Understanding Salinity in Northwest Florida’s Waters with a Family Activity
Dana Stephens, 4-H Agent
Salinity is the amount of total dissolved salts in water. This includes all salts not just sodium chloride, or table salt. Salinity is important in aquatic environments as many flora and fauna depend on salt and the level of dissolved salts in the water for survival. People interested in the composition of water frequently measure chemical and physical components of water. Salinity is one of the vital chemical components measured and often measured by a device determining how readily electrical conductance passes between two metal plates or electrodes. These units of electrical conductance, the estimate of total dissolved salts in water, is described in units of measurement of parts per thousand (PPT).
At the large scale, Earth processes, such as weathering of rocks, evaporation of ocean waters, and ice formation in the ocean, add salt to the aquatic environment. Earth processes, such as freshwater input from rivers, rain and snow precipitation, and ice melting, decrease the concentration of salt in the aquatic environment. Anthropogenic (human-induced) activities, such as urbanization or atmospheric deposition, can also contribute to changes in salinity.
Salinity and changes in salinity affect how water moves on Earth due to contrasts in the density of water. Water containing no dissolved salts is less dense than water containing dissolved salts. Density is weight per volume, so water with no dissolved salts (less dense) will float on top of water with dissolved salts (denser). This is why swimming in the ocean may feel easier than swimming in a lake because the denser water provides increased buoyancy.
Northwest Florida is a unique place because we have a variety of surface waters that range in salinity. There are ponds, lakes, streams, rivers, and springs, which have no to low salinity levels (0 to 0.5 PPT), and commonly referred to as freshwater systems. We house six estuaries—Perdido Bay, Pensacola/Escambia Bay, Choctawhatchee Bay, St. Andrews Bay, St. Joseph Bay, and Apalachicola Bay. Estuaries are bodies of water with freshwater input(s) (e.g., rivers) and a permanent opening to the ocean (e.g., Destin Pass in the Choctawhatchee Bay). Estuarine waters are termed brackish water (0.5 to 30 PPT) due to the dynamic changes in salinity at spatial and temporal scales. Waterbodies with an even more dynamic change in salinity are the coastal dune lakes Northwest Florida’s Walton and Bay Counties. Coastal dune lakes are waterbodies perched on sand dunes that intermittently open and close to the Gulf of Mexico. Sometimes these waterbodies are fresh and sometimes they have the same salinity as the Gulf of Mexico, like after a large storm event. Finally, the Gulf of Mexico, or ocean, has the highest salinity (> 30 PPT) among the waterbodies of Northwest Florida.
Here is an educational activity for the family to explore salinity and how salinity differs among Northwest Florida waters.
This year, the non-profit organization Oyster South held their annual Oyster South Symposium in the Big Easy, aka New Orleans. First stop was the Director’s Welcome at Sidecar Patio and Oyster Bar Thursday night. Oyster farmers, researchers, distributors, educators, writers and fans from all over USA were treated to New Orleans favorites like red beans and rice and jambalaya, but the star of the party was inside the bar area underneath a disco ball oyster. I wish I had taken a picture, but the lure of oysters from the Gulf, East, and West Coasts held my attention. Being able to jump coasts from oyster to oyster was quite an experience, and to have them freshly shucked right in front of you with a knowledgeable shucker took it over the top.
An Awesome Oyster Bar Selection at Sidecar Patio and Oyster Bar – Thomas Derbes
Friday we were greeted with gray skies, but you couldn’t tell from the vibe inside of the Contemporary Arts Center. When you walked in, you were immediately introduced to the trade show wall to wall with oyster equipment and other oyster related things. Once through the trade show, you could take a seat and listen to a plethora of oyster talks. We listened to reports of oyster mortality and the intensive efforts being taken to address this issue, a panel of farmers discussing how their peers can get an alternative source of income from catering and tours, oyster hatchery and farm research updates, and stories of oyster farmers and chefs on what an oyster means to them. The future of oyster farming looks very bright, and researchers are doing great things to help build the strength and resiliency of oyster farming. After the talks, we visited the trade show again and caught up with friends, old and new.
Distinguished Panel of Oyster Farmers Discussing Alternate Income Opportunities – Thomas Derbes
Tomorrow brings more talks, and the amazing Shuck and Tell closing ceremonies. Stay tuned for a Part 2 and Overall Thoughts.
Kayaking over seagrass beds and stingrays, hiking among pitcher plants, boating past diving ospreys, and meeting hundreds of fascinating, like-minded people—these are just some of the great experiences I’ve had while teaching the Florida Master Naturalist Program. More than 20 years since its inception, the Florida Master Naturalist Program (FMNP) has inspired the creation of dozens of similar courses in other states and proven itself to be one of the most popular outreach programs to come out of UF IFAS Extension.
