Chelonian Conservation and Biology, 2009, 8(2): 150–160 g 2009 Chelonian Research Foundation Status, Ecology, and Conservation of Sea Turtles in Guinea-Bissau

1 2 3 4 5 PAULO CATRY ,CASTRO BARBOSA ,BRUNO PARIS ,BUCAR INDJAI ,AMADEU ALMEIDA , 6 2 2 BENOIT LIMOGES ,CRISTINA SILVA , AND HONO´ RIO PEREIRA

1Eco-Ethology Research Unit & Centro de Biocieˆncias, Instituto Superior de Psicologia Aplicada, Rua Jardim do Tabaco 34, 1149-041 Lisboa, Portugal [[email protected]]; 2Instituto da Biodiversidade e das A´reas Protegidas, Bissau. Guinea-Bissau [[email protected]; [email protected]]; 3Department of the Environment, Canada [[email protected]]; 4Instituto Nacional de Estudos e Pesquisas, Bissau [[email protected]]; 5Centro de Investigac¸a˜o Pesqueira Aplicada, Bissau; 6Ministe`re du De´veloppement durable, de l’Environnement et des parcs du Que´bec [[email protected]]

ABSTRACT. – This paper provides the first overview of sea turtles in Guinea-Bissau, presents data on their ecology, and analyzes threats and conservation initiatives. The green turtle (Chelonia mydas) is by far the most widespread and abundant of the 5 species that nest in Guinea-Bissau. Between ca. 7000 and 29,000 green turtle nests are laid per year at the globally important site of Poila˜o Island, with a few hundred more on surrounding islands. There is a marked interspecific variability in nesting seasonality, with green and hawksbill (Eretmochelys imbricata) turtles nesting mostly during the rainy season and olive ridley (Lepidochelys olivacea) and leatherback turtles (Dermochelys coriacea) during the dry season. Informal interviews all over the coastal zone suggest that sea turtle populations have markedly declined within living memory. Main threats are poaching of eggs and of nesting females and the incidental capture in fishing gear. Amongst the major achievements of sea turtle conservation efforts are that all species are protected by law, the most important nesting beaches have been included in the protected area network, and significant progress has been made in removing the presence of settlements of foreign fishermen from the areas near the turtle concentrations where accidental captures used to occur. On the down side, it should be pointed out that protection in the national parks is insufficient. The main problem seems to be the weak enforcement of park and national rules by park authorities, which creates a feeling of relative impunity in park residents and visiting fishermen.

KEY WORDS. – Reptilia; Testudines; Cheloniidae; Chelonia mydas; Lepidochelys olivacea; Eretmochelys imbricata; Dermochelys coriacea; green turtle; olive ridley; hawksbill; leatherback; Poila˜o; West Africa

Marine turtles have suffered catastrophic declines of sea turtles in this country. Most information gathered over the past few centuries and in many regions and all so far, however, has remained unpublished. The few evidence points to the fact that only a tiny fraction of the published reports with a wider diffusion (Barbosa et al. original numbers remains (e.g., King 1995; Jackson et al. 1998; Fortes et al. 1998; Fretey 2001; Catry et al. 2002; 2001). In many regions, such decline continues or is Formia et al. 2006) do suggest that national turtle accelerating, even though data are often sparse. In most populations may be of regional and even global recent decades, many research and conservation projects significance. Five species have been confirmed to occur have been developed, with large improvements in in the country, namely green (Chelonia mydas), hawksbill knowledge and some successful conservation stories (Eretmochelys imbricata), olive ridley (Lepidochelys (e.g., Hays 2004; Chaloupka et al. 2008). Still, particu- olivacea), loggerhead (Caretta caretta), and leatherback larly in developing nations, there are many countries and turtle (Dermochelys coriacea) (Limoges 1989; Barbosa et regions from where it is difficult to find published al. 1998). Green turtle nesting numbers are particularly information on marine turtles and where conservation relevant in an international context (Catry et al. 2002). efforts are limited. This is particularly true in parts of From the early 1990s, several Guinea-Bissau biolo- Africa, where some of the most important nesting and gists, forest and park guards, local collaborators, and other foraging grounds are known or suspected to be located technicians received training on sea turtle monitoring, (Fretey 2001). supervised by expatriate researchers. Over the past 20 Guinea-Bissau is a West African country with a years, many expeditions and small research projects relatively large coastal archipelago (the Bijago´s). There (under the umbrella of various institutions) were carried have been several efforts to improve the conservation out, often resulting in short internal reports (many of status and the knowledge of the ecology and distribution which with little or no quantitative data) or simply in an CATRY ET AL. — Sea Turtles in Guinea-Bissau 151

