Stock Characteristics and Management Insights for Common Carp (Cyprinus carpio) in Anatolia: A Review of Weight-Length Relationships and Condition Factors

Abstract

The common carp (Cyprinus carpio) is a species of primary importance for commercial inland fisheries of Anatolia, where it is native to some areas but has become almost ubiquitous due to historical translocations. Yet, there are concerns that this 'semi-naturalised' species can ultimately pose a threat to aquatic ecosystems, especially when present at high biomass levels. For estimating the latter, knowledge of length-weight relationship (WLR) and condition factor (K) parameters is needed, and these also represent useful indicators of fish population dynamics in general. In this study, WLR and K parameter values from published literature data were comprehensively reviewed for 68 and 75 common carp stocks, respectively, from 52 water bodies across Anatolia, which were surveyed between 1953 and 2011. Overall, Anatolian common carp stocks were characterised by slightly negative allometric growth, which became more pronounced in some over-exploited stocks and/or under critical conditions of pollution and water quality. This tendency to negative allometric growth was unlike other stocks world-wide, which showed isometric growth. Also, no altitudinal gradients were detected in the parameters under study and only slight differences amongst waterbody types (i.e. man-made lakes, natural reservoirs and water courses) were revealed (possibly a result of biassed sampling). It is argued that the level of nativeness present in Anatolian common carp stocks may be responsible for the observed patterns and differences relative to domesticated/feral common carp stocks introduced to non-native areas world-wide. This finding should be accounted for when evaluating ecological benefits vs economic losses of intervention measures for control.