KEEPING FISH HEALTHY

Growing Fish Field Creates Big Splash

By Douglas P. Anderson.

Fishing is a national recreation, fish are a nutritious and staple food, and raising fish as pets and for display is a delightful hobby for millions of Americans. Clean streams and lakes are sources of healthy foods and places to escape and relax from our busy social and work-a-day world.

We use more fish for sport and food than nature can provide; therefore, growing fish on farms, called aquaculture, is developing into a multibillion-dollar business. Raising fish interests entrepreneurs and established farmers who search for new ways for making profits and seek to diversify by expanding into little-used marginal river lowlands or other clean water sources.

The National Aquaculture Development Plan prepared by a Joint Subcommittee on Aquaculture and edited by the U.S. Departments of the Interior, Agriculture, and Commerce, reports that catfish farming is the largest aqua-culture industry with over $120 million invested at the beginning of the 1980's. Raising baitfish is second in value with over $100 million, and trout farming third at $48 million. The value of tropical fish farms is probably underestimated at $20 million. A rapidly growing industry is Pacific salmon culture, often done in sheltered marine bays. It is valued at over $4 million.

Pollution Effects

Keeping fish healthy and their waters clean are major concerns of all Americans. Pollution from cities, industries and agriculture affects our Nation's waters. Reports of fish kills due to spills of chemicals into the water are not uncommon.

The fact that we use more fish for sport and food than nature can provide is the main reason aquaculture is developing into a multibillion dollar business. Catfish farming is the largest aquaculture industry with over $120 million invested at the beginning of 1980.

From long term environmental research studies we now realize that the slower, insidious effects of lingering, low concentrations of chemicals such as pesticides, fertilizers, and industrial exhausts may result in the gradual deterioration of fish health. Acid rain can kill small plants and animals on the lower part of the food chain, indirectly affecting fish populations. The effect of some pollutants may suppress defense mechanisms, causing the fish gradually to be more susceptible to infectious diseases.

Infectious diseases of fish are similar to those of other wild and domestic animals. Fish may harbor, or be exposed to, parasites and pathogenic disease-causing agents during much of their life.

Most healthy animals are able to resist or at least accommodate their microscopic enemies. But when fish are domesticated and raised under intensive conditions, the magnification of environmental conditions can make them more susceptible to disease.

"Fish" this word brings smiles to the faces of millions of Americans with memories of an enjoyable day of fishing on the water ... the sport and anticipation of a possible freezer full of fish for some, a livelihood and business for others ... and hours of enjoyment with a pet for the rest.