When I first joined Florida Sea Grant, my advisory committee told me one of the larger issues in our community was water quality.  As I dug a little deeper, they mentioned reducing fish kills and health advisories.  Those who lived in the bay area in the 1960s and 1970s will remember large fish kills, particularly in the bayous, and these were more often than not caused by low levels of dissolved oxygen.  Though there are several things that can cause low dissolved oxygen, excessive nutrients were a major problem.

The process worked like this.  Excessive nutrients (nitrogen and phosphorus) were washed into the bay from a variety of human and natural sources.  Human sources would include soaps and detergents used in washing cars, boats, etc.  It would include plant waste such as grass clippings and leaves from mowing and raking yards that were placed on the streets and washed into the bay during rain events.  It would include animal waste such a pet waste and human sewage that was either ran into the bay via stormwater drains, or accidentally from poorly maintained septic and sewer systems.  It would include the use of synthetic fertilizers used to maintain our lawns.  And there was also the problem of nutrients (from all the above sources) being discharged into creeks and streams in the upper part of the county washing down into the bay.

Once these nutrients reached the bay, they would trigger large algal blooms that began removing dissolved oxygen in the early hours before dawn.  These algae have short live spans and large die-offs would decrease the dissolved oxygen even further as their cells decomposed on the bottom.  The result, low dissolved oxygen and thousands – sometimes hundreds of thousands of dead fish.  The dead fish carcasses would draw the dissolved oxygen down even further.  You would have a dead zone.

The thing is I have only seen one major fish kill in our bay system in the last 20 years.  This was in Bayou Chico and was attributed to excessively warm water, which will also lower dissolved oxygen.  But the concern was there and so our first response was to begin monitoring nutrients.  We did this by enhancing the University of Florida’s LAKEWATCH program.  This is a program where we train citizen scientists (folks like you) how to sample local waterways.  These samples are analyzed at the LAKEWATCH lab in Gainesville and an annual report is provided every August.  We are currently monitoring six local waterways; lower Perdido Bay, Big Lagoon, Bayou Chico, Bayou Texar, Bayou Grande, and upper Pensacola Bay.  There are three sample stations in each body of water.  Since 2002 the numbers have looked good.  Most run between 200-300 µg/liter.  Bayou Chico is slightly elevated between 300-400 µg/liter, but these are still not high enough to be considered “hypereutrophic” (or at levels that could cause a fish kill).  There is one station that has caught our attention.  Station 1 in Bayou Texar has an average of 800 µg/liter.  Though this is still below levels of concern, there were questions as to why it is so much higher here.  The hypothesis is discharge (possibly human waste) from upstream in Carpenter’s Creek – but we do not know.

Though the current nutrient levels are okay, and fish kills have not happened in a long time, there are still things you and I can do to help avoid this problem again.

1. Wash your vehicles in a location where the soapy water does not reach the bay. If you wash your car in your driveway and the water runs down the street into a storm drain, it will reach the bay.  Rather, wash your car over your lawn.  If washing your boat at a local marina, use a product that is low phosphorus and deemed environmentally friendly.
2. Place your yard waste off the street, or in paper bags you can purchase from local stores. Many are not happy when the city comes to collect yard waste and leaves holes in their yards.  But this can be handled by placing the waste in paper bags and placing those on the side of the street.  We do not recommend using plastic bags for this.  Our local landfill can use this yard waste and make compost for landscaping – which is free to the community.  But they cannot compost yard waste in plastic bags.  You could also consider generating your own compost on site.  If you would like to learn more about how to do that, contact your county extension office.
3. Pick up after your pets waste. Pet waste left in yards and streets will eventually find its way to the bay.  Placing it in the trash can will help reduce this problem.
4. Maintain your septic/sewer system. One sewage treatment center manager told me if I could tell the public one thing, tell them to please quit pouring bacon grease down the drain.  Fats, oils, and grease harden in the septic/sewer lines just like it does in our arteries and can cause sewage overflows, which will find their way to the bay.  You can solve this problem by participating in ECUA’s FOG program.  In this program ECUA will provide you with a free plastic 1-gallon jug to pour your fats, oils, and grease in.  When full, you exchange it for a new at one of their numerous exchange stations around the county.  It is all free of charge.  You can find out more about this program at Fats, Oils & Grease. If you have a septic system, make sure you know what size it is and that you are not using more water than the system was designed to manage.  It is also recommended to have the septic system pumped every 3-5 years.  If you are on sewer, remember that the lateral pipe that connects your home to the sewer line in the street is the responsibility of the homeowner and should be inspected every few years to make it is working correctly.
5. Consider using the University of Florida’s Florida Friendly Landscaping Program. This program uses nine principles to help grow a beautiful lawn without the high use of water and fertilizers.  Not only does this reduce nutrients reaching the bay, but it will also save you money.  You can read more about FLORIDA FRIENDLY LANDSCAPING at Florida-Friendly Landscaping™ Program – University of Florida, Institute of Food and Agricultural Sciences – UF/IFAS.
6. If on rural or farmland, consider using agricultural BMPs. If you are interested in how to reduce fertilizer use and water run-off on a farm, contact your county extension office.

Again, though we have not seen this problem at the level it was in the 1960s and 1970s, there are still things we can do to help keep it from happening again.  As always, if you have questions about any of the above best management practices, contact your county extension office.

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