Much of the original seagrass habitat in the Laguna Madre has been lost over the last several decades. 

What remains is now federally protected, and faces many challenges to stay alive.

Seagrass is a home for spawning fish and other marine life, and UTRGV professor Dr. Hudson Deyoe said the seagrass needs a delicate mix of light, nutrients, salinity and wave action to thrive.

"You can't replace seagrass with anything else," Deyoe said. "If you're going to lose x amount of acres of seagrass, you should have a plan to replace those in some manner."

Deyou is looking at the plan for a second causeway to South Padre Island that calls for an 8-mile bridge across the Laguna Madre.

READ MORE: Project for second South Padre Island causeway moves forward

Causeway planners showed Deyou several alternative causeway designs, he said.

"They were looking at these from a perspective of how much shading and stuff like that,” Deyou said.

Under federal policy, any damaged seagrass will need to be planted somewhere else.

"It's not like putting a seed in the ground and watering it, Deyou said, adding that the challenge ahead for planners is to transplant seagrass.

“You can't just take them from anywhere, you can't go in with a shovel and dig them up,” Deyou said. “You have to get permission to do those things, especially on a scale like this."

Cameron County Regional Mobility Authority Director Pete Sepulveda told Channel 5 News different causeway designs which may reduce how seagrass is impacted are being evaluated.

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