Columbia subject headings:
Harvard subject headings:
Conservation of natural resources--Great Lakes.
Environmental monitoring--Great Lakes (North America)
Environmental monitoring--Great Lakes.
Fishes--Conservation--Great Lakes (North America)
Fishes--Effect of chemicals on--Great Lakes (North America)
Fishes--Effect of chemicals on--Great Lakes.
Fishes--Effect of water pollution on--Great Lakes (North America)
Fishes--Effect of water pollution on--Great Lakes.
Fishes--Great Lakes (North America)--Effect of chemicals on.
Fishes--Great Lakes (North America)--Effect of water pollution on.
Water--Pollution--Great Lakes (North America)
Water--Pollution--Great Lakes.
Princeton subject headings:
Conservation of natural resources--Great Lakes.
Environmental monitoring--Great Lakes.
Fishes--Great Lakes--Effect of chemicals on.
Fishes--Great Lakes--Effect of water pollution on.
Water--Pollution--Great Lakes.