Figure 1. The coastal area of Guinea-Bissau with names of places mentioned in the text (see also other figures). The small black dots scattered along the coast show confirmed nesting sites of green turtles. ONP 5 Orango National Park; JV/PMNP 5 Joa˜o Vieira–Poila˜o Marine National Park. accumulation of knowledge by the people involved. well beyond the coast and the numerous islands. Most of Countless formal and informal interviews with local the mainland coast is characterized by wide intertidal people were carried out all over the coastal area. areas with mudflats and sandbanks and extensive Deficiencies in planning and implementation of monitor- mangrove areas. Only in the extreme north and south ing schemes (due to insufficient funding and training, can one find sandy beaches facing the open ocean. The logistical difficulties, etc.), plus the fact that many Bijago´s archipelago is made of 88 islands and islets, of original data files have been lost (particularly during the which only 21 are permanently or temporarily inhabited. 1998 war) mean that although there is a very large Sandy beaches with deep water approaches are uncom- accumulated experience among the people involved, data mon, being mostly found on the outer face of the outer are often scant or need to be handled with care. Still, islands. Most of the Bijago´s are sparsely populated, with a much valuable information can be presented in a total population of ca. 25,000 people in a land area of qualitative way. Furthermore, some major surveys were 90,000 ha (Cuq 2001). Besides resident populations, carried out in a more systematic fashion. which live mostly on subsistence agriculture, there are This paper has 3 objectives. First, by analyzing old increasing numbers of seasonal immigrants (mostly from and recent unpublished data on the marine turtles of Senegal) who fish from large open pirogues, mostly Guinea-Bissau, we intend to bring to light the valuable targeting sharks, rays, barracudas, snappers, and other information that is in the ever-present danger of falling large predatory fish. There is no industrial fishing within into oblivion. Second, we present the first comprehensive the archipelago or near the mainland shore. The climate is review of the available biological data on sea turtles in tropical, hot, and humid. Rainfall is highly seasonal, with this country. Finally, we provide an overview of a monsoonal type rainy season from May to November conservation efforts developed so far, discuss their that, in coastal areas, averages around 2000 mm per year. successes and weaknesses, and provide suggestions for future priorities. Field Surveys

METHODS Most of our detailed knowledge on the sea turtles of Guinea-Bissau results from a number of field surveys that Study Area are described below in some detail. Surveys for green and hawksbill turtles generally occurred during peak nesting Guinea-Bissau is a small West African country with a activity in August–October, whereas those for olive ridley generally flat coast indented by numerous flooded valleys turtles occurred during the peak nesting period in and estuaries (Fig. 1). A large continental shelf extends January–February. 152 CHELONIAN CONSERVATION AND BIOLOGY, Volume 8, Number 2 – 2009

Figure 2. Main nesting beaches in the Orango National Park that were object of detailed surveys in 1992–1994 and less intense monitoring in subsequent years.

