Annual 2024 Biological Monitoring Report for Sand Dollar Island

On April 17, 2025, during the Hideaway Beach District Monthly Meeting, Marielle Nageon de Lestang of Turrell Hall and Associates presented the 2024 Annual Biological Monitoring Report on the Tigertail Sand Dollar Island Restoration Project. This report included Water Quality Samples, Submerged Aquatic Vegetation (SAV), Berm Data, which included bird nesting season results and sea turtles nesting results for 2024, and Mangrove Health for 2024.

According to Nageon de Lestang, “Total nitrogen (TN) has been consistently high in the system since we’ve been collecting sampling. It was really, really high in November after the three summer storms, but it was also really, really high in the entire City, but maybe it is just storm damage that was causing this.”

On total phosphorus (TP), Nageon de Lestang added, “This kinda went up and down, and the South End was hardest hit with total phosphorus, but there was a strange outlier in July and we don’t know why. It could just be that when all the birds have shown up and it started to rain, and people also have been using the berm, so there was a lot of fecal material, and potentially that was the cause. We also don’t have as much sea grass with all those summer hurricanes, so water does not get filtered.”

Vice Chair Dick Delawder made the following comments on Water Quality: “The City is very concerned with the amount of nitrogen and phosphorous found in the waters in the canals and also in the waters surrounding the Island. It has made the newspaper at least ten times this year. And they are somewhat blaming us for something, and one is draining of our ponds but where are we in terms of nitrogen and phosphorus? Does it look like it is leveling out now?

 “The total [phosphorus is doing what it has always done going back to 2021 and definitely not any worse,” said Nageon de Lestang. “There are a couple of high spots, but I suspect the total phosphorus has something to do with your bird population here on the island.”

On total nitrogen Nageon de Lestang added, “It does seem to be high, but if you look back to 2021, it was higher except for November 2024 with three hurricanes.”

Delawder added, “I think we need to notify the City through Turrell Hall that we don’t think we are doing anything incorrectly to make either TN or TP go higher.”

Chair Ryan added, “Justin Martin, Hideaway’s liaison, is also working on water quality issues through the Waterways Advisory Committee and can take this data and incorporate it with his work on water quality.”

On seagrass, Nageon de Lestang said, “The kayak bay recorded more seagrass in 2023, but it all got buried by the 2024 summer storms and further south, it has gotten a lot of sand.” Nageon de Lestang added, “There is a lot more human traffic with beach goers taking shortcuts to the beach. South lagoon does not have any seagrass this year; the system is in shock, starting with Hurricane Ian.”

On the Berm and Bird Nesting Report - “For 2024, there were nine black skimmer nests last year but were predated by coyotes and crows; 12 Wilson’s Plover also predated by coyotes, crows, and summer storms; one Least Tern nest.” According to Nageon de Lestang, “Our bird situation is at the mercy of wildlife, and FWC is already working on some coyote control this year.”

Sea Turtle Season 2024 was skewed this season due to storm breaches created by the summer storms, which prevented the sea turtle monitors from surveying Tigertail and Sand Dollar areas past mid-August.