Results and Conservation Recommendations
The main results of the expedition are outlined below. The full report can be viewed in the RAP report.
Fourteen sites on the Palumeu River, Tapaje Creek and Makrutu Creek revealed typical water quality conditions for undisturbed aquatic ecosystems in Suriname’s interior, except for mercury. Although analysis of rainwater samples taken on the Grensgebergte did not have any mercury, levels above international norms were occasionally found in sediment and fish tissue samples. This indicates that there might be an external mercury source. Further monitoring is needed to confirm this. This aspect is very important and needs immediate action because these headwaters provide drinking water and food for many local communities downstream.
Out of 609 plant specimens collected, 354 species, 152 genera and 93 families have so far been determined. At site 1, along the upper Palumeu River, we collected 188 plant specimens. At the Grensgebergte (site 2) we collected 69 plant specimens and 75 at the Makrutu camp (site 3). We also collected 11 plant specimens at the Palumeu village and 27 specimens at the rapids of the Palumeu River. We found 15 new plant species records for Suriname and two new genera. Two of these belong to lianas, four to shrubs and herbs and ten to trees. The surroundings of the Grensgebergte and the Kasikasima Mountains contain several vegetation types that are dominant and floristically distinct for the central and southern parts of Suriname. These vegetation types include tall dryland tropical forest on laterite/granite hills, short savannah (moss) forest and open rock vegetation, including rocky outcrops around rapids, and tall seasonally flooded forest. Within these vegetation types, we recorded nearly all of the 15 new plant species records and the two new genus records for Suriname. We also recorded several rare species with only a few known occurrences in Suriname and/or in the Guianas. The noteworthy species include several rare orchids that are listed in Appendices I & II of CITES, some carnivorous plants, and three tree species that are listed on the IUCN Red List, including one tree species listed as Critically Endangered. Plot surveys (0.1 ha) also indicated that the forests of South Suriname are floristically distinct from those of North Suriname, but do not significantly differ in tree alpha diversity. The forests on the Guiana Shield basement complex are not uniform as stated by some. Our findings indicate the pristine status of the forests and vegetation types in Southeastern Suriname, and the fact that these forests are still poorly explored.
More than 2500 specimens of water beetles were collected representing 157 species in 70 genera. Twenty-six species and 8 genera are confirmed as new to science, with an additional 10–15 species likely to be undescribed. Surprisingly, more species were recorded here than during the Kwamalasamutu Region RAP in Southwestern Suriname despite less collecting effort. Additionally, there was a high species turnover between these RAP sites: 40% of the species recorded here were not found in the Kwamalasamutu Region. The families Lutrochidae, Hydroscaphidae, and Torridincolidae are recorded from Suriname for the first time. While a broad range of habitats contributed to the high species and lineage diversity, hygropetric habitats on granite outcrops in particular provided a wealth of new and interesting taxa.
Dung beetles are among the most cost-effective of all animal taxa for assessing biodiversity patterns, yet RAP’s recent surveys are among the few that are expanding our knowledge of Suriname’s little known dung beetle fauna. In addition to cost-effective sampling using standardized pitfall traps, dung beetles depend upon large mammals for food and consequently can be used to rapidly assess the health of the overall mammal community and hunting impacts in a fraction of the time it would take to survey the mammals themselves. I sampled dung beetles using baited pitfall traps and flight intercept traps in the Grensgebergte and Kasikasima regions of Southeastern Suriname. I collected 4,483 individuals represented by 107 species. This ranks among the most diverse places on the planet for dung beetles, and exceeds the extraordinarily high species richness observed in nearby southwestern Suriname (94 species, Larsen 2011). Ten species are most likely new to science, while an additional 10–20 species may be undescribed pending further taxonomic revisions.
Dung beetle species richness, abundance and biomass were higher around Upper Palumeu than at Kasikasima, probably due to the extensive intact forest and lack of hunting pressure in this remote headwater region where no one currently lives. Dung beetle diversity and abundance at Kasikasima were still relatively high, indicating only mild to moderate hunting of large mammals and birds in the region. All sites, including the Grensgebergte Mountains, supported high endemism, including several rare species, demonstrating the exceptional biodiversity value of the region. Surprisingly, dung beetle species composition varied strongly among sites within this survey, as well as among sites sampled on previous surveys, including nearby southwestern Suriname. This high Beta diversity shows that the forests of Suriname and the Guiana Shield are not nearly as homogenous as is often assumed, and consequently protecting this varied biodiversity requires conserving many different forest areas.
