Aquatic Habitats Answers

The deep sea, sea floor, and open oceans would have the least access to phytoplankton. Phytoplankton are only found near the surface of marine habitats, in the photic zone, so the ocean floor and deep sea habitats do not directly support phytoplankton. The open ocean habitat does support some phytoplankton, but the amount of surface area with access to sunlight is actually quite small relative to the volume of the habitat so it also has little access to phytoplankton.

The water in freshwater ecosystems like lakes, ponds, and rivers are more likely to freeze over in winter because the salt dissolved in marine environments prevents the water from freezing.

Since energy is lost going up every trophic level of the pyramid of energy, the biggest levels are always on the bottom. An organism can only pass as much energy as exists in its body, so when the loss associated with each transition is included, the bottom of any two levels must be larger.

These three habitats, estuaries, salt marshes, and mangrove forests, appear along coasts where rivers and streams empty into the ocean. This mixing of fresh and saltwater varies based on the flow of fresh water from the river or stream, so the level of salinity in these habitats is highly variable.

Phytoplankton are the aquatic producers that form the bottom of aquatic food webs, but their total biomass at any given time is actually very small. They are able to support the higher trophic levels because they grow and reproduce much more quickly than the other organisms in the food web.