Determination of some population parameters of the veined rapa whelk (Rapana venosa) in the Central Black Sea

Abstract

The veined rapa whelk is one of the most important invasive species in the Black Sea ecosystem since the 1940s. Following its introduction to the Black Sea, it destroyed most of the bivalve populations, mainly the Mediterranean mussel and oysters. However, the veined rapa whelk has commercial importance for the Black Sea fisheries as an alternative product. In this study, we aimed to determine some population parameters of the veined rapa whelk based on indirect ageing through length-frequency data by using the Bhattacharya method. We collected 1704 specimens by dredging along the coasts of Samsun Province in the Central Black Sea in 2011 from June to November. The age of the population varied from 0 to 6. Von Bertalanffy growth parameters were estimated as L-infinity = 112.35 mm, k = 0.310, t(0) = -0.486 and W-infinity = 243.94 g. Mean length and weight, length-weight relationship, mortality and exploitation rates were derived as L = 56.80 +/- 0.36 mm, W = 45.67 +/- 0.89 g, W = 0.0006 L-2.719, Z = 0.96, M = 0.57, F = 0.39 and E = 0.40, respectively.