More than 70 percent of the Earth's surface is covered by ocean. The oceans are the largest ecosystem of all. Beneath these waters lives 20 percent of the Earth's species. Each species contributes to this vast ecosystem differently, and all relate to each other in their own unique way. Life is found below the depths of 4km. Rich in nutrients, the ocean floor is home to nine out of ten water species. There are many different habitats in the oceans, from sandy underwater deserts and huge mountains to coral reefs and open water. These various habitats can be divided into two main ones: the pelagic habitat, or the water itself, and the benthic habitat, or the ocean floor. The pelagic habitat is divided into several depth zones. Sunlight reaches down to 100m, and in muddy waters considerably less. This thin zone, where plants photosynthesize, is called the euphotic zone. Down 2000m is the bathyal zone, where there is little or no light. The vast ocean deeps, or abyssal zone, go down to 6000m.
Descriptive oceanography first began with the "Challenger Expedition." Under the direction of Scottish professor Charles Wyville Thompson and British naturalist Sir John Murray, the expedition took place from 1872 to 1876. It cruised nearly 130 000 km in the Atlantic, Pacific, and Antarctic oceans, gathering data on temperature, currents, water chemistry, marine organisms, and bottom deposits at 362 oceanographic stations scattered over 36 million sq km of ocean floor. The major contributions of their explorations included: the first systematic plot of currents and ocean temperatures, a map of bottom deposits, the discovery of 715 new genera, 4,717 new species of ocean life forms, and the discovery of numerous life forms, even at great ocean depths.
The Vancouver Aquarium Marine Science Centre has made significant contributions to marine life. The Centre is home to a variety of water - based life of both salt and freshwater species from British Columbia's lakes, streams and coastal waters, as well as Arctic waters, the Amazon jungle, and the tropical Pacific. The Vancouver Aquarium Association was formed in 1950, and the aquarium first opened its doors in 1956. Found in Canada's Pacific National Aquarium in Stanley Park, the center is a self-supporting, non-profit association that is dedicated to preserving aquatic life through displays and interpretation.
In addition to water-based life, and perhaps more intriguing, the depths of the world's bodies of water offer explorers keys to times past. Water exploration can solve mysteries and provide clues to questions unanswered. The Canadian Coast Guard has played a major role in the rescue and recovery of ships in and around Canada's waters. The CCG was founded as the "Marine Branch" of the Department of Marine and Fisheries in 1867. In 1936, it came under the jurisdiction of the Department of Transportation, Marine Services, and in 1962 it was officially named the Canadian Coast Guard. Its current budget is $700 million, and it has 6200 employees. The vessels of the CCG fleet are stationed at the regional offices (Western, Central, Laurentian, Maritimes, and Newfoundland), with their head-quarters at Vancouver, Toronto, Quebec City, Dartmouth, and St John's, as well as at 11 strategically located bases and 5 subbases. The fleet consists of 56 major vessels, as well as 35 helicopters and one fixed-wing aircraft. In addition to the larger ships, there are 74 frontline rescue vessels and 4 hovercraft.
Canadian Coast Guard responsibilities include icebreaking, search and rescue, aids to navigation, and northern resupply. The CCG also has a regulatory responsibility under the Canada Shipping Act with respect to ship inspection and standards. The CCG provides and maintains some 13000 channel buoys and 10000 land-based aids of which 266 are major lighthouses; 33 coastal radio stations and 15 vessel traffic centres provide navigational hazard and weather advice. The CCG enforces safety standards and regulations, investigates marine casualties, and responds to emergency oil spills. …