In our time at UWF in Pensacola, we covered watershed as it flowed from the wet prairies to the bay. Starting in upland habitats, we learned how plants adapt to natural and restorative fires. Aristida is a wiregrass that feeds the fires dry plant material; as long as the bunch/roots (which the grass sprouts from) are not destroyed during the burn, the plant will grow back. We identified several trees including the longleaf pine, slash pine, and loblolly pine, all of which were present in the upland environment, which happens to be the largest continuous longleaf pine forest. Longleaf pines are a fire dependent plant; without fires, hardwood trees would become the dominant species and out-compete the pines. If there are more hardwood trees than pine trees in an area, more prescribed burns will be implemented. The pines are adapted to fires by having a long ‘bush’ phase, where they accumulate energy for a quick growth spurt above the fire line, bypassing the period of susceptibility. If the needles to the pines burn, the trees will die. Similarly, the tulip poplar grows two big leaves in its initial growth to allow photosynthesis and a collection of energy for a growth spurt past the fire line.

We then followed the watershed to the seepage slope, where we saw obligate wetland species (such as star flowers and pitcher plants) indicating the muddy area below. Wetlands need to be burned at night because the heat and humidity during the day make the fire too hot. At the Rock Creek Track in the Blackwater watershed we noticed a calcium carbonate watershed. Erosion from this area moves down stream through the waterway systems and into the Gulf of Mexico. As the water moves around a bend, the sediment drops off on the inside of the bend because the outside flows faster, forming a bank. The bank makes the stream shallower and pushes back plants, which causes a temperature rise in the water and the death of organisms intolerant to hotter temperatures. Loggers are restricted to off-bank trees, as the timber holds the stream in place (otherwise the stream will widen) and also helps control flood levels.

One of the more exciting parts of the day was meeting with the team that actually performs controlled forest fires. We saw multiple burn sites ranging from having been burned 6 years ago to 2 months ago. Burns are ideally performed every 1-3 years; however, several factors must be accounted for, including weather conditions, time of year, time of day, wind direction and speed, and location. Surprisingly, the area that had been burned 2 months prior had a bountiful diversity, as all of the native species to the area were able to grow without competition, because sunlight and nutrients are aplenty following a burn. An ideal method of burning is by helicopter, where ping pong balls filled with potassium protagonate are injected with a reactive chemical as they are shot from the plane, causing a spot-fire to formulate below. The closer the spacing of the balls, the cooler the fire because it has less space to grow; the fires also burn out faster because when two fires meet, they burn one another out as there is nothing left for them to catch ablaze. In the Forest Service office, there was a map hanging that marked the locations of forest fires with associated reasoning and I was shocked to see that the number one cause of forest fires was not prescribed burns nor accidental but rather arson. Ian explained that many people start fires for a number of reasons, most commonly being a mental illness (enjoy watching things burn) or out of malice; oftentimes when people are let go from a logging company or have their hunting license pulled, they burn down the forest to prevent the logging company from profiting off the timber or to ruin the habitat of the wildlife that they can no longer hunt. Ian said that though the people are often caught, it is extremely difficult to get a conviction because they need to be caught with the lighter in-hand, lighting something that will set the forest ablaze (caught in the act), otherwise they will get away with it. This was the first of several problems we learned of concerning wildlife vs. law.

The day ended with a shrimp boil at Gulf Islands park, something I had never done but look forward to doing again!

Sea turtle season runs from May 1-September 30 but most nesting and hatching is performed from the end of May to early September. The hatching time depends on the time of year, as it varies according to temperature. Sea turtles are subject to death by fishing line, fast cars, raccoons, coyotes, fish, birds, and having nests laid too close to the water. Rangers patrol the beach 24/7 in-season to mark nesting areas and relocate nests that are dug too close to the water. Nests need to be relocated within 12 hours of being laid, as the membranes form after 12 hours. The most well known issue with hatchlings is their tendency to head towards the Santa Rosa Sound rather than the Gulf because the developed Sound is a greater source of light than the moon and the turtles follow the light rather than quickly disappearing in the vastness of the Gulf.

