Scraping the bottom

Paint containing tributyl tin stops marine life fouling the bottoms of boats,
but the chemical also leaches into the water and kills shellfish. Danisco of
Copenhagen is patenting a paint and enzyme mixture that prevents fouling without
causing pollution (W0 00/75293). A substance called hexose oxidase is extracted
from the marine alga Chondrus cripus and mixed into paint. When oxygen
is available, the enzyme breaks down any glucose and maltose nutrients nearby,
which stops marine life growing on the boat. The same paint can be used in an
aquarium to stop submerged metal, glass or plastic collecting gunge.