National Estuaries Week! – Problems in Our Bays

National Estuaries Week! – Problems in Our Bays

The red area indicates where dissolved oxygen levels are low.

The red area indicates where dissolved oxygen levels are low.

I don’t want this to sound like a “Debbie Downer”… but there are problems with our estuaries and panhandle residents should be aware of them. There are things you can do to correct them – which we will discuss in the final issues of this series – but you need to understand the problem to be able to solve it. Unfortunately there are many issues and problems our bays and bayous face and we do not have time in this short article to discuss them all, but we will discuss some.

 

We’ll start at the top… with our rivers. Since the founding of our nation many communities were built on estuaries; those that were not were built on the rivers. Water was an easy way to move throughout the country – much easier than wagon crossing over the Appalachians or through a bog. There are several communities that developed along the rivers that feed the panhandle bays. Though the situation has improved in the last few decades, most of these communities have used these rivers as a place to dump their waste. Assorted chemicals, sewage, and solid waste were discharged… and it all came down to us. The Mississippi River is an example of this problem. Discovered in the 1990’s the Louisiana Dead Zone is an area in the Gulf where the levels of dissolved oxygen are so low that little or no life can be found on the ocean floor there. It is believed to be trigger by nutrients, chemical fertilizers and animal waste, being discharged upstream. These nutrients create a bloom of plankton, which can darken the water. Though the phytoplankton can produce oxygen during the daylight hours, they consume it in the evening, lowering the concentration of dissolved oxygen within the water column. The plankton are relatively short lived and eventually die. As the dead plankton fall out to the seafloor bacteria begin to decompose their bodies thus dropping the dissolved oxygen levels further. When the dissolved oxygen concentrations drop below 4.0 millgrams/liter we say the water is hypoxic (low in oxygen). Many species of aquatic organisms begin to stress. At 2.0 mg/L many species will die and we have a “dead zone”. If it reaches 0.0 mg/L we say the water is anoxic (without oxygen). This process is called eutrophication and not only a problem at the mouth of the Mississippi River, it occurs in almost all of the bays and bayous of the panhandle and is the primary cause of local fish kills.

 

A more recent issue with our rivers has been the reduction of water. In the so called “Water Wars” the state of Georgia has used its damn system to block the flow of the Chattahoochee River to create electricity and a reservoir of drinking water for river communities. Under normal conditions this has not created a problem however in recent years the southeast has experienced drought and the state of Georgia has had the need to hold back water for large communities – such as Atlanta. This has reduced the amount of water flowing towards the Gulf and has impacted communities all along the way. It is not the only issue but is the primary factor triggering the collapse of the oyster industry in Apalachicola. The reduced freshwater flow has increased salinities in the bay. This has disrupted the life cycle of the eastern oyster and has increased both predation and disease within these populations. Apalachicola produces over 90% of Florida’s oysters and 10% of the oysters for the entire country! Oysters are a huge industry in this town. Many are oystermen and many others process the product when it is landed… the industry is on the verge of collapsing. (Learn more).

 

Oysterman on Apalachicola Bay. Photo: Sea Grant

Oysterman on Apalachicola Bay.
Photo: Sea Grant

These are just some the issues stemming from the rivers… what about the issues initiated from the communities that live along the bay…

 

How about the seafood? We discussed the oyster industry in Apalachicola Bay but oyster production in other local bays has declined as well (for other reasons). Scallops are gone from many of their historic estuaries, shrimp and blue crab landings are down, this year mullet seem to be hard to find. What is going on here? For the most part the decline in seafood products can be tied to either a decline in water quality or from over harvesting. The harvesting issue is easy… do not harvest as much. However these fisheries management decisions impact many lives and has caused a lot of debate. First you need to determine whether the decline is due to overharvesting or some other environmental factor… easier said than done. Certainly the biology of your target species will give you an idea of how many animals you can remove from the system and sustain a healthy population (maximum sustainable yield) but this method has triggered debate as well. Most fishermen do not want to see the fishery collapse and are willing to work with fishery managers to assure this – but they do have bills to pay. Fishery managers have a responsibility to assure the fishery remain for current and future generations of fishermen and they are basing their decisions on the best available science. It is a touchy subject for many and a problem within our estuaries.

