Why is Everyone so Concerned About Nitrogen and Phosphorus in the James River?

by Anna Salzberg, JRA's Outreach Intern 

Too much nitrogen and phosphorus in the James River can have negative effects on wildlife and the economy. Nitrogen and phosphorus are both nutrients that are used on land in fertilizers to help plants grow.  When these compounds end up in the waterways they can cause aquatic plants, particularly algae, to grow in excess. The growth of algae reduces light penetration and dissolved oxygen in the water.

In short, an overload of nitrogen and phosphorus (nutrient loading) impacts wildlife by altering habitat, the quality of available food sources, and the availability of dissolved oxygen. Specifically: 

1. An overload of nitrogen and phosphorus causes harmful algal blooms (HABs), which increase turbidity.  Turbidity is the measure of the amount of material suspended in the water.  Increasing the amount of turbidity of the water decreases the amount of light that penetrates the water column.  When sunlight is blocked out, then the underwater grasses aren’t able to grow and the whole food chain is disturbed.
2. HABs can result in fish and invertebrate kills when the algae damages and/or clogs gills. 
3. HABs result in the depletion of dissolved oxygen.  The HABs take up a major portion of the oxygen in the water; once formally available to other aquatic life, and then further depletes the dissolved oxygen upon decomposition.  This condition of impaired water quality due to an overall depletion in dissolved oxygen is called hypoxia.  Once all the dissolved oxygen is depleted, then the condition escalates to anoxia, which is commonly referred to as a “dead zone,” in which only a very limited species can survive. 
4. Some HABs form toxins that can cause illness or death for some animals.  These toxins are not that serious when ingested in small amounts by small fish or shellfish.  However, an accumulation of the toxins once ingested in large amounts by predators can result in health impairment or death.

In addition to having a negative impact on wildlife,  HABs cost governments and citizens billions of dollars in monitoring costs, water treatment, reduced property values, commercial fishery losses, and lost revenue in the tourism industry.  Consider this:

1. Monitoring and treatment of water is needed to catch indicators of affected resources, 
2. Upgrades to wastewater treatment plants are needed to remove nitrogen and phosphorus, 
3. Additional treatment of drinking water supplies is needed to remove algae, 
4. Property values are reduced by HABs (unfavorable in neighborhood lakes, ponds, etc.), 
5. The commercial fishery industry experiences losses due to increase in fish kills, 
6. Tourism Industry experiences losses from reduction in recreational fishing and boating trips.

Becoming a River Hero Home is one way you can reduce your contribution of nitrogen and phosphorus to local waterways. Do an analysis of your home’s stormwater runoff on JRA’s online calculator, www.whatsinyourrunoff.com/, follow six simple steps to protect water quality and you are on your way to becoming a becoming a River Hero Home.

The results of nutrient (nitrogen and phosphorus) loading can look like this! Fortunately, this photo was not taken in the James River watershed.

Source:  http://greenharvestgroup.com/feed-the-earth-blog/eutrophication-overview-results-excessive-nitrogen-amp-phosphorous-runoff-photos