Resumption of traditional drive hunting of dolphins in the Solomon Islands in 2013

The ‘drive hunting’ of dolphins has a long history in the Solomon Islands, specifically at the island of Malaita. In 2010, the most active village, Fanalei, suspended hunting in exchange for financial compensation from an international non-governmental organization but resumed hunting again in early 2013. Here, we report on a visit to Fanalei in March 2013 to document the species and number of dolphins killed in the renewed hunting. Detailed records for the 2013 hunting, up to the time of our visit, included at least 1500 pantropical spotted dolphins (Stenella attenuata), 159 spinner dolphins (Stenella longirostris) and 15 ‘bottlenose’ dolphins, probably Tursiops truncatus. Molecular identification confirmed two of the species, pantropical spotted and spinner dolphins. A summary of all available records from 1976 to 2013 documented a minimum total of 15 454 dolphins killed by the Fanalei villagers alone. We also found the local price of a dolphin tooth had increased from about US$0.14 (SBD$1) in 2004 to about US$0.70 (SBD$5) in 2013. The large number of dolphins killed and the apparent incentive for future hunting offered by the increasing commercial value of teeth, highlight an urgent need to monitor hunts and assess the abundance and trends in local populations.


Summary
The 'drive hunting' of dolphins has a long history in the Solomon Islands, specifically at the island of Malaita. In 2010, the most active village, Fanalei, suspended hunting in exchange for financial compensation from an international non-governmental organization but resumed hunting again in early 2013. Here, we report on a visit to Fanalei in March 2013 to document the species and number of dolphins killed in the renewed hunting. Detailed records for the 2013 hunting, up to the time of our visit, included at least 1500 pantropical spotted dolphins (Stenella attenuata), 159 spinner dolphins (Stenella longirostris) and 15 'bottlenose' dolphins, probably Tursiops truncatus. Molecular identification confirmed two of the species, pantropical spotted and spinner dolphins. A summary of all available records from 1976 to 2013 documented a minimum total of 15 454 dolphins killed by the Fanalei villagers alone. We also found the local price of a dolphin tooth had increased from about US$0.14 (SBD$1) in 2004 to about US$0.70 (SBD$5) in 2013. The large number of dolphins killed and the apparent incentive for future hunting offered by the increasing commercial value of teeth, highlight an urgent need to monitor hunts and assess the abundance and trends in local populations.

Introduction
The Solomon Islands, in the western South Pacific, are well known for the practice of dolphin hunting, where hunters use unique traditional techniques to drive schools from the offshore into shallow coastal waters [1][2][3]. Hunters operate in close coordination from 20 to 30 traditional canoes and, when dolphins are found, clap together rounded stones to create a percussive underwater sound [3]. The reported size of these catches raised concerns about the conservation status of these hunted populations, as well as concerns about animal welfare, given the presumed suffering experienced by these social species during the capture and killing [10]. Here, we report on our efforts to confirm the number and species identity of dolphins killed during recent hunting, by visiting Fanalei in March 2013.

Material and methods
Two of us (M.O. and J.L.) visited Fanalei on 22 March 2013 with the main objectives of confirming numbers of dolphins hunted during this season and identifying the species that were killed. To do so, we discussed local hunting with representatives, hunters and elders of the village at the community house. The meetings also provided us with an opportunity to discuss the community's future plans for hunting and conservation issues. J.L. acted as translator and recorded information on catches in his capacity as a Chief officer (Research) of the Ministry of Fisheries and Marine Resources. As well as discussions and reviews of catch records, we collected biological samples of the recent hunts to confirm traditional species names through species identification by molecular methods [11]. These samples were collected from four sources: (i) meat from recently hunted dolphins, found in the village's kitchens; (ii) skin from a few carcasses found at the dumping area; (iii) bone samples from the dumping area in the mangrove; and (iv) teeth from recent hunts, provided by villagers. However, given the variable state of decay and the limited time of our visit, no attempt was made to identify species using the morphology of the carcasses or skulls.

