Explain how fish stocks can be conserved using education, closed seasons, protected areas, controlled net types and mesh size, quotas and monitoring

Describe the harmful effects of: (a) water pollution by untreated sewage and nitrogen-containing fertilisers leading to eutrophication, limited to: (i) increased availability of nitrate and other ions (ii) increased growth of producers (iii) increased decomposition after death of producers (iv) increased aerobic respiration by decomposers (v) reduction in dissolved oxygen (vi) death of organisms requiring dissolved oxygen in water (b) air pollution by greenhouse gases (carbon dioxide and methane), contributing to global warming and its likely effects (c) pollution due to insecticides and herbicides (d) non-biodegradable plastics in the environment, in both aquatic and terrestrial ecosystems

Describe how fermenters can be used for the large-scale production of useful products by bacteria and fungi, including the conditions that need to be controlled, limited to: temperature, pH, oxygen, nutrient supply and waste products