The tallest trees in the world are (1) the coastal redwoods of California, (2) Mt. Ash, a eucalypt from southeastern Australia, and (3) the Douglas-fir and Sitka spruce trees of British Columbia and Washington State.
Fishing for an end to algae
Fishing for an end to algae A biologist has developed and innovative
waste-water purification system using fish and algae! Devastating
blooms of algae often grow from sewage discharges into lakes and
rivers, but Ray Drenner has discovered a way to use the algae and
found a fish that will eat it. The algae feeds on phosphorus and
nitrogen that is still in the water after it is treated in sewage
plants, and its growth can suffocate fish, plants and insects.
However, Drenner has found a species of African fish, the
Mozambican mouth brooder, which thrives on the algae. In a system
of tanks filled with fish and algae, sewage water is cleaned of
phosphorus and nitrogen by the algae, and then of algae by the
fish. This leaves the water clean to be discharged or recycled. And
as long as there are no heavy metals in the water, the fish are
safe to eat! FEBRUARY 24, 2000
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