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Spotted rays to come under researcher Matt's eagle eye

MATT Ajemian wants to fly like an eagle to the sea. But not in the way you'd expect.He is in Bermuda doing research for his PhD and has created a project called <I>The Ecology of Spotted Eagle Rays (Aetobatus narinari)</I>.It's been an ongoing project since May last year and Mr. Ajemian is working in co-operation with the Bermuda Aquarium Museum and Zoo (BAMZ) to study this previously little examined animal. He also received funding from the Bermuda Zoological Society (BZS) which enables him to do his research.

MATT Ajemian wants to fly like an eagle to the sea. But not in the way you'd expect.

He is in Bermuda doing research for his PhD and has created a project called The Ecology of Spotted Eagle Rays (Aetobatus narinari).

It's been an ongoing project since May last year and Mr. Ajemian is working in co-operation with the Bermuda Aquarium Museum and Zoo (BAMZ) to study this previously little examined animal. He also received funding from the Bermuda Zoological Society (BZS) which enables him to do his research.

"The species is virtually unknown," said Mr. Ajemian. "Not a lot of studies have been conducted on this animal, and none have been done in Bermuda."

The study focuses on where the eagle rays go, how long they stay there and what their impact is on the marine ecosystem, with a focal point on Harrington Sound. Mr. Ajemian is currently a PhD student at the University of South Alabama, which is using Harrington Sound as a model for assessing the impact the eagle ray has on local shell fish population dynamics.

Mr. Ajemian explained: "Harrington Sound is important because of the high abundance of milk conch, calico clam, scallops and oysters.

"The calico clam is especially important because Harrington Sound is one of the only places to find them in Bermuda.

"We have strong evidence that the rays eat calico clam and we can monitor their residency in Harrington Sound efficiently due to the fact there is only one way in and out (Flatts Inlet)."

After originally going to the Florida Keys to conduct the experiment, Mr. Ajemian found that Bermuda was a more workable environment and that it was easier to monitor the movements of the rays.

Mr. Ajemian noted: "The rays are not only very charismatic, but they are important predators to Bermuda and thus help maintain a healthy balance in the marine ecosystem."

One of the reasons he is interested in studying the eagle ray is that it is a close relative of the cownose ray.

"Understanding the predation of rays is important because their numbers are potentially increasing," Mr. Ajemian explained.

"This is cause for concern because in North Carolina the ray populations have grown so large that the bay scallop industry, which once thrived, is now almost dead, presumably due to the cownose ray population explosion and their ability to find highly dense patches of prey.

"Studying the spotted eagle ray will give us great insight into the roles of these animals in different ecosystems."

The project uses acoustic monitoring to track the rays in Harrington Sound. These are submersible hydrophones (underwater microphone) which listen for acoustic tags.

The tags are attached to the ray by corralling the rays and bringing them on board a skiff where they take an identification picture (each ray has a unique pattern like a fingerprint) measure the length, disc width (the wingspan a ray) and if they can they try to examine any stomach contents to see what the ray is eating. There are nine hydrophones in Harrington Sound, and one in Flatts inlet. They call the gate keeper because the rays have to pass it to enter or exit Harrington Sound. That means that the data obtained is solid and that they are unlikely to miss any (tagged) rays that come in and out of the sound.

Mr. Ajemian, who is originally from the north shore of Long Island, has spent his entire life on or around the water. He has been in Bermuda for the last two and a half weeks with another week to go and will return in September to examine all the data recorded from the acoustic monitoring stations.