Broad Bijago´s Survey. — After gathering preliminary curved carapace length and width were measured with a information of the location of important potential nesting tape. Eggs were counted as deposited. Results from daily beaches, a survey was conducted from 11 to 27 August counts of tracks and nesting turtles have been lost. 1990, during the peak green turtle nesting season. This Poila˜o Green Turtle Tagging. — From 1994 until survey included 23 islands and islets and a total of 2007 (in 9 different years), at least 5453 green turtles 118 km of beach. Many beaches were surveyed on foot were double-tagged on Poila˜o with metal flipper-tags. A and all of them were inspected from a Zodiac traveling small number (ca. 10) of hawksbill turtles were also parallel to the shore at low speed. Tracks were identified marked. Local recaptures were noted during tagging by their imprinted characteristics and width (see Limoges sessions. Daily tagging from July till December, in 2000 and Robillard 1991b, 1991c for more details). and 2007, allowed the calculation of internesting Orango National Park Survey. — Between December intervals. When 2 records for an individual female were 1992 and November 1994, frequent surveys of the 6 most separated by an interval greater than 18 days (Broderick et important beaches of the Orango group of islands, more al. 2003), we considered that it represented more than one recently classified as the Orango National Park, were nesting interval. Each female contributed one (randomly carried out (Fig. 2). Beaches were walked in the early chosen) single value for the internesting interval statistics. morning, up to 5 times per month, with an overall full Unhocomo Green Turtle Surveys. — Local fisherman coverage of all the months of the year. Overall, 320 beach sometimes target immature green turtles in inshore surveys were carried out. The mean number of surveys feeding grounds around the Unhocomo group using per individual beach is 53.3 ± 15.5 (range 26–71). Tracks monofilament nets. In May and September 2003, we and nests were identified and noted, making a distinction recruited local fishermen and organized 3 fishing sessions between ‘‘fresh’’ (, 24 hours) and ‘‘old’’. Tracks were that resulted in the capture of 19 immature turtles that erased to avoid posterior counting. The fate of old nests were measured, tagged, and released. Each fishing session was also noted as intact or depredated (in which case, the lasted about 1 hour and involved dragging a large net with type of predator was noted). To obtain a broad estimate of a small boat in a rocky area where turtles are commonly the total number of nests laid per beach and per month, found. the mean number of ‘‘fresh’’ nests recorded per visit was Poila˜o Nesting Surveys. — Surveys of nesting multiplied by the number of days of that month. Values beaches to assess sea turtle numbers coming ashore are from different beaches and months were then added to usually based on track counts. On Poila˜o, 2 extensive obtain a general estimate for the Orango group. surveys were carried out in 2000 (from 19 July and 14 Adonga Olive Ridley Survey. — During 3 months, December; Catry et al. 2002) and in 2007 (from 27 June from December 1993 to March 1994, the beach of to 18 November). Tracks were counted daily in the early Adonga was surveyed on a nightly basis looking for morning. For various reasons, there were 1-day gaps of nesting turtles. Nesting turtles were flipper-tagged and coverage in 23 (15% of the period covered) and 11 (8%) CATRY ET AL. — Sea Turtles in Guinea-Bissau 153

Figure 3. Results from the August 1990 survey of the Bijago´s Archipelago (for green turtles only). scattered dates, respectively in 2000 and 2007. Values for use this index rather than estimate total nesting numbers days with no counts were estimated by linear interpolation per year given that some year estimates were based on a (Catry et al. 2002). reduced number of counts, leading to a large uncertainty Because not all adult female emergences result in in total numbers present. clutch deposition, it is important to estimate the For the study of the nesting biology on Poila˜o, we proportion that results in egg laying. Around Poila˜o, and used standard methodologies, such as marking nests and at different times throughout the study period in 2000 and following their fate until hatching (see Catry et al. 2002 2007, we randomly chose 75 turtles emerging from the for more details). In 2007, the high density of nesting sea and followed them from a distance (without resulted in a massive loss of nest markers, which disturbance) until they laid their clutch (on 61 occasions) prevented any rigorous estimate of nesting success. To or returned to the ocean without laying. Laying success obtain an idea of the damage caused by digging females was thus estimated as 61/75 5 81.3% (95% confidence on other turtle nests, we checked for evidence of damage limits: 70.6%–89.4%). The estimations of numbers of around 20 laying females per night, during each night in nests were obtained by multiplying the laying success by August, September, and October 2007. the numbers of tracks counted. Less extensive surveys Other Sources of Data. — While preparing this were carried out from 2001 to 2006 using a similar review, we compiled data from all the published and methodology, including from 3 to 93 daily counts per year unpublished reports discussing sea turtles in Guinea- in the months of July–October. Bissau that could be located. Additionally, we had To summarize data on interannual variation of laying extensive discussions with people involved in previous effort on Poila˜o we calculated a nest population index by work and surveys, to clarify aspects of their research and the following procedure. The year 2000, for which we to obtain first-hand accounts of their experiences. have the most complete and reliable counts, served as a baseline for all other comparisons. We calculated the RESULTS mean daily number of tracks by periods of 10 or 11 days (21–31 July, 1–10 August, 21–31 October 2000), and Green Turtle, Chelonia mydas arbitrarily set the index value of the year 2000 as 100. We then applied the formula Status and Distribution. — The green turtle is the most common sea turtle in Guinea-Bissau. Its reproduc- Nest population indexa~ X .X tion has been confirmed in virtually all the Bijago´s islands. Furthermore, it nests in small numbers along the 100 z 100 | ðÞXia{Xi2000 ðÞXi2000 mainland coast (Fig. 1). The initial 1990 survey (Limoges Where Xi2000 is the mean number of tracks on the relevant and Robillard 1991b, 1991c) and subsequent work i 10–11 day period in the year 2000 and Xia is the indicate that, by far, the most important nesting site is corresponding value for the focal year (a). We opted to located at Poila˜o (Fig. 3). 154 CHELONIAN CONSERVATION AND BIOLOGY, Volume 8, Number 2 – 2009

Table 1. Results from the December 1992–November 1994 beach surveys in the Orango National Park. ‘‘Old’’ nests were more than 24 hours when found and ‘‘fresh’’ were from the previous night. Estimates of numbers of nests for the whole park were made by extrapolating from the numbers of fresh nests seen to days without surveys (see methods for more details).

