Biological oceanography is the study of how organisms affect and are affected by the physics, chemistry, and geology of the oceanographic system. Biological oceanography may also be referred to as ocean ecology, in which the root word of ecology is Oikos (oικoσ), meaning ‘house’ or ‘habitat’ in Greek. With that in mind, it is of no surprise then that the main focus of biological oceanography is on the microorganisms within the ocean; looking at how they are affected by their environment and how that affects larger marine creatures and their ecosystem. Biological oceanography is similar to marine biology, but is different because of the perspective used to study the ocean. Biological oceanography takes a bottom-up approach (in terms of the food web), while marine biology studies the ocean from a top-down perspective. Biological oceanography mainly focuses on the ecosystem of the ocean with an emphasis on plankton: their diversity (morphology, nutritional sources, motility, and metabolism); their productivity and how that plays a role in the global carbon cycle; and their distribution (predation and life cycle). History of marine biology In 325 BC, Pytheas of Massalia, a Greek geographer, explored much of the coast of England and Norway and developed the means of determining latitude from the declination of the North Star. His account of tides is also one of the earliest accounts that suggest a relationship between them and the moon. This relationship was later developed by English monk Bede in De Temporum Ratione (The Reckoning of Time) around 700 AD. Understanding the ocean began with the general exploration and voyaging for trade. Some notable events closer to our time, include Prince Henry the Navigator’s ocean exploration in the 1400s. In 1513, Ponce de Leon described the Florida Current. In 1674, Robert Boyle investigated the relationship between salinity, temperature, and pressure in the depths of the ocean.