Question

questions 1 and 2 refer to the following. long island sound is a body of water off the northeast coast of the united states. over one - million people live in the small watershed area that feeds into the sound. to determine the effect of the population density on the watershed, scientists measured the oxygen content of bottom waters in the sound. the data from late summer 2013 are displayed in the map below. on the image, which of the following conclusions can be drawn about conditions in the long island sound? a) the sound has high levels of dissolved oxygen as a result of storm water runoff from urban areas. b) the sound has high levels of phosphorus and nitrogen from an increase in the number of producers. c) the sound has large numbers of phytoplankton blooms that are decomposing and consumed by respiring bacteria. d) the sound has high numbers of respiring fish populations and very low turbidity.

Explanation:

High levels of phosphorus and nitrogen can lead to eutrophication. Phytoplankton blooms occur when there are high nutrient levels. Decomposing these blooms consumes oxygen. High numbers of respiring fish also consume oxygen. Low dissolved - oxygen levels can result from these combined factors. Storm water runoff from urban areas can carry nutrients into the water body, increasing nutrient levels. High turbidity is not mentioned as a factor here. So, the most likely reason for low dissolved - oxygen levels is the combined effect of high nutrient inputs leading to phytoplankton blooms and their decomposition along with high numbers of respiring organisms.

Answer:

C. The sound has large numbers of phytoplankton blooms that are decomposing and consumed by respiring bacteria