Diagnostic uses

CAPTILARVES – Haute-Garonne lakes (France)

Context

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.

R&D works:

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.

Future Prospects:

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.

Téléchargement

Project sheet Captilarves (PDF)

LANDEAU – Brusc Lagoon (France)

Context

The Brusc lagoon (Var) is considered as a potential good nursery area for young stages of fish, due to its configuration and the presence of a Cymodoce herbarium. The LANDEAU project aims to confirm this hypothesis, through three actions:
1) An inventory of the existing diversity of post-larvae in the lagoon using two different techniques: the crest net (manufactured by Ecocean and already used in Polynesia) and light attractors CARE® (designed and manufactured by the company Ecocean).
2) Post-larvae capture and rearing in order to release them on their natural habitat and thus enhance the populations of the herbarium.
3) The monitoring of these recruits in natural sea grass bed, restored by transplantation or using micro-habitats. These last two solutions are developed by SM² Solutions Marines.

Interest & Objectives

Besides a contribution to the identification of post-larval fish, the expected results should provide an understanding of the important role that the lagoon of Brusc plays as a nursery site, compared with various sites around Embiez Island. Because of the degradation of the Cymodocea sea grass beds in the lagoon, the ecological restoration by transplantation of sea grass and key fish species will allow an estimation of the potential for improving ecosystem function.
• Technical innovation: The use of an innovative technique never applied in the Mediterranean Sea (Crest nets) allows the capture of species other than those that are photosensitive.
• Ecological innovation: The combination of post-larval capture & restocking with restoration of sea grass has never been performed before.

R&D works

• Two crest nets has been installed on the two channels that connect the lagoon with the sea. The nets collect a flow on one meter width by 70 cm depth. There are six nights of fishing per month over a period of six months (from April to September).
• For the light trap CARE®, eight sites have been chosen, the fishing is done at the same time as the crest nets.
• The identification and the breeding are performed in the facilities of the Paul Ricard Institute, located in border of the lagoon.
• The monitoring of the populations of the young recruits of fish is lead on five zones with three replicates of 1 m² among which two restored zones and three natural zones.

Expected impacts and benefits

• New knowledge about the dynamics of coastal fish populations. This might help local fisheries that are an economic and cultural asset of the PACA region.
• Potential for application in other shoreline areas
• Patent on the new processes of ecological restoration.

Téléchargement

Project sheet LANDEAU (PDF)

RESPIRE monitoring network – Mediterranean Sea

Context

The aim of the European Union's ambitious Marine Strategy Framework Directive is to protect more effectively the marine environment across Europe and achieve Good Environmental Status (GES) of the EU's marine waters by 2020. This strategy is applied at the French national level through an Action Plan for the Marine Environment (Article L 219-9), which consists of the implementation of research projects to improve knowledge and develop solutions that reduce the ecological footprint of human coastal infrastructures. These actions match with the objectives of the Rhone Mediterranean and Corsica French Water Agency (AERMC), especially on marine ecosystems surveillance and identification of human-based pressures affecting them. The implementation of the RESPIRE project taking place along Mediterranean coastal infrastructures will contribute to these efforts.

Interests & objectives

The RESPIRE network is a complementary surveillance network to those that already exist (like REPHY for Phytoplankton or REBENT for benthic fauna and flora survey). Initiated by the AERMC, the new network will consolidate the local strategies as well as the national objectives of public policies responsible for marine environment. The short term objectives of the project is to monitor spatial and temporal fish recruitment on the Mediterranean coast inside 23 marinas located between Port-Vendres and Monaco as well as on the Corsica Island. Diversity and abundance of young-of-the-year species will be monitored. The medium term objective aims to ascertain and measure the nursery role provided by marinas’ calm waters.

R&D works

In this project, ECOCEAN offers the use of Biohut®, an artificial fish habitat that aims to bring back the nursery function in marinas. Tested during previous research programs (for instance NAPPEX & GIREL), the Biohut® correspond to a suitable area to monitor fish recruitment in marinas habitats due to their capacity to provide young-of-the-year fish a shelter and a source of nutrient adapted to their metabolism.

Future Prospects

In this project, the installation of Biohut® doesn’t aim to restore the nursery functions in ports. The module will serve as an observation unit for scientific monitoring given its ability to house and protect the young recruits in this environment.. The results on abundance and fish species diversity observed will help to measure the condition and health of fish recruitment along the Mediterranean coast. The main issue identified by the AERMC being the « critical decrease of biodiversity due to the damage of shallow coastal waters », the RESPIRE network will provide to decision makers and scientists a new tool to assess habitats quality and health condition in marinas regarding biodiversity and fish recruitment.

Téléchargement

Project sheet RESPIRE (PDF)