Old nests Fresh nests Nest population estimate 1992–1993 1993–1994 1992–1993 1993–1994 1992–1993 1993–1994 Chelonia mydas 225 69 92 34 751 274 Lepidochelys olivacea 98 125 25 15 620 170 Eretmochelys imbricata 46435015 Dermochelys coriacea 14143147

Results from the 1992–1994 survey of the 6 main correct for laying success, we obtain an estimate of beaches of the Orango Group are presented in Table 1. 29,016 nests (95% CI 5 25,197–31,907) laid on Poila˜o in Low intensity monitoring in other years further confirmed 2007. those results, suggesting that a few hundred nests are laid Nesting Biology. — Peak nesting for green turtles on annually in the Orango National Park. A survey of those Poila˜o is in August–September, but large numbers nest same 6 beaches in early January 2008 revealed the during most of the rainy season (see Catry et al. 2002 for presence of at least 374 shells of individual green turtles detailed data on seasonal variation). We have numerous that, according to local witnesses, had been killed and records of green turtles nesting in all months of the year, consumed during 2007. Of these, 91% were found at a with fewer records from April to June. beach that had an estimated 22% of the total number of Mean clutch size (± SD) in Poila˜o during the peak nests laid during the 1992–1994 survey. From these data, nesting season of 2007 was 131.2 ± 27.3 eggs (range 51– one can reasonably speculate that during the peak year of 190; n 5 96), which is not significantly different 2007 (see data on interannual variability on Poila˜o) there (ANOVA: F1,163 5 2.6, p 5 0.11) from values (mean were a few thousand nests laid in the Orango National 124) reported by Catry et al. (2002) for the year 2000. Park. Mean internesting interval did not differ between 2000 In the year 2000, 9733 tracks were counted at Poila˜o, and 2007 (ANOVA F1,94 5 0.48, p 5 0.49) and the and it was estimated that 7397 clutches were laid in this overall mean (± SD) was 12.2 ± 1.6 days (range: 8–17, season (Catry et al. 2002). Subsequent surveys with n 5 95). Some individual females were confirmed to variable field effort show that this was not an exceptional have laid up to 5 different clutches and there were several year, but rather a normal one (Fig. 4). recapture histories consistent with the deposition of 6 The total number of tracks from 27 June to 18 clutches. Unfortunately, there were not enough data for a November 2007 was estimated at 33,991. Multiplying this robust estimate of the mean number of clutches per number of tracks by 1.05, to account for the period of the female. It is also worth pointing out that there were 4 year when no counts were carried out, and by 0.813, to cases of turtles tagged in 2000 that came back to nest again in 2001. In 2000 nesting success was generally high (Catry et al. 2002). In 2007, 32.6% of 910 females engaged in nesting had at least some scattered fresh eggs around them, indicating that they had (partly) destroyed one or more other clutches. Using a GPS, it was estimated that the overall area apparently suitable for nesting in Poila˜o was 22,500 m2, but the turtles were not distributed uniformly in this area, which means that some portions of the beach have, during peak season, in excess of 1 nest/m2. During the 1992–1994 survey in the Orango Group, 44.8% of the old nests (n 5 288) when first detected had suffered predation. Humans were responsible for 36.4% of the cases of predation, ghost crabs for 34.9%, and monitor lizards for 28.7%. These are minimum estimates because the nests remained susceptible to predators for a Figure 4. Annual variation of the green turtle nest population long time; nevertheless, most predation usually happens at Poila˜o. The value for the year 2000 was arbitrarily set at 100. shortly after egg deposition. Indexes were calculated, from 1990 to 2007, respectively on the basis of 1, 113, 93, 4, 13, 8, 6, 3, and 113 counting days during Foraging Areas. — Foraging sea turtles are frequent- peak nesting season. ly seen around many islands of the Bijago´s Archipelago CATRY ET AL. — Sea Turtles in Guinea-Bissau 155

Table 2. Measurements of sea turtle samples from Guinea-Bissau. Samples from Poila˜o and Adonga are from nesting females while those from the Unhocomo group are from juveniles (a possible adult male with a CCL of 91 cm was excluded from this sample) captured for research purposes. Measurements of samples from the North Coast were from shells obtained in coastal villages from Varela to Jeta (data from Dontaine et al. 2001). CCL 5 curved carapace length; CCW 5 curved carapace width.

