During late-night discussions last night over a massive spending package, congressional negotiators dropped two riders that had angered environmentalists. Alaska Sen. Frank Murkowski’s (R) effort to extend commercial fishing in the waters of Glacier Bay National Park was killed, as was Sen. Pete Domenici’s (R-N.M.) rider that would have prevented the Interior Department from setting aside habitat in the Rio Grande to protect the endangered silvery minnow. Domenici may have been reassured by a letter he received yesterday from Sen. John Chafee (R-R.I.), who said he would introduce legislation next week that would force federal biologists to complete endangered species recovery plans before making habitat decisions.