Observation: pond scum

- Class introduction. Defining citizenship, sustainability and leadership. Students' input.

- What natural phenomena have you observed this summer? 

The case of pond scum (aka blue green algae, aka cyanobacteria) found this hot summer in lakes and ponds all over NY state: 

(Photo A. Leclercq 2016, on Sandy Pond, NY)

Although seemingly not a worthy subject of study, we learned that blue green algae or cyanobacteria is possibly 2.7 billion years old, that through photosynthesis and the production of oxygen, it has contributed to the Great Oxygenation Event 2.3 billion years ago and the ensuing first mass extinction event (of anaerobic organisms). We also learned that as an endosymbiosic organism, it is a precursor to the chloroplasts found in plants and algae. We saw that it can produce dangerous toxins, which occasionally kill cattle, wildlife and pets. Finally we learned that it can be used in the production of ethanol, along with other worthy applications.