I spent most of this past week (ending Sun 27/6) in the micro plastics laboratory conducting filtration of the second turtle (stranded in 2017). This small turtle was found deceased covered in barnacles – this is a sign that the turtle was sick and therefore too weak to fight off the barnacles. The necropsy of this turtle suggests that it died of starvation because there was nothing but bile found in its stomach or intestines. I aided Dr. Guido Pietroluongo (marine mammal supervisor) in the dissection and sampling of this sea turtle therefore I was able to see the empty stomach and intestines.
As per the protocol, the samples were placed in hyper saline solution to separate the lighter plastics from the organic matter. However, with this sea turtle there was a lot of stomach and intestine lining that was a similar density to the plastics; therefore the filtration of these samples took a very long time because some of the organic matter was blocking the filter paper. Megan spent Monday and Tuesday evening doing filtration so that we could finish the filtration of this last turtle by the end of the week.
We have two filtration pumps in the laboratory but there are three different micro plastics projects happening at this time. Therefore we meet each Monday to organize a timetable of the filtration units and the microscope room. On Tuesday morning the two other students who are conducting their master’s dissertations here were using the filtration units. Therefore, I went out on the kayak to collect surface samples for my future micro plastic project. Unfortunately though the GPS was being problematic and the wind had picked up a lot. The waves became very large as we kayaked a little further out, and we got soaking wet. The sea state was not ideal for collection of surface samples because the waves were so large. Therefore, we decided to come back in after about twenty minutes. The wind did not really calm down over the course of the week so we did not go out on the kayaks any other day.
The images below were taken by the media team on the first sampling that I did in the previous week. In the front is Loutje who works with the GPS points – she records the time and GPS coordinates at the beginning of the transect whilst I place the plankton net in the water behind the kayak. We then kayak along the transect for about 10-15 minutes at a constant speed. We follow landmarks to mark the ends of the transects and then I pull the net out of the water whilst Loutje records the GPS coordinates and time. Distilled water is then used to rinse the contents of the net into the end piece. At the end of the net is a collecting piece (cod end) that is screwed off and rinsed into the sample jar. The cleaned cod end is then screwed back onto the net and the net placed into the water as we begin kayaking the next transect.
For the next three days of the week, I was in and out of the laboratory as we were conducting filtration of the turtle samples. We finished the filtration for our entire project on Friday morning!
My sister is visiting so I took Friday afternoon off to go explore the nearby town, Pythagorio.