Region
United States
20
North America
11
North Atlantic Ocean
8
Atlantic Ocean
6
Northwest, Pacific
6
Alaska
5
Central America
5
Klamath River Watershed (Or. and Calif.)
5
Mexico
5
Panama
5
Canada
4
Tropics
4
Africa
3
Arctic Coast (Alaska)
3
Bering Sea
3
Bermuda Islands
3
Brazil
3
California
3
Connecticut
3
Europe
3
Great Britain
3
Indian Ocean
3
Islands of the Pacific
3
Japan
3
Kuskokwim River Watershed (Alaska)
3
Mediterranean Sea
3
Minnesota
3
New England
3
Ohio
3
South America
3
Soviet Union
3
Yukon River Watershed (Yukon and Alaska)
3
Yukon-Kuskokwim Delta (Alaska)
3
Amazon River
2
Antarctica
2
Atlantic Coast
2
Atlantic Coast (Canada)
2
Columbia River Watershed
2
Costa Rica
2
England
2
Guiana
2
Illinois
2
Latin America
2
New York (State)
2
Northeastern States
2
Orinoco River
2
Orinoco River (Venezuela and Colombia)
2
Pacific Ocean
2
Russia (Federation)
2
Snake River (Wyo.-Wash.)
2
more ...