Saltwater Impoundment Water Sampling

Project Leads: Makayla Brown and David Wise | Organizations: University of South Carolina Beaufort and Brays Island Stewardship Fund

Within Bray’s Island, there are many saltwater impoundments used and managed for various purposes. These ponds occasionally experience sporadic algae blooms, resulting from an explosion of primary producers, or phytoplankton & diatoms, within the water. These ponds later undergo an anoxic, or oxygen lacking, phase ultimately resulting in a fish kill event. Our goal for this research is to collect as much pertinent information as possible to see if we can identify a cause, or methods of predicting, these fish kills.

Project Description

Our goal for this research is to collect as much pertinent information as possible to see if we can identify a cause of these fish kills. These impoundments produce different micro communities and experience algal blooms independently even though they are fed with the same water source. We will compare treated vs untreated systems. We will analyze salinity levels to determine freshwater imput into these systems. And we will track nutrients levels in these ponds.

It is important to note the history of these ponds play an important role in our research. Bray’s Island is a historic plantation consisting of farmland used for rice fields. As time passed saltwater was introduced to rivers and creeks around the area. Our findings could possibly be influenced by the historic past of Bray’s Island.

Methods

Throughout the summer of 2024, weekly water quality samples of all the salt water impoundments on Brays are collected for lab analysis. Water parameters are also recorded in the field weekly for each system. These parameters include:

- Temperature
- Salinity
- Dissolved Oxygen (DO)
- pH

In addition to weekly water quality data collection, we will implement two continuous DO sensors to continuously monitor dissolved oxygen over the course of a week. These sensors will be rotated to different ponds everyweek to collect continuous data from every system. in While we are in the field at Brays Island we’ll collect and store water quality data of the saltwater impoundments.

One-liter water samples are collected weekly from each salt water impoundment. These samples are placed under a microscope to identify any bacteria, cyanobacteria, diatoms, and algae that are present in the system. The samples are also filtered for:

- Total Suspended Solids
- Chlorophyll concentrations
- Phytoplankton DNA
- Bacteria DNA

Why this is Important?

Monitoring water quality in these saltwater impoundment fisheries is important because it helps sustaining marine ecosystem and supports a robust fishery.

- Ecosystem Health: Marine water quality directly impacts the health of plants, animals, and marine ecosystems. It affects the abundance of phytoplankton, which play a vital role in carbon sequestration and oxygen production.
- Fish and Marine Mammals: Water quality influences the growth and reproductive success of fish and marine mammals. Optimal conditions are necessary for their well-being and survival.
- Human Impact: Poor water quality affects us directly (e.g., beach visits) and indirectly (wildlife enjoyment, food harvest). Monitoring helps mitigate human impacts on marine environments.
- Fish Farming & Small-Scale Fisheries: In aquaculture, continuous monitoring of water quality parameters (e.g., CO2 levels) ensures optimal conditions for fish health, productivity, and yield. Maintaining appropriate water quality is critical for the livelihoods of small-scale fishery communities and the growth of aquatic species