The picture below shows two fairly typical hauls of plankton. Plankton are "(chiefly microscopic) drifting or floating forms of life found at various depths in the sea" [Oxford English Dictinoary]. These catches were obtained by filtering about a litre of water [??] from (top) a high-productivity sea area, and (bottom) a low productivity sea area such as a tropical ocean far from land. Most of the organisms are phytoplankton, including some of the chains and `javelins'. Some of the larger organisms are zooplankton or eggs (larval sacs) of larger animals.
