Belize—A Last Stronghold for Manatees in the Caribbean

Home , Sharon Matola, West Indian manatee

Belize—a last stronghold for manatees in the Caribbean

Thomas J. O'Shea and Charles A. 'Lex' Salisbury

Belize is a small country but it offers a safe haven for the largest number of manatees in the Caribbean. The authors' survey in 1989 revealed that there has been no apparent decline since the last study in 1977. However, there is no evidence for population growth either and as the Belize economy develops threats from fisheries, human pressure and declining habitat quality will increase. Recommendations are made to ensure that Belize safeguards its manatee populations.

Introduction extensive (Figure 1): straight-line distance from the Rio Hondo at the northern border The West Indian manatee Trichechus manatus with Mexico to the Rio Sarstoon at the is listed as endangered by the US Fish and Guatemala boundary is about 290 km. Wildlife Service and as vulnerable to extinc- However, studies reported 10-20 years ago tion by the International Union for suggested that manatee populations may have Conservation of Nature and Natural been high in Belize relative to other Resources (IUCN) (Thornback and Jenkins, Caribbean-bordering countries (Charnock- 1982). A long-lived, slowly reproducing, her- Wilson, 1968, 1970; Charnock-Wilson et al, bivorous marine mammal, the West Indian 1974; Bengtson and Magor, 1979). Despite manatee inhabits coastal waters and slow- Belize's possible importance for manatees, moving rivers of the tropical and subtropical additional status surveys have not been western Atlantic. This species first became attempted there since 1977 (Bengtson and known in Europe from records made in the Magor, 1979). We made aerial counts of mana- Caribbean on the voyages of Christopher tees over selected areas in May 1989, and dis- Columbus (Baughman, 1946). Estimating past cussed manatee status with locally knowl- manatee population sizes is impossible, but its edgeable residents. This report summarizes relative abundance in many areas was our findings, compares manatee status in undoubtedly once much higher than today. Belize with status elsewhere in the Caribbean, Historical accounts (including provisioning of and offers recommendations for manatee con- manatee meat to privateers), archaeological servation. records (McKillopp, 1985), and regional place- names including the word 'Manati' all support this assertion. Populations of West Indian Survey methods manatees have been reduced, and the current distribution is now fragmented in most coun- Aerial surveys were flown in a small, four- tries within the historical range, particularly in seater helicopter. A total of 6.5 h was spent the greater Caribbean. The manatee's decline searching, concentrating over five areas where results largely from hunting pressure and inci- manatees were expected to occur based on dental entanglement in gill-nets (Lefebvre et local knowledge and the single 1977 survey by al., 1989). Bengtson and Magor (1979). These regions In this report we provide an update on the were: Four Mile Lagoon and the New River in status of manatees in Belize. Belize is a small northern Belize; the lower Belize River from country and its Caribbean coastline is not Burrell Boom to Belize City; cays offshore near 156

Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.14, on 27 Sep 2021 at 03:05:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300034189 MANATEES IN BELIZE

DOMINICAN REPUBLIC PUERTO RICO

200 400 600 km

Figure 1. The Caribbean region. Belize is shaded. See Table 2 for a review of manatee survey results in other nations in this region.

Belize City; Northern and Southern Lagoons Lagoon area on the south-central coast (Figure near the central coast; and the Placentia 2). Rivers were surveyed by flying directly above them, coastal areas and cays were flown Table 1. Aerial counts of manatees in Belize by about 0.5 to 1.0 km offshore, and open lagoons water-body, May 1989 (this study) and September were flown along transect courses about 0.5 1977 (Bengtson and Magor, 1979). See Figure 2 for km apart. (Detailed maps of survey routes are general locations of these areas and text for on file with the authors, the Belize Center for cautionary remarks on comparing manatee survey Environmental Studies and the Belize Ministry data. c=small calves, NS= not surveyed of Agriculture, Forestry and Fisheries.) Manatees were noted as calves or adults, with Area May September 1989 1977 calves defined as small individuals less than about 2 m in length closely associated with an Four Mile Lagoon adult. An altitude of 100 m and flight speeds (near Rio Hondo) 1 NS of 100-130 km/h were maintained during Four Mile Lagoon searches. Speed and altitude were altered and New River 7+lc 12 when manatees were initially sighted in Belize River (Burrell attempts to count as many individuals present Boom to Belize City) 16+2c 2 as possible. Two observers recorded sightings Offshore cays near Belize City 10+lc 12+2c from each side of the aircraft. Although sur- Placentia Lagoon veys were scheduled at the end of the dry sea- region 8+lc 10+lc son to avoid muddy run-off, we rated visibili- Southern Lagoon 55 31+4c ty conditions during our flight as 'fair': light

