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!
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