The high abundance of several large-bodied dung beetle species in the region is indicative of the intact wilderness that remains. These species support healthy ecosystems through seed dispersal, parasite regulation and other processes. Maintaining continuous primary forest and regulating hunting (such as through hunting-restricted reserves) in the region will be essential for conserving dung beetle communities and the ecological processes they sustain. These results indicate that the intact headwater region of the Upper Palumeu watershed merits the highest conservation priority.
Fifty-two species of katydids were collected, representing 35 genera in 4 subfamilies. At least 6 species are new to science and 26 species were recorded for the first time from Suriname; one of the new species recorded during the survey represents the first example in the Neotropical region of the loss of the ability to produce sound in male katydids. The katydid fauna of this country exhibits a remarkably high turnover - 50% of species recorded during the current survey had not been collected during the 2010 survey in the Kwamalasamutu region, and all represent records new to Suriname. This may indicate a potentially high degree of uniqueness of the Grensgebergte mountains and warrants their protection.
A total of 149 ant species from 35 genera have been identified from the RAP collections. Additional work is ongoing to process and identify the remaining samples, which will undoubtedly raise the total number of species, possibly to over 200 species. The results indicate a healthy and diverse ant fauna reflective of pristine rainforest. Ants play important roles as predators, scavengers, and seed-dispersers in tropical forests. The ant data from Southeastern Suriname will add to a growing dataset on the ant fauna of the Guiana Shield, which is still poorly documented, to help identify areas of high diversity and endemism that are important to conserve within the region. Data on ants and other invertebrates are important since these groups may be able to illustrate differences between habitats within the Guiana Shield that larger animals with wide geographical ranges do not discern.
A total of 94 species of fishes were recorded which, in combination with a collection of fishes from Lower Palumeu River by Covain et al. (2008), makes a total of 128 species now known to occur in Palumeu River. This diversity is high compared to the rest of the world, but is typical for a medium-sized river of the Guiana Shield. Eleven species of fishes are potentially new to science, including a Bryconops species, a small Parotocinclus catfish, and a tetra (Hemigrammus aff. ocellifer). Two species are new records for Suriname: Hyphessobrycon heterorhabdus and Laimosemion geayi; a third and fourth species, Ituglanis nebulosus and Pimelodella megalops, may also represent new species for Suriname if their identity is confirmed. We did not find the same species at each site; sites 3 and 4 included large-sized fishes from the main channel of the Middle Palumeu River, while site 1 had many small-sized species of creek habitat. Overall, large top level predators were still common in Palumeu River.
Reptiles and Amphibians
A total of 47 species of amphibians and 42 species of reptiles were recorded during the RAP survey. These numbers are relatively high when compared with other sites sampled over the same time period (e.g., recent RAP surveys in other parts of Suriname). Seven (six frogs and one snake) of the total 89 species encountered could not be assigned to any nominal species. These unidentified taxa may represent novel species yet require validating genetic and morphological data before formal diagnoses can be made. A number of records represent range expansions for taxa within the Guiana Shield (e.g., Rhinatrema bivitattum, Alopoglossus buckleyi).
Additionally, a teiid lizard (Cercosaura argulus) was recorded for just the second time in Suriname. Encountering >80 total species (including 19 snake species) is evidence of a healthy, diverse and seemingly pristine forest ecosystem.
A total of 313 bird species were seen or heard at the three RAP survey sites, the village of Palumeu, and during excursions along the Palumeu River. We recorded fourteen species listed as Vulnerable or Near-Threatened on the IUCN Red List, and consider another seven species as likely to occur in the region. Our records of several species represent range extensions within Suriname and the Guiana Shield. Whereas the lowland forest avifauna was broadly similar at the different localities, 32% of species were only observed at one of the four survey sites. The abundance of parrots and cracids was particularly noteworthy, especially compared to the more populated Kwamalasamutu region that we surveyed in Southwestern Suriname in 2010. The high-elevation savanna forest harbored several species not known to occur in the adjacent lowlands, and therefore had the most unique species assemblage of any site. Our results indicate that the lowland forest of SE Suriname probably contains the vast majority of bird species known to occur in the country’s interior, including many species of high conservation value, arguing strongly for protection of the region’s forests. We recommend further surveys of high-elevation sites in the Grensgebergte and other mountain ranges in southern Suriname, to better determine the range limits of species restricted to high-elevation forests.
