Whistle blown on alarming 94% decline of hammerhead shark landings in Costa Rica

  • The Costa Rican Fisheries Institute (INCOPESCA) attributes decline to controls on the exportation of its fins.

(San José, Costa Rica – 18/11/2020).  The result of an analysis of official fisheries landing records for three species of hammerhead sharks (Sphyrna lewini, S. mokarran and (S. zygaena) along the Pacific coast of Costa Rica, shows an alarming 94% decline.  From 2010 to 2017, from 8,000 to 10,000 bodies of hammerhead sharks were landed per year.  Nonetheless, from 2017 to 2019 the landings dropped from 4556 to only 488 bodies of hammerhead sharks (Figure 1).

 Furthermore, from 2015 to 2019 the proportion of specimens landed that had not yet reached its size of first maturity ranged from 77% to 87% (Table 1).


When consulted, the Executive Presidency of INCOPESCA attributed the dramatic decline to the improved controls on the hammerhead shark fin export ban.  Costa Rican biologist Randall Arauz however, of the non-profit Fins Attached Marine Research and Conservation, denounces that this reasoning lacks any technical ground whatsoever, and is only a poor attempt to justify the lack of effective conservation policy for critically endangered hammerhead sharks.  “INCOPESCA has yet to adopt any measures whatsoever to improve the conservation of hammerhead sharks, as it continues to allow its indiscriminate fishing without size nor maturity restrictions under the guise of by-catch, as well as the domestic commercialization of their fins under no controls, the intention of which could only be their illegal exportation to Hong Kong,” complained Arauz.  “The best scientific information available clearly shows that we are facing a crisis caused by overfishing,” concluded Arauz.

According to Jeffry Madrigal, biologist with the Endangered Marine Species Rescue Center of Costa Rica (CREMA), an important source of data that could help elucidate the cause of the dramatic decline in hammerhead shark landings can be found in relative abundance data or catch per unit of effort, which is obtained by on-board INCOPESCA observers.  INCOPESCA however, claims that this information is provided to the Inter American Tropical Tuna Commission (IATTC) (Carrasco, 2020b) for the establishment of fishery policy, thus depriving national scientists from the possibility of performing independent analysis with information of public interest.

“If the 94% decline in hammerhead shark landing responds to overfishing, then we would observe a dramatic decline in the number of hammerhead sharks caught, or if by the contrary, such decline is due to improved controls on the exportation of their fins, we would observe a constant catch,” explained Madrigal.  “Therefore, if INCOPESCA’s claim is correct, one can only assume that fishers are catching the same number of hammerhead sharks as usual, but they are now discarding whole specimens at sea due to the impossibility of exporting their fins, an argument without any credibility,” denounced Madrigal.

Cases of illegal exportation of hammerhead shark fins have been documented.  The first one occurred on November 17 of 2014, when an attempt to export hammerhead shark fins mingled with fins of legal species was exposed in a shark fin cargo destined to Hong Kong.  Furthermore, in January and August of 2018, the Costa Rican Mail Service halted the export of suitcases with hundreds of hammerhead shark fins.  “You may ban the exportation of hammerhead shark fins, but by allowing their unregulated domestic commercialization you are in fact fostering overfishing and illegal exportation,” concluded Madrigal.

“The time has come to take decisive actions, or hammerhead sharks will be extinct within the next 20 years, that is nothing, its like saying tomorrow,” warned Arauz.  “Costa Rica must immediately ban the catch and retention of hammerhead sharks, as well the possession and domestic commercialization of their parts, if the country that is, sincerely wants to save this emblematic species from its imminent extinction,” sentenced Arauz.

For more information:

Randall Arauz

Fins Attached Marine Research and Conservation

+506 8708 8253 / rarauz@finsattached.org

Jeffry Madrigal

CREMA-Costa Rica

+ 506 8859 6514 / jmadrigal@cremacr.org

Sources of information:

 Marín, B., Durán, M., Dijeres, J., Otarola, A. y Alfaro, J.  2018.  Dictamen de Extracción No Perjudicial 2018-2019 para las especies de género Sphyrna presentes en Costa Rica e incluidas bajo el Apéndice II de la Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES) de Costa Rica.  INCOPESCA,  Autoridad Científica CITES para especies de interés pesquero y acuícola.  Costa Rica.

Carrasco, 2020a.  Oficio PESJ-228-2020 del 4 de agosto de 2020.  Respuesta al oficio FA-005-2020 del 2 de julio del 2020 emitido por Randall Arauz

Carrasco, 2020b.  Oficio PESJ-338-2020 del 1 de octubre del 2020.  Respuesta al oficio FA-10-2020 del 21 de setiembre del 2020 emitido por Randall Arauz

Cases of illegal exportation of hammerhead shark fins:

  1. https://www.nacion.com/sucesos/seguridad/senasa-frena-exportacion-de-aletas-de-tiburon/LBAQECPXVVCWFO5LI5UB3SYUFI/story/
  2. https://www.nacion.com/sucesos/judiciales/oij-investiga-dos-intentos-por-exportar-aletas-de/CF6KZ6YLW5BRZMPWFTFHTTMCIU/story/

Fins Attached Marine Research and Conservation conducts research, promotes conservation and provides education for the protection of marine ecosystems. Fins Attached believes in the preservation of our world’s precious resources and that through the protection of the ocean’s apex predators marine ecosystem balance can be maintained for the benefit of all living things on Earth.

Centro Rescate Especies Marinas Amenazadas (CREMA) is a Costa Rican NGO that works to conserve, manage and restore, populations of endangered marine wildlife. For more information visit www.cremacr.org