2. The material in this slide show is provided free for educational use only. All other forms of storage or reproduction are subject to copyright- please contact the National Marine Aquarium The slide show was designed and produced for the NMA by STEP, the Science Training & Education Partnership T raining & S cience E ducation P artnership www.national-aquarium.co.uk www.step-up-to-science.com

3. Toxic materials in marine food-webs

4. Toxic materials Where they come from Summary Where they end up

5. Toxic materials Where they come from Summary Where they end up

6. Many different types of toxic materials enter the marine environment

7. Some are natural, but most are man- made

8. The list includes: ‘Heavy’ metals such as mercury and cadmium Pesticides such as DDT and lindane Industrial compounds such as some lubricants and fire-retardants Combustion products such as dioxins

9. High levels of these toxic materials will kill animals However, normal levels in the environment are low

10. At low levels, there are still effects on animals These effects include cancers and reproductive changes

11. Toxic materials are often very slow to break down in the environment and in living things This means that they last for a long time

12. Toxic materials Where they come from Summary Where they end up

13. Few toxic materials enter directly into the marine environment Most come in from the land and via the atmosphere

14. Local sources include: Pesticides applied in coastal agriculture Anti-fouling treatments applied to ships Disturbance of polluted sediments by dredging Marine pollution incidents such as shipwreck

15. Transport from inland occurs by: Run-off and rivers Transport through the atmosphere Migration of animals Shipping

16. UNEP / Frank Wania

17. Toxic materials that are transported in the atmosphere will tend to evaporate in warm areas and condense in cool areas This means that they move polewards

18. Toxic materials Where they come from Summary Where they end up

19. Toxic materials enter the marine food-web largely at the bottom of the food-chain - the producers

20. These are then eaten by herbivores In turn, they are eaten by predators

21. Each copepod contains a small amount of toxic material from its plant food STEP

22. The fish stores most of the toxic material from its food STEP

23. The more copepods that it eats, the more toxic material is stored STEP

24. In turn, predators further up the food chain build up even higher levels of toxic materials

25. For some toxic materials, top predators in polar ecosystems show especially high levels

26. Toxic materials Where they come from Summary Where they end up

27. Various toxic materials enter the marine environment Many of these come from the land or via the atmosphere You have seen that -

28. Toxic materials enter the food chain mainly through the producers Top predators in a food chain build up highest levels of toxic materials You have seen that -

29. NOTES for USERS The material in this slide show is designed to support the teaching of science at Key Stage 1 A full description of the slide show, and linked activities for students, can be found on the National Marine Aquarium (NMA) web-site: Teachers are free to amend the slide show in whatever way they feel fit, or to use slides in other contexts. However, please note that neither the NMA nor the designers will accept responsibility for modifications, and original material remains copyright of the NMA Individual images used in the slides are copyright of NMA or STEP, except where acknowledged separately The slides have been set up to display as A4 landscape format. If they are incorporated into other slide sequences with different display settings, change in aspect ratio and text location will occur The slide sequence contains the minimum of effects and transitions. However, there are some automated animations, and teachers will wish to make sure that they are familiar with the sequence before use in class Use the PowerPoint notes viewer to obtain additional information for some slides www.justaddh2o.tv www.national-aquarium.co.uk