Plans to build a 350-foot long rock groin off Sea Island to protect eight multi-million dollar homes were jeopardized Thursday by a coastal politician who fears the environmental impact on neighboring St. Simons Island.

State Rep. Alex Atwood, a Republican from St. Simons, sent a letter to Georgia’s commissioner of the Department of Natural Resources requesting a coastal committee reconsider its December vote allowing the groin.

Rep. Atwood noted that the full Shore Protection Committee failed to vote on the plan and that two environmental agencies “revealed that a new groin will negatively impact wildlife and threaten marine life.”

“Of particular concern,” he continued, “is the potential impact of such an endeavor on the East Beach community of St. Simons Island which lies so near the newly proposed groin.”

The Sea Island Company wants to build eight luxury homes — lot prices alone will run $3.5 to $5.5 million — along a sliver of beach, dune and marsh below the famed Cloister resort. The company says the groin, including a 120-foot wall parallel to the beach, will protect the so-called “spit” and not harm other beaches. A new sand dune will also be built to further buffer the home sites from tides and waves.

Dozens of St. Simons and Jekyll Island residents, as well as environmentalists, opposed the 2-1 decision by the coastal committee last month fearing the groin will impede the natural flow of sand along the barrier islands off southeastern Georgia, including St. Simons.

DNR commissioner Mark Williams, who chairs the committee, hadn’t seen Rep. Atwood’s letter as of late Thursday afternoon, so he declined comment.

Scott Steilen, president of the Sea Island Co., said the groin and beach renourishment proposal “meets state and federal criteria for shoreline protection projects.” Steilen, in an email to The Atlanta Journal-Constitution, added that the new beach will increase habitat for sea turtles and reduce storm damage to “the spit.”

“The existing renourished beach on Sea Island is evidence that the shoreline can be protected without causing any significant impact to other shorelines locations,” he said, adding that only an Administrative Law Judge can weigh an appeal.

The U.S. Fish and Wildlife Service must also sign off on the project. Environmental groups are mulling legal action.