And there's one more source of confirmation tonight that the New River is polluted.

Dr. Marisa Tellez, the Executive Director of the Crocodile Research Coalition, is an expert in these apex predators. For several years now, she has been working with the government in a fascinating study and survey of the entire crocodile population in Belize. Her team and the Government are trying to come up with a conservation and management action plan to make sure there's less contact with human populations.

We'll have more on her research in subsequent newscasts next week, but today, in an extended Skype interview, she told us that while she and her team were surveying the crocodile population in Northern Belize, they encountered several of these animals in a very sick and weakened state. The only conclusion that she and her international colleagues have arrived at is that the New River's pollution is killing off these animals.

Here's that part of the conversation that she had with us today:

Dr. Marisa Tellez - Executive Director, Crocodile Research Coalition
"Conducting these surveys across the country, we did come to a point of concern in regard to what we were finding along the New River. Especially around Orange Walk Town. We were finding crocodiles that were highly lethargic. Their skin was peeling off. Their skin was turning a whitish-bluish tone. We found many young crocodiles with no teeth. And a few of the crocodiles that we did catch that was considered problematic in that particular area, within a few weeks, they would die. And when we conducted the necropsy, and I have conducted necropsies on hundreds of alligators, as well as crocodiles, and their organs were disintegrating. So, these crocodiles were illustrating that they were slowly dying for months. And I actually showed the results to some of my international colleagues who specialize in crocodile veterinary practices. And all of them had discussed that this was the result of some type of some chronic, or long-term exposure to stress or to pollution. We had seen this in other crocodiles elsewhere, where crocodiles were highly exposed to pollution or some type of external stress, such as in South Africa. I've seen it in Cayman and in Brazil. And, there was one particular crocodile. It was a 9-10 foot Morlet's Crocodile, highly lethargic, and when it finally passed away, when we did the necropsy, its kidneys dissolved in our hands. And a lot of the organs were just already deteriorated."

"Do you see this in other parts of the country?"

Dr. Marisa Tellez
"The only other area that we have seen this was on Ambergris Caye, and we have photos and we have data, from even before this CRC was established. So, this was as an individual researcher, at this point. This was about 2013-2014. We found a population of crocodiles on Ambergris Caye that was illustrating some of the same symptoms. But not as bad as the New River crocodiles. And then, it was about 2016, we went to a particular area, of Ambergris, and we have pictures of crocodiles, and we observed the behavior of crocodiles eating trash. And they were fighting over trash. And we caught some crocodiles that illustrated that they were slowly dying as a result of eating trash but also being exposed to some type of chemicals that were in the water."

"And we have to understand, that the crocodiles are at the top of the food chain. So, they bio-accumulate. They're fantastic red flags in regards to what's going on in the environment."

"When we conducted our capture population survey on New River, we did start seeing the symptoms. We did start observing the symptoms of the crocodile about a quarter-mile north of what seems to be the epicenter of the issue. And our boat captain did take us to the river where the effluent was of BSI. I did not know it was BSI at the moment. The water registered at 40 degrees Celsius. There were tonnes of algae, all over. And as we started going towards the river mouth."

"Going towards Orange Walk Town, that's where we started finding pockets of dead fish. That's where we started seeing some of these crocodiles with the algae. And we saw these issues in the Crocodiles. the Crocodiles that were living closer to BSI, illustrated more of the symptoms."

"I'm very concerned about the communities, not just for their health, but economically as well. So many people depend on that river for their livelihood, whether if it's fishing - and that's the other thing. People may be hunting in that area, but the mammals are going to the river to drink that water. What are they ingesting, and what then would we be consuming?"

Channel 7