Population responses of common carp Cyprinus carpio to floods and droughts in the Pampean wetlands of South America

Tomás Maiztegui,Claudio R.M Baigún,Javier R Garcia De Souza,Darío Colautti,Olaf L.F Weyl

doi:10.3897/neobiota.48.34850

Abstract

Common carp (Cyprinuscarpio) is a global invader that exhibits a wide distribution in Argentina, particularly in shallow lakes and wetlands of the Pampean region. The hydrological conditions of these environments are driven by variations in annual precipitation that determine inter annual changes in water levels leading to flood-drought cycles. The present study focused on understanding the C.carpio population responses to annual rainfall regime and long-term flood and drought events in the Ajó wetlands located in the east of the Pampean region. The results of a two-year biological sampling program showed that C.carpio feeding rate, reproduction, condition, and recruitment were associated with the hydrological cycle. Otolith derived age structure of the population and back-calculated recruitment strength revealed that extraordinary flooding events generated strong cohorts while dry years resulted in low recruitment. Its long-life span (maximum 14 years in Ajó) coupled with a high fecundity, and broad diet allows C.carpio to persist in refugia during dry years and capitalize on wet years when inundation of the floodplain enhances recruitment and facilitates spread. Management and control strategies for this invader should therefore incorporate hydrological variability by promoting intensive removal campaigns during dry years when populations are dominated by large fish confined in remnant water-bodies and, during wet years, carp harvest fisheries should be promoted to reduce population density when increased connectivity is likely to facilitate spread.

Highlights

Common carp Cyprinus carpio Linnaeus, 1758 is a freshwater fish native to the PontoCaspian region (Balon 2004) that, as a result of human introductions, has invaded freshwater ecosystems on all continents except Antarctica (Zambrano et al 2006; Vilizzi et al 2015)
This study represents the first attempt to understand how C. carpio biological responses and population dynamics are synchronized with the yearly seasonality and modulated by multi-annual hydrological regime in temperate South American wetlands
As is the case elsewhere (e.g., Balon 1995; Stuart and Jones 2006; Penne and Pierce 2006), C. carpio spawning occurs between spring and summer when water temperature exceeds 15 °C and when shallow vegetated areas are available (Horvath 1985; Sivakumaran et al 2003; Smith and Walker 2004; Winker et al 2011)

Summary

Introduction

Common carp Cyprinus carpio Linnaeus, 1758 is a freshwater fish native to the PontoCaspian region (Balon 2004) that, as a result of human introductions, has invaded freshwater ecosystems on all continents except Antarctica (Zambrano et al 2006; Vilizzi et al 2015). C. carpio is considered to be one of the most pervasive and destructive of freshwater fish (Koehn 2004; Matsuzaki et al 2009; Kloskowski 2011) and is listed amongst the world’s worst 100 invasive alien species (Lowe et al 2000) controlling C. carpio populations is a high priority in many countries. Approaches differ between regions and countries, it is widely accepted that an understanding of the biology and population dynamics of C. carpio in the invaded environment is critical to the efficacy of control measures (Driver et al 2005; Bajer et al 2012; Weber and Brown 2013; Koehn et al 2017)

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Conclusion