What species were added to the federal endangered species list in 1999?

The Sacramento splittail minnow and spring-run Chinook salmon were indeed added to the federal endangered species list in 1999 due to significant declines in their populations, primarily driven by habitat loss and changes in water management in California.

The Sacramento splittail minnow is native to California's Central Valley and has been adversely impacted by alterations to river systems, while the spring-run Chinook salmon, which relies on cooler waters for spawning, faced pressure from water diversions and habitat degradation. Their listing reflects the wider conservation efforts taking place in response to the pressures these species faced, aligning with broader initiatives aimed at protecting endangered aquatic species in California.

The other options consist of species that were either listed earlier or didn't receive federal recognition at that time, which is why they do not pertain to the events of 1999 specifically.