The dissolved oxygen in a reservoir was monitored for one year. based on this data, what might greatly reduce the available dissolved oxygen in an aquatic habitat?
a) thermal pollution
b) fertilizer run-off
c) increased water turbidity
d) decrease in ph due to acid rain

I would say A

Explanation:

Judging from the graph, you can tell that the dissolved oxygen line (the black one) is lowest during July and some parts of September ( or between those two). At the same time, you can see the blue line - for water temparature - is highest; which means that an increase in temperature ( or thermal energy) results in lower dissolved oxygen. The only answer choice that relates to higher temperatures is A, thermal pollution which is just a result of companies or people using natural bodies of water for industrial purposes.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).