Restoring the Health of Pensacola Bay; what can you do to help? Introduction

Restoring the Health of Pensacola Bay; what can you do to help? Introduction

Humans have inhabited the shores of Pensacola Bay for centuries. Impacts on the ecology have happened all along, but the major impacts have occurred in the latter half of the 20th century.  There has been an increase in human population, an increase in development, a decrease in water clarity, a decrease in seagrasses, and a decrease in the abundance of some marine organisms – like horseshoe crabs, scallops, and some marine fishes.  There has also been an increase in inorganic and organic compounds from stormwater run-off, fish kills, and health advisories due excessive nutrients and fecal bacteria in local waters.

A view of Pensacola Bay from Santa Rosa Island.
Photo: Rick O’Connor

Since the 1970’s, there have been efforts to help restore the health of the bay. Seagrasses have returned in some areas, fish kills have significantly reduced, and occasionally residents find scallops and horseshoe crabs – but there is still more to do.  In this series of articles, I will present information provided in a recent publication (Lewis, et. al. 2016) and from citizen science monitoring.  We will begin with an introduction to the bay itself.

 

The Pensacola Bay System is the fourth largest estuarine system in the state of Florida. The system includes Blackwater, Escambia, East, and Pensacola Bays.  There are numerous smaller bayous, such as Indian, Mulat, and Hoffman, and three larger ones, which include Texar, Chico, and Grande.  There are two lagoons that extend east and west of the pass.  To the west is Big Lagoon and to the east is Santa Rosa Sound.  The surface area of this bay system is about 144 mi2 and the coastline runs about 552 miles in length.  There are four rivers that discharge into the system: the Escambia, Blackwater, Yellow, and East Rivers.  The majority of watershed is in Alabama and covers about 7000 mi2.  The mouth of the bay is located at the Pensacola Pass near Ft. Pickens and is 0.5 miles across.  Depending on the source, the flush time for the entire bay has been reported between 18 and 200 days.

 

There are several ecosystems found within the bay system. Seagrasses are be found throughout the bay and bayous, but are more prevalent in Big Lagoon and Santa Rosa Sound.  Oyster reefs have provided income for some in the East Bay area in the past, but production has declined in the last 50 years.  Salt marshes are found throughout the bay as well, but the greatest acreage is in the Garcon area of Santa Rosa County.  There are, of course, freshwater marshes near the mouths of the rivers with the largest being at the mouth of the Escambia River.

Members of the herring family are ones who are most often found during a fish kill triggered by hypoxia.
Photo: Madeline

Members of the drum family are one of the more common fishes found in the system and would include fish like the Spot and Atlantic Croaker. However, speckled trout, striped mullet, redfish, several species of flounder, have also been targets for local fishermen.  Target fish include sardines, silversides, stingrays, pinfish, and killifish.  Brown shrimp, oysters, and blue crab have historically provided a fishery for locals, but other invertebrates include several species of jellyfish, stone crabs, fiddler crabs, hermit crabs, grass shrimp, several species of snails, clams, bay squid, octopus, and even starfish.  There is also a variety of benthic worms found within the sediments.

A finger of a salt marsh on Santa Rosa Island. The water here is saline, particularly during high tide. Photo: Rick O’Connor

There has been a decline in overall environmental quality since 1900 but, again, the biggest impacts have been between 1950 and 1970. Fish kills, a reduction in shrimp harvest, and hypoxia (a lack of dissolved oxygen) have all been problems.

 

In the articles to follow we will look deeper into specific environmental topics concerning the health of Pensacola Bay.

 

 

References

 

Lewis, M.J., J.T. Kirschenfeld, T. Goodhart. 2016. Environmental Quality of the Pensacola Bay System: Retrospective Review for Future Resource Management and Rehabilitation. U.S. Environmental Protection Agency.  Gulf Breeze FL. EPA/600/R-16/169.

The Benefits of a Living Shoreline

The Benefits of a Living Shoreline

Imagine this…

You are a sailor on a 16th century Spanish galleon anchored in a Florida Bay south of Tampa. You, along with others, are ordered to go ashore for a scouting trip to set up a base camp.  You transfer over to a small skiff and row ashore to find a forest of root tangled mangroves.  There is no dry beach to land so you disembark at the edge of the trees in knee-deep water.  The bottom is sandy and your footing is good but you must literally crawl through the tangled mess of mangrove prop roots to finding dry ground.  As you do, you encounter spider webs, numerous biting insects, and the bottom becomes muddy and footing is less stable.  I am sure I would have returned to the ship to report to the captain that there is nothing of value here – let’s go back to Spain!

