The following words or phrases have the following meanings in this subchapter, unless the context clearly indicates otherwise:(1) Fall--the period of time October through December, inclusive.(2) Spring--the period of time April through June, inclusive.(3) Sound ecological environment--an ecological environment that: supports a healthy diversity of fish and other aquatic life; sustains a full complement of important species; provides for all major habitat types including rivers and streams, reservoirs, and estuaries; sustains key ecosystem processes; and maintains water quality adequate for aquatic life.(4) Summer--the period of time July through September, inclusive.(5) Winter--the period of time January through March, inclusive.