James W. Avault Jr.
Aquaculture is evolving worldwide because of a shortfall of fishery products from oceans and inland waters. After World War II, it appeared that the world’s fisheries resources were virtually unlimited. World landings during 1948 to 1952 averaged 21.9 million metric tons per year and rose steadily until 1968, when increases continued but at a slower rate. By the early 1990s, global fisheries harvest plateaued near 100 million metric tons. Today, much of the catch has shifted from valuable species, such as flounder, haddock, Atlantic cod and swordfish, to much less desirable species, such as spiny dogfish, skate and shark. About 30 percent of the world’s fisheries harvest is reduced to fish meal and oil. One might think the vast oceans would be our salvation with respect to food problems, but 90 percent of our oceans are biological deserts.
Although the fishery harvest from the world’s oceans has stagnated, world population growth and per capita consumption are dynamic. About 90 million people are added to the world’s population each year. By 2025, the population is forecast to reach 8.5 billion. World per capita consumption of seafood is 28.6 pounds per year. With no change in per capita consumption, the world’s population will need more than 55 million metric tons per year of seafood by 2025. The wild fisheries may be able to produce a bit more with better management, but the bulk will have to come from aquaculture.
Aquaculture dates to about 2000 B.C. in China when carp were raised along with the manufacture of silk. The silkworm pupae and feces were used to feed fish. For centuries, aquaculture provided food mostly at a subsistence level. After World War II, some developing nations concentrated on farming staple aquatic species for animal protein and profit. Various carp and tilapia species were farmed. In the 1980s, many nations, both developed and developing, began shifting attention to aquatic species of high value, such as marine shrimp and salmon. Developed nations, such as the United States, Japan and those in western Europe, saw demand for highvalue species escalate. Developing nations saw the possibility of foreign exchange with affluent countries.
Records on world aquaculture production appeared around 1966 at which time the Food and Agricultural Organization (FAO) of the United Nations estimated production at 1.1 million metric tons, or about 3 percent of the world fishery production. Over the years aquaculture production has grown nearly 8 percent annually. By 1995, the FAO estimated world aquaculture production (excluding cultivated seaweeds) near 28 million metric tons, nearly 20 percent of the world fishery production, with a wholesale value of $42.3 billion. The FAO estimates, based on demographic population growth alone and no increase in per capita consumption, that global aquaculture will supply 35 percent to 40 percent of world seafood supply by 2010 and 50 percent to 60 percent by 2025.
Imports to the United States have reached record levels of nearly $8 billion. The United States is also a major aquaculture producer. Channel catfish dominates production. In 1998, 560 million pounds were produced with a value of about $415 million. The four major catfish-producing states are Mississippi, Arkansas, Alabama and Louisiana.
Other important species cultivated in this country include rainbow trout (57 million pounds); crawfish (40 million to 50 million pounds); tilapia (18 million pounds); salmon (33 million pounds); marine shrimp (6 million pounds); mollusks, primarily oysters (24 million pounds); and a myriad of other species, such as hybrid striped bass, bait fishes and ornamental fishes. Fastest growing segment in agriculture
According to the U.S. Department of Agriculture, aquaculture is the fastest growing segment of the nation’s agriculture, increasing at an annual rate of about 8 percent per year. Tilapia production alone has increased 300 percent in the past five years. Moreover, tilapia consumption in the United States increased 26 percent from 1996 to 1997.
The LSU Agricultural Center began exploring the niche of aquaculture around 1965. Scientists initiated a research program through the Louisiana Agricultural Experiment Station
(LAES). Meanwhile, the graduate program in the School of Forestry, Wildlife and Fisheries began adding aquaculture courses, and shortly thereafter the Louisiana Cooperative Extension Service
(LCES) added a wildlife and fisheries specialist and an aquaculture program. At this time token acreage was in crawfish production, and catfish farming was generating considerable interest. Early research by the LAES focused on the basics of farming crawfish and catfish. For years the crawfish industry was based on hit or miss with the wild crop from the Atchafalaya River Basin. Significant crawfish crops were produced three out of five years. Some years there was a bumper crop; some years virtually nothing. Through research, the LAES researchers developed methods for predictable farm-raised crops. With this came the establishment of markets other than the traditional family weekend crawfish boil. Eventually, overseas markets were established. Over the years, the LSU Agricultural Center, responding to the needs of the nascent industry, developed a cultivated forage crop food-delivery system to feed crawfish. With rice as a forage instead of formulated feeds, the cost of farming crawfish went down and profits up. Networking with LCES personnel and crawfish farmers, LAES scientists developed methods of doublecropping rice and crawfish, developed manufactured baits that evolved into a multimillion dollar industry, established guidelines for managing water quality, designed new traps and trapping programs for harvesting, and in general responded to the needs of crawfish farmers. Early catfish industry
The early catfish farming industry was viewed by the LSU Agricultural Center in the same manner. For example, a number of farmers hit brackish water when drilling water wells. LAES personnel working with scientists at the Louisiana Department of Wildlife and Fisheries’ Rockefeller Wildlife Refuge learned that catfish not only tolerate slightly brackish water, they thrive in it. Catfish, the studies showed, could be grown in waters up to 8 parts per thousand salinity. Moreover, these catfish never had off-flavor or brownblood disease caused by nitrite toxicity. Further research showed that a dreaded disease called white spot disease or “Ich” was controlled when fingerlings were held in salinity for a week. With continuous aeration and high feeding rates, more than 6 tons of catfish were produced per acre each season.
No other state has the potential for aquaculture as does Louisiana. It has all the essential prerequisites: (1) people with a heritage in fisheries, (2) a long growing season, (3) an established aquaculture industry well integrated into traditional agriculture, (4) abundant land well suited for aquaculture, (5) an abundance of both surface water and ground water, (6) LSU Agricultural Center personnel with expertise in aquaculture research and technology transfer and (7) people with a reputation for good cooking and a fondness for quality seafood.
In 1986, the LSU Agricultural Center undertook a two-year, statewide investigation of the potential for aquaculture in Louisiana. The study included an evaluation of soils and topography, climate, water resources, seafood processing capabilities, transportation systems and, in general, the infrastructure required to develop an aquaculture industry. Superimposed on these findings was the suitability of each parish for the culture of nine aquatic species, including catfish and crawfish. The report concluded that the potential for aquaculture development exists in every parish. More than 21 million acres, 75 percent of the land area in Louisiana, is sufficiently level and has sufficient water-retaining ability to allow leveed pond construction. Adequate supplies of ground water and surface water are available in most areas. Louisiana has potential to become the seafood market of the nation. Through the combined efforts of LSU Agricultural Center research and extension programs, and governmenta1 leadership, the citizens of Louisiana may reap the monetary and employment benefits of an expanded aquaculture industry.
James W. Avault Jr., Professor Emeritus, Aquaculture Research Station, LSU Agricultural Center, Baton Rouge, La.
(This article was published in the fall 1999 issue of Louisiana Agriculture.)