Fish farming

The world supply of wild fish is decreasing. Fish farming provides an alternative method of supplying fish.

The graph shows the change in total supply of fish and the supply of wild fish between 1950 and 2017. The graph also shows the predicted total supply of fish and supply of wild fish from 2017 to 2050.

The total supply of fish is the sum of the supply of wild fish and the supply of farmed fish. Describe the change in the supply of wild fish and the supply of farmed fish between 1950 and 2017.

Calculate the predicted rate of increase in the total supply of fish in tonnes per year between 2017 and 2050. Give your answer in tonnes per year. Show your working.

rate of increase =_........ tonnes per year

To increase production, fish farmers maintain water quality and food quality on a fish farm. Explain three other ways that farmers could increase production on a fish farm.

Fish farms provide food for many people.

State one way in which intraspecific predation can be reduced on fish farms.

Antibiotics are used on fish farms. Explain the advantages and disadvantages of using antibiotics on fish farms.

Fish produce faeces that can build up in the water. This may affect the fish growth. Design an investigation to find out the effect of fish faeces on fish growth. Your answer should include experimental details and be written in full sentences.

4 (a) Nile tilapia are fish. Their body colour is controlled by a single gene. The allele N produces normal body colour and the allele n produces pink body colour. Diagram 1 shows the phenotypes and the genotypes of Nile tilapia. normal body colour (NN) normal body colour (Nn) pink body colour (nn)

Diagram 2 shows all the possible crosses between the phenotypes and genotypes of Nile tilapia parents.

The table gives some descriptions of offspring. Complete the table by giving the number of crosses that would produce each description of offspring. The first one has been done for you.

Tilapia are farmed in many parts of the world to provide a source of protein. Farmers build large ponds and fill them with fish. The ponds are exposed to sunlight and the farmers add manure to help the growth of the fish. Some of the water in the ponds is changed every day.

Suggest how sunlight and manure help the growth of the fish.

Suggest why some of the water is changed every day.

A fish farm contains 6000 fish. The average (mean) increase in mass of a fish over a period of 32 weeks is 700 g. Estimate the total mass of fish, in kg, that the fish farm could produce after 32 weeks.

Methods of fish farming have changed as more countries become involved in the industry.

Suggest two reasons why more of our fish are supplied by fish farming rather than from traditional fishing.

This photograph shows a new type of fish farm which has been developed in

This new type of fish farm differs from traditional fish farms because it uses water from under the ground instead of from rivers it uses fewer antibiotics

Suggest one advantage of using water from under the ground rather than from rivers.

Suggest the advantage of using fewer antibiotics in fish farms.

Another advantage of the new type of fish farm is the reduction in waste discharge. The figures for a new type of fish farm and a traditional fish farm are shown in the

Calculate the total phosphate in the waste from the new type of farm as a percentage of the total phosphate in the waste from the traditional farm. Show your working.

If waste from fish farms is released into rivers it will cause pollution. Design an investigation to compare the pollution caused by waste released from the new type of fish farm with waste released from a traditional fish farm. Your answer should include experimental details and be written in full sentences.

A school in Uganda made a large freshwater pond so that their students could investigate the factors that fish need to grow well in a fish farm.

Suggest how the students should maintain the water quality in their pond.

Suggest how the students could control predation in their pond.

Suggest how the students could control disease in their pond.

Suggest the feeding methods the students should use in their pond.

The diagram shows how water flow is controlled in a fish farm to maintain water quality.

Name a waste product produced by the fish.

Explain how the removal of fish waste helps to maintain water quality.

Explain how adding antibiotics would also help to maintain water quality.

The fish waste from step 2 is used by the plants in steps 3 and 4. Describe how the fish waste helps the plants to grow.

Suggest what could be done on this fish farm to prevent interspecific predation.