Back in Jax

Cara McCann

Week 3, Blog 1
This week, we returned to my home university, University of North Florida. I was excited to be home but I was also excited to learn more about the area I moved to for school. Monday was spent traveling along the Atlantic coast. We visited the Guana Reserve in Ponte Vedra to observe protected dunes and learn about long shore currents - currents that move parallel with the shore line and thus moves sediment parallel with the shoreline, and then we made our way to Villano beach St. Augustine to observe some human-influenced structures such as jetties and a stabilized inlet. Matanzan, however, is a natural inlet and we observed how dynamic it was, and could see further down the beach where it used to be. I think Marine Land was my favorite, though, because of the coquina outcroppings which are made up mostly of invertebrate shells that have been dissolved and reformed under lots of pressure.

Protected dunes

Coquina outcroppings down the beach

A close-up of the coquina rocks - there are some barnacles that have colonized here!

 On Tuesday, we took water samples in the St. Johns river and discussed the impacts of various man-made structures on the river. One example that we could clearly see was how bridges and docks prevent light from reaching certain areas, which means that no photosynthesis and subsequent primary production can occur. One of the results we saw from the surface samples we worked up later that day was that the turbidity and chlorophyll a increased at the Buckman Bridge site from the Mayport (near the mouth of the St. Johns) site.