Species identity
From our discussions at Fanalei, we were told that three species were included in the hunting, as of the time of our visit. These three species are locally known as 'unubulu', 'raa' and 'robo manole' (figure 1). The 'unubulu' and 'raa' clearly refer to the pantropical spotted dolphin and the spinner dolphin, respectively. Takekawa [4] suggested that 'robo manole' referred to the common dolphin (Delphinus delphis), but expressed some uncertainty about this identification. After questioning the hunters on the group size and morphological characteristics of the 'robo manole', it seemed more likely this name refers to the common bottlenose dolphin (Tursiops truncatus). We note that at the time of Takekawa's work [4], the taxonomic status of Tursiops in the Solomon Islands and elsewhere was still poorly known, probably contributing to some confusion with traditional names. Indeed, recent molecular identification based on biopsy samples collected at sea has confirmed the presence of two Tursiops species in the waters of the Solomon Islands: the larger common bottlenose, T. truncatus, found in deep offshore waters, and the smaller Indo-Pacific bottlenose, T. aduncus, found in shallow coastal waters [12]. Although Takekawa [4] considered that 'olo folosi walo' referred to T. truncatus, his description of small group sizes and inshore habitat use now suggest the species was in fact T. aduncus.
DNA was extracted from a total of 37 teeth, 11 meat samples and seven skin samples originating from dolphins taken in the drive hunt. We were able to amplify and sequence fragments of the mtDNA control region from eight of the teeth, nine of the meat samples and all seven skin samples. Overall, results confirm that drive-hunted dolphins are primarily spotted and spinner dolphins, as known from historical records. Of the eight teeth sequenced, five were spinner dolphins and three were of spotted dolphins. Unfortunately, no sequence could be obtained from one larger tooth thought to represent the common bottlenose dolphin, based on size and shape (figure 1). All of the samples of skin and meat were identified as spotted dolphins, consistent with reports of the hunt just before our visit to Fanalei.

Catch records for 2013
Catch records for the 2013 hunting season were provided to us by one of the dolphin hunters from Fanalei, Albert Balei, who kept detailed notes of the dates, species and number of dolphins caught during each hunt. These catches (n = 11 hunting events) are summarized in table 1. It shows that the largest catch was the 'unubulu', or pantropical spotted dolphin, with over 1500 individuals taken. The second largest catch was the 'raa' or spinner dolphin, but in much smaller numbers with a total of 159 dolphins killed. Finally, a group of 15 'robo manole', presumed to be common bottlenose dolphins, were caught. The average number of dolphins taken per event was 154+. It appears that there is a substantial        Unfortunately, we were unable to obtain records for the 2003 to 2010 period, i.e. the period before the hunt temporally stopped. At that time, Albert Balei was away from the village and no one else seems to have kept accurate track of the catch records and hunt effort. However, Kahn [9] reported some overall annual catches for Fanalei for the period 1999-2004 (not 2001), which he collected during a visit to the community. For the year 2000, Kahn [9] reported a larger catch than the information given to us (800 versus 577), while for 2002, we were given fairly similar numbers (700 versus 648). The reason for the discrepancy in the numbers for the year 2000 is unknown. However, the records provided to us by Albert Balei seem to be otherwise accurate, including days not going to sea and days going out with no catch throughout the hunt season (electronic supplementary material, figure S1; and table S1).
To the record from 2000 to 2003 and those from 2013, we added the historical records from Takekawa [3], covering the annual total catches at Fanalei for the period 1976-1994 (figure 2). These annual totals are based on D. Takekawa's 1993 [3] personal observations as well as on records he extracted from [13] and records reported to him by J. Filei, a community member from Fanalei. Takekawa [3] 1976  1977  1978  1979  1980  1981  1982  1983  1984  1985  1986  1987  1988  1989  1990  1991  1992  1993  1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009 (table 3). However, this is clearly an underestimate of the number of dolphins hunted in the Solomon Islands, as we lack data for 16 hunting years across this period and only consider the community of Fanalei. If one considers that a usual annual catch would be between 600 and 1000 dolphins (i.e. ±200 around the average catch), it appears that success rate is fairly stable across years. The community had a lower success rate (less than 600 dolphins) for 3 years (1979,1987 and 2001) while they had a high success rate (more than 1000 dolphins) for 4 years (1978, 1986, 2004 and 2013). There is no clear trend in success rate across years. We note that the two successful years for which data were available during the next season (e.g. 1978 and 1986) were followed by a low catch rate the following year (1979 and 1987, respectively). This tendency could indicate local depletion of dolphin populations following intensive hunting. We note evidence that at least one local population of melonhead whales, Peponocephala electra, was depleted by hunting in the Solomon Islands [4] and a similar case for local depletion of this species by hunting around the Island of Hawai'i in the nineteenth century [14]. Alternatively, the tendency for low years to follow high could be explained by a reduced need for dolphin teeth in the community, i.e. a reduced effort following successful hunting years. Unfortunately, the absence of species information for most years precludes any analyses of population-specific trend.

Increasing market value of teeth
It is important to note that dolphin teeth are used by many villages in Malaita and not only by the hunting communities. Teeth (and meat) are also sent to other islands such as Guadalcanal and the Florida Islands. Indeed, it seems there is a high demand for this commodity and stopping the hunt had consequences that went beyond the village of Fanalei. Although adjusting for inflation of the Solomon Islands' currency is challenging, it appears that the price for dolphin teeth has increased beyond this expectation in recent years. Dawbin [2] reported that each tooth cost AUD$0.05 in 1964 (about US$0.06 or £0.02 2 ), while Takekawa [4] reported the cost was set, in Solomon Islands Dollars, at SBD$0.50 per tooth in 1994 (about US$0.16 or £0.10). We could not find data on the Solomon Islands inflation rate before 1980 but the price increase between these two reports seems compatible with inflation since 1980. 3 By 2004, Kahn [9] reported that the price had increased to SBD$1.00 per tooth (about US$0.14 or £0.07). According to inflation rates between 1994 and 2004 (about 238%), the price difference also seems in agreement with consumer price increase. The price for 'unubulu' and 'raa' teeth had remained little changed at the time of our first visit to Fanalei in 2009. However, by the time of our second visit in 2013, the price for 'unubulu'

