Learning objectives for this section on food security and food production

• Know and understand that at each stage in a food chain, less material and less energy are contained in the biomass of the organisms.

  • Realise that this means that the efficiency of food production can be improved by reducing the number of stages in food chains.

  • As you move up a food chain, at every stage you lose biomass and therefore energy, so the greater the number of stages in food chain from producer to final consumer, the food production becomes less and less efficient.

  • Because of the fewer stages in the food chain, it is more efficient to produce food by growing crops than raising herds of animals if you compare the efficiencies of equal areas of land.

  • However a healthy diet should be varied diet, so meat or meat substitutes are important, but it is possible to grow cereal crops with a higher protein content.

  • Also, not all land is suitable for growing crops and poor quality land in upland areas of wild moorland may be more suitable for sheep for mutton and deer for venison.

• Know and understand that he efficiency of food production can also be improved by restricting energy loss from food animals by limiting their movement and by controlling the temperature of their surroundings.

  • Intensive farming, where animals are constrained in large 'sheds' with limited movement and kept in a warmer environment, does improve efficiency of meat production making it cheaper for the farmer to produce food by reducing production costs.

  • This makes cheaper food for us via our local shops and supermarkets and supermarkets have a powerful influence on the cost of food but are increasingly being pressured to source from farmers who adhere to strict standards of animal husbandry - but this is not the case in all countries.

  • Less energy is wasted as body heat and animals grow fatter on less food, and animal feed is becoming increasingly costly, but, at what cost to the quality of existence of these factory farmed animals?

  • There are also disadvantages to intensive farming eg the over-crowded conditions are ideal for the spread of disease eg avian flu in chickens, foot-and-mouth-disease in cows. To combat these diseases by treating the animals with antibiotics increases production costs and introduces these same antibiotics into the food chain, so potentially weakening our own immune system if we become infected.

  • But, these 'factory farming' methods means the lives of the quality of life of these animals is much reduced compared to living out in open fields with plenty of space to move about freely, fresh air and sunlight, hence consumer demand for organic meat from animals not intensively farmed.

• Know and understand that fish stocks in the oceans are declining.

  • Know that it is important to maintain fish stocks at a level where breeding continues or certain species may disappear altogether in some areas.

  • Fish stocks of popular varieties are becoming alarmingly low in many regions of our seas and oceans due to over-fishing, which itself derives from the food demands of increasing population.

    • Its ironic that a lot of fish is used as 'unnatural' feed for the contained intensive farming of other species such as trout and salmon in fish farms.

  • Know and understand that net size and fishing quotas play an important role in conservation of fish stocks.

    • Fishing quotas are all about controlling the number of fish caught and the size of the fishes allowed to be caught e.g. fishing boat catches are carefully monitored and recorded and fishing nets inspected to check that the mesh spacing in the nets is not too small so that too many small immature fish (who can breed later) are not caught and hopefully unwanted species of fish or other marine creatures (eg crustaceans like crabs, lobsters, crayfish) can escape!

    • Understand that this is an example of sustainable food production, so that the numerical catch rate can match the numerical growth rate of the fish species we like to eat.

      • In fact in some areas, some fish species are so low in numbers, the catch rate is being highly restricted or banned all together to give the fish stock in the seas to get back to a sustainable level.

    • Such methods are needed because food chains are being disrupted and species may die out from particular oceanic regions from intensive fishing from huge trawlers and factory ships.

• Know and understand that the fungus Fusarium is useful for producing mycoprotein, a protein-rich food suitable for vegetarians and is a meat substitute eg like the commercial product 'Quorn' (though it does need tasting up a bit!).

  • Know that the fungus is grown on glucose syrup (supplies energy for the process as well as the carbon, hydrogen and oxygen for the protein molecules), in aerobic conditions (air containing oxygen needed), with a source of nitrogen eg ammonia or ammonia compounds (nitrogen is the other important element in amino acids and proteins).

  • Fungi grow rapidly in moist warm conditions so production rates are quite efficient and it doesn't require as much land - though do need sufficient land to the maize from which the glucose syrup is made. When the raw materials have been consumed by the Fusarium fungi the biomass is harvested and purified to be used in various food products.

  • The glucose syrup is made from breaking down maize starch with the appropriate enzyme containing microorganism, though in the mycoprotein production it is important that only the correct microorganism is present to ensure the right biochemistry happens and other microorganisms start multiplying. Therefore all ingredients must be heated and sterilised to kill all microorganisms and the air filtered to remove airborne microorganisms, before the mycoprotein forming fungi are introduced into the fermenter - which itself must be first sterilised with very hot steam.

  • In poor third world countries mycoprotein might be a good efficient substitute for inefficient meat production from animals grazing on large areas of relatively barren infertile land, but is the source of nitrogen from ammonia cheap? I don't think so?

• Know and understand that humans often upset the balance of different populations in natural ecosystems, or change the environment so that some species find it difficult to survive.

• Know and understand that with so many people in the world, there is a serious danger of causing permanent damage not just to the local environments but also to the global environment unless our overall effect is managed carefully.

• Know and understand that humans rely on ecosystems for food, water and shelter.

• You should be able to use your skills, knowledge and understanding to:

  • analyse and interpret scientific data concerning environmental issues,

    • In examination questions you may be given data to work on,

  • evaluate methods used to collect environmental data and consider their validity and reliability as evidence for environmental change,

    • There is a considerable amount of climate data being collected around the world every day and many weather records go back tens and even hundreds of years.

    • Thermometers provide temperature data of the air and oceans, water collectors for rainfall, snowfall records, glacier size and their rates of melting, satellites can map rain clouds, storm patterns, glacier areas etc.

    • So, we are not short on data, and the consensus is that the Earth is warming, and by 1-2^oC over that past 100-150 years. It doesn't sound much, but a 1^oC rise does represent a huge amount of extra energy in our global weather system!

    • It is important that the data record is as long and accurate as possible. Computer modelling of the climate and trying to make predictions is not easy because there are so many variables and many not very predictable.

  • evaluate the methods being used to feed and provide water to an increasing human population, both in terms of short term and long term effects,

  • evaluate the use of biogas generators,

    • You should have considered a number of biogas generator designs ranging from third-world generators supplying a single family to commercial generators,

    • you should understand how the output from a biogas generator might be affected by climatic conditions,

  • evaluate the positive and negative effects of managing food production and distribution, and be able to recognise that practical solutions for human needs may require compromise between competing priorities,

    • You should consider:

      • the differences in efficiency between producing food from animals and plants,

      • the pros and cons of factory farming of animals,

      • the implications of ‘food miles’ - some food imports have come from thousands of miles away from the source of food production.

      • There are several issues which makes this an undesirable situation It adds extra costs to the consumer.

      • The transport costs increase the price of the food.

      • There is environmental damage from burning more fossil fuels - carbon dioxide -global warming - climate change.

      • These food imports often originate from third world countries where this is pressure to increase the national income from selling cash crops to foreign countries, BUT, many of the people in these exporting countries do not access to good food supplies - its the richer important countries who often benefit the most.