Contributions to Zoology, 69 (3) (2000)Cornelis J. Hazevoet; Frederick W. Wenzel: Whales and dolphins (Mammalia, Cetacea) of the Cape Verde Islands, with special reference to the Humpback Whale Megaptera novaeangliae (Borowski, 1781)

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Introduction

The Cape Verde Islands (Fig. 1) are an archipelago consisting of 10 islands and several islets situated in the Atlantic Ocean c. 500 km west of Senegal, West Africa. The total land area is 4033 km2 scattered over 58,000 km2 of ocean. These volcanic islands emerge steeply from depths of about 4000 m. The climate is dry tropical but sea conditions are heavily influenced by the cool Canary current that comes from the north. Consistently strong northeast tradewinds produce rough seas, often making navigation around the islands difficult and hazardous. A former Portuguese colony, the islands gained independence and became the República de Cabo Verde in 1975.

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Fig. 1. Map of the Cape Verde Islands.

Apart from sparse accounts in the historical whaling literature, little has been written about the Cetacea that occur in Cape Verde seas. During the 19th century, a few specimens of dolphins from the area reached Europe and some of these became the holotypes of nominal taxa (cf. Perrin et al., 1987). Reiner et al. (1996) presented an overview of cetaceans recorded in the area, based on their own observations as well as published data, and added a list of taxa whose occurrence in the region they considered likely, referring to published records of strandings and offshore occurrences from the West African mainland. Jefferson et al. (1997) reviewed published records of dolphins and porpoises from West Africa, including the Cape Verde Islands.

In this paper, we report on our observations of whales and dolphins in the Cape Verde Islands. The status and occurrence of the Humpback Whale Megaptera novaeangliae is dealt with in somewhat more detail. A considerable number of additional sightings were obtained from local fishermen but these have been included only when identification proved to be sufficiently reliable. Also included are data from private reports, kindly put at our disposal by other observers, that would easily go unnoticed otherwise. Some corrections to Reiner et al. (1996) and other publications are made. A list of all cetacean taxa reliably recorded in the Cape Verde region – here defined as 14º00‘N-18º00‘N, 22º00‘W-26º00‘W – is presented (Appendix 1) and unsubstantiated reports are briefly discussed (Appendix 2).

Short history of whaling in the Cape Verde islands

There has been a long tradition of whaling in the Cape Verde Islands. Already during the 16th century, whale products from the islands were exported to Brazil (Ellis, 1969). As elsewhere, whaling during these early years was of a small-scale artisanal nature, probably not seriously affecting populations. From the mid-18th century onwards, European and North American whalers began to frequent these waters on a regular basis. João da Silva Feijó, a Portuguese naturalist who stayed in the islands during the 1780s, reported that baleias and cachalotes were common, attracting many American, English and French whalers (Carreira, 1986). Early reference works on the Cape Verde Islands invariably remarked on the abundance of whales in these waters (e.g. Chelmicki & Varnhagen, 1841; Lopes de Lima, 1844).

In the 19th century, New England whalers hunted Humpbacks during the winter months in Cape Verde seas (Kellogg, 1929; Mitchell & Reeves, 1983). The main hunting area for ‘humpbackers’ from Provincetown, Massachusetts, was in the West Indies, but “another favorite ground is around the Cape Verde Islands” (Atwood, 1887). Charts in Townsend (1935), mapping 19th century catches by North American whalers, show that Humpback whaling in Cape Verde seas took place in February-May, while another important West African hunting area (Gulf of Guinea) was exploited in June-September. Townsend’s (1935) charts of catches of Sperm Whale Physeter macrocephalus show that in the Cape Verde area this whale was mainly hunted from October to March.

From the late 18th century, when the first whaling station was established on Brava, considerable quantities of whale oil were also prepared locally. Catching whales from small man-powered boats was a risky business and vivid descriptions of the methods employed and the dangers involved were given by E.J.M. (1864) and Cardoso (1896). In 1874, the Empresa da Pesca da Baleia do Carriçal e do Tarrafal was founded on São Nicolau and in 1883 a similar enterprise was undertaken on Sal (Cardoso, 1896; Carreira, 1983). By that time, however, whale populations had already been severely depleted and towards the end of the 19th century foreign whalers began to abandon their activities in Cape Verde seas. Friedlaender (1913), who stayed in the islands for five months in 1912, wrote that there still existed whaling stations on São Nicolau and Maio but that operations had all but ceased due to the scarcity of whales. In 1914, when whales had been almost exterminated in these waters, the Portuguese colonial government issued a decree in which the capture of immature animals was forbidden and the maximum yearly catch set at 6,000 (Carreira, 1983). This measure, however, came too late to generate an increase of the populations and, in view of the catch size still allowed, probably even had the opposite effect.

Today, dolphins can be found quite regularly in the markets, especially on Santiago, and stranded or weakened offshore whales are readily butchered by the local population despite existing legislation that provides full protection for all cetaceans (Law 17/1987). As with other environmental legislation, there is little or no interest among the local authorities to enforce such laws and consequently the degradation of Capeverdian wildlife, both marine and terrestrial, continues at an alarming rate. The Republic of Cape Verde is not a member of CITES, although discussions about the country joining the convention have been going on for the past 10 years or more.