CCL CCW N x¯ ± SD, range (cm) x¯ ± SD, range (cm) Year Chelonia mydas Poila˜o 597 102.0 ± 5.6, 85–119 93.3 ± 5.4, 75–111 2007 Unhocomo 18 50.1 ± 9.7, 35–66 44.8 ± 9.0, 31–63 2003 North coast 8 45.4 ± 13.5 36–78 41.4 ± 12.9 34–73 2001 Lepidochelys olivacea Adonga 24 73.2 ± 6.1, 51–84 71.3 ± 6.6, 47–84 1993–1994 and even off some of the mainland beaches, for example, shoulder, in the shape of half a melon, of unknown near Varela. Some areas must have a very high density of significance. young turtles, which is suggested by the capture of 19 green turtles in only 3 short capture sessions near Olive Ridley Turtle, Lepidochelys olivacea Unhocomo and Unhocomozinho, in May and September 2003 (Table 2). The olive ridley turtle appears to be the second most Movements. — We have only 6 confirmed reports of numerous species in Guinea-Bissau, although its distri- green turtle tag recoveries away from Poila˜o. Three were bution may be less wide than that of other species, as we recovered in Mauritania, one in Gambia, one in southern only have confirmed nesting records from the Orango Senegal, and one in southern Guinea-Bissau (unpubl. National Park. Results from the 1992–1994 survey of the data). This extremely low recovery rate can be attributed Orango group are presented in Table 1. By far, the most to a high tag loss and a low reporting rate. Satellite important nesting beach was on the barrier island of tagging of 10 females nesting in Poila˜o confirmed that Adonga, with almost half of the nests recorded. Limited postnesting movements are mostly due north and surveys in January–March 2008 suggest these broad identified important foraging grounds in the Banc levels of nesting are still maintained, despite significant d’Arguin National Park, Mauritania (Godley et al. 2003). human predation, particularly at Adonga. Fibropapillomatosis. — In 2007, we carefully In Guinea-Bissau, olive ridleys are solitary nesters, inspected 274 nesting green turtles on Poila˜o, specifically with a peak nesting season in the central part of the dry looking for signs of this disease. No turtle had period (Fig. 5). Mean clutch size (± SD) for 7 nests at pedunculated or cauliflower-like structures or any large Adonga was 130.3 ± 14.2 eggs (range 5 109–150 eggs). external growths. There were no signs of ulcerated lesions During the 1992–1994 survey in the Orango Group, 35% or of tumors growing around the eyes or on the head. Two of the old nests (n 5 142) when first detected had of 74 turtles examined in more detail revealed small suffered predation. In 26% of the cases predation was by (4 cm long), rather smooth sessile low growths in the humans, 52% by crabs, and 22% by monitor lizards.

Figure 5. Monthly variation in the mean number of olive ridley nests seen per visit to Adonga in 1992–1994. 156 CHELONIAN CONSERVATION AND BIOLOGY, Volume 8, Number 2 – 2009

