The northeastern offshore population of Pantropical Spotted Dolphins in the ETP bore the brunt of the massive dolphin kill by tuna purse seiners from the late 1950s to the 1980s. For example, in the period 1959 to 1972, nearly five million dolphins were killed, and of this number, about three million were Spotted Dolphins from the northeastern offshore population (Wade 1995). Since the Inter-American Tropical Tuna Commission (IATTC) implemented per-vessel mortality limits on the international fleet, the combined annual mortality for all Pantropical Spotted Dolphins in the ETP has decreased greatly, to only 238 in 2016 (IATTC 2017). Mortality of all spotted dolphins has been <1,000 since 1998 (IATTC 2017). Although current mortality is greatly reduced, the northeastern stock appears to be recovering very slowly (Gerrodette et al. 2008) and potential factors such as fishery-related stress, unobserved mortality due to calf separation and orphaning during fishing operations (Archer et al. 2001), possible mortality caused by small vessels that do not carry observers, under-reporting of mortality, and ecosystem change, have been suggested as possible reasons for the species’ slow recovery in this region (Gerrodette and Forcada 2005).
In the eastern tropical Atlantic and western Indian Ocean, a combination of logbook (1980-2011) and observer (1995-2011) data from purse seine fisheries show that Pantropical Spotted Dolphin bycatch has been recorded, but suggest that numbers are relatively low (Escalle et al. 2015). However, mortality is suspected to occur more frequently in other fisheries, particularly in gillnets. In the Arabian Sea, Pantropical Spotted Dolphin bycatch in tuna drift gillnets has been recorded off Pakistan (WWF-Pakistan, personal communication). From 2000 to 2003, landing site surveys in Zanzibar (Tanzania) documented six Pantropical Spotted Dolphin deaths in drift gillnet fisheries, mostly off the north coast (Amir et al. 2002). Pantropical Spotted Dolphins are also taken incidentally in local fisheries along the Central American coast (Palacios and Gerrodette 1996). Yang et al. (1999) reported Pantropical Spotted Dolphin incidental mortality in Chinese fisheries, and Dolar (1994) found incidental takes in the Philippines.
Large numbers of Pantropical Spotted Dolphins have been taken for human consumption in hand harpoon and drive fisheries in Japan. The drive fishery for Pantropical Spotted Dolphins began in 1959 and is thought to have caused a slight decline in the minimum age at attainment of sexual maturity in females (Kasuya 1985). Kasuya (2017) compiled data on the catch of small cetaceans in Japanese coastal fisheries, including drive fisheries, hand-harpoon fisheries, culling, and incidental mortality within the 200 mile Exclusive Economic Zone, from 1972 to 2008. The years with the highest catches were 1978 with 4,184 and 1982 with 3,799. The total of catches for that 37 year period was just over 27,000 animals (Kasuya 2017).
Pantropical Spotted Dolphins are also taken in hand-harpoon fisheries in the Philippines (Dolar et al. 1994), and are regularly or opportunistically taken by gillnet and harpoon in India and Sri Lanka (Perrin and Hohn 1994). Drive hunts at Malaita in the Solomon Islands took several hundreds or thousands of Pantropical Spotted Dolphins annually in the 1960s (Ross et al. 2003, Kahn 2006). In 2010, hunting activities were suspended in the Solomon Islands, but hunting resumed in early 2013. From 1976 to 2013, at least 15,454 dolphins (mostly Spotted and Spinner (S. longirostris)) were killed by the Fanalei villagers alone, and at least 1,500 Pantropical Spotted Dolphins were taken in March 2013 (Oremus et al. 2015). Drive hunts also occur along the southwest coast of Madagascar. Andrianarivelo (2001) estimated that over 6,000 dolphins, predominantly Spotted and Spinner, Bottlenose, (Tursiops spp.), and Humpback (Sousa plumbea), were taken between 1985 and 1999 in the single village of Anakao. Small numbers are taken in numerous small-scale subsistence fisheries for dolphins and whales around the world, e.g. at Saint Vincent in the Lesser Antilles (Perrin and Hohn 1994) and at Lamalera in Indonesia (Kahn 2004). Most of those fisheries have not been monitored consistently and the effects on local populations are usually not known.
