Natural History Wanderings

NPR reported on the return of Harbor Porpoises to San Francisco Bay. After World War II Harbor Porpoises disappeared from S.F. Bay.  This is possibly due to the submarine nets and mines that out at time. Another reason that may have discouraged porpoises from coming into the bay had been pollution.  Today at least 250 porpoises have been identified in the bay. Possibly they are back due to the success of the Clean Water Act of 1972. Read more at NPR 60 Years After Leaving, Porpoises Again Play In SF Bay : NPR.