CORPUS CHRISTI, Texas — Environmental advocates say Corpus Christi’s latest desalination plans could threaten marine ecosystems by releasing highly concentrated brine into local waterways.

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Jake Hernandez with the Texas Campaign for the Environment said the group has long opposed the city’s desalination projects because of potential impacts to marine life.

“With the Inner Harbor desalination plant, the brine was planned to go right back out into the ship channel, which would create dead zones in the water,” Hernandez said. “The water would become over-concentrated with salt that could lead to a lot of things, like a loss in plant and animal life, red tide, and just generally degrading the bay in a way that we should not be tampering with.”

The Texas Campaign for the Environment has offered public comment against several of the city’s proposed desalination sites. Scientists have also raised concerns about how excess salinity could affect local marine ecosystems.

Dr. Edward Buskey with the University of Texas Marine Science Institute said changes in water chemistry could make conditions ripe for harmful algal blooms.

“Red tide is a harmful algal bloom. It’s caused by dinoflagellates — they’re protozoan organisms, they’re plants, they’re autotrophs,” Buskey said. “So they create toxins. It’s something we’ve had issues with in the past. But typically they don’t start in the Inner Harbor; they start in the Gulf of Mexico and move into the bays.”

Even the less controversial Harbor Island project, which would discharge brine into the Gulf of Mexico instead of local bays, raises ecological questions. Buskey said estuary-dependent species near Harbor Island could still be at risk.

“The problem is right at Harbor Island there are these estuary-dependent species,” he said. “There are larval fish and shrimp and crabs that could be impacted by that. The adults go out to the Gulf of Mexico, they feed for a while and have to go back in, and part of how they pick the location is the salinity level. So it’s possible to mess up all of that recruitment if you’re releasing brine into Harbor Island.”

City leaders have said desalination is key to meeting long-term water demands for residents and industry. Environmental groups counter that more research is needed before any project moves forward.

Stay with 3News for coverage of the city’s ongoing desalination proposals and potential environmental impacts as the situation develops over the coming weeks and months.