In many cases, secondary consumers cannot digest the bones of their prey. What conclusion can you draw from that?

energy used to create bone mass often does not travel farther up the food chain

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

true is the answer : )