Hawksbill Turtle Eretmochelys imbricata confirm that in Guinea-Bissau the species lays during the dry season, from November to April, with a single known Reports of hawksbill turtles and their shells can be record from June. found sparsely all over the Guinea-Bissau coastal zone, indicating a wide at-sea distribution. In the 1990 survey, 5 DISCUSSION fresh tracks were recorded on Poila˜o and 2 on Adonga. This hinted at the presence of a sizeable population in the Status and Biology Bijago´s, but posterior data did not confirm so. Few nests were found in the Orango group in 1992–1994 (Table 1). The present review highlights the importance of During the intensive Poila˜o survey in 2000, 4 turtles were Guinea-Bissau as a nesting area for sea turtles. Data seen ashore and 6 nests identified (Catry et al. 2002) presented here give the first insight into the annual while in 2007, 7 different individuals were recorded, one variation of nesting numbers on Poila˜o and confirm of them twice. It must be stressed that hawksbills females previous information showing this site to be of outstand- and their tracks are likely to be often overlooked amongst ing importance in an Atlantic context. The number of the large numbers of green turtles at this site. In any case, green turtle nests laid annually on Poila˜o varies between the total numbers nesting annually at Poila˜o must be in the ca. 7000 and 29,000, which possibly makes this site the low tens. An educated guess (based on data presented here third most important for this species in the whole Atlantic, and other personal observations) would be that there are after Tortuguero, Costa Rica (Bjorndal et al. 1999) and 50–200 nests being laid per year in Guinea-Bissau. We Ascension Island (Godley et al. 2001), and places it are unsure about the source of the estimate presented in amongst the top 12 sites in the world (see Spotila 2004). Spotila (2004) of 200 nesting females per year in this We should note here that we regard our estimates of nest country, but under our present state of knowledge, this numbers on Poila˜o as conservative (particularly the 2007 value would seem too high, given that each female should estimate). The very high density of turtle tracks makes lay several clutches. their counting difficult and on several occasions we According to reports from locals and observations on counted more turtles ashore during the night than tracks in Poila˜o and Orango, hawksbills have a peak nesting season the following morning. Hence, it is not unlikely that nest in July–October, but there are also several dry-season numbers were above 30,000 in the latest study year. records, for example, in January and March. Mean clutch Broderick et al. (2006) quote the Poila˜o population as size (± SD) for hawksbill nests at Poila˜o was 163.8 ± an example of a positive green turtle demographic trend, 29.7 eggs (range: 142–215 eggs, n 5 5). but this seems to be based on only 2 (relatively imprecise) data points. Considering the annual variability in nesting Loggerhead Turtle Caretta caretta numbers typical of this species (Broderick et al. 2001), such assessment seems to be premature. Loggerheads are very rare in Guinea-Bissau. At least Green turtle hatching and emergence success at one old carapace originating from the Bijago´s was Poila˜o was high in a year (2000) with ‘‘typical’’ nesting positively identified in the 1980s (Limoges 1989; Boesl density (Catry et al. 2002). In 2007, with a much higher 1995), but it is not known if this individual was nesting density, it is clear that many nests were destroyed by locally. In 2003, during detailed enquires on the island of laying females. The partial destruction of a nest can result Unhocomozinho, we were told by local collaborators that in rotting eggs that negatively affect both the original and turtles of a rare species had nested on 6 occasions, on 2 the overlapping clutch (Caut et al. 2006). Knowing that different beaches, between 28 February and 9 May 2003 approximately one third of the nesting turtles had (from the dates, at least 3 different individuals must have scattered eggs around them in 2007, it seems likely that been involved). These collaborators knew other turtle nesting success was significantly lowered by density- species well, gave a description that was consistent with dependent factors (see Bustard and Tognetti 1969; Caut et loggerheads, and furthermore positively identified the al. 2006), which also suggests that the potential for species when shown published images. population growth at Poila˜o is limited by the availability of suitable nesting habitat. Leatherback Turtle, Dermochelys coriacea The presence of small numbers of leatherbacks nesting in Guinea-Bissau is not surprising, given that Leatherbacks are rare on the beaches of Guinea- the species has been recorded reproducing in almost all Bissau. They have been recorded nesting on the mainland, West African countries (Turtle Expert Working Group at Varela, and on the islands of Unhocomo, Orango, 2007). Nesting populations of hawksbill and olive ridley Adonga, Orangozinho, Canhabaque, and Joa˜o Vieira. turtles may also be of international importance, at least in Surveys of the Orango group (Table 1) highlighted a West African context. Nesting loggerhead turtles are Adonga as the main nesting site. An educated guess for perhaps more unexpected. If confirmed to nest regularly, the present national nesting levels would point to 25–75 this would represent an extension of the known nesting nests per year. Information from several sources all range of the species in the Eastern Atlantic. CATRY ET AL. — Sea Turtles in Guinea-Bissau 157

