Farming, Fishing and Foraging: Keeping Ecosystems in Balance

Where your food comes from

Some of your food grows on farms: wheat for bread, corn, soybeans, apples, milk and eggs. Some of it is harvested from the natural environment: fish from lakes and oceans, maple syrup, wild blueberries, wild rice, game such as moose and deer.

Every way of getting food changes an ecosystem in some way. Food is a need, so the question is not whether to use ecosystems, but how to use them so they stay healthy for the future.

How farming can affect ecosystems

Turning land into a farm replaces a natural community (forest, prairie or wetland) with crops or pasture. How a farm is run makes a big difference.

Possible negative effects:

• Habitat loss: clearing forests and draining wetlands removes homes for many species. Much of southern Ontario's original forest and wetland was cleared or drained for farms and towns.
• Monocultures: one crop over a huge area gives food and shelter to only a few species, and a pest that likes that crop can spread fast.
• Pesticides: chemicals that kill pests can also harm helpful insects like bees and ladybugs, and some can move into water and food chains.
• Fertilizer runoff: extra nitrogen and phosphorus wash into streams and lakes and feed huge algae blooms. In Lake Erie, phosphorus from farm fields, manure and sewage has caused large blooms, some of them toxic. When the algae die, decomposers use up oxygen in the water.
• Soil erosion: bare fields lose soil to wind and rain.

Approaches that reduce harm:

• Crop rotation and mixed crops break pest cycles and keep soil healthy.
• Cover crops (like clover or rye) protect bare soil over winter and add organic matter; clover also adds nitrogen.
• No-till or low-till farming leaves crop leftovers on the soil, which reduces erosion.
• Buffer strips of trees, shrubs and grasses along streams catch runoff before it reaches the water and give habitat to wildlife.
• Integrated pest management: checking crops for pests and using natural predators, traps or crop rotation first, and pesticides only when really needed.
• Organic farming uses no synthetic pesticides or fertilizers.
• Indigenous agricultural knowledge, such as growing the Three Sisters together (Grade 6), uses relationships between plants to keep soil healthy.

How harvesting from nature can affect ecosystems

Harvesting wild food (fishing, hunting, trapping, gathering berries, nuts, mushrooms, wild rice and maple sap) can be sustainable for a very long time if people take less than the population can replace.

Overharvesting happens when people take a species faster than it can reproduce.

Example: the northern cod. For hundreds of years, huge numbers of Atlantic cod were caught off Newfoundland and Labrador. In the second half of the 1900s, large factory ships with powerful technology caught more and more fish. The cod population collapsed. In 1992, the Government of Canada closed the northern cod fishery. Tens of thousands of people lost their jobs, and many coastal communities were deeply affected. The large commercial fishery stayed closed for more than 30 years. In 2024 the government allowed a limited commercial fishery again, but the cod are still far fewer than before the collapse.

Removing a species also affects its food web: its predators lose food, and its prey can increase.

Strategies for a sustainable harvest

• Quotas and catch limits: only a set amount can be taken.
• Seasons: no fishing or hunting during spawning or breeding times.
• Size limits: release young fish so they can grow and reproduce.
• Licences so governments know how much is taken.
• Protected areas where no harvesting is allowed, so populations can rebuild.
• Monitoring: counting populations every year and changing the rules if numbers fall.
• Respectful harvesting practices from Indigenous knowledge.

Wild rice (manoomin): for Anishinaabe communities in Ontario and the Great Lakes region, manoomin is a sacred food and an important part of culture. Traditional harvesters travel through the rice beds by canoe and use two wooden sticks to gently bend the stalks over the canoe and tap the ripe grains loose. Unripe grains stay on the plant to ripen later, and many grains fall into the water, which reseeds the rice bed for the next year. Many communities also work to protect rice beds from changes in water levels and pollution.

Many Indigenous teachings about harvesting share ideas such as: take only what you need, never take the first or the last, ask permission and give thanks, share what you harvest, and leave enough for the plants and animals to renew themselves.

Restoring balance

When an ecosystem is out of balance, people can help it recover:

• Restoring wetlands by blocking drainage ditches so water returns.
• Planting native trees, shrubs and wildflowers along streams and field edges.
• Reducing phosphorus runoff: Canada and the United States have agreed on targets to cut the phosphorus flowing into Lake Erie.
• Closing a fishery or lowering quotas until fish recover.
• Bringing species back: for example, Atlantic salmon were wiped out from Lake Ontario by the late 1800s, and groups are now working to restore them to some Lake Ontario streams.