In late October, St. Johns RIVERKEEPER (SJRK) returned to the river for its third and final 2024 field visit as part of the five-year SAVe Our River’s Grasses Expedition. This trip wrapped up year two of the expedition. We continue to seek answers that will lead to solutions and help the struggling submerged aquatic vegetation (SAV) of the St. Johns River.
SAV is essential to the health of our river. It offers biofiltration, critical fish habitats, and nourishment for diverse aquatic species. Unfortunately, mounting threats to the St. Johns are placing intense pressure on this crucial vegetation.
Over four days, our team conducted our 6th survey of an 80-mile stretch of river between Doctors Lake and Lake George. During each field visit, we identify remaining grass beds, take detailed measurements, perform water quality tests, and explore solutions to restore this essential habitat with local residents and scientists.
What We Found
Unfortunately, there was an alarming loss of SAV along the expedition route due to back-to-back hurricanes, Helene and Milton, since our August field visit.
Consecutive hurricanes flooded the river with excess tannins from nearby swamps, transforming our blackwater river from iced tea clarity to a coffee-like opacity. These conditions block essential sunlight from reaching the river’s struggling eelgrass.
Hurricane Milton’s floods were prolonged as its sustained northeasterly winds caused the river to reverse flow for several days. Downstream water levels remain elevated due to the slow flow of the St. Johns and seasonal king tides that increase tide levels by 1-2 feet.
To make matters worse, the protective enclosure that was located at Dancy Point in East Palatka was compromised in early September. The eelgrass that was reaching historic lengths and density was reduced to stubble, succumbing to grazer pressure in approximately three weeks.
Post-storm conditions further complicated our survey efforts. Six of our 14 sites were inaccessible due to high, choppy water, and one site was inaccessible because of the presence of potentially toxic blue-green algae.
At the accessible sites, we measured water depth and SAV using a modified survey method due to high, dark water. At Dancy Point, we conducted a full survey with consistent methods from past visits to capture conditions before and after the fence breach.
Data Summary
Here are our findings from the seven accessible sites:
- All 7 Sites: Average depths from each site were 66.1 cm – 112.7 cm.
- Average water temperatures were in the mid to low 70s, averaging 74°F
- Open Sites: Average canopy heights ranged from 2-2.89 cm
- Average grass bed density ranged from 0%-34%
- Protected Sites: Average canopy heights of 10.5 cm
- Average grass bed density 67%
Our October visit was a stark reminder that much more needs to be done to give our river’s grasses a fighting chance.
What’s Next?
We are currently consolidating data from our three 2024 field visits, integrating additional agency data, and developing recommendations for advancing the restoration and protection of SAV in the St. Johns River.
2024 SAVe Our River’s Grasses Expedition Report Release Event
Join us on Wednesday, December 4, at Azalea City Brewing in downtown Palatka for an Expedition Report Release Event. We’ll share our 2024 SAVe Our River’s Grasses Expedition Report, answer your questions and express our gratitude to all of our partners. Learn more and RSVP for the event here.
This effort would not be possible without the support of riverfront residents who have volunteered their docks for our research, their neighbors who have supported us and gotten involved, advising scientists, community leaders, anglers, media experts, and all those who care for the river.
Exploring Solutions and Strategies for Moving Forward
Once finalized permits are received, we will install protective enclosures along our expedition route that will provide temporary relief for SAV from grazing pressures. While the enclosures are not the solution, they will provide valuable data as we search for long-term strategies to restore the river’s grasses.
To make this a reality, we appreciate the generous support of the Coastal Conservation Association (CCA) and Mighty River Recovery. Their dedication in conserving and restoring fish habitat aligns with our shared goal – to SAVe Our River’s Grasses.
Together, we are making a difference.
For The River. For Us All.
Support the Expedition
St. Johns RIVERKEEPER is conducting three more 80-mile research trips next year as part of our five-year expedition to SAVe Our River’s Grasses. Each multi-day trip costs up to $15,000 for staffing, water quality testing, lodging, fuel, equipment, and supplies. Please consider a gift to support our efforts to protect and restore these vital grasses.