Body sizes, internesting intervals, and clutch sizes taboo involves the remote islet of Poila˜o, which can only measured for green, hawksbill, and olive ridley turtles are be visited during occasional and rare ceremonies of social within average values for those species (see Hirth 1997; and religious significance. This could justify its favorable Miller 1997; Weir et al. 2007). Nesting seasons also seem conservation status. Elsewhere, there do not seem to be to be similar to other locations in the northern hemisphere any general traditional rules protecting sea turtles, for green and hawksbill turtles (Richardson et al. 1999; although at some places we have been told that Spotila 2004; Pe´rez-Castan˜eda et al. 2007), which in leatherbacks can only be killed under special circum- Guinea-Bissau nest mostly during the rainy season. stances (see also Bernatets 2005). However, olive ridley turtles display a pronounced In the Bijago´s, marine turtles can be used in religious nesting peak in the middle of the dry season, which ceremonies (e.g., Bernatets 2005), but their meat is not contrasts to what is found, for example, in Angola or in reserved for special occasions and can be consumed at the eastern Pacific (Plotkin 2007; Weir et al. 2007), but is any time. In fact, the consumption of turtle meat and eggs similar to the situation found in India (Spotila 2004). A seems to occur very frequently and, on most nesting similar pattern may apply to the leatherback, which in beaches, few if any turtles or nests are left alone when Guinea-Bissau seems to avoid nesting during the rainy found by locals. The data from the Orango National Park, season, while elsewhere in the Atlantic it often nests in where at least 374 adult female green turtles were killed periods with considerable rainfall (e.g., Caut et al. 2006; for consumption in 2007, somewhat illustrates the Weir et al. 2007). Such inter- and intraspecific variability magnitude of the problem. On the other hand, there is in nesting seasons is interesting in the context of very little use of turtle shell for manufacture of goods. temperature-dependent sex determination. Given that Marine turtles are strictly protected by the national pivotal temperatures for sex determination seem to be a fisheries law, although there is no specific mention to conservative trait in sea turtles (Wibbels 2003), one might their eggs and nests in the law text. Turtle meat or eggs not expect such strong variability of the timing of nesting are very seldom seen on markets anywhere in the country in a geographical narrow range such as the Bijago´s and most harvesting results in local consumption. archipelago. More research is needed to understand the Nevertheless, there are recent reports of turtles being differences between the reproductive seasonality of exported alive by foreign fishermen. Targeted capture at different species and implications for hatchling sex ratios. sea is only known to be done by nationals on a small Along the Atlantic coast of Africa, fibropapilloma- scale, around Unhocomo and Unhocomozinho. Whether tosis has been confirmed to occur in green turtles from there are occasions and places where foreign fishermen Gabon and equatorial Guinea (Formia et al. 2007), and specifically target turtles in Guinea-Bissau waters is turtles showing large tumors likely to be fibropapilloma unknown, but we have first-hand reports of this happening have been recorded in Guinea-Bissau (3 cases recorded by not far from the national border, in Senegalese waters, us from the year 2000) and neighboring countries, such as which, given the mobility of fisherman across frontiers, Gambia and Senegal (Barnett et al. 2004). This disease makes it likely that it happens in Guinea-Bissau too. has a very high prevalence in some areas and there are Off Guinea-Bissau, many industrial fishing trawlers concerns that it may have a significant impact on sea operate, coming from countries as diverse as China, turtle populations, particularly green turtles (Aguirre and Spain, France, Italy, and Portugal. There are no Lutz 2004). Our results from Poila˜o suggest that the impositions from the national government to use turtle incidence of fibropapillomatosis is currently extremely excluder devices and many fishing vessels operate low in the adult green turtle population, which may be illegally. Very little is known of the impact of the linked to the fact that the turtles live in waters relatively industrial fishing fleet in Guinea-Bissau waters. An early free of sources of pollution and is an indicator of good study suggested that between 500 and 1000 turtles could ecosystem health in their foraging and mating grounds be caught per year (Limoges and Robillard 1991c), but (Aguirre and Lutz 2004). there is no information on the methods used or on the reliability of this estimate. A latter (superficial) assess- Threats and Conservation Initiatives ment based on 11 interviews with national fisheries observers and on information on the number of licenses Interviews carried out all over the coastal area of for the international fleet, indicated that the annual catch Guinea-Bissau in the last 2 decades clearly indicate that might be on the order of 300 turtles, of which many could there is a general feeling that sea turtles have decreased in be released alive (Broderick and Catry 1998). numbers within living memory. It is easy to obtain verbal Sea turtles are regularly captured in monofilament reports stating that turtles used to be numerous on specific nets set from open boats, in coastal waters, to catch nesting beaches where they are now scarce or almost predatory fish, such as sharks, rays, barracuda, jacks, and absent. snappers. In Guinea-Bissau, such fishing is mostly carried The Bijago´s people maintain many of their traditional out by foreign fishermen (generally from Senegal, beliefs and their life is governed by numerous taboos and Guinea-Conakry, and Sierra Leone), but also by nationals, rules, even if this may be rapidly changing. A rather strict often in association with