The Atlantic blue crab Callinectes sapidus Rathbun, 1896 expands its non-native distribution into the Ria Formosa lagoon and the Guadiana estuary (SW-Iberian Peninsula, Europe)

Pedro Morais

doi:10.3391/bir.2019.8.1.14

Abstract

Author(s): Morais, Pedro; Gaspar, Miguel; Garel, Erwan; Baptista, Vania; Cruz, Joana; Cerveira, Ines; Leitao, Francisco; Teodosio, Maria Alexandra | Abstract: The Atlantic blue crab Callinectes sapidus Rathbun, 1896 is native in the western Atlantic, however it is a non-indigenous species across Europe since 1900, among other world regions. In this paper, we report the first occurrences of this species in the Ria Formosa lagoon and in the Guadiana estuary (SW-Iberian Peninsula, Europe) which occurred in 2016 and July 2017, respectively. We hypothesize that the introduction of this species into these ecosystems might be due to the expansion of the Guadalquivir estuary population through natural processes (larval advection, active movement), or due to unintended introduction events after being transported aboard fishing boats, or, less likely, through ballast water. Changes in Guadiana’s river flow after the construction of the Alqueva dam might also explain the presence of another non-indigenous species in the Guadiana estuary. The hypotheses presented, regarding the introduction of the Atlantic blue crab into these ecosystems and of its co-occurrence with other decapod species, are framed in a broader context to serve as a future research framework. The use of the Atlantic blue crab as a new fishing resource is also proposed, namely if it is to be used exclusively by local communities and if no deleterious impacts upon other fisheries and the ecosystem occur from this new fishery.

Highlights

At least 11 Atlantic blue crab specimens were collected in the Ria Formosa lagoon, but we only have detailed information on one specimen (Table S1)
The Atlantic blue crab in the Ria Formosa lagoon and in the Guadiana estuary The Atlantic blue crab is one of two non-indigenous Callinectes species present in Europe (Mancinelli et al 2017a), the other is rugose swimming crab Callinectes exasperatus (Gerstaecker, 1856) (Decapoda, Brachyura) – a single specimen was collected in the Bay of Cadiz (Cuesta et al 2015)
The Guadalquivir estuary is the closest site to the Guadiana estuary and to the Ria Formosa lagoon, which is located 120 km and 133 km away, respectively

Summary

Introduction

The Atlantic blue crab has the potential to impact benthic communities at multiple trophic levels and displaying significant spatial and temporal variability between populations (Mancinelli et al 2013, 2017c) This species is native to the western Atlantic, and its distribution ranges from Cape Cod (USA) to northern Argentina, including the Gulf of Mexico (Nehring 2011). The Atlantic blue crab is expanding its distribution north of Cape Cod probably due to warming coastal waters (Johnson 2015) This species has been observed away from the native range in Africa, Asia, and Europe (Nehring 2011). In some of these areas, the species has established populations (Mancinelli et al 2017a)

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