Once more, I joined the sail training tall ship Pelican of London for STEM at SEA education voyages with Sail Training Ireland youngsters on board. We have a little more time than usual in Dublin and we make the best of the glorious sunshine with some science on the beach…
A short train ride to Killiney Strand and we were in the perfect place to appreciate the beauty of the sea and discuss its importance for life on the planet:
To illustrate the somewhat abstract concept of ocean acidification, we conducted an experiment where we breathed out through a straw into a vial of seawater. Our outbreaths contain a higher concentration of carbon dioxide (CO2) than the ambient air. This serves as an analogue to the increased atmospheric CO2 concentrations we have now (~420 ppm), compared to before we burned vast quantities of fossil fuels since the start of the industrial revolution (280 ppm, NOAA).
Measuring the seawater acidity with pH indicator strips before and after the experiment, we saw a reduction from pH8.2 to below pH6.5 as the CO2 dissolves in the seawater, forms carbonic acid and dissociates into bicarbonate and carbonate while releasing protons (H+) into the water that cause the lowering of the pH (see illustration below).
In preparation for daily meteorological observations on Pelican at sea, some of the watch leaders went through sky observations with trainees to identify the clouds (just a few cirrus and cumulus), cloud cover and opacity. This data was submitted to the NASA Globe Observer: Clouds app for climate research, weather forecasting and educational purposes.
We also had some time to play and relax, which resulted in one of the trainees being buried under a mountain of pebbles.
To round the day off, trainees learned how to identify different whale and dolphins species by their size, shape of dorsal fin and its position along the length of the animal, behaviour, markings and colour, as well as visibility and appearance of their blow. To provide a handy reminder, everyone received a handy identification guide to cetaceans, pinnipeds and sea birds. We will use these identification skills during our voyage across the Irish Sea to gather valuable data for the Seawatch Foundation.