foreigners. Turtles may drown in 158 CHELONIAN CONSERVATION AND BIOLOGY, Volume 8, Number 2 – 2009 the nets or, if caught alive, they are generally killed and The regular presence of monitoring and research consumed. We have no quantitative data on the level of teams in Poila˜o has certainly reinforced the traditional this type of mortality, but it is almost certainly very high, protection that benefits this site. Without such presence, it as informal contacts with fisherman indicate that turtles is likely that temporary camps of foreign fisherman would are frequently captured and that one large fishing canoe be established and the illegal harvest of turtles would take can, at certain times and locations, capture several turtles place as happened in the past. per day. According to the villagers of settlements near The development of ecotourism activities in the important nesting beaches in the Orango National Park, in Bijago´s may contribute to raise the interest of both local the past 2–3 decades, the capture by foreign fishermen of populations and government officials in the conservation very numerous turtles was witnessed and, as a result, of the area and its natural resources, demonstrating that nesting turtles (particularly olive ridleys and perhaps the conservation of marine turtles can promote, rather hawksbills), which were previously abundant, became than prevent, the sustainable development of the area. For scarce in the area. Green turtles, being captured in nets this to effectively happen, it is essential that local less often (partly because they nest at a season with communities derive direct benefits from such initiatives. comparatively little fishing activity), were less affected and their populations did not decline so much, despite CONCLUSIONS important harvest on the nesting beaches. Sea turtle nesting beaches and adjacent mating Guinea-Bissau harbors globally important popula- grounds were taken into consideration when planning tions of sea turtles. Due to the negative influence of the creation of a network of national protected areas (e.g., various factors, it appears that such populations are Limoges and Robillard 1991a; Catry et al. 2002). declining (with the possible exception of the population Conservation efforts resulted in the recognition by the nesting in Poila˜o). Much progress has been achieved over UNESCO of the Bolama-Bijago´s Biosphere Reserve that the past couple of decades in gathering essential covers the entire Bijago´s archipelago, within which 3 knowledge, training national personnel, setting up pro- protected areas have been formally created by the national tected areas and an institutional framework, and providing government. The most important sea turtle nesting sites in permanent vigilance of Poila˜o during critical nesting Guinea-Bissau are situated in the core zones of those seasons. As is obvious from our review, many other issues protected areas. The main direct effect of the creation of need to be tackled. In particular, there is a need to the protected areas was the removal, since 2004, of large increase the focus on law enforcement activities on the semipermanent foreigner fishing camps and the preven- nesting beaches and on marine protected sectors. Local tion of further temporary or permanent settling. Further- communities could be more involved, for example, more, many environmental education campaigns and through ecotourism initiatives. This is, however, unlikely conservation messages have reached the Bijago´s villages to provide by itself sufficient incentive for conservation through the community radio. (see Kiss 2004) and innovative methods, such as direct On the other hand, few enforcement activities have payments for community involvement in conservation taken place. There have been virtually no penalties for and monitoring, may be worth considering (Ferraro and people found to have killed sea turtles or harvested eggs. Kiss 2002). Research and monitoring should also be given This results mostly from a situation in which investments high priority, particularly because the presence of in protected areas have been mostly directed toward researchers in the terrain supports and promotes conser- community-based development initiatives and where vation in parks with insufficient baseline surveillance, as enforcement activities have often been seen as contrary seen in Poila˜o and elsewhere (Oates 2002). As a longer- to the principles of protected areas comanagement. This, term effort, a better understanding of the interactions of and the insufficient human and financial resources for turtles and fishing and the development of mitigation patrolling and vigilance, mean that Guinea-Bissau parks measures will have to be a priority. Finally, as everywhere share the fate of most of their West African counterparts, else, the effects of global warming on these vertebrates where most megafauna are seriously threatened for these with temperature-dependent sex determination need to be better studied, in order to allow the prediction of future very same reasons (e.g., Oates 2002). However, the population trends and the development of appropriate attitudes are changing, even if slowly. In the last 2–3 long-term conservation strategies. years, there have been some fishing parties fined for illegal fishing in the core areas of marine parks, which ACKNOWLEDGMENTS may help deter the use of such areas. Nevertheless, the illegal use of nets by foreigners and nationals in those This compilation is based on research projects that critical sectors is still common practice. In the core areas received support from a broad range of people and of the Orango National Park, for example, illegal fishing institutions, far too many to be listed individually. We boats were present every day when surveys were carried would like to highlight the sustained financial support for out in January–March 2008. research and conservation given by the Swiss Cooperation CATRY ET AL. — Sea Turtles in Guinea-Bissau 159

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