true

ISRA FACTSHEETS

WESTERN INDIAN OCEAN REGION

ISRA FACTSHEETS

WESTERN INDIAN OCEAN REGION

Europa Island ISRA

1/125

Europa Island ISRA

Europa Island

Summary

Europa Island is a small, remote, low-lying coralline island in the Mozambique Channel, ~500 km off the coast of Mozambique and ~300 km off Madagascar. This coral atoll has a continuous rim of fringing reef that steeply drops to abyssal depths and consists of ~28 km2 of land, with mangrove forests lining the lagoon shore and sandy beaches on the western shore. It lies within the Iles Éparses and the Mozambique Channel Ecologically or Biologically Significant Marine Areas and overlaps with the Europa Key Biodiversity Area and the Ile d’Europa Marine Protected Area. Within this area there are threatened species (e.g., Scalloped Hammerhead Sphyrna lewini); reproductive areas (Blacktip Reef Shark Carcharhinus melanopterus); and undefined aggregations (Scalloped Hammerhead).

Europa Island

Europa Island

DESCRIPTION OF HABITAT

Europa Island is a remote coral reef island located ~500 km off the coast of Mozambique and ~300 km off Madagascar in the Mozambique Channel. The atoll is 6–7 km in diameter and has 28 km2 of land surface (Guillaume & Séret 2021). The island rises steeply from the abyssal seafloor, with a depth of 3,000 m only ~15 km from the reef crest. Water flow in the Mozambique Channel is dominated by large anticyclonic and cyclonic eddies that propagate southward (Schouten et al. 2003). These eddies result in patchy productivity of surface waters with strong temporal and spatial variation, including off Europa Island (Weimerskirch et al. 2005). The area includes varied habitats including pelagic waters, steep reef slopes, shallow fringing reefs, a lagoon with seagrass beds, and mangrove areas. The 22 km long coastline of the island has a continuous fringing reef surrounding it. A shallow lagoon of ~7 km2 opens to the sea over the reef flat in the north. The lagoon is mainly fringed by mangroves, with some areas in the west having sandy beaches.

Europa Island lies within two Ecologically or Biologically Significant Marine Areas (Mozambique Channel and The Iles Éparses; CBD 2023a, 2023b) and overlaps with the Europa Key Biodiversity Area (KBA 2023). It also lies within the Ile d’Europa Marine Protected Area and is a Ramsar site (Wetland of International Importance).

This Important Shark and Ray Area is benthopelagic and is delineated from inshore and surface waters (0 m) to 1,043 m based on the depth range of the Qualifying Species in the area.

CRITERION A

VULNERABILITY

Two Qualifying Species considered threatened with extinction according to the IUCN Red List of Threatened Species™ regularly occur in the area. These are the Critically Endangered Scalloped Hammerhead (Rigby et al. 2019) and the Vulnerable Blacktip Reef Shark (Simpfendorfer et al. 2020).

CRITERION C

SUB-CRITERION C1 – REPRODUCTIVE AREAS

Europa Island is an important reproductive area for one shark species.

Visual surveys in the shallow mangrove system of the island in April 2009 recorded Blacktip Reef Sharks of various sizes (Wickel et al. 2009). Compared with published size-at-birth (48 cm total length [TL]) and sizes of young-of-the-year and juveniles (Lyle 1987; Chin et al. 2013), the observations consisted of nine neonates of ~40–50 cm TL, nine young-of-the-year of <70 cm TL, and six likely juveniles up to 100 cm TL (Wickel et al. 2009). A 3-day survey in 2011 also reported young Blacktip Reef Sharks in the mangrove areas, but no further details were recorded (Séret et al. 2011). In four surveys in April–June 2013, 18 Blacktip Reef Sharks were recorded in the lagoon, and only one individual was seen on the reef (Guillaume & Séret 2021). Some of these were neonates (~40 cm TL) reported in the mangrove system and the others were larger juveniles (80–100 cm TL) reported in a channel between the mangroves and the lagoon. Overall, the evidence from the surveys show that the shallow mangrove areas likely function as a nursery habitat for the species (as defined in Heupel et a. [2007]). The isolated geographic area of this atoll, >300 km from the nearest coast where Blacktip Reef Shark nurseries could exist, further emphasises the importance of this area for their reproduction.

CRITERION C

SUB-CRITERION C5 – UNDEFINED AGGREGATIONS

Europa Island is an important area for undefined aggregations of one shark species.

Visual dive/snorkel surveys (n = 79) conducted in April–June 2013 found 16 aggregations of Scalloped Hammerheads, comprising an average of 23 individuals, and up to 150 individuals, per school (Guillaume & Séret 2021). In April­–June 2018, Scalloped Hammerheads were regularly encountered, and in December 2018 several small schools and one larger school (17 individuals) were recorded (Guillaume & Séret 2021). Additional visual and baited remote underwater video systems (BRUVS) surveys from July 2010 found 55 Scalloped Hammerheads in the area, with the largest aggregation comprising 35 individuals (Save Our Seas Foundation 2010; Clarke et al. 2012). Unlike other shark species recorded using bait, Scalloped Hammerheads were seen in passing and not interested in the bait. It is likely that these aggregations are for resting and social interactions during the day (Klimley 1985), but further research is needed to understand the drivers of these aggregations.

Europa Island

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