true

ISRA FACTSHEETS

EUROPEAN ATLANTIC

ISRA FACTSHEETS

EUROPEAN ATLANTIC

Belle-Île & Loire Estuary ISRA

79/124

Belle-Île & Loire Estuary ISRA

Belle-Île & Loire Estuary

Summary

Belle-Île & Loire Estuary is located in the Bay of Biscay in the west of France. This coastal and continental shelf area is split into a western section between Belle Île and the mainland and an eastern section off the Loire and Vilaine estuaries. The habitat is characterised mainly by rock, boulder, and gravel substrates, with some soft sediments near the estuary outflows. It is influenced by freshwater and sediment input from the estuaries, as well as by tidal currents. Within this area there are: threatened species and reproductive areas (Marbled Torpedo Ray Torpedo marmorata).

Belle-Île & Loire Estuary

Belle-Île & Loire Estuary

DESCRIPTION OF HABITAT

Belle-Île & Loire Estuary is located in the Bay of Biscay of western France. This split area encompasses continental shelf waters in the western section from Lorient to Belle Île and in the eastern section off the Loire and Vilaine estuaries but excludes the Bay of Quiberon and the Quiberon Peninsula. The habitat is characterised mainly by rock, boulder, and gravel substrates, with some sand and mud substrates near the estuary outflows (Garlan & Marchès 2010). The area is influenced by freshwater and sediment input from two large estuaries: the Loire and Vilaine estuaries. It is also influenced by semi-diurnal tides leading to tidal currents (Le Cann 1990).

This Important Shark and Ray Area is benthic and is delineated from inshore and surface waters (0 m) to 80 m based on the bathymetry of the area.

CRITERION A

VULNERABILITY

One Qualifying Species considered threatened with extinction according to the IUCN Red List of Threatened Species regularly occurs in the area. This is the Vulnerable Marbled Torpedo Ray (Finucci et al. 2021).

CRITERION C

SUB-CRITERION C1 – REPRODUCTIVE AREAS

Belle-Île & Loire Estuary is an important reproductive area for one ray species.

Between 2010–2021, Marbled Torpedo Ray neonates and young-of-the-year (YOY) were regularly captured in this area based on data from the French fisheries on-board observer program (ObsMer; IFREMER SIH 2022) and from the International Council for the Exploration of the Sea (ICES) database on scientific trawls surveys (ICES 2025). These studies and observations cover a wide area, and sampling effort was considered in the analysis because of the heterogeneity of the number of fishing operations sampled. For fisheries-dependent data (i.e., ObsMer), only data from fishing gear suitable for catching neonates and YOY were used (i.e., defined as gear types that captured at least one neonate/YOY; primarily benthic trawls and trammel nets).

Marbled Torpedo Ray neonates and YOY were defined as being <17 cm total length (TL), considering a maximum size-at-birth of 14 cm TL for the species and a slow growth coefficient of 0.175 (Ebert & Dando 2021; Bellodi et al. 2024). Neonates and YOY were captured in 9 of the 12 years (2010­–2021) within this area. Belle-Île & Loire Estuary was the clear regional hotspot for captures of neonates and YOY when standardised for survey effort. A total of 30 of the 177 neonate and YOY recorded in the survey were captured in this area, representing ~17% of all the occurrences within a large survey region spanning from northern Spain to northeastern France (IFREMER SIH 2022; ICES 2025). This is the main hotspot for neonates and YOY, with one other hotspot at Île de Ré – Pertuis, highlighting the importance of this area for early life stages of the species.

Belle-Île & Loire Estuary

SUBMIT A REQUEST

ISRA SPATIAL LAYER REQUEST

To make a request to download the ISRA Layer in either a GIS compatible Shapefile (.shp) or Google Earth compatible Keyhole Markup Language Zipped file (.kmz) please complete the following form. We will review your request and send the download details to you. We will endeavor to send you the requested files as soon as we can. However, please note that this is not an automated process, and before requests are responded to, they undergo internal review and authorization. As such, requests normally take 5–10 working days to process.

Should you have questions about the data or process, please do not hesitate to contact us.

    * indicates required

    Industry or sector (*)

    Under the terms and conditions of our User License Agreement , full and appropriate acknowledgement is required in any materials and publications derived from the data (and copies should be sent to the IUCN SSC Shark Specialist Group through the contact form). For any publications making substantial use of the data, the ISRA welcomes the opportunity for co-authorship, collaboration, and to comment prior to publication.


    Furthermore, we need to know whether you are a commercial or non-commercial user. Non-commercial includes scientific research, education or conservation. Commercial is defined as follows: any use by, on behalf of, or to inform or assist the activities of a commercial entity (that operates ‘for profit’) or use by a non-profit for the purposes of revenue generation

    Type of use(*):

    Please specify which layer (ex. all layers, layers within a specific Region, layers within a Jurisdiction or a single ISRA): Purpose (*):

    Please provide a description of how you intend to use the ISRA GIS Dataset. The more details you provide, the faster we can respond to your request. We may require further clarification prior to providing access. (min. 100 characters – max 1,000 characters)



    File format request (*)

    By providing your personal data, you consent to its processing as described below. The IUCN SSC Shark Specialist Group will use the information you provide on this form to send the documents you requested. You can change your mind at any time by writing to the ISRA Data Coordinator www.sharkrayareas.org/contact. All personal details provided will be treated with respect. For any information you can visit our Privacy Policy.
    Please read the User License Agreement and ISRA Layer Metadata Description

    This form uses Google reCaptcha to reduce spam. Privacy - Terms