Endangered and Threatened Wildlife and Plants; Proposed Listing Determinations for Ten Species of Giant Clams Under the Endangered Species Act

We, NMFS, have completed a comprehensive status review of seven species of giant clams (Hippopus hippopus, H. porcellanus, Tridacna derasa, T. gigas, T. mbalavuana, T. squamosa, and T. squamosina) in response to a petition to list these species as threatened or endangered under the Endangered Species Act (ESA). Based on the best scientific and commercial data available, including the Status Review Report, and after taking into account efforts being made to protect these species, we have determined that H. porcellanus, T. mbalavuana, and T. squamosina are in danger of extinction throughout the entirety of their respective ranges, T. derasa and T. gigas are in danger of extinction in a significant portion of their respective ranges, and H. hippopus is likely to become an endangered species within the foreseeable future throughout a significant portion of its range. Therefore, we propose to list H. porcellanus, T. mbalavuana, T. squamosina, T. derasa, and T. gigas as endangered species and H. hippopus as a threatened species under the ESA. We have determined that the fluted clam, T. squamosa, is not currently in danger of extinction throughout all or a significant portion of its range and is not likely to become so within the foreseeable future. Therefore, we find that T. squamosa does not meet the definition of a threatened or an endangered species under section 4(a) of the ESA. Further, we propose to exercise the discretionary authority of section 4(d) to extend the prohibitions of section 9 of the ESA to the proposed threatened species, H. hippopus. At this time, we do not propose to designate critical habitat for the three species proposed to be listed that occur within U.S. jurisdiction (H. hippopus, T. derasa, and T. gigas) because critical habitat for these species is not yet determinable. Using the authority of section 4(e) of the ESA, we also propose to list T. crocea, T. maxima, T. noae, and T. squamosa as threatened species due to the similarity of appearance of products derived from these species (e.g., meat, worked shell products, and pearls) to those derived from the six aforementioned species proposed to be listed based on their extinction risk. We propose a special rule to define activities that would and would not be prohibited with respect to these four species in order to mitigate the substantial enforcement challenge associated with this similarity of appearance concern. We solicit information to inform the final listing determination and to inform a future proposal for any determinable critical habitat.