600
Kahn [9] . or 'raa' teeth had increased to SBD$5.00 per tooth (about US$0.68 or £0.45). The price of teeth from any 'robo' species (larger teeth) could even be higher but we were not given accurate figures. Based on a price of SBD$0.5 per tooth in 1994 [4] and annual inflation rates since that time, the price in 2013 should have been only about SBD$2.5 per tooth. The reason(s) for the unexpectedly higher prices in 2013 is unclear but it is possible that absence of hunts over the last 2 years created a higher demand for dolphin teeth. The increase in the price of teeth could have been a factor in the decision by the village of Ata'a to resume hunting in December 2012. It was apparently the only hunt from this community this season and the first reported hunt in a very long time. From discussion with Fanalei elders about the hunt of 134 dolphins by Ata'a villagers in December 2012, we were told that the species caught was the pantropical spotted dolphin and not 'bottlenose dolphins', as reported in the local newspaper (Solomon Star News, 18 December 2012). There is indeed little reason to believe these were bottlenose dolphins (Tursiops sp.) as they are rarely taken and never with a school size this large. However, we were not able to collect any biological samples to confirm the species identity.

Conclusion and recommendations
It was our impression that the people of Fanalei were puzzled by the attention they attracted in resuming the recent dolphin hunt. To them, it seemed that the agreement with EII represented only a rather brief lapse in a long history of hunting. They explained that stopping the hunt had brought much tension in the village and that resuming it brought back peace among community members. Therefore, they made it clear that they intended to continue the hunt. However, it was also our impression that the hunters were aware of, and willing to discuss, the conservation implications of over exploitation. They also expressed concern about dolphin 'by-catch' by purse seiners in the Solomon Islands, seeing this as a threat to their local resource. They were not very receptive to the idea of introducing a quota or catch limit for the drive hunt, as they are concerned that would be too restrictive. On the other hand, they could see the value of collecting scientific data that might help increase the probability that the drive hunting could continue in future generations.
The International Union for the Conservation of Nature does not consider the primary species hunted in the Solomon Islands to be vulnerable or endangered: the pantropical spotted and common bottlenose dolphins are listed as 'Least Concern', the spinner dolphin is listed as 'Data Deficient'. However, these species-wide threat classifications do not necessarily reflect the status or threats to local populations. The potential vulnerability of local populations in the Solomon Islands to over exploitation is suggested by recent evidence that several species, including the primary species targeted in drive hunts, tend to form small insular and genetically isolated populations around islands elsewhere in the Pacific [14][15][16][17]. Given this potential and our observation that the recent resumption of drive hunting showed no signs of abating, there is an urgent need to improve the monitoring of these catches, with the eventual objective of implementing a management procedure. First, there is a need to collect systematic records of all future hunts and, if possible, provide some verification through independent observers or photographic documentation. Second, samples from each hunt should be collected and archived, with the intent of confirming species identification and tracking changes in diversity and population identity over time, via genetic monitoring [18]. Finally, surveys of local waters are also needed to estimate the abundance of dolphins around Malaita. These recommendations are consistent with the Whale and Dolphin Action Plan developed by the Secretariat for the Pacific Regional Environment Programme [19], the inter-governmental agency responsible for providing management advice on cetaceans in the region.
In making these recommendations, we recognize that improved management of the hunt does not address the animal welfare concerns associated with drive hunting, although it might reduce the magnitude of the catches. Further reductions in catches might be achieved by providing an alternate, non-lethal value through dolphin-watching programmes or other ecotourism opportunities. Such programmes could take advantage of the local knowledge and skills available in the communities as a result of drive hunting, providing a more sustainable future for both the dolphins and the cultural traditions of the hunters.

Ethics statement. The research was conducted under a MoU between the Solomon Islands Ministry of Fisheries and
Marine Resources, the Solomon Islands Ministry of Environment, Climate Change, Disaster Management and Meteorology and the South Pacific Whale Research Consortium, a collective of independent scientists working on issues related to the conservation of whales and dolphins in the region. No animal was killed for the purposes of scientific research. Samples collected from carcasses disposed of by the hunters were considered to be appropriate 'secondary use' of ongoing activities, following the guidelines of the Society for Marine Mammalogy [20].
Data accessibility. The sequences used for identification of species from teeth and meat have been submitted to GenBank as KP756626 to KP756648.