New study shows effects of hypoxia in Florida's Banana River

A new study by Florida Tech assistant professor of marine sciences Austin Fox, Ph. 15, found that low oxygen levels are contributing to the rerelease of nutrients buried on the river floor that feed harmful algal blooms.

This article has been reviewed according to Science X's editorial process and policies. Student Ben Crews, master's student Rebecca English and research technician Mary McDonald, was published in August in the journal Frontiers in Marine Science.

Using data on oxygen levels at the floor of the Banana River from 80 test locations, researchers mapped the places in the shallow estuary within the Indian River Lagoon system that had the most severe hypoxia, a condition of low dissolved oxygen levels that is dangerous to.

The testing found that oxygen levels were 10%–15% lower at the sediment level, what Fox called the "sediment-water interface"—than they were near the surface or at mid-depth, where accurate measurements are taken by other sensors for more typical water quality monitoring.

Importantly, the research team found that deposits of muck, a regional term used to describe the fine-grained, organic-rich, often gooey sediment that has accumulated on the floor of the Indian River Lagoon, are contributing to hypoxia as much as 500 meters (1, 640 feet) away. The data showed that 90% of the time, one or more of the sensors somewhere in the lagoon were recording hypoxic conditions.

It shows that nutrients such as phosphorus that have already been processed out of the system are being reintroduced to the water because of the hypoxia now detected at the sediment layer.

Fonte