How abundant and diverse were the animals?
Sediment cores, like the ones being collected at left, preserve a record of the plants and animals that lived at that site over time. The plant and animal remains in the core, and the core sediments tell us about the biological, chemical and physical properties that existed in the past. Cores taken from Florida Bay are generally 1-2 meters long, and preserve a 100-200 year history of the Florida Bay estuary. By studying the modern environment we learn how the animals live today. We gather data on how salty the water is, what temperature, how deep, and what is the bottom like. Then when we find the same shells in the core, we can figure out how salty the water was in the past, what was the bottom like, etc. This is a basic principle of all paleoecologic studies: the present is the key to the past.