Shore birds nest on the ground where people and predators are their largest concern. Birds defend their nesting areas by dive bombing invaders or performing a ‘broken-wing’ display to deter predators from going for their eggs and encouraging the predator to hunt the bird instead, leading the predator away from the nest then flying to safety. The USDA traps coyotes to remove them; creating fences or other preventative measures have proven unsuccessful in the past. We saw Gulbill Turns and Snowy Plovers, which nest together. Initially it was thought that the adjacent nesting of these species was a good thing, as it would decrease inbreeding; however, it turned out the turns ate the plover eggs, making yet another predator for the plovers to be weary of. A major issue for the shore birds is the road way through their nesting sites. Beyond the degradation of the asphalt mixing in with the sand the birds nest in, and the storm surges breaking apart the road way and dispersing it throughout the habitat, the roads allow traffic to fly through nesting zones, causing several bird deaths. One dead bird on the road in turn means four dead birds because nests typically hold 2-3 eggs, and if the parent is dead, the babies are not raised. Speed limits, oftentimes, are not adhered to and construction is continuously performed during nesting season to fix the roads that the storms ruin. The Migratory Bird Treaty Act and NEPA are supposed to protect the birds nesting areas during nesting season, however government often turns a blind eye to the Act as people want the roadways open and operational in the summer for easy access to the beaches. Though the construction can be performed in the winter rather than during nesting season, companies do not follow through with their contract deadlines and rather prolong construction into summer without punishment.

As we looked at sand dunes we learned about the formation of primary dunes and secondary dunes; primary being the initial dunes on the beach that protect against storm surges and secondary dunes being behind them as a second structure of protection. Dunes maintain the dynamics of the beach. Waves crash at the slope trough and slosh up the beach, pushing sand to form the dune. As the sand is pushed, plants hold it in place (such as ____), forming the dune. The dune grows with the plants, which grow with the dune, which grows larger with the plants. Behind secondary dunes, the ecosystem is protected from salt spray allowing greater diversity. We saw dunes with oak trees and magnolia trees within the dune! The back-bay habitat also provides shade/protection from the sun.

The back-bay water was tannic with soil consisting of a variety of colors. The pink/purples of the soil are caused by sulfur while the black is caused by iron sulfide. Bacteria in the soil get energy from electricity available in the redox gradient; there is positive redox at the surface, which lowers to negative redox as depth increases. Electrons are available in oxidized area. As we move deeper, the soil gets lighter because there is no more iron available. In south FL and the Bahamas, the sand is very light because there is no iron. Bioturbinators bring oxygen from water into the soil.

We learned how to use several tools while performing water quality tests on the boat in Perdido Bay. We moved from the upper Bay where the watershed meets the water and went to the lower Bay, where the Bay meets the Gulf. We learned how to use the secchi disc to measure turbidity as a measurement of light, the CTD to measure conductivity, temperature, and depth, PAR to test photosynthetic active radiation, a 4pi and cosine sensor were used to calculate where 1% light levels are using the attenuation coefficient, a quantitative comparison can be made. The PUV was used as a profiling underwater radiometer to measure ultraviolet light, a Vandorin bottle was used to attain water samples with which we could measure chlorophyll and bacterial content, and finally we used a Ponar to grab sediment. With our sediment grabs, we saw that there was sand in the upper bay even though the water was not salty, which was interesting. It was likely deposited alongside the watershed, as it resembled the Appalachian quartz sand we had seen earlier in the wetlands. Prior to Perdido Bay sampling, we did species identification by doing pulls with seine nets, producing a variety of fish, crabs, and burrowers; we also suctioned worms from holes and did a phytoplankton productivity assay using the light-dark bottle experiment, in which productivity is measured in the light bottle while respiration is measured in the dark bottle.

On the final days we analyzed the samples we had been collecting throughout the trip, using microscopes to identify phytoplankton. We saw the larvae of shrimp, clams, and fish, as well as a variety of phytoplankton and zooplankton.

We were able to see DAPI counts of bacteria in our water samples; the samples are died with DAPI dye, which fluoresces blue when bound to DNA. Larger dots represent larger bacteria as they have more DNA.

In Wade’s lab we incorporated radioactive sodium bicarbonate with our phytoplankton samples, which converts to carbon dioxide and, after being subjected to 2 hours of light and killing the cells to stop the photosynthetic process, can be used to quantitatively measure photosynthesis by using a machine to count light flashes that occur from the radioactivity. We also incorporated radioactive leucine with bacteria from our water samples; the leucine was used by the bacteria to build proteins, by which we could monitor bacterial growth over a period of time, also by quantifying the resultant amount of radioactive leucine by counting light flashes.

Last, but not least, we were able to do a little more group bonding by attending the Blue Wahoos game together (minor league baseball team); the Wahoos did not win but we still had a great time!