Abundance and population structure of the blue crab Callinectes sapidus (Decapoda, Portunidae) in Thermaikos Gulf (Methoni Bay), northern Aegean Sea

Abstract

The blue crab Callinectes sapidus is an alien decapod established in the Mediterranean Sea. Since 2007, increased abundance has been reported from the northern Aegean Sea sustaining local scale fishery. The present work aims to assess the abundance and population structure of C. sapidus in Thermaikos Gulf using fyke nets. Population abundance, estimated as CPUE, exhibited strong temporal variability with decreased values in the cold season; this pattern was correlated with seawater temperature. Females exhibited also spatial differences with increased abundance close to the Aliakmon estuary. In total, 543 individuals were measured for carapace width. Males prevailed in the population; however, mean size was similar between sexes. Larger individuals were caught from deeper waters and the estuarine areas, whereas mean size decreased temporally. The fyke nets used proved to be size-selective, thus preventing fisheries mortality for juveniles. However, recurrent monitoring is necessary for a sustainable management of blue crab fisheries in the gulf.

<i>Callinectes sapidus</i> Rathbun, 1896 (Brachyura: Portunidae): An assessment on its diet and foraging behaviour, Thermaikos Gulf, NW Aegean Sea, Greece: Evidence for ecological and economic impacts

“…In the Mediterranean, an important fishery exists in Turkey (Tureli-Bilen and Yesilyurt, 2014) and a smaller scale fishery exists in the Adriatic Sea (Manfrin et al, 2015) and Egypt (Abdel Razek et al, 2016). In Greece, though that a relative fishery is developed (Perdikaris et al, 2016;Mancinelli et al, 2017b;Kevrekidis and Antoniadou, 2018), blue crabs have a very low commercial value and are a by-catch product, yet some quantities are exported (pers. com.).…”

“…com.). In Greece, the blue crab is not wellstudied, with only a handful of published data being available (Kevrekidis et al, 2012(Kevrekidis et al, , 2013Perdikaris et al, 2016;Kevrekidis and Antoniadou, 2018). None of them is related with the species feeding ecology.…”

Further records of Callinectes sapidus (Rathbun, 1896) (Decapoda, Brachyura, Portunidae) in the Strait of Sicily

“…In some areas of the Mediterranean, such as Turkey (Bilen and Yesilyurt 2014), the Adriatic Sea (Manfrin et al 2015), and Egypt (Abdel-Razek et al 2006), the American blue crabs have become a valuable fishery resource. On the contrary, in Greece, the Blue crab has a poor commercial value (Perdikaris et al 2016;Mancinelli et al 2017c;Kevrekidis and Antoniadou 2018).…”

Morphometric Relationships of the Global Invader Callinectes sapidus Rathbun, 1896 (Decapoda, Brachyura, Portunidae) from Papapouli Lagoon, NW Aegean Sea, Greece. with Notes on Its Ecological Preferences

“…In the Americas and in some countries of north-western Europe, blue crabs are commercially important [5][6][7]. In the Mediterranean Sea, the species is exploited in Turkey [8] and, to a lesser extent, in Italy [9], Egypt [10] and Greece [11][12][13][14]. Blue crabs are a well-studied species-at their native distribution.…”

“…Most of the studies are related to new occurrences of blue crab or review the blue crab current distribution. Information on blue crabs' fishery biology and population dynamics is very limited, with a few exceptions [11,13,14,33]. The blue crab's length-weight relationships have been studied in some cases along the East Mediterranean coasts: 1.…”