Kayaking Santa Rosa Sound in Navarre is one of the highlights of our Coastal Systems FMNP class. Photo credit: Carrie Stevenson, UF IFAS Extension
The mission of the FMNP is simple—to promote awareness, understanding, and respect of Florida’s natural world among Florida’s citizens and visitors. I have always felt strongly that if you want people to care about something, they need to understand it. And to really understand something, you need to experience it. I know my own passion for science and ecology was ignited early on by teachers who took us outside and helped us encounter the many wondrous surprises in the natural world. With the FMNP, we seek to do just that.
Master Naturalist students conduct field work in small groups. Photo credit: Carrie Stevenson, UF IFAS Extension
Over a span of 40 hours in 6-7 weeks, we spend about half our time with classroom presentations and the other half in the field, seeing the plants, animals, and ecosystems we discuss in class. In addition to classes and field trips, students produce a final project and present it to the class. These can range from labeled collections and slide presentations to building bird houses and new trails. The program is composed of three 40-hour core courses; Coastal, Upland, and Freshwater Systems. Seven “short courses” with 24 hours of class/field time include the Land Steward series (Conservation Science, Habitat Evaluation, Wildlife Monitoring, and Environmental Interpretation) and the Restoration courses (Coastal Restoration, Marine Habitat Restoration, and Invasive Plants). Locally, we try to rotate the core modules every couple of years and incorporate the short courses periodically. Registration includes a detailed course manual and, upon completion, FMNP patch, certificate, and pin denoting area of expertise. There are a handful of scholarships available for those interested in applying to offset costs.
Master Naturalist students walk “The Way” boardwalk in Perdido Key. Photo credit: Carrie Stevenson
The classes do not count towards university credit but are an excellent certification and professional development opportunity that many will list on a resume. While we’ve had ecotour operators, park rangers, environmental consultants, teachers, and archaeologists participate, most of our FMNP students are not professionals in the field. They come from every background imaginable but share an interest in the outdoors. Because we meet weekly, class members often form long-lasting friendships during the courses.
Information on upcoming classes in northwest Florida and all around the state is available online. Classes range from fully in-person to hybrid and online options. FMNP classes are restricted to adults 18 and over, but a new “Florida Youth Naturalist” curriculum has been designed through our 4-H program for young people. For more information on that, check out their website.
Health advisories issued by the Department of Health (DOH) due to high levels of fecal bacteria have been a problem for some parts of the Pensacola Bay system for decades. Though most of the samples collected near our beaches rarely require them (usually between 0-5%) the bayous near downtown have been at, or above, 30% of the samples. Bayou Chico is often between 50-60% of the samples. Fecal bacteria have been such a problem in Bayou Chico that it was required to adopt a state Basin Management Action Plan (BMAP) to rectify the problem.
Closed due to bacteria.
Photo: Rick O’Connor
I began following the health advisory reports provided by DOH’s Healthy Beaches Program in 2012. As mentioned above, swimming beaches near our islands rarely have health advisories issued. The problem was with the three bayous near downtown. In 2012 all three consistently reported 30%, or more, of their samples required an advisory to be issued.
To rectify the problem the city and county have been doing a lot of work replacing old infrastructure that allowed sewage to leak from pipes or reach surface waters through sanitary sewage overflows. Many communities around these bayous are converting from old septic systems to sewer, the communities around Bayou Texar are now all on sewer. These same efforts are occurring along the north shore of Bayou Grande, and in neighborhoods around Bayou Chico. Between 2012 and the present, I have seen the frequency of health advisories decline some. Bayou Texar hovers around 30%, some years they are below, others above the mark. In recent years Bayou Grande has consistently been between 25-30%. Bayou Chico has declined some but is usually at or above 30%.
In 2023, for the first time since I began following this, all 13 sites monitored in Escambia County were below 30%.
2023
Body of Water
Number of samples taken
Percent of samples requiring an advisory
Bayou Texar
45
22
Bayou Grande
18
22
Bayou Chico
19
21
Bruce Beach
46
9
Big Lagoon State Park
19
5
Sanders Beach
46
4
Casino Beach
18
0
Park East
18
0
Park West
18
0
Quietwater Beach
18
0
Ft. Pickens
7
0
Johnson’s Beach
7
0
Opal Beach
7
0
It is worth noting that our rainfall was low this year as well. Historically, Pensacola received 60-61 inches of rain a year. Over the last decade this has increased to 70-71 inches. The current rainfall total for 2023 is 58 inches. Many studies show a strong correlation between rainfall and the number of advisories issued. It may very well be that the reduction in rainfall played a large part in the reduction of health advisories. Despite a lot of progress repairing infrastructure, and this effort needs to continue, there are still some issues.
