of Columbia, or any territory or possession of the United States. (E) Toxic algae zone (i) In general The term toxic algae zone means any census tract or political subdivision of a State which has been designated by the Secretary, in consultation with the National Oceanic and Atmospheric Administration, as experiencing economic hardship which is directly attributable to a qualified incident. (ii) Limitation A census tract or political subdivision of a State may not be designated as a toxic algae zone for a period of consecutive years in excess of 3 years. (F) Toxic algal bloom The term toxic algal bloom means the existence of algae on or near the surface of water in quantities sufficient to cause anoxic conditions in such water. . (b) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2017.