Aquaculture is the practice of farming fish and shellfish in marine and fresh water environments. In order to meet the demand of consumers, an alternative to wild-caught fish and shellfish became necessary. Aquaculture has both positive and negative aspects to it, depending on what is being raised. Here are a few examples of both positive and negative aspects of aquaculture:
Oysters, mussels and clams are very successful at being "farm raised," another term for aquaculture. These invertebrates are filter feeders that remove tiny plankton from the water. They do not require any additional nutrients and therefore require a minimal amount of care. These organisms also play a key role in keeping the environment clean by filtering out particles from the water. Having farm raised oysters, clams, and mussels near our coastlines can actually help maintain a healthier ecosystem. Farmers need to be careful that the animals are not too efficient, resulting in removing too much of the nutrients from the water so that other species in the area are deprived of them.
A problem with aquaculture arises when we discuss fish such as salmon. Large nets are used to keep farmed raised salmon in a confined area. Lots of salmon in one area produces lots of feces. The waste build up adds a stress to the environment where the fish are kept. Since the aquaculture pens are located in areas near wild species sometimes diseases can be spread from farmed raised fish to the wild species. The wild species may not be equipped to deal with newly introduced diseases and as a result entire wild species of fish may be eliminated due to their inability to fight off the disease.
In some cases, the farmed raised species is not a native species. This can create a problem if some of the farm raised species escape their nets. They will not have a natural predator and as a result could dominate an area, taking up the food and space of the native species. In no time at all an invasive species could eliminate the existence of a native species.
Aquacultures are easiest to care for when they are placed close to the coastline. Unfortunately, in most cases, being close to the coastline can be destructive to the ecosystem located there. Many acres of mangrove forests and estuaries have been destroyed in order to place aquaculture farms. These coastline communities are necessary for many species of fish survival in that they are treated like a "nursery" for developing eggs and juvenile fish.