Plankton

Plankton are the smallest creatures we saw, but they're also the most important, since all the other creatures we saw depend on them. Plankton are very small or microscopic organisms that have little or no power of locomotion, looking like specks of dust in the water. Some plankton are tiny plants (phytoplankton), which are an important food source for the animal life in the water. They are eaten by tiny drifting marine animals (zooplankton) and small fish. These animals are in turn eaten by larger fish, which are eaten by seals, sharks and dolphins. Amazingly, some very large fish and mammals, such as whale sharks and baleen whales, depend on plankton as their main source of food!

It's easiest to view plankton through a clear, flat-sided container, but a jar will also work fine. Try using a magnifying glass or hand lens to get a closer look. You also may want to have a small notebook with you so that you can make some notes or sketches of what you've observed. Can you see how some of the plankton forms differ from one another?

Because plankton are often more numerous near the surface of the water, they are more likely to come in contact with surface or dispersed oil; however, the effects of toxic levels of oil on micro-organisms, such as plankton, are poorly understood.

(08.09.04, Edmonds, Washington)