Along with the city and county retrofitting old infrastructure, there are things area residents can do as well.
Many of these are related to poorly maintained septic systems throughout the area. If you are a septic system owner and would like to learn more on how to properly maintain your septic system, contact your county extension office.
If you are a septic system owner and are interested in converting to sewer to reduce the need for maintenance, contact our county extension office. For some communities in the Pensacola area, there is a cost share program with DOH to help make this conversion.
If you are on a sewer system in one of the older parts of town, the pipe leaving your house and connecting to the line under the street is your responsibility and may need repairing or replacing. Many plumbing companies have a television scope that can examine this line and provide you feedback.
For everyone, be careful what your pour down the drain. Fats, Oils, Grease, and even milk can clog the pipes and cause sanitary sewage overflows or backups in the system. Heavy rains only make this worse. In the Pensacola area the Emerald Coast Utilities Authority (ECUA) provides free plastic gallon jugs to place your cooking oil and grease in and, when full, can be swapped for another at several locations around town. To find the closest disposal site to you visit https://ecua.fl.gov/live-green/fats-oils-grease.
The FOG gallon containers are found in these metal cabinets placed around the county.
Photo: Rick O’Connor
Despite low rainfall this year, it is still good that all 13 sites were below 30% this year. With the help of the local governments, agencies, and residents, hopefully it will remain so.
The information provided here can be used by communities all along the Florida panhandle. High fecal bacteria count, and health advisories are not limited to the Pensacola Bay System. Contact your county extension office for more information on how you can help to reduce health advisories in your area.
Based on an annual evaluation recent competed, and feedback from my advisory committee, water quality issues are the number one natural resource concern for those who follow my extension programs. It makes sense. Poor water quality can negatively impact businesses who depend on clean water, waterfront property values, tourism, and the untold numbers of Florida panhandle residents who recreate in our estuaries and bays. The water quality issues I provided education on in 2023 are focused on the Pensacola Bay system, but these issues are probably similar across the Florida panhandle. Those issues include excessive nutrients, fecal bacteria (and other microbes), and salinity. We also wrote one article on the increasing water temperatures occurring in the summer.
Let’s begin with the fecal bacteria issue. In the Pensacola Bay area, it may be our number one concern. The Florida Department of Health posts local health advisories each week and some bodies of water are issued advisories for over 30% of the samples that are taken. Frequently Bayou Chico (in Pensacola Bay) is issued an advisory over 50% of the samples taken. However, in 2023 (in the Pensacola area) the number of advisories never exceeded 30% for any body of water. Seven of the 13 swimming beaches monitored did not post an advisory at all. This is one of the best years we have had since I began monitoring them.
Closed due to bacteria.
Photo: Rick O’Connor
In 2023 eight of the 13 water quality articles I wrote were on this subject. Three additional articles were posted by other extension agents on our panhandle e-newsletter team. But my annual follow up survey showed very few adopted best management practices (BMPs) they could adopt to help reduce fecal bacteria in area waterways. The reduction was more likely due to the effort by our local city and county to improve sewage infrastructure and the fact that we were in a drought for much of the year – there is a positive correlation between rainfall and the number of advisories issued for local waterways. Despite the fact that few readers adopted BMPs this year, and advisories declined – at least in Pensacola – we still believe adopting these practices would help reduce this issue. We will be developing a fact sheet in 2024 to help homeowners better understand these practices and help reduce health advisories.
Another local water quality issue that is high on everyone’s mind is excessive nutrients. This is actually one of the largest concerns nationwide. Excessive nutrients can lead to algal blooms, which can lead to harmful algal blooms or low dissolved oxygen, which can lead to fish kills. In the Pensacola Bay area large fish kills have not occurred in decades, but nutrient monitoring continues. The UF IFAS Lakewatch program trains local volunteers how to collect water samples and measure water clarity. The samples are analyzed in the Lakewatch lab on campus in Gainesville and the results sent back to the community. In the Pensacola Bay area, we are currently monitoring six bodies of water (three stations in each). Nutrients values are stable, or improving, in four of the six locations. They are slightly elevated in Bayou Chico and one station in Bayou Texar is quite high in total nitrogen. Despite the values at those stations, no algal blooms or fish kills occurred in either Bayou Chico or Bayou Texar (or anywhere else in the Pensacola Bay area) in 2023. There are numerous sources for nutrients in local waterways and many behavior practices businesses and residents can adopt to help reduce nutrient pollution. In 2023 I wrote only one article on this topic but plan to provide more education in 2024.
