Since life began in the ocean more than three billion years ago, species have evolved from one-celled algae into an untold number of amazingly complex plants and animals. All are interconnected in a vast web of life. The cement that holds this web together is biodiversity, or biological diversity, which means the variety of species, the assortment of gene pools within each species, and the array of ecosystems these species inhabit. We've scarcely begun to understand the diversity hidden in the ocean and the interrelationships among its innumerable parts. What we do know is that, if even a single species, gene pool, or ecosystem disappears or declines, the whole web weakens.
Any human impact that harms the ocean also harms biodiversity. Among these impacts are habitat destruction, marine pollution, acid rain, the invasion of aquatic habitats by alien plants and animals, overfishing, and accidental captures of non-targeted species, such as dolphins and sea turtles, in fishing gear. Some of the life forms already lost from Canadian waters are the sea mink, Labrador duck, Steller's sea cow, great auk, and Atlantic grey whale. How the extinction of even one of these creatures has affected the marine ecosystem is anyone's guess.
We must conserve ocean biodiversity because it is essential to the web of life, because it is a key resource for millions of people whose livelihoods depend on the fruits of the sea, because countless life-saving medicines have yet to be discovered in the ocean depths, and because every plant and animal has its own incalculable beauty and inherent value. The Canadian Biodiversity Strategy — a national plan for the conservation of species and ecosystems — reflects Canada’s intent to protect the web of life. Conserving biodiversity is everyone's responsibility by virtue of the fantastic variety of species that live in the three oceans under our care.
There are at least two sides to every issue, and biodiversity is no exception. In this activity, students will examine the critical need to conserve ocean biodiversity while recognizing that human interests may be in conflict with this need.
Biodiversity Field Study
Tide pools are ideal environments to investigate biodiversity. Ranging in size from that of a dishpan to a Jacuzzi, these water-filled basins are found along rocky, surf-pounded shores. They are living, interacting collages of colour, containing plankton, periwinkles, sculpins, limpets, mussels, sea urchins, and snails — a virtual all-you-can-eat buffet for predators like sea stars, crabs, gulls, and plovers. At night, mink, foxes, raccoons, and skunks join the banquet too. In this hands-on biodiversity study, students will explore the vast variety of life forms and their interrelationships in a coastal habitat such as a tide pool.
- Bring sampling equipment, including wide-mouth jars, tweezers, microscopes, slides, hand lenses, and kitchen sieves or dip nets. Make a dip net by bending a coat hanger into a circular frame. Attach it to a broom handle with duct tape. Stretch an old nylon stocking leg around the frame, holding it in place with safety pins.
- In small groups, survey species found in a tide pool (always minimize your impact). Use dip nets or sieves to gather samples of tiny invertebrates such as animal plankton. Empty specimens into a wide-mouth jar for closer observation.
- Use shoreline field guides, microscopes, and hand lenses to identify species, listing them in a biodiversity chart under headings like plants, molluscs, fish, and crustaceans. Record each species' degree of abundance, structural and behavioural adaptations, habitat requirements, and interactions with other plants and animals (for example, sea urchins grazing on kelp). Sketch species observed, indicating their place in the food web, if possible. Identify keystone species, such as blue-green algae, which hold more vital positions in their food webs than other plants and animals.
- Compare separate tide pools: one usually covered with seawater (near the low-tide mark); another rarely exchanging water with the sea (near the high-tide mark); and a third, regularly flushed with water (at mid-tide).
- Return all specimens to the tide pools where you found them.
- Follow up your survey with a report of your observations.
Dare to Diversify
Become a biodiversity booster by keeping the following strategies in mind:
- Do projects that appeal to wide varieties of species. Whether you're planting a shoreline meadow, restoring a seaside buffer strip, or revitalizing a salt-marsh plant community, include a diversity of native trees, shrubs, wildflowers, grasses, or aquatic plants. You'll provide food and cover for myriad creatures and boost our native plant heritage. Build wildlife shelters with an eye to structural diversity.
- Take part in a biological survey, such as the Marsh Monitoring Program. The data inform scientists of the state of wildlife populations.
- Support conservation groups, such as CWF, the Foundation for the World's Oceans, and the North American Wetlands Conservation Council (Canada). These organizations inform Canadians about the need to safeguard biodiversity.
- Find imaginative ways to communicate the need to save biodiversity hot spots like coastal wetlands, to curb overfishing, to prevent the accidental by-catch of sea birds, dolphins, and other species in fishing gear, and to discourage other harmful activities.
- Find out about the Canadian Biodiversity Strategy and how it promotes understanding of the necessity to conserve biodiversity while encouraging the sustainable use of biological resources.
- Ask what the government of Canada is doing to solve the biodiversity crisis and to prevent extinctions.
- Fight the invasion of aquatic habitats by purple loosestrife, zebra mussels, Eurasian ruffe, round goby, spiny water flea, and other exotic plants and animals. Learn how to monitor their spread and report any new invasions.
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