Oceanic Manta Rays

In the summer of 2019 a trial study of oceanic Manta rays was undertaken in New Zealand by a collaboration between researchers from the Tindale Marine Research Charitable Trust, Conservation International and the NZ Department of Conservation. The aim was  to track the movements of these large ocean wanderers using state of the art satellite tracking technology. The first mission in the far north of NZ we encountered 8 Oceanic Manta rays and the team were able to deploy the latest Splash 10 satellite tags on two of them. Lack of available time and the onset of winter postponed further missions until the following season where Covid-19 halted proceedings until 2021 when we were finally able to get out amongst it tagging a further 8 Oceanic Manta Rays in the Hauraki Gulf.

 

Logistics in tagging these ocean wanderers is not an easy task. Mantas are a summer visitor to our shores and arrive with other pelagic fish including their close cousin the spine tail Devil ray . They spend much of their time foraging at depth so in order to attach a tag we first have to find them. Luckily Scott had recorded hundreds of sightings and GPS locations while big game fishing off the northland coast over the past decades. This experience gave us a much better chance of locating them as they rose to the surface to feed and play. The next challenge was maneuvering the boat close enough to allow Mark to dive in and swim in for the tag shot. The tags were fitted to a short Hawaiian sling to seat the tag anchor just under the skin on the shoulder.

Photos above, Dr Mark Erdman in pursuit of an Oceanic Manta ray off the New Zealand east coast, summer of 2019