INDEPTH: OCEANS
PART III
The Components of the Marine Census
Robin Rowland, CBC News Online | November 12, 2003
Courtesy CoML
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The marine census has four components:
- The History of Marine Animal Populations uses historical and environmental archives to compile information that can create a picture of the oceans before fishing began and to study the impact of human activity and environmental changes after fishing became widespread.
- Future of Marine Animal Populations uses information from the marine census to develop mathematical models of the ocean ecosystems to predict possible future changes caused both by human and environmental influences.
- Ocean Biogeographic Information System is a web-based catalogue of global information on marine species using geographic information software as well as online tools to visualize the relationships between species. The census is also working on an educational version aimed at students.
- Field Projects - There are seven field projects underway with eight more planned:
- Shore areas: An international project to inventory and monitor biodiversity in the shore zones where the depth is less than 20 metres.
- The Gulf of Maine: This project studies biodiversity in the heavily fished Gulf of Maine, examining everything in the water, from bottom sediments and microbes to whales.
Courtesy CoML
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- Salmon and coastal migrants: Electronic tagging equipment and a monitoring network along the West Coast of North America to study the routes of the Pacific salmon and the environment they inhabit.
- Top Predators-Pacific: The census is using electronic tags to study the migration patterns of large open-ocean animals.
- Abyssal Plains: A deep-sea project is monitoring species diversity in the abyssal plains as well as looking at the historical and ecological factors affecting changes in biodiversity.
- An Underwater Mountain Range: The Mid-Atlantic: A study of the huge mountain ranges in the middle of the Atlantic Ocean.
- Vents and Seeps: A global study of deep-sea life around the dark, deep seafloor vents to discover how these isolated ecosystems work and serve as nurseries for new species.
The first seven field studies were largely in the Northern Hemisphere. The new field projects, including studies of microbes, plankton, reefs, the ice region and seamounts will be mainly based in the Southern Hemisphere.
Discoveries
Among the discoveries by the marine census are:
Salmon migration: The results of tracking Pacific Salmon is challenging traditional ideas of how young salmon survive after they leave their home rivers.
This may be the key to understanding how the salmon maintain their populations.
Satellite tracking: Electronic tags track three species of Pacific sharks by satellite, tracking their migration patterns for the first time. Other species tracked by satellite include bluefin tuna, turtles and elephant seals.
Florida Keys: Scientists have discovered a new genus of bright red sponge off the Florida Keys, now called the "rasta sponge."
Abyssal Sediments: Census researchers found a region in the abyssal sediments off Angola with more species per area than any other known aquatic environment. So far the scientists have collected 500 new species-that's about 80 per cent of the species in that one area. They eventually expect to find 1,000 new species in the small area they are studying.
Coral reef ecosystems: The census has established that coral reef ecosystems have been degrading for centuries. It has examined records of major types of carnivores, herbivores and architectural species from 14 regions. Some of the records go back thousands of years. The decline of coral reefs began long before current problems of coral diseases and bleaching. Research shows that large animals decline before smaller ones and that Atlantic corals declined before the reefs in the Red Sea and Australia.
North Atlantic: The census research shows that as early at 1600, fishing in the north Atlantic was affecting the ecosystem. The European grey whale was hunted to extinction. In 1600, the herring catch was 100,000 tonnes per year. By 1900, the catch was five times that figure and by the 1960s the fishery had collapsed and had been closed. After strict conservation measures, the herring fishery has recovered enough to sustain an annual catch of 307,000 tonnes.
Pacific Leatherbacks: The census is tracking the endangered Pacific Leatherback turtle and has already identified critical habitat and foraging grounds in the eastern Pacific.
Three dimensional habitats: Underwater video has shown that the sea bottom environment is rich and three dimensional. The accepted belief was that the bottom was mostly mud. Some of these habitats have been flattened by trawling.
Atlantic migration: Research indicates that some fish indigenous to one side of the Atlantic Ocean may use extinct undersea volcanoes as stepping stones to the other side. Scientists studying the Bear Seamount near Georges Bank off Newfoundland-the most western north Atlantic undersea mountain--identified 17 species of fish from the eastern Atlantic not seen previously in the western Atlantic.
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