 

The other cause of declining seafood is poor water quality. You can talk to any “ole timer” and they will tell you about the days when the water was clearer, the grass was thicker, and the fish were more abundant… what happen? I spoke with my father-in-law before he passed away about the changes he saw in Bayou Texar in Pensacola. He remembers being able to see the bottom, more seagrass, and being able to catch a variety of finfish as well as shrimp the size of your hand. The first change he remembered was a change in water clarity… it became murkier… and this happen about the time they began to develop the east side of the bayou. As our communities grew more land was cleared for development. The cleared land allowed more runoff to reach the creeks, bayous, and bays. Infrastructure had to be placed to reduce flooding of yards and streets – Bayou Texar has 38 storm drains. All of this led to more runoff into our water ways. With the increase in turbidity the amount of sunlight reaching the bottom was reduced and seagrasses began to decline. Many species of seagrass require salinities of 25 parts per thousand or higher and the increase in freshwater runoff lowered the salinity which also stressed these grasses. Much of this runoff included sand and silt and the grasses were basically buried. All in all seagrasses declined… and with them many of the marine creatures. Salt marshes were removed for coastal developments, industries were located on our rivers and bays and introduced their chemical discharge, and boating activity increased… our estuaries were being literally “loved to death”. I have seen in my lifetime the decline of sea urchins and scallops from our bay, the increase in turbidity, and the decline of seagrasses. But we cannot blame all of this on habitat loss and pollution. Speaking recently with fisheries managers they believe the recent decline in blue crab landings is due to drought. Reduction in rainfall means reduction in river discharge, which means an increase in salinity and a disruption of the crab reproductive cycle.

Power plant on one of the panhandle estuaries. Photo: Flickr

Power plant on one of the panhandle estuaries.
Photo: Flickr

 

Another problem that is associated with runoff has been the increase in bacteria. Fecal coliform bacteria are found in the stomachs of birds and mammals. They assist with our digestion and are released into the environment whenever we (or they) go to the bathroom. So finding fecal coliforms in the water is not unusual… the problem is TOO many fecal coliforms. As mentioned coliforms are not a threat to us but they are used as an indicator of how much waste is in the water. Feces harbors many other microbes in addition to coliforms – hepatitis and cholera outbreaks have been linked to sewage in the water. So agencies monitor for these each week. Most agencies will monitor for E. coli when sampling freshwater and Enterococcus in saline waters. E. coli values of 800 colonies / 100 milliters of sample or higher, and Enterococcus values of 104 colonies / 100 ml of sample will trigger a health advisory being issued – and some bodies of water being closed. In the Pensacola area the Florida Department of Environmental Protection and the Escambia County Health Department both monitor for bacteria. They post their results each week and I, in turn, post to the community. Our local bayous are averaging between 8-10 advisories each year. The problem with these advisories is that residents who live on the waterways, businesses (such as hotels and ecotours) who use the waterways become concerned about entering the water. It is not good for business or property values if the body of water you are on has high levels of bacteria and signs posting “no swimming”.

 

Closed due to bacteria. Photo: Rick O'Connor

Closed due to bacteria.
Photo: Rick O’Connor

 

There are many problems our estuaries are facing but for this article we will end with solid waste. Trash and garbage has been a problem since I can remember. Campaigns have been launched each decade to try and reduce the problem but the problem still exist. Plastics and monofilament litter the beaches and waterways creating problems for marine life and an “eye soar” for those enjoying the bay. I am currently working with the Wildlife Sanctuary of Northwest Florida and CleanPeace to monitor solid waste in Pensacola Bay. Each week CleanPeace host a Saturday event they call “Ocean Hour” where they select a location on the bay and clean for an hour. They submit the top three items to me each week and have been doing this since January… it has been pretty consistent… cigarette butts, plastic food wrappers, and plastic drink containers. We are not going to get rid of garbage on our beaches but if we can consistently reduce the “top three” we should be able to reduce the problem.

 

More on what we can do to help in the final issue.

Looks like a Typical Year for the Gulf of Mexico Dead Zone

Looks like a Typical Year for the Gulf of Mexico Dead Zone

What is the Gulf of Mexico Dead Zone you ask? Well…it’s a layer of hypoxic water (low in dissolved oxygen) on the bottom of the Gulf of Mexico. It was first detected in the 1970’s but reached its peak in size in the 1990’s. The low levels of dissolved oxygen decrease the amount of marine life on the bottom of the Gulf within this zone, including many commercially valuable species supporting the Gulf seafood industry.

 

The red area indicates where dissolved oxygen levels are low.

The red area indicates where dissolved oxygen levels are low.

What Causes this Dead Zone?

Drops in concentrations of dissolved oxygen within the water column can occur for a variety of reasons but is usually caused by one of two reasons. (1) Increasing water temperatures—as water temperature increases, its ability to hold dissolved oxygen decreases. (2) A process called eutrophication.

 

What is eutrophication?

Eutrophication is a process where an increase of nutrients in an aquatic system triggers an algal bloom of microscopic phytoplankton. These phytoplankton produce oxygen during the daylight hours but consume it in the evening. Once the bloom dies, decomposing bacteria begin to break them down and consume larger amounts of dissolved oxygen in doing so. When the dissolved oxygen concentrations drop below 2.0 mg/L we say the water is hypoxic and many marine organisms either begin to move out or die. The nutrients that trigger such blooms are primarily nitrates and phosphates. These can be introduced to the water column with plant and animal waste and with synthetically produced fertilizers we use on our fields and lawns. There is natural eutrophication, but when the process is triggered or accelerated by human activity we use the term cultural eutrophication.

 

So which is it; warming waters or eutrophication?

