Coal from swamp plants that formed millions of years ago.
The vessels use three main colors (white, green and red) where each color alone, combination of two colors as well as the three colors together each has a certain meaning. This meaning is sort of an international code that is agreed all over the globe.
So, based on this code, the presence of only visible white light means that your vessel might be overtaking another vessel. In this case, you should give way to either sides. The other vessel should standby until an action is taken from your end.
Biodiversity boost the eco-system which essentially is the same reason we have plants without biodiversity we wouldn't have plants or trees. Therefore we wouldn't have oxygen so the more we kill the Eco-system the more our planet and life becomes more and more threatened therefore the more food supply and demand becomes less and less. Which basically leads to extinction. So biodiversity is also helpful for biodegradable products like plastic instead of foam. Essentially recycling basically saves our planet.
