Spatial Coverage
- Long Island Sound.1
- Lower Peninsula (Mich.)1
- Lucca (Italy : Province)1
- Macerata (Italy : Province)1
- Maine1
- Manhattan (New York, N.Y.)1
- Mantua (Italy : Province)1
- Massa-Carrara (Italy : Province)1
- Massachusetts Bay.1
- Massachusetts.1
- Medway, River (England)1
- Messina (Italy)1
- Mexico, Gulf of1
- Mexico, North1
- Middle West1
- Missouri1
- Missouri River Watershed1
- Modena (Italy : Province)1
- Modena (Italy)1
- Molise (Italy)1
