Biogenic sediment is made up of at least 30 percent a) skeletal remains b) acidic chemicals c) alkeline properties d) limestone or rocks

A) skeletal remains

Biogenic sediment (Biogenic ooze) are formed directly or indirectly through biological activity and it is one of the most important constituents of marine sediments. Furthermore, they made from variety skeletal remains of marine zooplankton or phytoplankton. However, these sediments are made up of either siliceous ooze or carbonate ooze and skeletal remain in carbonate ooze is calcium carbonate.

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.