A total of 39 species of small mammals (<1 kg) were documented during the RAP survey. Taxonomic composition included 28 species of bats, 8 species of rats, and 3 species of opossums. Of the 3 sites sampled, the lowland sites were most similar, with Upper Palumeu having the highest diversity of bats and Kasikasima having the highest abundance for bats. The highland site of Grensgebergte had the highest diversity and abundance for small non-volant mammals but the lowest for bats. The species composition was heterogeneous with no opossums shared among sites, whereas 25% of rats and just over 50% of bats were shared among sites. The most noteworthy records were the documentation of the poorly known water rat (Nectomys rattus) near the open granite outcrop of Grensgebergte. This region of Southeastern Suriname has a mix of primary rainforest in a mosaic of lowland and highland habitats that supports diverse and different faunal communities of small mammals.
Large Ground Dwelling Mammals
During the survey of large and medium-sized ground dwelling mammals of the Kasikasima and Upper Palumeu river region, we recorded 18 species. Camera traps were the most important tools for the survey, but direct observations were made and tracks, scat and scratch marks were also recorded. We observed important species, including Endangered and Vulnerable species, such as Jaguar, Tapir and Giant River Otter. All these species fulfil important roles in the ecosystem such as by dispersing seeds or regulating populations of other species. The occurrence of a high diversity of large and medium-sized mammals in the surveyed area indicates that the ecosystem is healthy and relatively pristine. Southeastern Suriname is very important for large mammal species, especially wide-ranging species, because the area encompasses vast tracts of pristine forest and rivers.
Six of the eight primate species known from Suriname were recorded during the RAP survey. These included the black spider monkey (Ateles paniscus), red howler monkey (Alouatta maconnelli), bearded saki (Chiropotes sagulatus), brown capuchin (Cebus paella), squirrel monkey (Saimiri scuireus), and golden handed tamarin (Saguinus midas). The large-bodied species (black spider monkey, red howler monkey) were fairly abundant, indicating sustainable hunting practices by local communities. Although we did not record the white faced saki or wedge capped capuchin, they may occur in the area. These species are quite difficult to observe due to rarity and elusiveness. Primates play keystone ecological roles in maintaining healthy ecosystems, and also are important for local people. The high diversity and abundance of primates in the area make it a high conservation priority.
We strongly recommend protection of Southeastern Suriname to preserve its unique and diverse species, as well as its forest and freshwater resources. Protection of Southeastern Suriname will:
• Protect unique biodiversity that is found nowhere else,
• Conserve critical natural resources for the well-being of Suriname and the world,
• Guarantee perpetuity of Suriname´s freshwater resources - a prerequisite for economic activities (agriculture, energy, mining, oil) and human health (consumption, sanitation, transportation) - by protecting and conserving the headwaters of one third of Suriname’s Rivers,
• Mitigate global climate change through the conservation of large tracts of carbon rich tropical forest,
• Ensure sustainable flow of forest resources (e.g., food, medicines, building materials) and freshwater for the indigenous and Maroon communities in the interior of Suriname, and
• Maintain large-scale ecological processes and protect wide-ranging species and species vulnerable to climate change through establishment of a vast network of international conservation areas.
Protect the freshwater resources of Southeastern Suriname
Water quality and flows
Water quality of Southeastern Suriname is currently very high and typical for undisturbed aquatic ecosystems in Suriname’s interior. This region contains the headwaters of several of Suriname’s largest rivers, including the Marowijne, supplying much of the water used downstream for drinking, agriculture, energy, mining, sanitation, transportation, etc. Thus, maintaining high quality freshwater for the people and natural ecosystems of Suriname is essential for long-term sustainability. While the area may not be directly affected by mercury pollution from downstream sites, the RAP results show that it does receive atmospheric mercury deposition probably from trans-boundary sources. Protecting the headwaters of Southeastern Suriname and minimizing mercury pollution from neighboring countries will be important for safeguarding this source of clean freshwater and protecting human health.
Our findings also show that Southeastern Suriname will be disproportionately important for future water resources for the country. Watersheds in Southeastern Suriname are predicted to be more resilient to climate change than other parts of Suriname, where water scarcity could become a problem.
The fishes of Southeastern Suriname are a major food source for the local indigenous and Maroon communities. The primary threat to the fishes of the region is the Tapajai Project, which proposes to build one or more dams in the Tapanahony River in order to divert its water via Jai Creek to Brokopondo Reservoir and thus increase power generation by the hydroelectric station at Afobaka. The dam(s) would not only directly affect migratory fishes, fishes of running water and creek habitats and fishes downstream of the dam(s), but also effectively mix the fish faunas of the Marowijne River System and the Suriname River System, each with its own endemic species, likely leading to species extinctions. Local communities along the Tapanahony River should be extensively informed about the potential impacts of the Tapajai Project on their immediate environment so they can make rational, well-informed choices about their future with or without the Tapajai Project.
