The article examines how alterations in nutrient loadings, particularly nitrogen (N) and phosphorus (P), impact water quality in various aquatic ecosystems, with a focus on the Chesapeake Bay watershed. High concentrations of these nutrients can lead to increased primary productivity, affecting entire landscapes. The study specifically investigates the relationship between phosphorus loading and its accumulation in stream biofilms using an in situ enrichment system (ISES) to simulate realistic P loading conditions.
Researchers hypothesized that polyphosphate (PolyP) accumulation in biofilms could indicate past legacy P loading and the capacity of streams to assimilate new P. The study involved multiple sampling sites in Pennsylvania, where biofilms were enriched with different levels of P, and various forms of P were analyzed, including total particulate P (TP), polyP, and inorganic particulate P (PIP).
Results showed that P accumulation in biofilms correlated positively with increasing P loading, demonstrating the potential of PolyP as a storage mechanism during nutrient pulses. The findings suggest that ecosystem legacy P loading influences the ability of stream biota to take up additional P and that areas with high legacy loads exhibit reduced capacity to assimilate new P. Overall, the research highlights the importance of understanding nutrient dynamics for assessing stream health in the context of watershed management and climate change effects.
