Mantas & Stingrays

Giant manta ray. Photo by Scott Bennett
Giant manta ray

How big is it? Drones assisting in manta ray research

A global breakthrough in recording manta ray information has been made by an Auckland University doctoral candidate. In a study entitled “How Big Is That Manta Ray?” published in Drones, Edy Setyawan outlined how a drone camera, with the addition of a PVC pipe in the ocean, can be utilised to accurately measure the world’s largest ray species. “I could see that from the drone there was some size variation, some mantas, they are bigger than the others,” said Setyawan.

Stingrays' bulging eyes makes them more streamlined

Stingrays have a higher swimming efficiency than most other aquatic animals, and many studies regarding high-performance swimming have focused on the hydrodynamic benefits of stingrays swimming styles: “Rajiform” locomotion (undulation) and “mobuliform” locomotion (flapping), which are considered the key to stingrays' high-performance swimming.

A whitespotted eagle ray gliding through the waters
A whitespotted eagle ray gliding through the waters

Where eagle rays spread their wings in US waters

Until recently, the geographic wanderings of the whitespotted eagle ray have always been a mystery.

Now, in a study that took place from 2016 to 2018, a team of researchers have started to unlock some of its movement patterns.

The 54 rays in the study were tagged with acoustic transmitters, along both the Gulf of Mexico and the Atlantic coast of Florida, using collaborative acoustic telemetry networks.

Shark fishing makes pregnant sharks abort

The lead researcher, Kye Adams, a PhD student at the University of Wollongong, said that shark fishermen should be made aware of the danger of inducing abortions in pregnant sharks, rays, or skates. So far, the loss of the young aborted by fished sharks has been ignored by both science and fishermen.

Adams said, "It's quite prevalent across a lot of species and also seems to be not well known by both researchers and recreational fishers. "They don't realise these events are abortions, they think they are witnessing a natural birth."

Spotted eagle rays have been observed in Keys waters, but little is known about where they spend most of their time. (Image above is a unrelated filephoto)

Help keep an eye out for spotted eagle rays

In 2009, Mote Marine Laboratory with the National Aquarium in Baltimore initiated a conservation research program on the life history, reproduction, and population status of the elasmobranch Aetobatus narinari, commonly known as the spotted eagle ray To identify where these rays migrate, Mote has tagged animals with traditional tags and with satellite tags that allow the rays’ movements to be followed as they travel.

We don't know if the rays in the Keys come from Southwest Florida, or perhaps even Mexico or Cuba, and we don't know if rays in the Keys favor particular reefs

—Mote biologist Kim Hull

Giant Mantas of Equador

There is a recently developed term making its way into common use amongst the wider dive community, and that term is, citizen scientist. The science community is waking up to the fact that the common man and woman are valuable resources for acquiring many missing pieces in the jigsaw puzzle that is marine research, particularly for migratory species