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Influx of red tide patients seen at CROW

By Staff | Nov 8, 2017

The Clinic for the Rehabilitation of Wildlife has seen an increase of brevetoxicosis patients over the last few weeks, which coincides with past years of when the influx of red tide patients flock through the door.

CROW Hospital Director Dr. Heather Barron said although they always have an occasional brevetoxicosis patient here and there, this year they did not have a red tide patient for a six week time span.

“They kind of trickle in here and there, but we really started seeing them, where we started getting multiple animals a day, about two weeks ago,” Barron said Thursday, Nov. 2.

Barron said they usually see signs of brevetoxicosis in patients October through April.

The hospital’s main patient for brevetoxicosis has been the double crested cormorant. Barron said Thursday morning that they had taken in 10 new cases of double crested cormorants.

“The age of the animal seems to often have an impact,” she said. “We will see immature cormorants and immature brown pelicans. It is much less likely to see a full sexually mature breeding adult coming in. It’s almost like they learn over time that if the fish is acting sick that maybe they should leave them alone. It is interesting to me that it is almost always the immature birds, the first and second year birds, with these clinical signs. I think it is because when you are an immature bird you are not a very good, proficient fisherman, so you will eat anything you can get. A sick fish is easier for them to get.”

In addition, they had an ibis, brown pelicans and some laughing gulls that were showing signs of brevetoxicosis. Barron said although the signs differ by species, red tide patients typically show an imbalance, weaving around like they are drunk. She said they also lose their fear of humans, resulting in the bird walking right up to them on the beach.

“Humans should be very careful, despite the fact that they are a little drunk they are not in a very good mood and they will definitely bite you. If they go to catch them up to bring them into CROW, they need to make sure to use a towel and that they are very careful to control the head of the bird,” Barron said.

CROW is currently looking at a new novel treatment. She said they are doing a clinical study and are hoping to get funding from a START grant, which is when they will go live with the information.

“Right now we are keeping it under wraps because it is a very novel, good idea and we are pretty encouraged that it will work. We are trying it with sea turtles in conjunction with the University of Florida, this new treatment, and we are also trying it in seabirds with brevetoxicosis,” Baron said.

She said they are going to work with sea turtles and sea birds with brevetoxicosis and collect data by treating a group of them the way they always do, as well as issuing the new treatment on another group.

Right now CROW treats the sea birds affected with red tide poisoning with fluids and often times blood transfusions.

“Sometimes they need blood transfusions because they are often anemic from this disease. Sometimes they need antibiotics because they get garbage gut from eating these very sick fish that are dying from red tide poisoning and makes them sick. They often present gastrointestinal signs and have diarrhea and vomiting and it often really damages their GI tract, so they often have bleeding and ulcers,” Barron said, which results in other treatments.

When they first arrive at CROW they find out exactly what is wrong, which is followed by treatment based on that diagnosis. Barron said for example if their potassium levels are low they are going to get potassium, or if anemic they are going to receive iron.

In addition, she said they will receive a special nutrition diet, a liquid diet that is easy for them to digest. They will gradually be worked up through a series of nutritional diets until they are back on whole fish.

Based on the species of the bird, it varies on how long they remain at CROW. The double crested cormorant typically spends seven to 10 days, pelicans recover within a couple of weeks and laughing gulls and terns can spend up to several weeks at the hospital.

When CROW starts seeing higher numbers of patients showing signs of red tide poisoning they notify the Sanibel-Captiva Conservation Foundation. She said every week they share with SCCF how many birds, and the types of birds they are receiving.

“Sometimes we have blooms where we only see cormorants, or only see pelicans, or we are pretty much just seeing gulls and terns. Then you will have other blooms where you see everything. But, right now it is mostly cormorants,” Barron said.

When Barron first arrived at CROW in January 2012 it was during a “horrendous red tide bloom.” She said there was dead fish everywhere, resulting in the hospital being swamped with cases.

Barron recalled thinking red tide is a common problem, so there must be a great deal of information in the literature about the problem.

“It turns out there was basically nothing,” she said, adding that there was literature about population affects and how red tide is documented, as well as a blood test to determine if it is red tide poisoning.

“There was little about how you diagnosis the individual and how you treat an individual and what are all the things that can be wrong with that individual because of brevetoxicosis,” Barron said. “So that is when we started doing our work. We did a study that was five research clinical trials based on birds and sea turtles with brevetoxicosis.”

She said through those trials they have learned quite a bit. Due to that research they have increased the probability of the sea turtles and sea birds recovering and being released.

“If you look globally at other rehabilitation facilities, treatment and survival rate is usually somewhere between 25 to 30 percent. We have brought it up to 55 percent here at CROW. Our survival rate is quite good and its actually up to 88 percent for sea turtles. We do have an excellent survival rate,” Barron said.

Sea turtles suffering from brevetoxicosis, she said typically take a minimum of 30 days, and sometimes up to 90 days, to recover and be released.

Barron said if individuals see an animal that is not acting right to call CROW and they will walk them through how to get the bird into the hospital, or they will send someone to catch the bird.

Humans, Barron said should be concerned with red tide as well because if they are walking along the beach they can inhale the toxins.

“As those algae wash up in the waves, it breaks the algal cell open and releases the toxins and they become aerosolized and you can breath them in. That can irritate anyone. You can sneeze a lot, or your eyes are itching, or the back of your throat is hurting,” Barron said.

In addition, if individuals eat sea animals that have brevetoxicosis, they can also get it as well, which causes severe GI upset. Barron said it’s rare that people show neurological signs, which is the main clinical sign that they see in species seen at CROW.

“All species tend to present differently, even in just bird species,” she said.

Although occasionally people will report irritation to the skin, Barron said it will not harm an individual if they swim during red tide.