Plankton and SeaTurtles

Joey and Emily snuggle to stay warm.

     Today and tomorrow are supposed to be the coldest two days we've had this winter.  Nevertheless, we traveled to James Island once again for a fabulous field trip at the Department of Natural Resources!  This time we had the option of keeping Joey with the older kids, so we chose to stay together.

 Yes, it was cold near that water!

First, the kids met in a classroom for a presentation about phytoplankton and zooplankton. Plankton is important and must be monitored. It is the base of the food chain and 60 % of our oxygen is produced by it. The phytoplankton are microscopic plant material that depend on photosynthesis, and the zooplankton are microscopic animals such as baby crustaceans.  Even jellyfish are a type of zooplankton, because they "drift". Although some jellyfish can "propel", they cannot steer themselves. Some plankton are toxic and destructive like the dinoflagellites that cause "red tide".

Here, the instructor holds a filter the students will use to collect their own plankton for study.

The kids gathered outside on the dock.

Emily and Joey filter the plankton.

The students look at their collected samples under the microscope.

An instructor also projects the image from her microscope onto a screen to help the students identify the different types of plankton. This technology is amazing to me. A "ruler" runs along the top of the screen and measures the plankton to "scale". The instructor can also take "pictures" of her observations as they move across the screen.  It was fascinating to see a variety of things scitter about and occasionally even eat each other.

A large, wiggly, adult copepod takes center stage.

After viewing their samples, the students used a chart to identify their plankton.

Daddy looks on.

Joey's zooplankton
The students sketched and labeled what they saw under their microscopes.

Hayden, our first homeschool graduate, listens to the presentation too.

She couldn't resist checking things out under the microscope too.

The students switched classrooms with another group for the presentation about sea turtles.

After the presentation, small groups were given a bucket representing a turtle nest and an inventory sheet.  In April, many volunteers will begin training to assist in turtle nest protection along the coast of South Carolina. If a nest is located in a dangerous place, the volunteers may have to relocate the nest or even assist the babies.

The kids sort and take inventory of their nests. The boys had a "nest" from Folly Beach.  The ping pong balls represented the eggs. "Crushed" ping pong balls ones were the "hatched" ones.  Small turtle toys represented live babies stuck in the pit-like nest that have to be rescued.  If the baby has an "x" its belly, it didn't survive.

A "hatched" egg

After counting eggs, empty shells, and live and dead babies, the students recorded how many were male and female.

The "hatched" eggs have temperatures written on them. If the temperature on the shell is under 30 degrees Celsius, the baby was a male.  If it was over 30 degrees, it was a female.  Temperature manipulates the gender of the turtles.  Eggs on the top of the nest (closer to the sunlight) tend to be female, while the eggs underneath where it is colder tend to be male. The instructor said the kids could remember this by the phrases, "hot chicks and cool dudes". I suppose that is okay for turtles..... An overly hot summer can produce an overabundance of females and a cooler one would have the opposite effect.

Emily's nest was from "Botany Bay".  After each group gathered their data, the instructor compared the combined, class results on the board to look for patterns, concerns, or surprises.

A lone egg from each nest is taken for DNA samples.  Each bucket nest had a "reading".
The students wandered around the room trying to match their DNA samples to other DNA sample readings of tagged females in various areas of the classroom. In other words, they were looking for their "mommys".

Here, a student compares her baby DNA with the mother's.

 Sometimes a female will have more than one nest.  The scientists track and record this information.

A model of a turtle nest.  The babies follow the light of the moon to the ocean.  When the babies begin hatching, streetlights are turned off, and folks who live nearby turn off their lights, so the babies don't get confused and go the wrong way.

The last activity was kind of like a turtle C.S.I.  Each group was given a large plastic turtle that had "died".  The group had to determine what had happened.  First the turtle had to be measured, and its species identified.

 The boys' case was obvious.  Their turtle had mistaken a plastic bag for its favorite food, jellyfish.  Since the turtle cannot process the bag, it would make the turtle feel continuously full and contribute to its starvation.

Emily's turtle didn't have obvious injuries, so an x-ray had been taken.  The outline of large fishhooks were seen in the x-ray. In the other groups, one turtle had a gash on its shell where it had been most likely hit by a boat, another's fin was missing from a boat propeller, and another had fish netting stuck around its head.  Although predators eat turtles, the scientists try to prevent accidental,
man-made tragedies for the turtles.

It was a fun, cold, and interesting day at the Department of Natural Resources!
Now off to Chick fil-A for some lunch!

Then God said, "Let the waters abound with an abundance of living creatures...." Genesis 1:20