The growing problem of harmful algal blooms & hypoxia in the U.S. & beyond
How is it that a chemical process developed prior to 1910 in Germany is now having significant effects on U.S. waterways?
Agricultural productivity is directly related to the holding capacity of the planet’s human population. Some estimate that the Earth could only support 3.5 billion people if fertilizers were not used. Indeed, the significance of manufactured nutrients is evident; more than half of the nitrogen in a typical person’s body originates from the nitrogen fixation process developed by Fritz Haber and Rudolph Bosch in the early 20th century. This breakthrough, along with other technological advancements in farming, led to the introduction of nutrients into our environment that increased agricultural production by 400% and supported the global population explosion, as pointed out by researcher Hugh Gorman in 2013.
Another impact of the Haber-Bosch process is the abundance of fertilizers in our environment, the water environment in particular. This source of nutrients, along with wastewater discharges, has led to a rise in harmful algal blooms (HABs) and hypoxic areas (“dead zones”) in the U.S. and across the globe. This was the topic of a panel I sat on at the National Council on Science and the Environment on behalf of the Water Environment Federation (WEF). The panel centered on HABs and their impacts on drinking water sources. As a water professional with more than 20 years of experience, I thought I had a handle on most major issues, but I learned a lot by participating in this discussion.
The prevalence of hypoxic zones and HABs has increased dramatically. Around 1910, there were fewer than 10 hypoxic zones globally, but the latest data show this number has increased to more than 480. The most significant of these areas in the U.S. are Chesapeake Bay and the Gulf of Mexico, which is the second largest dead zone in the world. The ability to monitor more effectively explains some of this increase; however, increases have occurred over the last few decades using the same or similar monitoring techniques.
There also have been increases in HABs both in number and geographic range. Recent examples of HABs in freshwater systems include Lake Erie, Lake Okeechobee, Utah Lake and the Jordan River. Coastal waters impacted include Chesapeake Bay, Florida estuaries, coastal waters of the Pacific Northwest, and waters off the coast of Maine. Much of this information is tied to research and support from groups such as the National Oceanic and Atmospheric Administration and U.S. Environmental Protection Agency, which track HABs and provide important information to states and communities on how to prepare and deal with issues surrounding them. The problems are not limited to the U.S., however. Chaohu Lake, which is 780 sq kilometers in size and one of the largest lakes in China, is severely impacted by algal blooms due to industrial and wastewater discharges as well as agricultural inputs that have been largely unchecked until recently.
Making an Impact
The species of algae associated with these events vary, but they all release toxins that impact either aquatic biota or humans, or both. The impacts to people are not limited to those who come into contact with or ingest water; there is evidence that those within the airshed of some HAB events also can be adversely impacted. The ability to predict these events is challenging, as they are highly variable due to the many factors involved, but it is clear that climate change is playing a role and likely will continue to do so. Advancements in monitoring and modeling have been made; however, reductions in the budgets of federal programs may stymie these efforts.
The ultimate result of HABs and hypoxic zones is economic loss and potential human health impacts. Losses of billions of dollars have occurred over the past few years due to impacts to tourism and the shellfishing industry. There have been at least four deaths and more than 100 cases of illness attributed to HABs. The nutrient sources associated with these events are well known and well documented: wastewater discharges and storm water runoff (urban and agricultural). The Clean Water Act (CWA) has effectively targeted the former.
The CWA, however, has not addressed runoff from urban and agricultural sources nearly as effectively yet, and this should not be surprising, as the CWA was specifically designed to address traditional point-source pollution. What is surprising is that we have not updated the CWA to shift with the changing focus of water quality challenges in this country. Unfortunately, when the CWA was assembled, agriculture was given a pass on water pollution impacts, with a few exceptions, and the agricultural sector has been resistant to change this. Other stakeholders also fear alterations, but for different reasons, namely that an altered CWA will be less effective in producing the environmental outcomes needed. If all stakeholders involved—farmers, environmental non-governmental organizations, municipalities and utilities—can set aside fears associated with change, then progress can be made to ensure that the responsibility to addresses issues such as HABs and hypoxic zones is shared by all stakeholders.
As William Ruckelshaus pointed out in his op-ed in the Wall Street Journal in 2010, “Yesterday’s solutions worked well on yesterday’s problems, but the solutions we devised back in the 1970s aren’t likely to make much of a dent in the environmental problems we face today.” The question then is not, “What should we do about the growing problems associated with HABs and hypoxic zones?” The question is whether we will have the courage and the will to make the changes necessary to be effective stewards of our water resources and the value these provide to our social and economic well-being.
Barry Liner of WEF and Steve Dy of Nexus Government Relations reviewed and provided input on this piece.