Explain the zonation of organisms in the rocky intertidal area of mid-latitude coasts. Between the spring and neap high water lines blue-green algae are found because they tolerate desiccation much longer that the barnacles and mussels. Below the spring low tide line Brown algae are dominant because when flooded they can expand their leaves to gather light from a large area and are seldom dried Between these levels, barnacles and mussels dominate with larger organisms at the lower levels. Describe the difference between suspension and deposit feeders. Suspension feeders extract food by passing water through organs that can remove the organic material.
Deposit feeders ingest sediment and then extract the food.
Bacteria recycle organic material to inorganic nutrients and also serve as a food source for micro zooplankton . A reduction occurs in the summer and a secondary bloom occurs in the fall . In stratified conditions inorganic nutrients can become isolated from the photic zone . Upwelling can then control productivity by delivering nutrients. Equatorial upwelling is the dominant feature in the central ocean.