Management of the Chinese mitten crab, Eriocheir sinensis (H. Milne Edwards, 1853) in the Guadalquivir Estuary (Southern Spain).

The Chinese mitten crab Eriocheir sinensis was first recorded in the Guadalquivir Estuary in 1987. Management actions by the Andalusian Regional Government were implemented in 2001 to contain and reduce the population of this invasive crab in the estuary and also to prevent its dispersal to neighbouring natural protected areas. Our results showed a heterogeneous distribution of the mitten crabs in the estuary, concentrated in the Sevilla port area. The catch-per-unit-effort (CPUE) in traps was significantly higher in October-April. Annual CPUE decreased from 0.04 crabs net(-1)d(-1) to minimum values of 0.006 crabs net(-1)d(-1) in 2008, thus reducing the dispersal potential to neighbouring areas. However, given that a number of stochastic factors may be involved in fluctuations in population size and that ships' ballast water remains uncontrolled, the management of E. sinensis needs to be continued. Based on the results obtained and the expected sequence of the invasion process in the Guadalquivir Estuary, we propose further management improvements. These results may help to optimize the management of this invasive species both in the Guadalquivir estuary and in comparable scenarios in different parts of the world.