ISSN 2360-7955
Abstract: The objective of this study was to investigate and assess the occurrence and quantity of the invasive blue crab population in Kune Lagoon, located in Albania, south-east Adriatic Sea. Additionally, the study aimed to assess the population structure by examining biometric parameters. In contrast to prior research in the same lagoon, this study revealed a notably higher abundance of the blue crab during various periods of field observations. The data analyzed extends in three years of field observations and collections, with a specific focus on the ingress (March – April) and egress (November) of the blue crab into and out of the lagoon, respectively. The highest number of crab individuals was documented in September and October. From the examination of biometric parameters, including total weight, carapace length, and carapace width of 80 individuals, it was observed that the population was predominated by adult and large individuals. The sex ratio analysis indicated a prevalence of the males, with a F : M ratio 0.4 : 0.6 within the lagoon. Questionnaires were distributed to local fishermen to gather additional insights into the status of the blue crab in Kune Lagoon. The questionnaires also gathered information on the socio-economic impact of the blue crab, as well as its effects on native populations in the lagoon. The results suggested that the trade of blue crab from Kune Lagoon remains at minimal levels, providing little economic benefit to local fishermen. Fishermen reported examples of aggressive behavior by the blue crab and damage to fishing nets. The high prevalence of other invertebrates, particularly the Mediterranean mussel (Mytilus galloprovincialis), might be a main reason for the high abundance of blue crab in this lagoon, as it serves as a primary food source for the blue crab. Continuous presence of the blue crab population, the presence of ovigerous females, and juveniles indicate the stability of this species in Kune Lagoon.
Keywords: Invasive alien species, population structure, biometric parameters, socio-economic impact, Adriatic Sea.