ST. PETERSBURG, Fla. (WFLA) – Residents living near Coffee Pot Bayou and Riviera Bay Neighborhood Lake areas are complaining of dead pelicans.  Neighbors say dozens of dead pelicans have been popping up along the waterways since last week.

City officials have started to test the water to see what could be causing the birds to get sick.

Diane Cardin-Camleiter took photos of one of the dead birds Sunday.

“I was looking at the island and then I just looked down and there was one there just in front of me,” she said.

Cardin-Camleiter said the other pelicans did not look so well either.

Over the weekend, rescue groups took in more than 30 sick pelicans.

So far, city crews have collected 15 dead pelicans.

St. Pete officials said it’s a mystery on what’s causing them to get sick and die.

Some speculate a large fish kill from over the weekend, might be the culprit.

“We’re hiring a consultant firm to look at the water quality, develop an investigation and perhaps even if we can find any of the dead fish, maybe do some toxicology on those dead fish or any still present,” said John Palenchar, interim water resources director with the city of St. Petersburg.

In an effort to expedite and enhance current testing and investigation into a troubling discovery of sick birds near local waterways, the city of St. Petersburg is calling in an independent ecologist to assist.

Scientists with Arcadis U.S., based in Melbourne, Florida, have joined with St. Petersburg Water Resources and investigative crews from the Florida Fish and Wildlife Conservation Commission (FWCC) to gather clues into what is causing the Pelicans’ sickness.

City officials say they do not believe any partially treated waste water dumped into the bay late last year, caused the birds to become ill.

“The likely hood is so low, I hazard even comment what it could be. when you have a flushing system like this, anything that could have been here, has been gone for so many months now, any correlation would be wild speculation not based on any science I’ve ever seen,” said Palenchar.

Environmentalist speculate the fish kill from last week, could have a connection.

Preliminary test results for Coffee Pot Bayou and Riviera Bay show there are no quality control issues.