18.12 Sustainable Food Production

A free GCSE Biology lesson for AQA (8461) from OBA School: fishing quotas and net sizes, mycoprotein from Fusarium, and genetically modified organisms. Watch the video, read the explanation and worked examples, then try the revision questions. You can work through the full lesson, with every video, practice quizzes and printable worksheets with mark schemes, in our free online course.

What you will learn

• Explain what is meant by sustainable food production
• Explain how fishing quotas and net mesh size help to maintain fish stocks
• Describe how the fungus Fusarium is grown in fermenters to produce mycoprotein
• Describe how genetically modified bacteria and crops can help food security
• Analyse data on fish stocks

Key words

• Sustainable food production: Producing food in ways that meet the needs of people today without harming the ability of future generations to feed themselves.
• Fish stocks: The number (or mass) of fish of a species left in an area of sea that can breed.
• Fishing quota: A legal limit on the mass of each species of fish that can be caught in an area.
• Mycoprotein: A protein-rich food made from the fungus Fusarium; suitable for vegetarians.
• Fermenter: A large sealed vessel in which microorganisms are grown under controlled conditions.
• Genetically modified (GM): An organism whose genome has been changed by adding a gene from another organism.

Tackling overfishing

Fish stocks in the oceans are falling. If too many fish are caught, too few adults are left to breed, so the population cannot recover and some species may disappear from an area. Fish stocks must be kept at a level where breeding continues.

• Fishing quotas; How it helps Limit the mass of fish caught each year, so enough adults are left to breed and replace those taken.
• Control of net size; How it helps A larger mesh lets young fish escape. They survive to reach breeding age.

Worked example: fish stock data

Percentage decrease 1985 to 2005: (410 − 150) ÷ 410 × 100 = 260 ÷ 410 × 100 = 63.4%
Mean recovery after 2005: (290 − 150) ÷ 15 = 9.3 thousand tonnes per year

Answer: a 63% fall, then recovery at about 9.3 thousand tonnes per year

Exam tip: Quotas and net rules work only if they are enforced, and they can cost fishing jobs in the short term. This is a conflicting pressure.

Mycoprotein from Fusarium

Modern biotechnology lets us grow large quantities of microorganisms for food. The fungus Fusarium is used to make mycoprotein, a protein-rich food suitable for vegetarians.

• The fungus is grown on glucose syrup, in aerobic conditions, in large fermenters.
• The fungal biomass is harvested and purified, then made into foods.
• Microorganisms grow very fast, need little space and can be grown on cheap waste products, so this is an efficient way to make protein.

Genetically modified organisms

• GM bacteria; How it helps A bacterium given the human insulin gene makes human insulin. It is grown in fermenters, then the insulin is harvested and purified to treat diabetes.
• GM crops; How it helps Crops can be modified to give higher yields, resist pests or drought, or have better nutritional value. For example, golden rice makes beta-carotene, which the body uses to make vitamin A.

Some people worry about GM crops: genes might spread to wild plants, the effects on insects and food webs are uncertain, and seeds can be expensive for poorer farmers.

Common mistakes

• Saying quotas “stop fishing”. They limit the catch so the stock can breed and recover.
• Saying a smaller mesh helps. It is a larger mesh that lets young fish escape.
• Saying mycoprotein is made from bacteria. It comes from the fungus Fusarium, grown on glucose syrup in aerobic conditions.
• Forgetting the final step: the product (mycoprotein or insulin) must be harvested and purified.

Revision questions

Try these, then check your answers below each one.

Question 1. Which microorganism is grown to make mycoprotein? (Choose from: Fusarium, Lactobacillus, Salmonella, Plasmodium.)

Answer: Fusarium

Working: Mycoprotein is made from the fungus Fusarium.

Question 2. True or false? Fusarium is grown on glucose syrup in anaerobic conditions.

Answer: False

Working: False. It is grown in aerobic conditions, with sterile air supplied.

Question 3. The breeding stock of a fish species fell from 360 thousand tonnes to 135 thousand tonnes. Calculate the percentage decrease.

Answer: 62.5 %

Working: 360 − 135 = 225. 225 ÷ 360 × 100 = 62.5%.

Related lessons

• Previous lesson: 18.11 Making Food Production Efficient
• In this chapter: 18.1 The Human Population Explosion
• In this chapter: 18.2 Land and Water Pollution
• In this chapter: 18.3 Air Pollution

Continue in the full course

This lesson is section 18.12 (AGCBH1812) of our free GCSE Biology course for AQA. In the full course you get every video for this section, a self-marking practice quiz, a printable worksheet with a mark scheme, chapter tests, and your progress saved. Go to the full GCSE Biology course.