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tion from locally knowledgeable individuals. Chetumal Bay In addition to aerial surveys, we conducted interviews with residents and made boat trips

Ambergris Cay to offshore cays, the lower Belize River, and Southern Lagoon for reconnaissance of manatee habitat. San Pedro

High counts of manatees in selected areas

A total of 102 manatee sightings (including CARIBBEAN SEA five calves) was made in 5.4 h of search time (Table 1), excluding a preliminary 1.1-h survey of Southern Lagoon, which we surveyed twice. By far the greatest concentration was in the area of Southern Lagoon, where we count- ed 55 manatees in a single survey despite less than optimal visibility. None was observed by air in nearby Northern Lagoon. Manatees were also observed in the channels between Southern Lagoon and the Caribbean, some apparently travelling in from the sea. Water turbidity and large mud plumes raised by

20 km adults may have obscured calves from view in Southern Lagoon, accounting for a lack of calf Figure 2. Map of Belize. Aerial survey regions sightings in this body of water. Excluding correspond to numbered boxes as follows: (1) Four counts from Southern Lagoon because of the Mile Lagoon and lower New River, (2) lower Belize River, (3) waters and cays off Belize City, (4) probable strong visibility bias, five of 47 sight- Southern Lagoon, (5) Placentia Lagoon. ings (10.6 per cent) in Belize were calves. The frequency distribution of group sizes for all breezes predominated, with gusts to 18-33 aerial observations was (number of observa- km/h; water surface states varied from flat to tions in parentheses): one (43), two (9), three a Beaufort scale of 3; and water was turbid in (6), five (2), six (1), and seven (1). unsheltered expanses. Unfortunately, acceptable techniques to derive statistically based population estimates Status in Belize compared with other from manatee aerial survey data have not yet areas been fully developed or applied anywhere in the world (Packard, 1985a; Packard et al, 1985; The number of manatees observed in selected O'Shea, 1988). In addition, the 1977 survey areas of Belize was the highest for any aerial results are also not strictly comparable with survey conducted in the Caribbean region the present findings because the latter study (Table 2). Comparison of numbers seen on our was flown in fixed-wing aircraft during the flights with those seen during the 1977 survey month of September, and included different (Table 1) gives no evidence for any recent observers working under different conditions decline, although such comparisons are quali- (Bengtson and Magor, 1979). However, aerial tative and provisional (due to differences in counts are of value for qualitative assessment observers, aircraft, and other survey con- of manatee abundance and conservation ditions). The proportion of calves we observed needs, particularly if corroborated by informa- parallels the 7 per cent reported for a healthy,

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Table 2. Maximum counts of West Indian manatees from various parts of the Caribbean region. Populations are thought to have been reduced from historical levels throughout the range. The Lesser Antilles are not thought to harbour resident populations and have not been surveyed by air

Country/region Maximum Remarks Reference count Belize 102 Maximum based on single surveys of five areas This study in 1989 that were not comprehensive for the entire country. Survey path approx. 375 km

