true

ISRA FACTSHEETS

AUSTRALIA AND SOUTHEAST INDIAN OCEAN

ISRA FACTSHEETS

AUSTRALIA AND SOUTHEAST INDIAN OCEAN

Roebuck Bay ISRA

70/158

Roebuck Bay ISRA

Roebuck Bay

Summary

Roebuck Bay is located in the Kimberley region, Western Australia, Australia. It is situated in Yawuru Country and is a large, semi-enclosed tropical embayment, with extensive intertidal sand and mudflats. Extensive mangrove forests fringe the shoreline and seagrass meadows occur in shallow subtidal zones. This area overlaps with the Yawuru Nagulagun/Roebuck Bay Marine Park and the Roebuck Bay Ramsar Site. Within this area there are: threatened species and reproductive areas (Indo-Pacific Leopard Shark Stegostoma tigrinum).

Roebuck Bay

Roebuck Bay

DESCRIPTION OF HABITAT

Roebuck Bay is located in the Kimberley region, Western Australia, Australia. It is situated in Yawuru Country. This area is a large, semi-enclosed tropical embayment, in the Canning Basin, located near Broome. This bay is dominated by a macrotidal system with extensive intertidal sand and mudflats and intertidal creeks (DPW 2016). This area has one of the most biologically diverse and productive tropical intertidal flats in Western Australia (Bennelongia 2009). The seafloor is dominated by soft sediments, fine silts, clays, and muddy sands, derived from the erosion of nearby pindan soils and coastal mangroves (DPW 2016). These flats support dense populations of benthic invertebrates (e.g., polychaetes, crustaceans, molluscs). Extensive mangrove forests fringe the shoreline, primarily composed of White Mangrove (Avicennia marina) (Mathews et al. 2011). Seagrass meadows (mainly Halodule uninervis and Halophila ovalis) occur in shallow subtidal zones (DPW 2016).

The South Equatorial Current and Indonesian Throughflow supply warm, low salinity, nutrient poor waters to northern Western Australia (Suthers & Waite 2007). Nearshore water movement and mixing patterns in this area are mainly driven by the large tidal ranges, seabed topography, and local winds (DPW 2016). The climate is tropical monsoonal with a distinct wet season (roughly November–April) and a pronounced dry season (roughly May–October).

This area overlaps with the Yawuru Nagulagun/Roebuck Bay Marine Park (WA DBCA 2025) and the Roebuck Bay Ramsar Site (Wetland of International Importance; Ramsar 2025).

This Important Shark and Ray Area is benthic and pelagic and is delineated from inshore and surface waters (0 m) to 20 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 Endangered Indo-Pacific Leopard Shark (Rigby et al. 2024).

CRITERION C

SUB-CRITERION C1 – REPRODUCTIVE AREAS

Roebuck Bay is an important reproductive area for one shark species.

Between 2014–2025, sixteen records of small Indo-Pacific Leopard Sharks swimming close to the surface were posted on social media or reported by citizen scientists. Records come from December–June but are primarily from the wet season. These reports correspond to neonates and young-of-the-year (YOY) identified by their distinctive coloration and characteristic surface-swimming behaviour typical of this early life-stage (20–60 cm total Length; Dudgeon & White 2012). Local ocean users have noted that these sightings are regular and occur yearly during the wet season (J Hounslow & G Carlin pers. obs. 2014–2025). Neonates display an undulating swimming motion with their slender bodies on the sea surface, characterised by a striking banded coloration and a long, single-lobed caudal fin that mimics sea snakes (Dudgeon & White 2012; Ebert et al. 2021).

Although this area has been poorly studied, with no targeted research and records based solely on citizen science, early life-stages have been regularly observed for nine years, supporting its role as a reproductive habitat for this species. Across its known distribution, only four Important Shark and Ray Area have been identified for reproductive purposes of this species (i.e., pre-copulatory behaviour, egg cases) in Oman, Thailand, and New Caledonia (Jabado et al. 2023, 2024a, 2024b). Only one of these areas in Oman has reported one neonate; therefore, this area represents the only site where neonate and YOY individuals have been regularly recorded on a global scale.

Roebuck Bay

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