The dense vegetation of a black mangrove swamp in south Florida.
Photo: UF IFAS

Along the shores of northwest Florida it would have been different only that they would have encountered acres of grass instead of trees. The approach to Pensacola would have found a long beach of white sand and dunes.  Entering the bay, they would have found salt marshes growing in the protected areas, with the rare exception of dryer bluffs in some spots – which is where de Luna chose to anchor.  These marshes are easier to traverse than the emergent root system of the mangrove, but the muck and mire of the muddy bottom and biting insects still remain.

 

For centuries, Europeans have sought to alter these habitats to make them more suitable for colonization. Whether that was for log forts and houses or marinas and golf courses, we have cleared the vegetation and filled the muck with fill dirt. But have we lost something by doing this?

 

Yes… Yes we have, and some of what we have lost is valuable to us.

 

We have lost our water quality.

These emergent shoreline plants filter debris running from shore to the sea during rain events. The muck and mire we encounter within the marsh would otherwise entered the bay or bayou.  Here it would cloud the water and smother the submerge seagrasses.  My father-in-law told me that as a kid growing up on Bayou Texar in Pensacola he remembered clear water and seagrasses.  He remembered throwing a cast net and collecting 4-5″ shrimp.

 

That has changed.

In our modern world, it is not just mud that is running off towards our bays. We can add lawn fertilizers, lawn and garden pesticides, oils and grease from cleaning, and a multitude of other products – including plastics.

 

We have seen a decline in living resources.

The large shrimp my father-in-law talked about are not as common. He spoke of snapper – very few now.  Bay scallops are basically gone in Pensacola and have declined across much of Florida’s gulf coast. Horseshoe crabs have become rare in many locations.  Moreover, salt marsh/mangrove dependent species, such as diamondback terrapins, are difficult to find.

Storm drains, such as this one, discharge run-off into local bays and bayous.
Photo: Rick O’Connor

Maybe of more concern is the decline of commercially important aquatic species such as crabs, shrimp, and finfish. It is known that 80-90% of these commercially important species spend at least part of their lives in the marshes and mangroves.

 

And this we are losing.

 

And then there is the shoreline itself.

The emergent plants the Spanish encountered actually act as a wave break. Sand running off the land is trapped to form a “beach”, albeit a mucky one, and the wave energy is absorbed by the plants reducing the energy reaching the shore.  The damage in south Florida from hurricane Andrew was devastating.  But that same storm made a second landfall in the marshes of Louisiana and there was little to write about – the marsh absorbed much of the energy.  The removal of these vegetated shorelines has enhanced the loss of coastline across the Gulf States.

 

Can we restore these shores and return these “services”?

 

Yes…

Whether communities want to or not is another question, but we can.

Studies have shown that a marsh 10′ across from water to land can remove 90% of the nutrients running off. Nutrients can trigger hypereutrophic conditions in the bay – which can lead to algal blooms – which can lead to low dissolved oxygen – which can lead to fish kills and seagrass loss.  In addition to removing nutrients, marshes and mangroves can remove a variety of other contaminants and plastics.  Many sewage treatment facilities discharge their treated effluent through the coastal plant communities before it reaches the bay, thus improving water quality.

 

We know that restoring a living shoreline will enhance the biological productivity of the bay. Studies have shown that swamps and marshes can produce an annual mean net primary production of between 8000 – 9000 kcal/m2/year, which is equivalent to tropical rainforest and the open estuary itself.

 

Finally, living shorelines will stabilize erosion issues, much longer than seawalls and other harden structures. Studies have shown that seawalls will eventually give in.  Wave energy is increased when it meets the wall and reflects back.  This generates higher energy waves that decrease seagrasses and actually begins to remove sediment around the wall itself.  You will see the land begin to erode behind the wall and eventually it begins to fall forward into the bay.  The east coast of Florida recently experienced this during hurricane Irma.  Interestingly the west coast experienced negative tides.  The exposure of these seawalls to an empty bay had the same effect.  Without the water pressure to hold them, they began to crack and fall forward.  A living shoreline can sustain all of this.

FDEP planting a living shoreline on Bayou Texar in Pensacola.
Photo: FDEP

So how do restore my shoreline?

 

  1. You will need a permit. The state of Florida owns land from the mean high tide seaward. To plant above this line you do not need a permit, but you will want to plant at and below to truly restore and benefit from the services. Permitting can be simple or complicated – each property is different. Visit http://escambia.ifas.ufl.edu/permitting-living-shorelines/ to learn more about the process.
  2. You will need plants. There are a few nurseries that provide the needed species. There is a zonation to the plant community and it is important to put the right plant in the right place. The above link can help with this and the Extension office is happy to visit your location and give recommendations.
  3. You will need to plant them. Fall and spring are good planting times. A recent project we helped with planted in April and it has been very successful.
  4. You may want to monitor the success of your project. This not needed, but if interested the Extension office we can show how to do this.I certainly understand why many would rather remove these shoreline ecosystems, but I think you can see the benefits outweigh the problems. It is not an all or none deal. Living shorelines can be designed to allow water access. If interested in learning more contact your county Extension office.