Colombia None No aerial counts have been attempted. Lefebvre et al. available Sightings along the Caribbean are rare in (1989) comparison with reports from large rivers and their estuaries Costa Rica None No recent attempts at aerial counts. Although Lefebvre et al. available favourable habitat is present, the manatee is thought (1989) to be one of this country's rarest animals Cuba None Areas where manatees are thought to be locally Estrada and available abundant have been documented through status Ferrer (1987) interviews, but no aerial surveys have been reported Dominican 41 Maximum count based on six bimonthly entire coast Belitsky and Republic aerial surveys in 1977. Survey path approx. 825 km Belitsky (1980) Guatemala None No comprehensive aerial survey has been conducted Lefebvre et al. available A sighting of one manatee was made during a 6-h (1989) aerial survey in 1976 Haiti 8 Maximum count based on one entire coast aerial Rathbun et al. survey in 1982. Survey path approx. 1100 km. (1985) Honduras 11 Maximum count during one entire coast aerial Rathbun et al. survey in 1979. Survey path approx 875 km. (1983) Jamaica 13 Maximum count based on 13 entire coast aerial surveys Fairbairn and in 1981-82. Survey path approx. 675 km Haynes (1982) Nicaragua None No aerial counts have been completed, but excellent Lefebvre et al. available manatee habitat persists (1989) Panama 24 Maximum count for separate river systems surveyed Mou-S. et al. in 1987 in Bocas del Toro province, assuming no (1990) interchange and no duplicate counting. Panama Canal system not included. Caribbean coast surveyed to Ustupo. Survey pathllOO km Puerto Rico 62 Maximum count based on 12 monthly entire coast Rathbun et al. aerial surveys in 1984-85. Survey path approx. 575 km (1986) Quintana Roo, 6 A total of 16 sightings were made in 22 hours of Colmenero-R. Mexico (excluding searching during eight separate surveys in 1987-88. et al. (1988) Bahia de Chetumal Survey path approx. 800 km near Belize border) Quintana Roo, 49 A total of 251 sightings were made in 21.5 hours of Colmenero-R. Mexico: Bahia de searching during seven separate surveys in 1987-88. et al. (1988) Chetumal area Survey path approx. 250 km Venezuela 0 None observed along entire Caribbean coast in one O'Shea et al. aerial survey in 1986; absence corroborated by status (1988) interviews. A few reports of sightings continue to come from Lake Maracaibo. Survey path approx. 1600 km 159

The West Indian manatee (Trichechus manatus) (/. P. Reid/US Fish and Wildlife Service).

growing subpopulation in Florida's Crystal killing continues. General knowledge of mana- River (Rathbun et a\., 1990). From this we sur- tees being intentionally killed in the areas of mise that manatees in Belize have no apparent Ambergris Cay, Dangriga and Punta Gorda problems in reproduction and recruitment. was reported to us from several sources. None of the manatees we observed by air had Fishermen near Southern Lagoon were said to any visible propeller scars, as are commonly occasionally bludgeon manatees to death fol- observed in Florida. Seven manatees (includ- lowing incidental entanglement in fishing ing three calves) observed within 30 m by boat nets. Manatee meat is not openly sold but is at in the Belize River were also free of scars. least occasionally available illicitly, as was Accounts of manatees being struck by boats reported for markets in Corozal. Pendants and are rare in .Belize, and the effects of boat traffic scrimshaw made of manatee bone are some- on manatees in most areas of this country are times sold to tourists on Ambergris Cay, but not likely to be as serious as in Florida. sellers claim bones are from manatees found dead. However, sale of such products may fall under the ban provided by Part II, Section 8 Manatee exploitation and protection in (1) of the Wildlife Protection Act No. 4,1981. Belize The greatest potential economic value of manatees could lie in their tourist appeal. Tour Manatees are fully protected in Belize under groups have recently included nature trips to the Wildlife Protection Act No. 4, 1981, and Southern Lagoon to observe manatees from were originally afforded such status during small boats, and tourists sometimes visit the the colonial period with the Manatee lower Belize River in search of manatees. Protection Ordinances, 1935-36 (McCarthy, Residents have fed wild manatees from their 1986). Despite official protection, some illegal boats in the lower Belize River, suggesting that 160

