Quantifying Nutrient Transport and Transformation in Stream Channels Associated with Active, Retired, and Restored Cranberry Farms

Scientists, postdoctoral research associates, and research technicians from the United States Department of Agriculture's Agricultural Research Service and the University of Massachusetts Cranberry Research Station have been conducting weekly water sampling in streams running through active and retired cranberry farms since the summer of 2022. Water sampling also occurs on former cranberry farms that have undergone active restoration to freshwater wetlands. The researchers are investigating differences in water chemistry among these diverse ecosystems. 

Eel River is one of the restored wetland sites of interest.

As part of this sampling, water quality sensors are used to measure dissolved oxygen, temperature, and pH. Monitoring these parameters is important for understanding stream health, as these factors impact growth and survival of many aquatic organisms.

Summer field technician Brenna Weston measures dissolved oxygen, temperature, and pH using water quality sensors (left) at a restored wetlands site, Manomet Brook (right).

After these data have been recorded, water samples are collected using a sampling pole.

Brenna collects a water sample at Manomet Brook (left) and Beaver Dam Pond (right).

One sample is collected to measure total nitrogen and total phosphorus. An additional sample is filtered to measure dissolved forms of nitrogen and phosphorus, including nitrate, ammonium, and orthophosphate. Nitrogen and phosphorus are of interest because when present in excess, these nutrients can contribute to nuisance algal blooms in coastal waters and freshwater ponds. Decomposing algal blooms can lead to low dissolved oxygen and impairment of sensitive aquatic ecosystems. A final sample is filtered to measure dissolved organic carbon. Measuring carbon can provide an indication of organic matter in the stream from sources such as algae and aquatic vegetation. All water samples are frozen and later analyzed in the laboratory. 

Brenna labels an unfiltered water sample at Tidmarsh (left) and filters a water sample at Eel River (right).

Water level loggers installed below each stream’s surface measure continuous stream depth. Data are downloaded from these loggers every month.

Brenna downloads data from a water level logger at Manomet Brook.

Seasonal differences in water depth and chemistry will be evaluated as data collection continues!