 

I certainly understand why many would rather remove these shoreline ecosystems, but I think you can see the benefits outweigh the problems. It is not an all or none deal.  Living shorelines can be designed to allow water access.  If interested in learning more contact your county Extension office.

 

References

 

Permitting a Living Shoreline; can a living shoreline work for you? http://escambia.ifas.ufl.edu/permitting-living-shorelines/.

Miller Jr., G.T., S.E. Spoolman. 2011. Living in the Environment: Concepts, Connections, and Solutions. 16th edition. Brooks and Cole Cengage Learning. Pp. 674.

 

Sharma, S. J. Goff, J. Cebrian, C. Ferraro. 2016. A Hybrid Shoreline Stabilization Technique: Impact of Modified Intertidal Reefs on Marsh Expansion and Nekton Habitat in the Northern Gulf of Mexico. Ecological Engineering 90. Pp 352-360.

Coastal Erosion–a problem with new solutions

Coastal Erosion–a problem with new solutions

Life on the Gulf Coast can be beautiful, but has its share of complications. Photo credit: Carrie Stevenson, UF IFAS Extension

Life on the coast has tremendous benefits; steady sea breezes, gorgeous beaches, plentiful fishing and paddling opportunities. Nevertheless, there are definite downsides to living along it, too. Besides storms like Hurricane Harvey making semi-regular appearances, our proximity to the water can make us more vulnerable to flooding and waterborne hazards ranging from bacteria to jellyfish. One year-round problem for those living directly on a shoreline is erosion. Causes for shoreline erosion are wide-ranging; heavy boat traffic, foot traffic, storms, lack of vegetation with anchoring roots, and sea level rise.

 

Many homeowners experiencing loss of property due to erosion unwittingly contribute to it by installing seawalls. When incoming waves hit the hard surface of the wall, energy reflects back and moves down the coast. Often, an adjacent homeowner will experience increased erosion and bank scouring after a neighboring property installs a seawall. This will often lead that neighbor to install a seawall themselves, transferring the problem further.

Erosion can damage root systems of shoreline trees and grasses. Photo credit: Carrie Stevenson, UF IFAS Extension

Currently, south Louisiana is experiencing significant coastal erosion and wetlands losses. The problem is compounded by several factors, including canals dredged by oil companies, which damage and break up large patches of the marsh. Subsidence, in which the land is literally sinking under the sea, is happening due to a reduced load of sediment coming down the Mississippi River. Sea level rise has contributed to erosion, and most recently, an invasive insect has caused large-scale death of over 100,000 acres of Roseau cane (Phragmites australis). Add the residual impacts from the oil spill, and you can understand the complexity of the situation.

 

Luckily, there are ways to address coastal erosion, on both the small and large scale. On Gulf and Atlantic beaches, numerous coastal communities have invested millions in beach renourishment, in which offshore sand is barged to the coast to lengthen and deepen beaches. This practice, while common, can be controversial because of the cost and risk of beaches washing out during storms and regular tides. However, as long as tourism is the #1 economic driver in the state, the return on investment seems to be worth it.

 

On quieter waters like bays and bayous, living shorelines have “taken root” as a popular method of restoring property and stabilizing shorelines. This involves planting marsh grasses along a sandy shore, often with oyster or rock breakwaters placed waterward to slow down wave energy, and allow newly planted grasses to take root.

 

Locally in Bayou Grande, a group of neighbors were experiencing shoreline erosion.  Over a span of 50 years, the property owners used a patchwork of legally installed seawalls, bulkheads, rip rap piles, private boat ramps, piers, mooring poles and just about anything else one can imagine, to reduce the problem. Over time, the seawalls and bulkheads failed, lowering the property value of the very property they were meant to protect and increasing noticeable physical damage to the adjacent properties.”

 

Project Greenshores is a large-scale living shoreline project in Pensacola. Photo credit: Carrie Stevenson, UF IFAS Extension

In 2011, a group of neighboring property owners along the bayou decided to take action. After considering many repair options, the neighbors decided to pursue a living shoreline based on aesthetics, long-term viability, installation cost, maintenance cost, storm damage mitigation and feasibility of installation. By 2017, the living shoreline was constructed.  Oyster shell piles were placed to slow down wave energy as it approached the transition zone from the long fetch across the bayou, while uplands damage was repaired and native marsh grasses and uplands plants were restored to slow down freshwater as it flowed towards the bayou.  Sand is now accruing as opposed to eroding along the shoreline.  Wading shorebirds are now a constant companion and live oysters are appearing along the entire 1,200-foot length.  Additionally the living shoreline solution provided access to resources, volunteer help, and property owner sweat equity opportunities that otherwise would have been unavailable.  An attribute that has surprisingly appeared – waterfront property owners are now able to keep their nicely manicured lawns down to within 30 feet of the water’s edge.  At that point, the landscape immediately switches back to native marsh plants, which creates a quite robust and attractive intersection. (Text and information courtesy Charles Lurton).