without strong hunting pressure some mana- conclusion is bolstered by findings that in tees have lost their fear of man and have Mexico's Yucatan Peninsula recent counts of become relatively tame. In Florida, thousands manatees were negligible except for the region of tourists visit manatee refuges to see rela- near the Belize border (Table 2; Colmenero-R. tively tame, free-ranging manatees each year. et ah, 1988), and that our counts were surpris- This tourist attraction contributes millions of ingly similar to those obtained during 1977 dollars to local economies. (Table 1). Despite uncertainties in comparing We encountered a high level of awareness such data, we find no basis to suspect any about manatees and their protected status drastic changes in manatee population status among residents of Belize. Perhaps this is in Belize over the past 12 years. The propor- because manatees are relatively common, but tion of sightings that were calves in areas much credit may also be due to the education exclusive of Southern Lagoon, a low level of efforts of Belizean conservation groups includ- reported illegal killing, and a common aware- ing the Belize Audubon Society, Belize Center ness of manatees as part of the local fauna also for Environmental Studies, and the Belize Zoo. support this conclusion. The Zoo's manatee conservation education efforts are to our knowledge the strongest of any local organization in the Caribbean Habitat quality and low exploitation region. explain status Our survey resulted in the highest manatee count yet obtained anywhere in the Caribbean Why does Belize remain one of the last (Table 2). We believe this clearly demonstrates strongholds for manatees in the Caribbean? that Belize remains one of the last strongholds The answer lies in both the high quality of for this species in this part of the world. This habitat and low level of killing. The promotion

Mangrove islands (cays) along nearshore areas of Belize provide sheltered habitat for manatees and sea-grass. 161

of these two factors would not only serve to bly less than 5 per cent (Packard, 1985b). One maintain the positive status of manatees in calf is born every 2-5 years, and typical age at this country, but would allow a source for nat- sexual maturity may be 7 or 8 years. These ural repopulation of other countries in the kinds of vital statistics indicate that any sub- Caribbean. The second longest coral reef in the stantial increase in the current low level of world extends most of the length of the take in Belize could result in a manatee popu- Caribbean shores of Belize. The shallow, shel- lation decline. Increased take could result tered waters between the mainland and the from greater use of gill-nets, particularly in reef are dotted with mangrove islands and are rivers and inshore or nearshore lagoons; well-vegetated by extensive sea-grass beds increased settlement and human population that serve as manatee forage. Along the main- growth in areas supporting manatee popula- land there is good access to a number of tions, particularly by immigrants from coun- rivers, creeks and lagoons, which provide tries with a greater tradition of manatee hunt- other plant species as forage and serve as ing and use as food; and from decreases in sources of freshwater. Throughout their range habitat quality, particularly with respect to manatees are most often encountered where increased boat traffic and contamination. freshwater is available, which they seek out to Without doubt, as Belize advances in develop- drink (Lefebvre et al.r 1989). Southern Lagoon ment these factors will increase. We therefore has a well-known upwelling freshwater offer the following recommendations as possi- spring. Freshwater availability in the lower ble means to safeguard manatee populations Belize River may also attract manatees. in Belize. The character of Belize's coastal habitat has 1. Maintain the West Indian manatee as a pro- also guided historical factors that have slowed tected species as currently provided under the the rate of exploitation of manatees and other Wildlife Protection Act of 1981. Legal protection natural resources. Lack of a deep-water port undoubtedly contributes to the species's dampened economic expansion, export of healthy survival in Belize. Removal of protec- resources, and human population growth. The tion would be tragic because the manatee is in low number of people living in Belize has jeopardy everywhere else in the Caribbean resulted in maintenance of high quality habi- where its status is known. tat, a low level of intentional manatee hunting, 2. Maintain and increase manatee conservation and only a minor gill-net fishery. Gill-netting education efforts, and enforcement of laws regulat- in rivers is illegal. We seldom saw gill-nets ing manatee hunting and gill-netting of fishes in anywhere during our aerial surveys and boat rivers. Continued enforcement of laws, mainte- trips in Belize. Incidental entanglement of nance of a developing manatee conservation manatees in gill-nets and their subsequent philosophy, and restrictions on gill-netting killing is a major factor impacting manatee (the largest source of manatee mortality else- populations elsewhere (Lefebvre et al., 1989). where in the Caribbean) are imperative to per- petuating Belize as a last stronghold for this species. The need for future manatee 3. Designate areas known to he well-used by conservation in Belize manatees as manatee protection reserves. Specific areas well-used by manatees should be man- The population status of manatees in Belize is aged to benefit the species. Existing marine unique to this region of the world, yet without reserves do not encompass such areas. vision for the future this current stronghold Settlement near shoreline, boating activity, and can easily be eroded. Although our survey gill-netting should be strictly guarded against gave no evidence for a decline since the 1970s, in manatee reserves, with law enforcement there is also no evidence of population and manatee conservation education pro- growth. Manatee population dynamics are grammes targeting neighbouring communi- such that the intrinsic rate of increase is proba- ties. Small supervised nature tours, however, 162

