The fossil record indicates that the first organisms to appear on earth was

If you are talking about the name of the organisms then it would be Grypania Spiralis.

If you mean how long ago it was  that the first organisms was to appear on earth, it was roughly 3.4 billion years ago.

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.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.