In Scotland, the number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting, by pollution, and by various other threats to the fish's habitat.

A number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting
B number of wild salmon is reduced because deep-sea and coastal netting is not controlled
C numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting
D wild salmon's numbers are reduced by deep-sea and coastal netting that is not controlled
E wild salmon's numbers have been reduced by uncontrolled deep-sea and coastal netting