should be encouraged. One of the most impor- Charnock-Wilson, J. 1968. The manatee in British tant candidates for a manatee reserve is the Honduras. Oryx, 9,293-294. Southern Lagoon system. The up welling of Charnock-Wilson, J. 1970. Manatees and crocodiles. Oryx, 10,236-238. freshwater in Southern Lagoon may be a Charnock-Wilson, J., Bertram, K. and Bertram, C. major resource for manatees, which probably 1974. The manatee in Belize. Belize Audubon travel into the lagoon from much wider areas Society Bull. 6,1-4. along the coast. The number of manatees gath- Colmenero-R., L., Azcarate Capriles, J.C. and Zarate ering in this lagoon may be unmatched any- Becerra, E. 1988. Estado y distribution del manati en where in the Caribbean, Central or South Quintana Roo. Final Report, Centro de Investigaciones de Quintana Roo, Cancun, Q.R., America. Future research efforts should use Mexico. radiotelemetry and additional aerial surveys Estrada, A.R. and Ferrer, L.T. 1987. Distribution del to focus on how and why manatees use this manati antillano, Trichechus manatus (Mammalia: area. Based on the manatees' ability to quickly Sirenia), en Cuba. I. Region occidental. Poeyana travel long distances in Florida (Reid and 354,1-12. O'Shea, 1989), it is likely that individuals Fairbairn, P.W. and Haynes, A.M. 1982. Jamaican using Belizean waters also travel to nearby surveys of the West Indian manatee (Trichechus manatus), dolphin (Tursiops truncatus), sea turtles countries, or are drawn to Belize from other (Families Cheloniidae and Dermochelydae) and areas because of favourable conditions. booby terns (Family Laridae). United Nations Food Research investigating this possibility would and Agriculture Organization Fisheries Report, 278, clarify just how critical Belize is as a last 289-295. stronghold for this species in the greater Lefebvre, L.W., O'Shea, T.J., Rathbun, G.B. and Best, Caribbean. R.C. 1989. Distribution, status, and biogeography of the West Indian manatee. In Biogeography of the West Indies: Past, Present, and Future (ed. C. A. Acknowledgments Woods), pp. 567-610. Sandhill Crane Press, Gainesville, Florida. Financial support was provided by the Save-The- McCarthy, T.J. 1986. The gentle giants of Belize. Part Manatee Club and The Lowry Park Zoological II: Distribution of manatees. Belize Audubon Garden. Ged Caddick provided invaluable help Society Bull. 18,1-4. with local arrangements and logistic support. We McKillop, H.I. 1985. Prehistoric exploitation of the also thank the Belize Center for Environmental manatee in the Maya and circum-Caribbean areas. Studies, the Belize Zoo, and the British Forces Belize World Archaeol. 16, 337-353. (particularly Dave and Julie Wood) for advice, infor- Mou-S., L., Chen-H., D., Bonde, R.K. and O'Shea, mation, and assistance. Individuals who assisted T.J. 1990. Distribution and status of manatees and provided useful information included Victor (Trichechus manatus) in Panama. Marine Mammal Gonzalez, Sharon Matola, Amy Bodwell, Mickey Science, 6,234-241. Craig, and Joe Garel. This survey was authorized O'Shea, T.J. 1988. The past, present, and future of under a scientific research permit issued by the manatees in the southeastern United States: reali- Belize Ministry of Agriculture, Forestry, and ties, misunderstandings, and enigmas. In Fisheries. The interest and support of Dean Lindo, Proceedings of the Third Southeastern Nongame and Vincent Gillett, and Oscar Rosado of the Ministry Endangered Wildlife Symposium (eds R. R. Odom, helped make this study possible. K. A. Riddleberger and J. C. Ozier), pp. 184-204. Georgia Dept. Natural Resources, Game and Fish Division, Social Circle, Georgia. References O'Shea, T.J., Correa-Viana, M., Ludlow, M.E. and Baughman, J.L. 1946. Some early notices on Robinson, J.G. 1988. Distribution, status, and tra- American manatees and the mode of their cap- ditional significance of the West Indian manatee ture. /. Mammal. 27,234-239. (Trichechus manatus) in Venezuela. Biol. Conserv. Belitsky, D.W. and Belitsky, C.L. 1980. Distribution 46,281-301. and abundance of manatees Trichechus manatus in Packard, J.M. 1985a. Development of manatee aerial the Dominican Republic. Biol. Conserv. 17, survey techniques. Manatee Pop. Rts. Rep. 7, Tech. 313-319. Rep. 8-7, Florida Coop. Fish Wildl. Res. Unit. Univ. Bengston, J.L. and Magor, D. 1979. A survey of man- Florida, Gainesville. atees in Belize. /. Mammal. 60,230-232. Packard, J.M. 1985b. Modelling manatee popula-