 

Successes like these all over the state have led the Florida Master Naturalist Program to offer a new special topics course on “Coastal Shoreline Restoration” which provides training in the restoration of living shorelines, oyster reefs, mangroves, and salt marsh, with focus on ecology, benefits, methods, and monitoring techniques.  Keep an eye out for this course being offered near you. If you are curious about living shorelines and want to know more, reach out to the Florida Department of Environmental Protection Ecosystem Restoration section for help and read through this  online document.

 

 

Working to Restore Oyster Habitat

Working to Restore Oyster Habitat

Nature has provided us with an incredible resource in the diverse assemblage of molluscan shellfish that inhabit our coastal bays and estuaries. One bivalve species in particular provides many human benefits. The eastern oyster (Crassostrea virginica) has not only proven to be a preferred food species for people but also derives many vital ecosystem services through its existence in our near-shore estuaries.  Oysters are born as planktonic larvae that drift in the water for about 2 weeks.  They are called a spat when they settle out of the water column and glue themselves to a suitable hard surface, such as another oyster shell, and begin to grow their own shell.  Oysters feed on particulates in the water throughout their life and when mature can filter as much as 50 gallons per day.  Because of this life style they provide some degree of water purification and improvement in water clarity.  The structure of an oyster reef is also a valuable habitat component which provides shelter for a plethora of small creatures that support a vast food web in the estuary ecosystem.

 

Oystermen participate in shelling program for Apalachicola Bay

Oystermen participate in shelling program for Apalachicola Bay

Barges will also be used to relay shells for replenishing oyster habitat.

Barges will also be used to relay shells for replenishing oyster habitat.

 

 

 

 

 

 

 

 

Although we have several native species of oysters in the Gulf of Mexico the eastern oyster is the only species that supports a commercial industry.  in Florida, the bulk of that industry has traditionally been centered around Apalachicola Bay in the mid-Panhandle region of the state.  This one estuary system typically produces 90 percent of the state’s oyster crop and 10-13 percent of the nation’s harvest.  Some good harvest years have yielded 4-6 million pounds of oyster meat (shells excluded) from this single bay.  In recent years however there has been a dramatic decline in oyster abundance. The industry, along with concerned natural resource managers, is seeking to rebuild numbers to a sustainable harvest level.  The reasons for this precipitous drop in numbers is the subject of much debate but savvy natural resource professionals believe a combination of factors have been involved over several years to cause the current situation.

 

Fossil oyster shell being relayed to bay bottom.

Fossil oyster shell being relayed to bay bottom.

So, how do you bring back a thriving oyster industry from the brink of collapse?  Several factors need to be considered and addressed as part of a holistic management approach.  At the present time there are two primary mechanisms being employed to support increased oyster recruitment to Apalachicola Bay.  The first involves “planting” a suitable material on the bay bottom for oyster spat attachment and growth.  In the past this has primarily consisted of oyster shells from the shucking plants.  More recently the industry has been employing the use of fossil shell material from a local mine.  Oystermen are being employed to transfer the shell from land-based loading areas to the designated deposition sites in the bay.  Funding is also forthcoming to allow shelling by barges to cover more area.  The other strategy to assist with recovery has involved the use of regulatory authority in consultation with local experts and oystermen with decades of experience on the bay.  This approach can reduce the harvest pressure on oysters and support a more rapid recovery, given proper conditions in the estuary.  Bag limits have been reduced, enforcement has been stepped up to ensure compliance with the rules, and harvest areas have been adjusted.

 

Oystermen line up early to receive shell for relay project.

Oystermen line up early to receive shell for relay project.

There are, of course, other important aspects to the solution for bringing back the thriving industry of the past and many of them relate to natural cycles of drought and flooding.  Increasing human demands for water from the river system that feeds the bay tend to magnify the effects of natural drought cycles.  If salinity remains high for longer periods there is an increased pressure from oyster predators that typically are limited by lower salinity.  Factors related to oyster diseases and parasites are also in the mix.  To say that it is a complicated situation would be an understatement.  Researchers who have studied the system for their entire careers find it difficult to quantify the problems and solutions for this large, complex natural ecosystem that has been an important cultural and economic component of Florida’s makeup since early humans roasted or cracked open the first oyster.  Hopefully, with enough concerned partners working towards effective management strategies we can once again enjoy in abundance the wholesome, delicate morsels that have been called the food of the gods.

 

Article by: Erik Lovestrand

Franklin County Extension Director

Sea Grant Regional Agent II