FOX10 Investigates: Testing the Bay: Pollution making some seafood unsafe in Mobile Bay

An aerial view of Mobile Bay from the Theodore Industrial Canal. (Credit: Bill Flowers, WALA FOX10 News IT Administrator)

For folks who live on the Gulf Coast, the Mobile Bay plays an integral role, whether you enjoy the Bay's seafood, or just taking a swim.

But, how clean is the bay, really?

FOX10 News Investigates found eating some seafood from Mobile Bay could pose a danger to your health.

State agencies have prohibited shellfish harvesting and oyster growing in the northern end of the Bay, because of pollution concerns.

That prompted FOX10 News Investigates to take a closer look at what's accumulating in the Bay, even testing the sediment at the bottom.

Now, some fishermen say they'll think twice before biting into their fresh catch.


FOX10 News Investigates collected 13 years of sediment testing data from the Army Corps of Engineers.

The corps tests the sediment at the bottom of the Bay before they begin to dredge it.

According to their testing reports, arsenic and mercury are two of the most prevalent metal pollutants to have been found in Mobile Bay sediment over the years. Interactive map: See what areas of the Bay have seen elevated pollution levels over the yearsWhen the southern end of the Bay was tested in 2014, more than half of the samples had arsenic levels above the threshold effects level used by government agencies, which means the pollutant has the potential to create a negative effect on the aquatic life nearby.

In 2010, documents show the Corps found elevated arsenic levels in every sediment sample taken, spanning the entire length of the Bay.

In 2006, the Corps tested the northern end of the Bay, near the mouth of the Mobile River. Half of those samples tested had mercury levels above the threshold effects level, also posing a possible threat to marine life.

According to the Environmental Protection Agency (EPA), both arsenic and mercury can bioaccumulate, which means as those contaminants are ingested, they build up in the body over time, threatening the health of predators, like humans, as the pollutant makes its way up the food chain.

To see a complete list of metal pollutants found in the Corps testing, click here.


With the historical data from the Corps in mind, FOX10 News Investigates took four sediment samples from the Bay in May 2017.

The areas tested were the eastern tip of Dauphin Island, the Fairhope Pier, just south of the Mobile River, and just outside the Theodore Industrial Canal.

The Dauphin Island Sea Lab lent a device to assist in collecting the samples. Known as a Petite Ponar, the device works like a pair of jaws to scoop up the sediment from the bottom of the Bay and bring it up securely to the surface to be collected as a sample.

Our samples were all taken on the same day, and were kept in a cooler to be preserved, per the laboratory instructions.

The samples were then sent to the Agricultural and Environmental Services Laboratories at the University of Georgia to be tested for 13 different metal pollutants, as well as fecal matter.

Dr. Jason Lessl supervised that testing.

“We do an acid digestion, (where) we are basically stripping the metals off of the clay, sand, and silt particles in the sample, we digest it at a high temperature, we're trying to get as much of those metals off of the surface, and then we measure those,” he explained in an interview with FOX10 News Investigates after conducting the testing.

The samples from Dauphin Island coast and the Fairhope Pier had low contamination levels.

Dr. Lessl said that may be because those samples had more sand than mud, making it difficult for pollutants to stick to the sediment.

However, the samples taken outside the Theodore Industrial Canal, and the mouth of the Mobile River had more mud and clay, as well as more contamination.

Just like the Corps of Engineers testing, those two samples also showed arsenic levels above the threshold effects level, meaning there could be a potential for negative effects to marine life.

Dr. Lessl said the threshold effects levels set for metal pollutants are very conservative values, so it would be important for scientists to further assess the sediment toxicity levels before drawing any conclusions.

"That would warrant further investigation, to verify, whether there is cause for concern as far as potential health risks are concerned,” explained Dr. Lessl.

The mercury results in the Theodore and Mobile river samples were borderline to the threshold effects level, which means there would be a small possibility that the pollutant could cause adverse effects to marine life nearby.

However, Dr. Lessl said that could still raise a red flag, because remember, pollutants like arsenic and mercury can accumulate in the body, posing health risks over time.

According to the World Health Organization, "arsenic and arsenic compounds (are) carcinogenic to humans… and exposure to mercury - even small amounts - may cause serious health problems" including "toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes."

