August 2024
About Karen Bohnsack
Karen Bohnsack works with the superintendent and deputy superintendent to support the day-to-day operations of Florida Keys National Marine Sanctuary including leading Florida International University affiliate staff, supporting science and resource protection efforts, and serving as site lead for water quality and South Florida ecosystem restoration activities. Prior to joining Florida Keys National Marine Sanctuary, Bohnsack worked with the Florida Department of Environmental Protection's Office of Resilience and Coastal Protection where she supported the state's co-management of the sanctuary, oversaw two aquatic preserves, and coordinated coral disease response activities. Bohnsack holds a bachelor's degree in political science from the University of North Carolina-Chapel Hill, and a master's degree in coastal marine resources management from the Bren School of Environmental Science and Management at the University of California-Santa Barbara. Born and raised in Miami, Bohnsack spent much of her childhood in the Keys where she later began her career working for the Newfound Harbor Marine Institute and Reef Relief.
What does the term “water quality” mean in your field of work?
The term “water quality” refers to the condition of water, including its biological, chemical and physical characteristics, relative to the intended use of that water. In other words, there is a different expectation for what water quality should be depending on the intended use of the water. For example: fish consumption, swimming and other recreational activities, drinking water, agricultural water, etc. All surface waters are classified by their designated use, and each classification has specific water quality criteria to protect those uses.
In my work, water quality is important for maintaining a healthy, balanced population of fish and wildlife and recreational opportunities in Florida Keys National Marine Sanctuary. The Water Quality Protection Program (WQPP) was established as part of the sanctuary’s designation for this purpose. We are also concerned about human health, because poor water quality can pose a risk to ecosystems and people.
Why should people care about water quality?
It’s essential not only for the survival of our marine ecosystem, but for human health, the economy, and our way of life.
What benchmarks do you use to evaluate water quality?
There are many different components that can be measured to evaluate water quality. These include nutrient concentrations (nitrogen and phosphorus), salinity, temperature, how clear or cloudy the water is (turbidity), light attenuation (a measure of light transmission), bacteria (including fecal coliform bacteria from human and animal waste), dissolved oxygen, and acidity (pH), as well as various contaminants such as heavy metals, pharmaceuticals, pesticides, herbicides, and others.
The concentration of chlorophyll-a is also used to assess water quality. Chlorophyll-a is a green pigment found in microscopic algae which is filtered from water samples to give a measure of the microalgae living in the water column. Elevated levels of chlorophyll-a can often indicate degraded water quality due to excess nutrients.
Are there trends in water quality that people should be aware of? Why?
Through the WQPP, water quality has been monitored in the sanctuary for almost 30 years. This monitoring program provides information on long term trends in the various parameters (mentioned above) that are used to measure the condition of sanctuary waters. Overall, these data show relatively stable trends across the region. However, increases in nitrogen, phosphorus, and chlorophyll-a have been measured in areas close to shore, which indicates land-based pollution coming from the Keys.
The Florida Keys has made great progress in upgrading infrastructure, such as installing central sewer systems, and putting other protective measures in place to reduce pollutants entering our waterways and protect water quality. We expect nutrient concentrations nearshore to decline over time in response to these protective measures.
Worldwide, nutrient pollution is also increasing. It is important for people to be aware of these so we can collectively work to improve how we manage water—including reducing inputs of nutrients and other contaminants, and supporting protective water treatment, reuse and disposal methods.
What are the biggest factors affecting water quality?
Water quality in Florida Keys National Marine Sanctuary is affected by a mix of local, regional, and global factors. Surface runoff, wastewater, and other land-based sources of pollution from the islands themselves affect water quality. The Keys are made of a porous limestone bedrock, so pollutants that soak into the ground eventually reach nearby surface waters.
Florida Keys National Marine Sanctuary is also connected to and influenced by waters that flow to the Keys from other locations, including the Gulf of Mexico and South Florida. Activities occurring upstream thus also impact water quality locally.
There are a number of other threats at play in the equation. Globally, increasing temperatures and ocean acidification will also affect our waters, and sea level rise and changing storm and rainfall patterns may exacerbate local water quality issues by increasing runoff of various land-based pollutants into nearshore waters.
Why does water quality matter for Florida’s corals? How does it compare or contribute to other factors that affect Florida’s corals?
The coral reefs and seagrasses thrive in and rely on clean, clear water that is low in nutrients. Exposure to nutrients, toxins, and other pollutants negatively affects these resources and their associated marine life, which over time causes shifts to algae dominated areas with cloudier water and fewer fish.
Good water quality provides a solid foundation for coral survival, but there are many other global, regional, and local factors that also affect Florida’s Coral Reef, including climate change-induced temperature stress, hurricanes, vessel grounding, habitat loss, overfishing, invasive species, disease, etc.
Restoring and protecting water quality is critical for the overall recovery and sustainability of habitats, fish, and wildlife in the Keys.
Can we restore corals without maintaining water quality?
Good water quality is essential for coral reefs and all the habitats of the Florida Keys, and is important for the long term success of any restoration effort.
We have and will continue to work on restoring and maintaining water quality within Florida Keys National Marine Sanctuary and regionally. However, understanding that water quality issues are extremely complex, it is important to simultaneously pursue proactive restoration and other coral reef management strategies to protect these resources.
Coral reef management is a multifaceted process that involves a variety of different strategies to protect and restore these resources. Addressing water quality is one piece of the puzzle, which helps to create more favorable conditions for coral survival. Coral reef restoration is another key tool that is necessary to maintain key ecosystem functions.
What has been a noticeable or striking difference in the water quality field since you first started?
Although the WQPP was established in the early 1990s, well before I started in this field, this was an important and first-of-its kind program to be implemented within a national marine sanctuary. We are fortunate to have this foundation which has helped to lead the way for water quality protection and restoration in the Keys and serves as a role model for efforts elsewhere.
Technological advancements have and will continue to improve our ability to monitor and understand the world around us.
Was there a moment that inspired you to go into water quality research?
It wasn’t so much of a moment as it was an evolution. I have long loved the Florida Keys and wanted to work to protect these amazing ecosystems. My early career was in coral reef management, although I also spent a little bit of time working in the Everglades. Over the years I increasingly became aware of the importance of looking upstream, and thinking about the bigger picture of conditions that corals need to survive, including good water quality. Upon moving to my position at Florida Keys National Marine Sanctuary, I shifted my focus from working on the coral reefs themselves to water quality and those upstream, regional factors. In this job, my goal is to work with the community and suite of partners who have authority over activities that impact water quality to understand the sources of water quality decline, and develop and implement solutions that can have a positive and meaningful impact for our coral reefs and our communities.
What would be your advice to future researchers and conservationists?
The problems we face are vast and seem to grow year after year. Don’t be discouraged and don’t give up! This work is more important now than ever, and If we stay committed to the problems, the solutions will follow. The coral conservation world is also a small one, so build relationships and maintain the connections you’ll make as your career progresses; you never know where those might lead. If you’re interested in helping out with water quality issues in Florida Keys National Marine Sanctuary, get involved by attending Water Quality Protection Program meetings.
Taylor Schultz is a Virtual Student Federal Service communications intern with Mission: Iconic Reefs in Florida Keys National Marine Sanctuary
Rachel Plunkett is the content manager and senior writer at NOAA’s Office of National Marine Sanctuaries