Farming and Fishing

3 Key excerpts on "Farming and Fishing"

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  Fish

  • Elizabeth R. DeSombre, J. Samuel Barkin(Authors)
  • 2013(Publication Date)
  • Polity

    (Publisher)

  CHAPTER FIVE Aquaculture

  Aquaculture is the technical term for fish farming. It is not a new phenomenon – on the contrary, it has been around for millennia. But it has expanded rapidly over the past few decades, both in the volume of fish farmed, and in the breadth of species farmed. The proportion of the world’s total seafood production accounted for by aquaculture increased from 13 percent to more than 35 percent in the period between 1990 and 2007.1 With the production of the global capture fishery having peaked at a little over 90 million tonnes a year, all of the growth in global production of seafood comes from the rapidly growing aquaculture sector. To the extent that global capture fisheries are at or near (or even beyond) their maximum sustainable yield, future growth in the supply of fish and other seafood can be expected to come exclusively from aquaculture.

  This sector is dominated by developing countries. China alone accounts for almost two-thirds of the global total aquaculture production as measured by weight (although under half by value), and the top five aquaculture producers globally – India, Vietnam, Indonesia, and Thailand follow China – are all developing countries (again by weight; measured by value Japan comes in fifth).2 A large majority of the world’s fish farming happens in Asia – almost nine-tenths by weight, and about three-quarters by value. The differences between weight and value are caused by the different kinds of aquaculture practiced in different places. Most of the fish farmed in Europe and North America are species that have a high price per weight, such as salmon and oysters, whereas much of the aquaculture in Asia is of lower-value species such as carp, grown with less capital for a more local market.

  The range of activities undertaken under the heading of aquaculture, and the range of scales on which it is practiced, is as broad as for capture fisheries. The range extends from small ponds in which a few herbivorous fish, such as carp or tilapia, are raised for local consumption, to massive industrial operations, involving millions of fish, that raise open-water predator species in pens at sea. Many aquaculture practices, including the small-scale fish pond example, are essentially benign. But as the scale of fish farming operations increases, and as it comes to involve species that are higher up the food chain, potential problems associated with aquaculture multiply. Unfortunately, it is the species that have the greatest value on the global market, such as salmon, shrimp, and tuna, that generate the greatest environmental challenges. These challenges include pollution from high concentrations of animals in confined spaces, the spread of disease among confined and in-bred populations, ecosystem disruptions, and threats to the biological integrity of the species in the wild.

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  Freshwater Ecology

  Concepts and Environmental Applications

  • Walter K. Dodds(Author)
  • 2002(Publication Date)
  • Academic Press

    (Publisher)

  In India, the catla (Catla catla), rohu (Labeo rohita), and mri-gal (Cirrhinus mrigala) are used. There are about 2.5 million ha of carp ponds in India and China. In most cases, these ponds are fertilized with manure, and fish are fed with vegetation or invertebrates. It takes 20 years of training to become adept at all the techniques of disease control, fish feeding, manipulation of reproduction, and fertilization associated with these traditional forms of fish culture (Zweig, 1985). SUMMARY 1. Biodiversity of fish is related to factors that operate at a variety of temporal and spatial scales. In general, fish communities are more diverse in tropical areas, on large landmasses, in older drainage basins, where greater habitat diversity exists, and where more prey species exist. 2. Physiological ecology of fishes is described successfully by the energetic requirements of various processes, including osmoregulation, O 2 requirements, responses to temperature, food quality and quantity, and behavioral considerations. 3. Stock size, production, recruitment, and mortality are central aspects of fish populations that are used in their management. 4. A variety of methods are used to capture fishes depending on their size, the habitat being sampled, and reasons for obtaining data on the fishes. 5. Many indices are used by managers to assess fish populations and potential yields, including the relative stock density, which is the percentage of fish in a specified length or age class relative to the total number of fish estimated by population sampling. 6. A variety of regulations are used to control overexploitation of fish populations. These regulations require consideration of human dimensions but also generally involve a trade-off between high numbers of fish and fewer large fish. 7. Aquaculture of fishes requires understanding of aquatic ecology of fishes

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  Understanding Aquaculture

  • Jesse Trushenski(Author)
  • 2019(Publication Date)
  • 5m Books

    (Publisher)

  In aquaculture, the primary costs are fingerlings and feed – there is tremendous opportunity to reduce both costs through research and development in fish nutrition and genetics. In capture fisheries, the primary costs are labor, fuel, and maintaining the fleet – innovation may reduce costs here, too, but there is substantially less room for cost-savings in these sectors and the fishing industry is not especially influential in any of them (Anderson, 2007). Based on these variables, it would seem that aquaculture is destined to become more economical than fishing, but disease outbreaks, shifts in consumption patterns, or changes in the pricing of fish meal or other commodities used in feed manufacturing could quickly derail such progress (Kobayashi et al., 2015). The cost of a fillet may become increasingly dependent on whether the fish was caught or raised, but whether farmed or wild fish will be more affordable in the future depends on the movements of many invisible hands.

  Notes

  1 “Do the Benefits of Aquaculture Outweigh Its Negative Impacts?” (SENCER, 2017).

  2 “Farmed and dangerous? Pacific salmon confront rogue Atlantic cousins” (Braun, 2017).

  3 From a strict supply–demand perspective, increasing demand for fish meal and fish oil would be expected to increase harvest pressure, but reduction fisheries are governed by more than market forces and supply–demand dynamics. Today, regulations limit harvest and protect these fisheries from overharvest (Asche and Tveteras, 2004).

  4 That aquaculture has generally not displaced fisheries cuts both ways: critics use this as evidence that aquaculture is not able to relieve harvest pressure on wild fish populations, but some would also lament the loss of traditional livelihoods if capture fisheries were to contract as a result of competition with aquaculture.

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  Chapter 16 Resource utilization in the production of animal protein – seafood versus other meats

  We must plant the sea and herd its animals using the seas as farmers instead of hunters. (Jacques Cousteau, French explorer, conservationist, and world-famous marine biologist)

  T he world is hungry and increasingly hungry for protein. There are just over 7 billion of us on the planet at this time, and over the next three decades or so, it is estimated that our ranks will swell to more than 9 billion. By next century, the human population may be nearly 11 billion strong. Based on population growth, we will need to be producing 60% more food by 2050. Not only will we need more food in general, we will need a lot more animal protein in particular. Increasing urbanization, lower production costs, greater buying power, and the like have led to increases in total per capita consumption of animal protein. The protein supply has steadily increased from about 61.5 g/capita/day in the 1960s to more than 81 g/capita/day in 2013, with the increase coming largely from an increased supply of protein from animal products (Figures 16.1 and 16.2 ). These increases – while impressive – are not enough. We need 60% more food by 2050, but we need 60% more animal protein

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