Each day is a continuous reminder that this is an experience of a life time and that each person has their own wealth of knowledge to offer. From day one of this week we were immersed in ecosystems unlike any other that I’ve engrossed myself in; from estuarine ecosystems to beaches and everything in-between!
We began this eventful week with a trip down the Saint John’s river; a black water river that collects tannins as it flows and maintains a darker color. We were all so excited to see what the river had to offer! I believe we saw eight different dolphin pods and the OCEARCH vessel, all while taking water samples and catching numerous plankton! Once we returned to the lab we examined our samples, assessing the differing water qualities and the kinds of plankton that we collected. As we hypothesized, the salinity of the water increased as we neared the Atlantic Ocean and the planktonic quality varied from the regions of low salinity and those of higher salinity.
The second and third days were extremely interesting; we investigated the ecological changes that occur throughout a 24-hour span in a system that was separated by a weir; however, due to severe weather conditions from early evening into early morning hours, we were unable to take consistent samples. When samples were taken we observed differences between tides, places, and time. When there were low tides there was higher abundance of certain species; Litopenaeus setiferus, for example, is the white shrimp or grass shrimp and avoids predation by hiding among marsh plants, however when the tide is low it is forced out into the open. During this extended study I learned that no matter how well you think you know a place, you never truly do… do not forget to stop and observe, you never know what you will see!
Our fourth day was a tour of the local beaches in the Jacksonville area and observing how they evolve. Have you ever stopped to think what happens when you put a house on the beach or where the sand comes from when the beach is “re-nourished”? I did not anticipate these questions being such a large focus of beach dwelling communities but in-fact they can be huge problems! If a house is built on beach front property, beach dunes may have to be taken out and could lead to the whole property being swept into the ocean by various rain events and currents. For example, the beach migrates each year based on what events have occurred in addition to the typical nearshore current, wind, and waves; keeping it all in a constant state of change. When a beach has been moved or it has migrated, as natural inlets and beaches do, it may be “re-nourished” in an attempt to save that beach’s property. To do this sustainable sand must be found and pumped in at a reasonable cost to the body paying for the operation. This addition of sand temporarily halts the natural movement of the beach and can be seen in the various sandy horizons that are visible in scarps along the shore.
Last week was such fun and I cannot wait to discover all that I can about our next locations!