First whale shark satellite tagged on the Great Barrier Reef

First whale shark satellite tagged on the Great Barrier Reef

The first whale shark has been tagged with a satellite transmitter on the GBR! The transmitter is currently sending data on the shark’s movements off the East Coast of Australia

As the Run for the Reef Megamouths project is about to move into its third year, we have had success with the manta ray research (tagging and aerial surveys), but whale sharks have been elusive. However, on the 24th of October Dan McCarthy from Big Fish Down Under deployed one of our satellite tags on a whale shark. This is the first whale shark to be satellite tagged on the Great Barrier Reef (GBR). The whale shark was tagged from the side of the boat Moana, so we do not know if it’s a female or a male, but it was estimated to be a 5 m juvenile.

 

Dr Adam Barnett with Satellite Tag.

Distribution

Whale sharks are distributed throughout all tropical and warm temperate seas. Aggregation sites are known from several locations around the world (including Western Australia), where large numbers of whale sharks (hundreds in some locations) reliably aggregate, more often seasonally (see map of whale shark hotspots below). These aggregations are often associated with increased primary productivity. The northeast of Australia is one of the holes in terms of global knowledge of these large charismatic plankton feeders.

 

Figure 1. Global whale shark hotspots (1, Ningaloo Marine Park; 2, Mexico–Atlantic; 3, Mozambique; 4, the Philippines; 5, Seychelles; 6, Honduras; 7, the United States, Gulf States; 8, the Maldives; 9, Mexico–Pacific; 10, Thailand; 11, Djibouti; 12, the Galapagos; 13, Belize; 14, South Africa; 15, Tanzania; 16, Oman; 17, Qatar; 18, Red Sea; 19, Christmas Island; 20, Indonesia). The circled groupings represent hotspots within which international whale shark movements have been confirmed via photo-identification (i.e., between 2, 6, 7, and 13; between 3, 14, and 15; between 5 and 15; between 16 and 17; between 11 and 18; and between 1 and 20). Figure taken from Norman et al. 2017.

 

Aggregations and Protection

No reliable aggregations of whale sharks have been discovered on the GBR. However, sporadic sightings of whale sharks have been reported on the GBR and out in the Coral Sea. These sightings are normally of single individuals, but schools of whales sharks have also been reported, particularly by commercial fisherman who have seen the whale sharks feeding.

Whale sharks are listed as endangered on the IUCN Red List, and there are concerns about these species moving across international borders into territories where they are still exploited, e.g. moving from Australia into Asia. So, knowing how much time they spend in Australian waters, where they are protected, and where they move internationally is important for their broader management and conservation.

 

Oceanpedia Education Resource – Biopixel Oceans Foundation – Whale Sharks

Research and Tracking

The tagging of this first whale shark on the GBR is the initial step in understanding the importance of the GBR and Coral Sea for whale sharks, and determining if there are aggregation sites or key habitats they return to in our corner of the world.

Given this is the first whale shark satellite tagged on the GBR – please meet “GBR1”! Tracking information is live on Ocearch so check this link to follow its movements: https://www.ocearch.org/tracker/?details=316 and look for updates on our facebook page and website https://biopixelresearch.org/blog/. So far, GBR1 has been heading north in the Coral Sea after being tagged near Ribbon 4, straight out from Cooktown on the GBR.

 

Shark tracked for 8 days over 500 km

 

Reference for hotspot map: Norman BM et al. (2017) Undersea constellations: the global biology of an endangered marine megavertebrate further informed through citizen science. Bioscience 67: 1029-1043

Free access to paper here https://academic.oup.com/bioscience/article/67/12/1029/4641655

 

Biopixel Whale Shark footage

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