Why Care About Biodiversity?
The term "biodiversity" refers to the diversity of all life. Biological diversity is one measure of how healthy an ecosystem is. Healthy environments support high diversity; stressed ecosystems do not. A diverse community is also a stable community with an abundance of genetic and structural variation available to deal with unexpected environmental change. Populations of organisms with more genetic diversity are better able to cope with environmental change than are populations with low diversity. The latter can become so highly adapted to local conditions that any environmental disturbance may be enough to drive them to extinction. Therefore, diversity is critical in ensuring the continued existence of our natural world.

To bring the issue even closer to home, the diversity of plants and animals on earth provides us with a wealth of products that we have come to depend on in our daily lives. Food, medicine, clothing, the air we breathe, and, in fact, our very survival is dependent on the life around us. Selfish human activity is resulting in a loss of biodiversity on a scale greater than the mass extinctions of 65 million years ago when the dinosaurs went extinct. The recent rate of extinction due to habitat destruction has been estimated at 10,000 times the baseline rate (i.e., excluding major extinction events) prior to human influence. Thousands of species are lost each year, and we have no idea what tremendous benefits to mankind these organisms might have provided-a cure for cancer or an end to global hunger? By preserving biodiversity, we preserve a higher quality of life and, indeed, promote our continued existence.

The vast majority of the planet's biodiversity is made up of small, inconspicuous, and often microscopic organisms. Small organisms occupy less space, consume less food individually, complete their life cycles more quickly, and are able to partition the environment into more niches. More niches mean more species. Preserving biodiversity, then, means protecting small things, even when we may never see them. This is the case with many of our inconspicuous, non-game fishes. They form the majority of our provincial fish diversity; so they are worthy of protection for this reason alone. However, they also perform a critical role in maintaining the health and well-being of our more "charismatic" fish species.

"Behind the Scenes" in an Aquatic Community
Many people, including anglers and naturalists, are familiar with a handful of the game fishes that occur in Alberta. Of this handful, a few, like northern pike, walleye, and sturgeon, are relatively easy to identify; others, like some of the trout species, require a little more attention to detail in order to recognize them at all life stages. Nevertheless, these species show up regularly in angler's creels, on supermarket shelves, in popular books, and even on TV; so most people are aware that they exist.

But what about the fishes that anglers don't catch regularly, or those that are of little obvious commercial value? In Alberta, these make up the majority of our fish fauna. Only about 18 of the approximately 60 species that occur here are considered game fishes. The other 42 species, or 70% of Alberta's fishes, are relatively unknown to most people. Yet these small but often abundant species are critical components of aquatic ecosystems and the fundamental building blocks of food webs that support the large, predatory game fishes.

Predator-prey interactions among these species are the simplest and most easily understood concepts relating forage fishes to game species. Knowing "who eats whom" is important to an understanding of how ecosystems function as a whole. However, the linkages among fish species and their environment are far more intricate than a simple food chain. Some species compete with each other for food and space, some parasitize their neighbours, some live in tight symbiotic relationships where each is completely dependent on the other. Interactions among species affect behaviours, life cycles, and life history strategies in such a way as to minimize niche overlap in co-existing species and allow all to survive together.

Ecosystems have been described as a "house of cards" where each card, or species, supports the others. Removing one piece can cause the entire structure to collapse. We often describe a species that is known to support many other species in a community as a keystone species. These may not be the showy, charismatic organisms that we all recognize, but their importance in maintaining a healthy environment cannot be overstated. We need them more than many people realize. We must ensure they are protected from human disturbance-just as we protect the more conspicuous plants and animals. And the first step toward protection and conservation is to have people become more familiar with these creatures and to recognize their importance in the natural world.

Click here to take a peek into the lives of some of Alberta's diverse fish species.>>>