The capture of larvae from marine coastal animals (Ecocean’s core business) has proved to be a good tool to study and better understand the early stages of the life cycle of fish or crustaceans and to obtain new knowledge about the dynamics of communities living in coastal areas.
Thus, hundreds of marine species were captured in the state of post-larvae then bred at land. The technique that stems from this knowledge - the PCC for "Post-larval Capture and Culture" - was first launched in tropical, marine environments, and from 2009 it has been tested and established in temperate environments (Mediterranean). The use of this new method in European inland waters is still very rare, even though it helps provide new elements for the understanding of a key phase of the life cycle of freshwater fish.
Interests and objectives
The project was specifically designed to test and validate this technique in 2014 - in both lakes of Lamartine site (Commune of Roques sur Garonne). It has led to the capture of fish larvae in fresh water using CAREs - passive fishing gear using a light attractor - and monitoring of their laboratory growth. To assess its reliability as a new bio-indication tool to help managers better understand the dynamics and the factors structuring lentic fish communities (living within calm/slow water renewal ecosystems) and - forward - its potential use in monitoring restoration projects.
The work lead by the teams of the EDB laboratories - Evolution and Biological Diversity (UMR 5174 EDB: CNRS / University Paul Sabatier / ENFA) and Ecolab - Functional Ecology & Environment (UMR 5245 CNRS / University Paul Sabatier / ENSAT), but also by Ecocean and Haute-Garonne fishing federation helped adapt the CARE technology to shallow depths and get information about particular species fishing period, the size of captured individuals and morphological characteristics of these very young stages of life.
Eventually, these results might represent a good health indicator for lakes (abundance and diversity of PL collected) and lead to a possible restoration of some wild fish populations.
A first post-larvae identification guide of these lakes has been published, including pictures of various stages of development.
TéléchargementProject sheet Captilarves (PDF)