A body of water receiving excess nutrients can turn green and unhealthy from too much algae growth. Photo Credit: UF IFAS FFL program
A third topic that caught attention this year was the warm water that occurred this past summer. Extreme water temperatures can decrease dissolved oxygen below levels where most estuarine creatures can survive. Many creatures have a thermal tolerance that could have been exceeded this year. Industries like oyster farming are negatively impacted. Many varieties of harmful algae thrive in warm conditions. My extension program does not conduct any citizen science project that monitors water temperatures within the bay. Working with our local oyster farmers, the local estuary program is beginning to monitor such, and more folks are taking notice of the issue. Extension agents posted four articles on the subject this year. Whether the summers of high-water temperatures will become more common is unknown. The first thought on cause is climate, and management practices on how to reduce climate change are well documented. It is also understood that adopting such practices will not reduce intense warm summers immediately but should still be adopted for the long term. It is also possible that the current extreme heat summers are cyclic, and things will cool down (relatively) in coming seasons. 2023 was an El Nino year. Monitoring and time will tell how this issue will play out. That said, it would be smart to consider behavior changing practices for the future. Extension will post more information on this topic in 2024.
The Gulf of Mexico at sunrise. Photo: Rick O’Connor
One issue of concern personally was the impact of increased rain on the salinity of our bay. There has been a noticeable (and measured) increase in rainfall in recent years. For Pensacola, we historically received about 60 inches of rain each year – one of the wetter locations in the southeast. But over the last decade this has increased to 70 inches per year. Along with the increase in rainfall, there has been a noticeable increase in development. This increase in development reduces the surface area of land that would naturally absorb this rainwater and recharge the much-needed aquifer. Instead, this rainwater is diverted from the new developments to stormwater management projects – some that work well, others that do not. The question I have on the table is whether this increase in stormwater run-off is decreasing the salinity of area waterways? And, if so, is it to a level where local marine species (and those we are trying to restore) will be negatively affected? To answer this question, I have trained volunteers to monitor salinity at locations around the bay area. They are monitoring once a week, at the surface, near the shoreline. Though the sampling location is not ideal, it is what our volunteers are able to do. I had determined that the data would be collected until each volunteer reached 100 readings (about two years). As of the end of 2023, five of the 13 monitoring locations (38%) have reached that 100-reading mark. We know that the turtle grass and bay scallops, both species we would like to see increase in our bay, require salinity be at (or above) 20 parts per thousand. Though there are many more weeks of monitoring needed to reach our mark, current data suggests that salinities have not altered from data posted decades ago and are high enough for these species to return in areas where they historically existed.
I will finish this review with a comment that articles were posted in 2023 on issues I am not directly involved with, but know they are a concern in many areas of the panhandle. Private drinking wells being one. There were several articles posted by Dr. Andrea Albertin addressing this issue in 2023 and for those interested in this topic I recommend they read these, and/or reach out to her directly (albertin@ufl.edu.). There was also an article that focused on water quality improvement BMPs in general posted by Khadejah Scott (Wakulla County) that may be of interest. https://nwdistrict.ifas.ufl.edu/nat/2023/10/05/simple-steps-to-improve-local-water-quality/.
With this being a large issue with many in the Florida panhandle, extension will continue to publish articles and have programs on this topic. Reach out to your local county extension office for more information.
October is Dune Lake Awareness month and as part of the celebration, Walton and Okaloosa County UF/IFAS Extension Agents are joining together to host a Coastal Dune Lake Tour at Western Lake in Grayton Beach State Park. This free event will include a brief lecture and guided tour of the nature trail surrounding the lake. Laura Tiu, Marine Science Agent, will start the tour with a history of the lakes, the unique ecology and some of the local protections. Sheila Dunning, Horticulture Agent, will share information on the unique flora in the dunes including which plants have been used by native Americans and pioneers for food and medicine and the trees we find in the dune landscape surrounding the dune lakes and their adaptations to this sometimes-harsh environment. If you have an interest in our local dune lakes or the tour, you may visit the Walton County Dune Lake website at https://www.co.walton.fl.us/97/Coastal-Dune-Lakes. If you would like to register for this free tour go to https://www.eventbrite.com/e/panhandle-outdoor-live-2023-coastal-dune-lake-lecture-and-trail-tour-tickets-722764316527?aff=oddtdtcreator or use our Facebook event link https://www.facebook.com/events/811943803961304. Feel free to call our office, 850-892-8172, with any questions.
