Algae in lakes: exploring the economic impact

     Exposure to toxins produced by blue-green algae can cause everything from mild nausea to major neurological damage. As a result, state agencies sometimes need to restrict access to bodies of water. This presents a difficult situation for decision-makers. On one hand, they must consider safety and liability. On the other hand, the economic impact can be substantial.

Who (not WHO) decides whether to shut down lake access due to algae

     The World Health Organization (WHO) has guidelines for safe levels of algae in lakes based on cyanobacteria density and toxin concentrations. However, these WHO thresholds are simply guidelines not formal rules. Therefore, a shutdown is often a local decision based on local standards.

How algae in lakes can hurt state and local finances

     There are several economic impacts of algae blooms. The most serious impacts include:

Loss of recreational and tourism income

     The most visible impact of lake shutdowns is on recreation and tourism. Take, for example, two Midwestern states that found elevated levels of blue-green algae in lakes used for recreation this summer. In Kansas, the state’s Department of Health and Environment needed to issue public health warnings for seven lakes. In Oklahoma, the state’s Tourism Department was forced to discourage swimming at several state parks.

     When people can’t enjoy the water, they don’t go to the water – and they don’t spend money or generate tax revenue near the water.

Increased water supply costs

     Algae in lakes can lead to greater costs for water treatment. First, it can be very expensive to repair damage from clogging. In addition, water treatment facilities need to budget more money for products to manage and remove algae. Algae derived taste and odor compounds have perhaps the greatest negative impact on drinking water quality. In the worst-case scenario, a water treatment plant may need to be shut down completely. That is what happened last summer in Ohio when a massive algae bloom occurred on Lake Erie.

Effects on other industries

     Algae blooms can affect other industries such as fishing and wildlife – especially with nuisance mat-forming algae, which may affect fish habitats.

     Control of algae in lakes is essential for a public health and safety. In addition, it can help maintain the health of your balance sheet, as well.


West Bishop is an Algae Scientist and Water Quality Research Manager at SePRO Corporation. He has an M.S. in Aquatic Toxicology from Clemson University and is a Certified Lake Professional through NALMS. He blogs about algae management and other algae-related topics for StewardsOfWater.com.