Conserving the forested headwaters and middle reaches of the Palumeu River will be important for maintaining food for people for many years to come. Large stretches of seasonally flooded forest and swamps predominantly occur in southern Suriname. These habitat types, as well as mountain headwaters, appear to provide important spawning grounds for a variety of fish species, including large migratory species which are one of the most important food sources for people throughout Suriname. The fishes of Palumeu River can also be of interest to the aquarium hobby and sport fishers and thus generate income for local people if catches are regulated.
Actions that should be taken to protect the fisheries:
1. Assess which fish species from the Palumeu River are used for food, determine the amount caught and eaten, and study their life histories to determine how fast they reproduce and grow
2. Determine the amount of fish that can be sustainably harvested, both for food fishes and aquarium fishes
3. Conduct more research to understand migratory fish behavior in Southeastern Suriname
4. Set catch limits and/or seasons if necessary to avoid overfishing
5. Create picture guides of fishes, especially colorful species and fun-to-catch fish species
6. Promote sustainable catch and export of aquarium fishes to generate local income and conservation incentives
Protect the unique habitats and biodiversity of Southeastern Suriname
Vegetation plot studies revealed that species composition of the forests in the South of Suriname is different from the North, and a small set of significant indicator species and genera were found for the South of Suriname. The RAP results indicate that forests on the Guiana Shield basement complex are not one uniform forest type as has been suggested. Some forest types like the tall dryland forests on laterite/granite hills are more dominant in the South of Suriname, and are floristically distinct.
The flora of southern Suriname is surprisingly varied, and contains at least sixteen distinct habitat types (see Chapter 1 this volume). The surroundings of the Grensgebergte and the Kasikasima Mountains contain several vegetation types that are dominant within southern Suriname and floristically distinct for this region. Within these vegetation types, we recorded nearly all of the fifteen new plant species and two new genera for Suriname we found during this study. Nine plant records including one genus new for Suriname were found in the hilly landscape and at higher elevations. The other six new plant records including one plant genus new for Suriname were found in seasonally flooded forest and swamp forest along the Palumeu River. We also recorded several species with a restricted distribution in Suriname and/or in the Guianas, orchids listed on Appendices I & II of CITES, some carnivorous plants and three tree species that are listed on the IUCN Red List. Amongst these is a unique palm species, Syagrus stratincola, which is only known from ten localities in the Guianas, and is listed as Vulnerable on the IUCN Red List. We also found the tree species Vouacapoua americana that is listed as Critically Endangered on the IUCN Red List. As plant collections from several plant families still await identification, we expect to find more new records or noteworthy species for Suriname. These findings indicate the pristine status of the forests and vegetation types in Southeastern Suriname and the fact that these forests are still poorly explored.
As with plants, the differences in species composition for most animal taxa between this expedition and the 2010 Kwamalasamutu RAP survey, combined with the high turnover between camps within Southeastern Suriname, suggest very high Beta diversity and species turnover within southern Suriname. Many species appear to be very localized or patchily distributed, which leads to high overall diversity over relatively small areas. Forests of southern Suriname and of the Guianas in general are often considered relatively homogenous, but our findings contradict this pattern. Because of this high heterogeneity, conserving a wide range of species requires conserving numerous large areas of forest that only superficially appear to be the same.
The findings of dozens of species new to science on both RAP surveys, while not unexpected given the paucity of collecting in the region, reinforces how much further we have to go before we have an understanding of the biological diversity of southern Suriname. The collection of eleven potentially new fish species in the Upper and Middle Palumeu River under unfavorable (high-water) conditions during the present study and the absence of many fish species from the rapids in the present collection both indicate a richer fish fauna in Palumeu River than the fish fauna that is currently known (128 species). In order to arrive at a more complete list of the fish fauna of Palumeu River the following actions are recommended:
• Additional scientific surveys are necessary to document the fish biodiversity at different times of the year, but especially when river levels are lower; and collection efforts should be aimed mainly at the major rapid complexes and the main river channel and tributaries in middle reaches of the Palumeu River.
• The 1966-collections of King Leopold III of Belgium and J.P Gosse from the Palumeu River (Table 8.2) should be studied.
