A dead specimen of gray whale inEl Salvador: a southernmostdistribution record

jose enrique barraza

Ministerio de Medio Ambiente y Recursos Naturales, Col. y Calle Las Mercedes, San Salvador, El Salvador

I present the first documented record of a dead gray whale (Eschrichtius robustus) discovered at Playas Negras, La Union onthe Pacific coast of El Salvador, Central America, on 21 July 2010. The stranded specimen also represents the southernmostrecord of this species anywhere. No necropsy was performed thus the cause of death is unknown.

Keywords: Eschrichtius robustus, El Salvador, gray whale, stranding

Submitted 12 December 2010; accepted 16 February 2011

Marine mammal observations at the Central American PacificOcean coast reflect the occurrence and migration of whales,dolphins and sea lions (Reilly, 1990; Acevedo-Gutierrez1994; Acevedo & Smultea, 1995; Fertl et al., 1996;

Acevedo-Gutierrez et al., 1997; Escorza-Trevino et al., 2001;Saenz et al., 2004; Quintana-Rizzo & Gerrodette, 2009; Scott& Chivers, 2009). Also, 19th Century whaling records con-sidered this zone important for wintering humpback whalesfrom the southern hemisphere (Best, 2008).

On 21 July 2010, fishermen observed a floating carcass of alarge cetacean south of Isla Pirigallo, El Salvador, in the Gulf ofFonseca (Figure 1). One day later, a gray whale (Eschrichtiusrobustus Lilljeborg, 1861) stranded on Playas Negras Beach,

Fig. 1. Area where fishermen observed a large whale carcass floating at sea off southern El Salvador on 21 July 2010 (1), and Playas Negras (2) where a dead graywhale appeared on 22 July 2010. Bahıa de Banderas (3) is the place with the southernmost record for gray whales prior to this report.

Corresponding author:J.E. BarrazaEmails: ebarraza@marn.gob.sv; eulaliabarr@yahoo.com

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Marine Biodiversity Records, page 1 of 3. # Marine Biological Association of the United Kingdom, 2011doi:10.1017/S1755267211000376; Vol. 4; e35; 2011 Published online

La Union, on the continental mainland, 30 km west of theat-sea sighting (13o09′ 34.2′′N, 87o56′ 7.8′′W, Fig. 1), whichmay have been the same animal.

This whale was identified as a gray whale by its moderatelyarched mouthline (Figure 2) and in having eight to nine dorsalknuckles and only three short throat grooves (Figure 3).Balaenopterids bear falcate dorsal fin, but balaenids lackthis, also, the former whales present several ventral grooves(throat to chest) and in the latter family are absent (Reeveset al., 2002). The specimen was 13.4 m long, making it anadult because among gray whales, the largest reported imma-ture female and male was 12.92 and 11.75, respectively (Rice &Wolman, 1971). Sex was not determined.

The carcass did not have any scars that could help deter-mine the cause of death. Field observations reflect noobvious signs of tooth rakes or scarring to suggest a killerwhale (Orcinus orca) attack or that a ship strike was involved.Local authorities buried the carcass and no tissue sampleswere collected.

Eastern North Pacific gray whales summer in arcticwaters of Alaska and Russia, and during the autumn theymigrate south to winter in waters off western centralCalifornia, western Baja California, the Gulf of Californiaand western mainland Mexico, where females have their

calves (Calambokidis et al., 2002; Urban et al., 2003;Rodriguez de la Gala-Hernandez et al., 2008). The find ofthe dead specimen coincides with the occurrence of graywhales in the North Pacific Ocean (Reeves et al., 2002), thusan explanation for this event is unclear. The previous south-ernmost record of occurrence of live gray whales in theeastern North Pacific was Bahia de Banderas, Jalisco, Mexico(20845′N 105834′W; Jones & Swartz, 2009), about 2000 kmnorth from the stranding reported in this paper (Figure 1).However, the dead whale could have come from anywhereand not necessarily from Mexico.

A C K N O W L E D G E M E N T S

The author recognizes the support from Wilfredo Fuentes inpreparing Figure 1, as well as important comments fromRobert Pitman (SWFC-NOAA, USA). The anonymous refer-ees improved the quality of this paper.

R E F E R E N C E S

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Acevedo A. and Smultea M.A. (1995) First records of humpback whalesincluding calves at Golfo Dulce and Isla del Coco, Costa Rica,suggesting overlap of northern and southern hemisphere populations.Marine Mammal Science 11, 554–560.

Acevedo-Gutierrez A., Brennan A.B., Rodriguez P. and Thomas M.(1997) Resightings and behavior of false killer whales (Pseudorca cras-sidens) in Costa Rica. Marine Mammal Science 13, 307–314.

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Fig. 2. A gray whale that stranded at Playas Negras Beach, La Union, ElSalvador on 22 July 2010. Photograph by Wendy Toledo.

Fig. 3. Ventral image of the head of a gray whale that stranded in El Salvador;notice there are only three short throat pleats. Photograph by Wendy Toledo.

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Correspondence should be addressed to:J. Enrique BarrazaMinisterio de Medio Ambiente y Recursos NaturalesColonia y Calle Las Mercedes, San SalvadorEl Salvadoremails: ebarraza@marn.gob.sv, eulaliabarr@yahoo.com

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