By hatching its own fish, carefully controlling feed and raising fish offshore in clean water, mercury and other pollutants can be kept to extremely low levels, contends Spencer.

FORBES: Breakthroughs

Colin Cheney, from the Environment Department, said ground water and streams were as low as they normally would be in June.

BBC: Jersey water boss wants water behaviour change

His comments come as ground water levels are reported to be low and still falling, despite an increase in reservoir depths.

BBC: Jersey water boss wants water behaviour change

And while the extra water from the melting glacier may be increasing the fertility of adjacent lowland areas in the short-term, water supplies would become critically low if it disappears.

UNESCO: 83e