1.   However, if too much phosphorus gets into lakes and rivers it can encourage excessive growth of the microscopic plant life, called algae, and other water plants.

2.   And nutrients have run off farms into the water, causing microscopic plants known as phytoplankton to multiply, further clouding the lakes in a process known as eutrophication.

3.   Before European settlers arrived, some scientists believe, the central role at the bottom of the food chain was filled primarily by phytoplankton, microscopic plants.

4.   It first attacks the base of the food chain, microscopic plants and animals upon which fish and other life depend.

5.   Meanwhile, the life cycle of this tenacious microscopic plant has become the focus of an unprecedented five-year government research effort.

6.   Millions of microscopic plants and animals in fact live here, hidden in its soil, under the perennially frozen surfaces of its lakes and even inside its rocks.

7.   Millions of microscopic plants and animals live here, hidden in the soil, under the perennially frozen surfaces of the lakes and even inside rocks.

8.   Scientists suspect man-made pollution is fueling the growth of a microscopic plant.

9.   Scientists know that excess nitrogen promotes the growth of microscopic plants that form the base of the aquatic food chain.

10.   The contaminants start out at the bottom of the food chain in microscopic plants and animals that are eaten by larger animals.