The Gulf of Mexico Dead Zone usually forms in spring and lasts through September. These are certainly the warmer months of the year, but the warmer waters are near the surface and much of the water column is not warm enough to cause this. Another point is that the Dead Zone is near Louisiana and there are warm locations in other parts of the Gulf where dead zones do not occur. However the Mississippi River does discharge near Louisiana. This river drains 41% of the continental United States, which contains 52% of the nation’s farms. The agricultural waste (plant, animal, and synthetic fertilizers) discharged into the Mississippi River contains nitrogen and phosphorus, the two key nutrients that trigger algal blooms. Based on this, most scientists agree that cultural eutrophication is the primary cause of the Gulf Dead Zone.

 

When they say it will be a “typical year”, what does that mean – what is a “typical year”?

Scientists from NOAA, the U.S. Geological Survey, and six partnering universities have released their annual forecast of the Dead Zone. The 2015 prediction has the area of the dead zone about equal to the size of Connecticut, which has been the average size for the past several years. This is what they mean by typical.

 

Can these dead zones occur in our area waters?

Yes, and they do. We do not typically call them “dead zones” but the same process occurs all over the world, including the bays of the Florida panhandle.

 

What can we do to reduce cultural eutrophication locally?

If you can do without fertilizing your lawn (or field), then do. If this is not an option then only put the amount of fertilizer required for your land/lawn. Most people over fertilize, which not only reduces water quality but is expensive for the property owners. If you can compost your plant waste, do so. With animal waste, please dispose of properly, in a manner where it not reach local waterways.

 

For more information on hypoxia, eutrophication, and solutions to reduce this problem, contact your county Extension office.

 

 

http://www.tulane.edu/~bfleury/envirobio/enviroweb/DeadZone.htm

http://www.iseca.eu/en/science-for-all/what-is-eutrophication

http://earthobservatory.nasa.gov/Features/Phytoplankton/

3 Ways You Can Help Keep Our Bays Healthy

3 Ways You Can Help Keep Our Bays Healthy

Following a previous article on the number of ways you can help sea turtles, this week we will look at ways that local residents can help keep our waterways clean. Poor water quality is a concern all over the country, and so it is locally as well. When we have heavy rain all sorts of products wash off into streams, rivers, bays, and bayous. The amount and impact of these products vary but most environmental scientists will agree that one of biggest problems is excessive nutrients.

 

Marine science students monitoring nutrient levels in a local waterway.  Photo: Ed Bauer

Marine science students monitoring nutrient levels in a local waterway. Photo: Ed Bauer

Nutrient runoff comes in many forms. Most think of fertilizers we use on our lawns but it also includes grass clippings, leaf litter, and animal waste. These organic products contain nitrogen and phosphorus which, in excess, can trigger algal blooms in the bay. These algal blooms could contain toxic forms of microscopic plants that cause red tide but more often they are nontoxic and cause the water to become turbid (murky) which can reduce sunlight reaching the bottom, stressing seagrasses. When these algal blooms eventually die they are consumed by bacteria which require oxygen to complete the process. This can cause the dissolved oxygen concentrations to drop low enough to trigger fish kills. This process is called eutrophication. In addition to this, animal waste from birds and mammals contain fecal coliform bacteria. These bacteria are used as indicators of animal waste levels and can be high enough to require health advisories to be issued.

 

So what we can do about this?

 

  1. We can start with landscaping with native plants to your area. Our barrier islands are xeric environments (desert-like). Most of our native plants can tolerate low levels of rain and high levels of salt spray. If used in your yard they will require less watering and fertilizing, which saves the homeowner money. It also reduces the amount of fertilizer that can reach the bay.
  2. If you choose to use nonnative plants you should have your soil tested to determine which fertilizer, and how much, should be applied. You can have your soil tested at your county Extension Office for a small fee. Knowing your soil composition will ensure that the correct fertilizer, and the correct amount, will be used. Again, this reduces the amount reaching the bay and saving the home owner money.
  3. Where ever water is discharged into the bay you can plant what is called a Living Shoreline. A Living Shoreline is a buffer of native marsh grasses that can consume the nutrients before they reach the bay and also reducing the amount of sediment that washes off as well, reducing the turbidity problem many of our seagrasses are facing.

These three practices will help reduce nutrient runoff. In addition to lowering the nutrient level in the bays it will also reduce the amount of freshwater that enters. Decrease salinity and increase turbidity may be the cause of the decline of several species once common here; such as scallops and horseshoe crabs. Florida Sea Grant is currently working with local volunteers to monitor terrapins, horseshoe crabs, and scallops in Escambia and Santa Rosa counties. We are also posting weekly water quality data on our website every weekend. You can find each week’s numbers at http://escambia.ifas.ufl.edu. If you have any questions about soil testing, landscaping, living shorelines, or wildlife monitoring contact Rick O’Connor at roc1@ufl.edu. Help us improve water quality in our local waters.