true

ISRA FACTSHEETS

SOUTH AMERICAN ATLANTIC REGION

ISRA FACTSHEETS

SOUTH AMERICAN ATLANTIC REGION

Namuncurá-Burdwood Bank ISRA

1/81

Namuncurá-Burdwood Bank ISRA

A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur e Islas Sandwich del Sur) and the surrounding maritime areas.

Namuncurá-Burdwood Bank

Summary

Namuncurá-Burdwood Bank is located on a submarine plateau east of Isla de los Estados, in Argentina and Falkland Islands (Malvinas). It includes part of the Burdwood Bank plateau and part of its the south-central slope. The habitat is characterised by substrates covered with sponges, soft corals, and bryozoans. The area is influenced by the Malvinas Current that circulates around Burdwood. The area overlaps with the Namuncurá-Banco Burdwood I and Namuncurá-Banco Burdwood II Marine Protected Areas. Within this area there are: reproductive areas (e.g., Broadnose Skate Bathyraja brachyurops).

Namuncurá-Burdwood Bank

Namuncurá-Burdwood Bank

DESCRIPTION OF HABITAT

Namuncurá-Burdwood Bank is located on a submarine plateau 150 km east of Isla de los Estados, Argentina and Falkland Islands (Malvinas). It includes part of the Burdwood Bank plateau and part of its south-central slope. Burdwood Bank is bordered to the north by the Malvinas Trough, which separates it from the Malvinas Plateau and extends eastward (Guerrero et al. 1999). The habitat is characterised by substrate covered with sponges, soft corals, and bryozoans (Falabella 2017). The area is influenced by the Malvinas Current that circulates around Burdwood Bank in an anticyclonic pattern, carrying cold subantarctic waters and bringing nutrient-rich upwellings to the surface (Piola & Gordon 1989). Surface temperatures range from 4–8°C, with salinity levels between 33.8–34.2 g/L. At the seabed, conditions remain stable, with temperatures between 4–5°C and salinity ~34 g/L (Falabella 2017).

This area overlaps with the Namuncurá-Banco Burdwood I and Namuncurá-Banco Burdwood II Marine Protected Areas (UNEP-WCMC & IUCN 2025 a, b).

This Important Shark and Ray Area is benthic and subsurface and is delineated from 70–785 m based on the bathymetry in the area.

CRITERION C

SUB-CRITERION C1 – REPRODUCTIVE AREAS

Namuncurá-Burdwood Bank is an important reproductive area for three ray species.

High densities of egg cases for Broadnose Skate, Patagonian Skate, and Cuphead Skate were found in the area (Matusevich et al. 2023). Between 2016–2018, four research cruises conducted bottom trawls surveys on the southern portion of the southwest Atlantic at depths of 33–785 m (Matusevich et al. 2023). Sampling employed a small bottom trawl net (50 mm mesh in the wings, and 20 mm in the cod end; horizontal opening 6 m) with trawling durations of 5–20 minutes at speeds of 1.5–5 knots, resulting in a total of 110 fishing hauls. Catch-per-unit-effort (CPUE) for each species’ egg cases was calculated based on the area swept by survey trawls (Alverson & Pereyra 1969) expressed as egg cases per km2 (egg cases/km2). After taxonomic identification, the number of egg cases per haul for each species was recorded (Matusevich et al. 2023).

Broadnose Skate egg cases were collected in the area and adjacent regions of Burdwood Bank. Egg cases from this species were the most frequently encountered during the surveys, accounting for 29.2% of observations. These were found at depths between 81–608 m, with the highest densities recorded at 98 m (Matusevich et al. 2023). The density of Broadnose Skate egg cases ranged from 25–2,411 egg cases/km2 (Matusevich et al. 2023). The highest densities were observed within the area including all four hauls with densities between 2,000–2,401 egg cases/km2, two hauls (of the four) with 1,000–2,000 egg cases/km2, and two hauls (of the four) with 500–1,000 egg cases/km2 (Matusevich et al. 2023).

Patagonian Skate egg cases were collected in the area and adjacent regions of Burdwood Bank. Egg cases of this species were the second most frequently encountered during the surveys, accounting for 24.6% of observations. These were found at depths ranging from 78–785 m, with the highest densities recorded at 124 m (Matusevich et al. 2023). The density of Patagonian Skate egg cases ranged from 40–1,671 egg cases/km2 (Matusevich et al. 2023). The highest densities were observed within the area including all two hauls with densities between 1,000–1,671 egg cases/km2, one haul (of the six) with 500–1,000 egg cases/km2, and five hauls (of the eight) with 200–500 egg cases/km2 (Matusevich et al. 2023). Based on initial (n = 2 individuals) and advanced-stage embryos (n = 1) and neonates (n = 1) captured in the area and adjacent regions, a potential egg-laying season was established during the austral autumn and spring months (March–November; Matusevich et al. 2023).

Cuphead Skate egg cases were collected in the area and adjacent regions of Burdwood Bank. Egg cases from this species were the fourth most frequently encountered during the surveys across the broader region, accounting for 4.6% of observations. The density of Cuphead Skate egg cases ranged from 254–1,446 egg cases/km2 (Matusevich et al. 2023). The highest densities were observed within this area including the two hauls with higher densities of 1,446 egg cases/km2 at 694 and 785 m depths (Matusevich et al. 2023).

Namuncurá-Burdwood Bank

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