The amount of light that the water receives depends on the time of day and season, depth, how clear the water is, what the weather is like, and the altitude of lakes. Streams and rivers usually have very high light levels due to shallowness and movement of particles, but can vary in places. Wetlands have very low light levels due to usually murky, stagnant water, and unvarying depth........ hope this helps!
If by that, you mean a freshwater lake, or aquarium, then lots of things! Abiotic means 'non living' so that can be rocks, gravel, water, filters, etc. Anything that isn't living, so even DEAD fish count.
