Thus buoyancy, mobility, vertical migration, and chemical sensing enables Copepods to search open water for concentrations of food. Trophic levels in zooplankton communities Energy incorporated in organic molecules by marine plants flows to the zooplankton community in a complex series of interconnected food chains. Each chain or part of the web serves to link phytoplankton to larger pelagic animals through the zooplankton. Nekton Free swimming organisms equipped to direct their movements through the sea including cephalopods, fishes, marine mammals, sea turtles and marine birds. Swimming allows escape or movement toward food and methods of locomotion are very diverse, from jets of water, flippers, large tail fins and flukes.
Planktivorous nekton are animals that feed directly on plankton such as baleen whales and some fish.
Carnivorous Nekton are the dominant carnivorous animals of the pelagic environment and generally these animals migrate great distances in search of food. Production Food production occurs mainly through Photosynthesis. It is measured and called Primary food production which will occur in the photic zone as phytoplankton manufacture organic matter during photo. The primary productivity varies seasonally and geographically. It seems that the more vertical mixing that occurs in an area, the higher the primary production is because in the tropics where there is little vertical mixing, their Primary Productivity is low because of the depletion of nutrients in the surface waters.