"If this is an area where people are just swimming, then there is a very, very low concern, but if they're fishing, especially eating any kind of bivalve, mussels, clams, oysters, if they're harvesting those kinds of animals from those waters, and consuming them, then there absolutely would be good reason to do further investigation to determine if there is any kind of health risk,” Dr. Lessl explained.


These findings seem to align with current shellfish and oyster harvesting restrictions placed in the Bay.

Documents show the Alabama Department of Public Health has prohibited shellfish harvesting and oyster growing in the northern section of the Bay, and the Delta, due to "dangerous" pollution concerns.

The Mobile River is even considered an "impaired" body of water by the state for high mercury levels, with government officials issuing a fishing advisory for the river, warning fishermen to not eat any Largemouth Bass caught there, due to dangerous levels of mercury in their tissues.

But, some locals, who love to fish recreationally in those areas, had no idea their health could be at risk.

“I'm glad you told me about it, because I didn't hear nothing about it,” local fishing enthusiast, James Whatley, told FOX10 News Investigates, “that scares me, that's not good."

“I have seen people fishing everywhere, and I have never seen the first sign about anything,” said Rob Morrison, who loves to fish in Mobile Bay.

FOX10 News Investigates also showed fishermen our sample results, as well as the sediment testing data from the Corps of Engineers.

“It aggravates me pretty bad, because they should let people know about this,” said local recreational fisherman Tommy Crooke. “This is a safety hazard, you know, how many people are dying because of this stuff, and they're not warning them about it?"

“It's depressing, because I know that so many people is affected by what comes out of Mobile Bay,” said Morrison.


A number of things can cause high pollution levels.

The EPA said industrial emissions, agricultural runoff, and urban waste can all play a part.

However, it's unclear as to what specific sources may be causing concerning levels specifically in Mobile Bay.

"That spooks me, they need to be doing something about it, as quick as they can,” said Whatley.

So what are state environmental enforcers doing about the sediment quality? They won't tell you.

In a state water quality assessment report sent to the federal government, the Alabama Department of Environmental Management (ADEM) said it has tested the sediment for metal pollutants near "shipyards, petroleum storage terminals, and (other) industrial sources" but it won't make a statement about the levels of toxic pollutants found in those areas, "because no state or EPA criteria for toxins in sediment exist."

However, other ADEM documents show that isn't exactly true; in a manual written by ADEM, the agency clearly explains that it uses EPA screening values to determine the toxicity of sediment.

"They hiding it, they don't want people to know just what they found, and the people want to know,” said Whatley.

FOX10 News Investigates tried reaching out to ADEM for clarification about this discrepancy, but haven't heard back.

Locals who love the bay, meanwhile, are worried.

"If anybody eats anything out of here, I firmly believe that we have the right to know what's going on in the water, if the government knows that the sediments is bad, then y'all better speak up,” said Morrison. Interactive map: See what areas of the Bay have seen elevated pollution levels over the yearsFOX10 News Investigates has taken the time to compile the 13 years of U.S. Army Corps of Engineers sediment testing data along with our FOX10 News testing results, and we have put all of that information in an interactive map, so you can see what pollutants were found in specific locations around Mobile Bay.

Also, if you would like to read more about certain fishing advisories currently in effect, here are some links to public websites explaining what you need to know.

First, here is a list of all of the bodies of water in the state that have fish with high levels of dangerous pollutants in their systems.

Second, here is a map of the prohibited shellfish harvesting and oyster growing areas in Mobile Bay.

To read ADEM’s complete Water Quality Assessment of state waters, click here:

To see a list of all of the bodies of water in the state that ADEM has listed as “impaired” due to pollution concerns, click here:

The EPA’s National Coastal Condition Assessment found that the ecological fish tissue quality in the Gulf Coast Region is the worst in the country. According to the EPA, 69 percent of the fish tissue studied in the Gulf Coast region is in poor condition, 26 percent in fair condition, and zero percent in good condition. The most prevalent contaminants in the tissues of fish are mercury, arsenic, and selenium. Remember, both arsenic and mercury have been found to be significant pollutants in Mobile Bay.

The assessment also found that Gulf Coast region has the worst coastal water quality in the country, and that the sediment quality in Gulf Coast waters has significantly decreased since 2005. To read the full assessment of the nation’s waters, click here:

All content © 2017, WALA; Mobile, AL. (A Meredith Corporation Station). All Rights Reserved.


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