Scalloped Hammerhead Shark (Sphyrna lewini)
Scalloped Hammerhead Shark
Did You Know?
ESA Proposed Endangered
--Eastern Atlantic "DPS"
--Eastern Pacific "DPS"
ESA Proposed Threatened
--Central and Southwest Atlantic "DPS"
--Indo-West Pacific "DPS"
CITES Appendix II - effective 09/14/2014
CITES Appendix III - included by Costa Rica
Scalloped hammerhead sharks are moderately large sharks with a global distribution. The eight or so species of hammerhead sharks are characterized by the flat, extended head or "cephalofoil." The cephalofoil of a scalloped hammerhead shark is characterized by an indentation located centrally on the front margin of the broadly arched head. Two more indentations flank the main central indentation, giving this hammerhead a "scalloped" appearance.
They feed on crustaceans, teleosts, cephalopods and rays.
The scalloped hammerhead shark is a coastal pelagic species that can also be found in ocean waters and occurs over continental and insular shelves and adjacent to deeper water. It has been observed close inshore and even entering estuarine habitats, as well as offshore to depths of 1000m. Adult aggregations are common at seamounts, especially near the Galapagos, Malpelo, Cocos and Revillagigedo Islands and within the Gulf of California, but otherwise adults can be solitary or occur in pairs.
Scalloped hammerhead sharks are found worldwide residing in coastal warm temperate and tropical seas in the Atlantic, Pacific, and Indian Oceans between 46°N and 36°S to depths of 1000 meters. Distinct Population Segment (DPS) boundaries are shown in the map below:
- targeted fisheries, shark fin trade
This species is highly desired for the shark fin trade because of its fin size and high fin ray count. They are caught in a variety of fisheries including artisanal and small-scale commercial fisheries, bottom longlines as well as offshore pelagic longlines, gillnets, etc. They are valuable in the international fin and are often used to make shark fin soup. Compilation of market prices from auction records indicates an average, wholesale, unprocessed fin market value of about $50-100 per pound.
In October 2012, a number of countries agreed to sponsor a proposal to add scalloped hammerhead shark to Appendix II of CITES to provide further protections from the high demand in international trade. The United States offered a similar proposal (co-sponsored by Palau) at the last CITES meeting in March 2010. The proposal garnered a simple majority but had failed to acquire the two-thirds majority needed for adoption.
On August 14, 2011, we received a petition from WildEarth Guardians and Friends of Animals to list the scalloped hammerhead shark (Sphyrna lewini) as threatened or endangered under the ESA throughout its entire range, or, as an alternative, to delineate the species into DPSs. On November 28, 2011, we published a notice that listing may be warranted, and we commenced a status review. We published the proposed rule to list and status review in April 2013.
|Scalloped Hammerhead Shark Status Review Report||04/2013|
Proposed Endangered and Threatened Listing Determinations for 4 Distinct Population Segments (DPSs)
|78 FR 20717||04/05/2013|
||78 FR 20717||04/05/2013|
|CITES Appendix II Proposal||10/04/2012|
|New import and export requirements under CITES Appendix III inclusion [pdf]||09/25/2012|
|90-Day Finding on a Petition To List the Scalloped Hammerhead Shark as Threatened or Endangered and Initiation of Status Review||76 FR 72891||11/28/2011|
|Petition to List Under the ESA||n/a||08/2011|
Updated: March 14, 2014