The Grensgebergte area is quite pristine, and is visited only occasionally by the local people while they travel from the villages in southern Suriname to villages in Brazil. Hunting does not seem to pose a threat for the large and medium-sized mammals in the Grensgebergte area, because the area is so remote and very inaccessible. We found no signs of hunting or any other human disturbance. The large bodied primates (black spider monkey and red howler monkey) are present in relatively high abundance. They were either spotted or heard on a regular basis at both sites. Since these two species are the most hunted by local communities, this indicates sustainable hunting practices by these communities. Southeastern Suriname provides a refuge for many species that are heavily hunted in other parts of the Guiana Shield, as well as a source of food as these animals reproduce and disperse into hunted areas.
In the Kasikasima area there are more human activities than in the Grensgebergte area, such as ecotourism and some hunting by a small number (10–20) of people that live in Kampu. Kampu is a small settlement along the Middle Palumeu River a few kilometers downstream of the Papadron rapids. Currently the greatest potential threat for large and medium-sized mammals at Kasikasima would be hunting, but the results from the RAP survey show that hunting pressure is currently low. Nevertheless, the presence of species sensitive to hunting and disturbance such as Jaguar, Puma, Tapir, curassows and large primates also suggests that hunting pressure is low, and that the important ecological processes maintained by these species, such as seed dispersal and population regulation, remain intact. Dung beetles, which are often used as a rapid indicator of hunting pressure, also suggest low levels of hunting, since they were diverse and abundant during the survey. However, dung beetle species richness and abundance were still lower around Kasikasima than around Grensgebergte, reflecting these differences in hunting pressures.
Hunting is probably limited by reduced river access to some areas in the dry season, and more generally by distance from Palumeu and other villages. The absence of a market and the concentration of the indigenous people in Palumeu both reduce hunting pressure on large vertebrates in the region as a whole. The extensive surrounding forest acts as a source to offset local population depletion due to hunting. Nevertheless, the most significant current threat to medium-and large-bodied mammals in the area is hunting from Palumeu village. This could change if plans to build a road from northern to southern Suriname move ahead. A road would make the area accessible and hunting and habitat destruction would become important threats for large terrestrial vertebrates. Further plans to increase hydro energy capacity of the existing hydro lake in Brokopondo by diverting water from the Tapanahony River to the Jai Creek could be a threat if the project would take place, because a part of the area in South Suriname will be flooded. Aquatic mammals, such as giant otters, may be particularly vulnerable. More data on large mammal populations will be necessary to manage these possible future threats. Recommended studies include more camera trapping and a sustainability evaluation of wild bush-meat hunting to have better baseline data.
The value of extensive wilderness and ecosystem services
Southeastern Suriname is very important for wide-ranging species, such as large mammals, birds and fish because the area encompasses vast tracts of pristine forest and rivers. In fact, there are few places left on earth that are as pristine as Southeastern Suriname. Many large mammal and bird species have broad home ranges and can move freely across Southeastern Suriname in the absence of disturbance. Large migratory fish species move long distances to spawn. The area is also connected to protected areas in Brazil to the south and to a national park in French Guiana to the east. This makes Southeastern Suriname part of a large wilderness area, which is important to sustain genetic diversity within large mammal species, as well as other taxa such as reptiles and amphibians. The RAP sites are most likely acting as a corridor for gene flow through this region of the Guiana Shield. The presence of species that are rarely seen or were previously unrecorded in Suriname helps to substantiate that there is (or was) an historical connection between this and surrounding areas. Maintaining the pristineness of this corridor should be a priority for healthy ecosystem function and to maintain natural gene flow throughout the Guiana Shield.
This contiguous network of protected areas, with Southeastern Suriname at its center, also allows species to persist in the face of climate change by providing corridors for redistribution. This is especially important as many species are being forced to move upslope from the lowlands into the mountains as climate warms. In addition to helping species adapt to climate change, the extensive, intact and carbon-rich forests of Southeastern Suriname also help to regulate regional climate and mitigate global climate change.
Furthermore the area is important for the production of ecosystem services directly used by humans, such as water, food, medicines, recreation and lands of indigenous people (see Chapter 1 this volume). Since a large part of the rivers in Suriname originate in this area, protecting Southeastern Suriname guarantees flows of fresh water which is used for economic activities downstream such as transportation, hydro energy, agriculture and mining. The area also has a high potential for ecotourism, because of the beautiful pristine landscape and rich biodiversity, particularly of charismatic birds and mammals.
As one of the last remaining wilderness areas and a key provider of ecosystem services, we believe it is essential to protect Southeastern Suriname and the numerous benefits the region provides to people throughout Suriname and the world, avoiding threats from large-scale projects such as roads, mining and hydropower in this part of the country.