compelling example of spatial control, whereby invasive crab densities are suppressed below damage thresholds in key productive areas. In addition, efforts to commercialize the blue crab, particularly through new export markets, have helped offset economic losses. These findings provide valuable insights into adaptive, community-driven strategies for managing aquatic invaders. Considering the substantial national government investment to subsidize fishers and support blue crab disposal, the present study demonstrates how bottom-up initiatives can complement, and even anticipate, formal management frameworks.

Source: Aquaculture Environment Interactions

DOI: 10.3354/aei00522

Authors: Sara Bonanomi, Emanuele Rossetti, Ernesto Azzurro

Institutions: National Research Council, Institute for Marine Biological Resources and Biotechnology

Language: English

Topic: Marine Ecology and Invasive Species

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life below water, Life on land

Open Access status: gold

Estimated APC paid: $2,157