New grant will help resource managers plan for increase in toxic algal blooms in Chesapeake waterways

September 19, 2017

Researchers from the University of Maryland Center for Environmental Science’s Horn Point Laboratory have been awarded funding to develop a new model to better predict the long-term occurrences of dangerous and costly harmful algal blooms in the Chesapeake Bay. The cooperative project is made possible by the Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program of the National Ocean and Atmospheric Administration's (NOAA) National Centers for Coastal Ocean Science (NCCOS).

algal blooms
“The harmful algal blooms in Chesapeake Bay have been increasing due to nutrient enrichment, and with climate change we are going to have more occurrences,” said co-investigator Professor Ming Li. “In this project we will be developing a new mechanistic model to predict the harmful algal blooms.”

The Chesapeake Bay and its tributaries have long suffered from harmful algae blooms, or HABs, caused by excess nutrients running off of the land, due largely to a continually growing population in the Baltimore-Washington corridor and the development of animal and plant agriculture in its watershed. Ecosystem-disrupting events, harmful algal blooms have shown marked increase in the past 20 years.

The three-year project will develop a framework for scientists and natural resources managers to understand the impact of blooms by two of the most common microscopic algae in the Chesapeake Bay. Prorocentrum minimum, better known as "mahogany tide," can severely reduce the amount of oxygen available to living things, killing fish and altering food webs. Kalrodinium veneficum produces a toxin that has been implicated in fish-kill events in the Chesapeake Bay, as well been as associated with failure of oyster spawning and development.

“This is not a forecasting model for three or four days out,” said Professor Patricia Glibert. “Our aim is to ask longer term questions, such as if temperatures warm by a certain amount, what effect will that have? If we were to reduce nutrients, how will that affect harmful algal blooms?”

The model would be a tool to play out a number of different scenarios to understand the impact of different potential management decisions and ecosystem responses over decades. Glibert, who has been working on understanding toxic algal blooms around the world, will be handling the physiological experiments. Li, an expert on modeling hypoxia in Chesapeake Bay, will focus on developing a numerical model for the HABs.

The Chesapeake Bay is not the only place facing such problems. Similar events are happening off the coast of China and in many parts of Europe.

"We're seeing this all over the world. More blooms, more often, lasting longer. In many places these trends are consistent with increased nitrogen loads," Glibert.

Climate change is expected to result in warmer temperatures, higher sea level, and a changing weather patterns that will further increase the amount of nutrient pollution running off the land into waterways. 

“We will be working closely with managers to develop scenarios and questions they wish to have us ask,” said Li, referring to groups like the Department of Natural Resources, Maryland Department of the Environment, and others. “We will add a model of the harmful algal blooms to an existing water-quality model and come up with a product that will be useful for managers.”