Variation over Time of Length–Weight Relationships and Condition Factors for Four Exotic Fish Species from a Restored Shallow Lake in NE Iberian Peninsula

Jorge Rubén Sánchez-González,Amadeo Arbonés,Frederic Casals

doi:10.3390/fishes5010007

Jorge Rubén Sánchez-González, Amadeo Arbonés + Show 1 more

Open Access

https://doi.org/10.3390/fishes5010007

Copy DOI

Abstract

Length–weight relationships (LWRs), condition factors, and their variation over time were analyzed for four exotic freshwater fish (bleak, common carp, pikeperch, and roach) in the Estany d’Ivars i Vila-sana shallow lake in Catalonia, Northern Spain. Fish samples were collected twice a year (early summer and autumn), between 2008 and 2016, by using between three and five multi-mesh nylon gillnets. This study provides novel information about four common exotic fishes outside of their natural range and within the context of a restored shallow lake, where the ichthyologic community is evolving in concordance with the ecosystem conditions and the fish community dynamics.

Highlights

The analysis of length–weight relationships (LWRs) and condition factors are common tools in studies of fish biology, ecology, and physiology, and they have been extensively used in fishery research and management [1,2,3,4]
Within the framework of long-term studies, we hypothesized that changes in the LWR slope and condition indices reflect changes of fish condition, the potential causes of which have their origin in alterations on the ecosystem and/or the ichthyologic community
LWRs are rarely used as a dynamic concept, as if describing factors remain unaltered over time and are characteristic of an ecosystem

Summary

Introduction

The analysis of length–weight relationships (LWRs) and condition factors are common tools in studies of fish biology, ecology, and physiology, and they have been extensively used in fishery research and management [1,2,3,4]. LWRs and condition indices of exotic species are essential tools within management and fish community monitoring contexts, and they allow for the evaluation of the state of the populations. There are no cases of using LWRs to evaluate and monitor fish communities within the context of a recently restored ecosystem during long-term monitoring To fill these gaps and contribute to the science and management of exotic fish communities in these ecosystems, we investigated the status of fish communities in a restored shallow lake in the NE Iberian Peninsula by analyzing the variation of LWRs over time and their differences between seasons. We estimated the LWRs—in our case, the fork length (FL)—and an analysis of their variation, and four condition indices for four of the most common exotic species in the Estany d’Ivars i Vila-sana, a restored shallow lake in NE Iberian Peninsula. For the first time, we report information about the community of exotic fishes in a restored shallow lake as a result of a long-term monitoring and temporal variation of LWRs

Results

Discussion

Materials and Methods

Fish Condition

Statistics