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tions. Manatee Pop. Res. Rep. 9, Tech. Rep. 8-9, 1985. The manatee in Haiti. Oryx, 19, 234-236. Florida Coop. Fish Wildl. Res. Unit. Univ. Florida, Reid, J.P. and O'Shea, T.J. 1989. Three years opera- Gainesville. tional use of satellite transmitters on Florida man- Packard, J.M. Summers, R.C. and Barnes, L.B. 1985. atees: tag improvements based on challenges from Variation in visibility bias during aerial surveys of the field. In Proceedings of the 1989 North American manatees. /. Wildl. Manag. 49,349-353. Argos Users Conference and Exhibit, pp. 217-232. Rathbun, G.B., Carr, T., Carr, N., and Woods, C.A. Service Argos, Inc., Landover, Maryland. 1986. The Distribution of Manatees and Sea Turtles in Thornback, J. and Jenkins, M. 1982. The IUCN Puerto Rico, with Emphasis on Roosevelt Roads Naval Mammal Red Data Book. Part I. Threatened Station. National Technical Information Service Mammalian Taxa of the Americas and the Pub. PB86-1518347AS, Springfield, Virginia. Australasian Zoogeographic Region (Excluding Rathbun, G.B., Powell, J.A. and Cruz, G. 1983. Status Cetacea). IUCN, Gland, Switzerland. of the West Indian manatee in Honduras. Biol. Conserv. 26,301-308. Thomas J. O'Shea. Sirenia Project, US Fish and Rathbun, G.B., Reid, J.P. and Carowan, G. 1990. Wildlife Service, National Ecology Research Center, Distribution and movement patterns of manatees 412 NE 16th Ave., Gainesville, Florida 32601, USA. (Trichechus manatus) in northwestern peninsular Charles A. 'Lex' Salisbury, Lowry Park Zoological Florida. Florida Marine Res. Pub. 48,1-33. Garden, 7530 North Boulevard, Tampa, FL 33604, Rathbun, G.B., Woods, C.A. and Ottenwalder, J.A. USA.

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