NMFS is issuing a final determination that the Central California coast coho salmon ESU (Oncorhynchus kisutch) is a ``species'' under the Endangered Species Act (ESA) of 1973, as amended, and that it will be listed as a threatened species. In the 1940s, estimated abundance of coho salmon in this ESU ranged from 50,000 to 125,000 native coho salmon. Today, it is estimated that there are probably less than 6,000 naturally-reproducing coho salmon. The threats to naturally-reproducing coho salmon are numerous and varied. In the Central California coast ESU, the present depressed condition is the result of several human caused factors (e.g., habitat degradation, harvest, water diversions, and artificial propagation) that exacerbate the adverse effects of natural environmental variability from drought and poor ocean conditions. Existing regulatory mechanisms are either not adequate or not being adequately implemented to provide for the conservation of the Central California coast coho ESU. The taking of this species is prohibited, pursuant to section 4(d) and section 9 of the ESA. Certain exceptions to this taking prohibition pursuant to section 10 are provided. The taking prohibitions go into effect as provided in Sec. 227.21.