Jacksonville

Our week at UNF has been a big eye opener for me on both a global scale and a microscopic scale.  We began with class on Monday (even though it was a holiday... dedication!!!)  at the beautiful Guana Tolomato Matanzas National Estuarine Research Reserve.

This was the North Beach access ramp.  

As the picture somewhat shows, this is a high energy barrier island beach habitat. The shoreline is dominated by waves and the primary sand dunes are covered by hardy plants such as sea oats, and saw palmetto. The plants on the dunes have many stresses on them such as salt on the leaves, salt on the soil, and water with a pH above 7. 

Next we went to the St. Augustine inlet and this beach was very different from the first. The longshore current causes inlets to move over time and people have large jetties built in the opening to hold it in place and it is constantly dredged to allow larger vessels through the inlet. Even with maintenance it is still challenging to navigate inlets because of the shifting sandbars in the opening.  The jetties cause high wave energy which increases erosion along the coast so the beaches further down have been impacted greatly by this inlet.

Moving south of St. Augustine, the Matanzas inlet was next on our tour. This inlet is natural and has been left unchanged for the most part. Unlike the St. Augustine inlet, this beach had a much larger shoreline/beach area and the inlet was very shallow. The changing tides even created small tidal pools that children could splash around in. A bridge was originally built across the inlet so that people can travel between barrier islands but because there are no jetties in place, the inlet has moved and is concentrated on only one side of the bridge (and is still moving technically). 

Our next stop was at Marineland and we explored coquina rocks that have been exposed on the beach. The coquina rocks form an intertidal habitat that houses an array of organisms including shrimp, barnacles, juvenile fishes, and even anemones. (Fun fact: The St. Augustine fort was never captured because the walls were made of coquina. They didn't break from the cannon balls, they would just mold around them.) We learned about the geological processes that took place to form coquina rocks from coquina clams (Donax variabilis), and quartz grains and bound by calcium carbonate in a process called cementation. 

We then got a chance to explore the outcroppings on our own and we found a bunch of neat "critters"

Day 2:
On our second day in Jacksonville was spent on the Lower St. Johns River where we travelled from the river's mouth to about 30 miles upstream (which happened to be south) where it was more freshwater influenced. Using YSI multimeters, we took depth profiles of the water temperature, dissolved oxygen, salinity, and conductivity. We also took measurements of turbidity using secchi transparency, and surface light, (we tried to take the air temperature but the batteries on the thermometer died so we based it on the weather report). Using the Van Dorn water sampling bottle, we could take samples from anywhere in the water column and then take the samples back to the lab to be analyzed for pH, chlorophyll a, and color using a fluorimeter and colorimeter. At the end of the day we compiled all of our data together into a spread sheet to create graphs that would show all of the relationships between the physical and chemical data.