Site Visit to Hog Creek

We were excited for our first field visit to Hog Creek in East Hampton last week, even though not on the best of days to be outside! Last Wednesday we planned our first monitoring visit for 2024 to Hog creek in order to determine if blooms of macroalgae were beginning to take form, as they did in previous years here.

Thanks to funding by East Hampton’s Community Preservation Fund, CCE Marine Program has been working in many waterbodies within East Hampton to identify where the highest levels of groundwater nutrients enter (seepage points). Our groundwater experts at CCE identified these areas and installed (and continue to manage) permeable reactive barriers (PRBs) that significantly lessen the amount of nitrogen in groundwater before it enters Hog Creek. As a second step to nitrogen remediation in Hog Creek, our coastal plant experts are leading bioextraction efforts to harvest macroalgae to improve water quality in the system and prevent eutrophication and anoxia. Macroalgae blooms consisting specifically of Ulva (sea lettuce) and potentially Cladophora, another fast growing green alga species that has been a nuisance in nearby creek systems in the past several years. Macroalgae overgrowth will be collected and weighed to quantify biomass, and approximate how much nitrogen is being removed through the harvest.

During our visit, we identified the areas along the western shoreline where large blooms had occurred in the past, and did observe Ulva beginning to grow in the area along with Cladophora. There were also hotspot areas in the headwaters, which will also likely end up with large blooms later in the season. With this information, we can now prepare the best areas to target and places on the shoreline we can bring the harvest to for analysis.

This project will engage the community through school visits educating students about macroalgae, teaching seaweed pressing, and an art show to showcase all of these efforts to the community. Stay tuned for more, including Ella’s first seaweed pressing adventure with John Marshall school, and opportunities for school visits to Hog Creek to help harvest seaweed!

Ulva, Cladophora and Gracilaria collected during our field visit.