Malebo Pool Research Articles

Contribution to the study of parasites present in the digestive tracts and gills of the fish Distichodus maculatus (Boulenger, 1898) and Schilbe grenfelli (Boulenger, 1900) caught in the Malebo Pool (Congo River) at Kinshasa (D.R. Congo)

Les poissons prélevés dans des milieux contaminés constituent un danger sanitaire pour les consommateurs étant donné que, les poissons comme les autres produits de la pêche sont capables de transmettre à l'homme des infections microbiennes et parasitaires. Cette étude a pour objectif d’identifier les parasites présents dans les poissons Distichodus maculatus Boulenger, 1898 et Schilbe grenfelli Boulenger, 1900 pêchés dans le Pool Malebo (fleuve Congo). Les analyses ont porté sur les observations microscopiques des échantillons d’eaux du fleuve Congo et de poissons D. maculatus et S. grenfelli. Les résultats obtenus montrent que l’eau du fleuve Congo ainsi que les tubes digestifs et les branchies de poissons D. maculatus et S. grenfelli sont infestés par quatre espèces de parasites (Strongyloides stercoralis, Ascaris lumbricoides, Entamoeba coli et Trichurus trichiura). Parmi ces espèces de parasites identifiées, A. lumbricoides avec 15 cas positifs, E. coli avec 5 cas positifs et S. stercoralis avec 3 cas positifs ont été les plus observés dans les branchies et tubes digestifs des poissons D. maculatus et S. grenfelli. Afin de diminuer la charge parasitaire et réduire le risque d’infestation par les humains et les écosystèmes aquatiques, les autorités politico-administratives sont appelées à prendre des mesures adéquates pour limiter la pression sur les écosystèmes aquatiques et leur ressource dont les poissons. La bonne cuisson de poissons frais avant toute consommation reste la meilleure solution pour éviter une probable infestation par des parasites. Mots-clés: Endoparasites, tubes digestifs, branchies, Distichodus maculatus, Schilbe grenfelli, fleuve Congo, Pool Malebo, Kinshasa

Brittle faulting and tectonic stress history on the western margin of the Congo Basin between Kinshasa and Brazzaville: Implications for the evolution of the Malebo Pool and the Congo River

The history of brittle faulting and associated paleostress states has been investigated in the rapids of the Congo River at the outlet of the Malebo Pool between Kinshasa (Democratic Republic of the Congo) and Brazzaville (Republic of the Congo). The aim of this study was to unravel the Meso-Cenozoic tectonic evolution of the western margin of Central Africa, as well as to investigate the dynamic evolution of the Pool and the capture of the Congo Basin drainage system by the Lower Congo River through the Central African Atlantic swell that formed between the Congo Basin and the Atlantic Ocean. We reviewed the geological evolution of the Pool area using recent data and new field observations to develop a consistent stratigraphic model for both sides of the Congo River. We collected a significant amount of data faults and fractures in the early Paleozoic Inkisi arkosic sandstones, identified four successive data subsets and determined their related paleostress tensors trough an iterative process utilizing relative chronological indications. All paleostress states exhibit a a strike-slip faulting regime, with varying orientation of horizontal principal compression. The timing of faulting was constrained by indirect observations based on the updated understanding of the Pool's evolution. The geodynamic interpretation of the brittle stages considered potential sources of compressional stress arising from plate boundaries and from the oceanic ridge push. A polyphase brittle tectonic history was identified, characterized by the gradual appearance of newly formed faults and reactivation of the existing ones, leading to the gradual saturation of the host rock with fractures. The most recent event let to a significant imprint on the current landscape and is believed to have facilitated the connection of the drainage system of the Congo Basin to the Atlantic coast in the Oligocene period. The current stress state, determined from earthquake focal mechanisms, aligns with the most recent paleostress state identified determined from fault-slip data, displaying similar stress axis orientations but with consistent with a transpressional stress regime instead of a strike-slip one.

IDENTIFICATION OF INVASIVE ALIEN SPECIES AND ASSESSMENT OF ECOLOGICAL FACTORS IN THE POOL MALEBO IN KINSHASA, DEMOCRATIC REPUBLIC OF THE CONGO

The aim of this study was to identify invasive aquatic species and assess ecological factors in 5 islands, namely Mipongo, Japon, Kabongo, Kingabwa and Molondo.of the Pool Malebo. A floristic inventory was conducted around these sites and physico-chemical characteristics were measured in each island between 8:00am and 3:00pm using an appropriate electronic probe. The floristic affinity between sites was determined by cluster analysis using MVSP software version 4.03, after highlighting the Jaccard's coefficient based on the presence/absence of species in the different collection sites. The comparison between the sites was carried out using the ANOVA test with SPSS 25 software for physico-chemical parameters. The findings show that 24 species were identified as invasive out of which, six were dominant, namely Eichhornia crassipes, Echinocloa pyramidalis, Pistia stratiotes, Leersia hexandra, Ludwigia abissinega, and Ludwigia sp. No significant differences were observed for the temperature (F=0.42 and p=0.66), conductivity (F=1.55 and p=0.25) and turbidity (F=2.28 and p=0.14) for the three sites. While the pH (F=4.98; p=0.026; LSD=0.361), dissolved oxygen (F=12; p=0.001; LSD=3.65) and salinity (F=4.06; p= 0.04; LSD= 1.69) showed significant variation in the three sites. The formation of vegetation groups around these islands in the Pool Malebo would also be justified by the influence of these parameters. The spread of invasive alien species on the surface of the river needs to draw more attention to scientists, policy makers and government in order to find a way to a good management of these species.

Sustainable exploitation and participative conservation of Mormyridae fishes in the Malebo Pool, Congo River, Kinshasa

Sustainable exploitation and participative conservation of Mormyridae fishes in the Malebo Pool, Congo River, Kinshasa

Converging on Cannibals: Terrors of Slaving in Atlantic Africa, 1509–1670

Converging on Cannibals: Terrors of Slaving in Atlantic Africa, 1509–1670

Localization and Distribution of Two Invasive Alien Species Eichhornia crassipes and Echinocloa pyramidalis in the Pool Malebo Eco-region, Democratic Republic of the Congo

Aim: To study the distribution of two invasive alien plants and associated plants as well as their distribution in the Malebo Pool eco-region.
 Methodology: The study was carried out by direct observation by circulating on a motorized canoe. Plant samples were randomly harvested (n=6) in August 2020 depends on the sites. Plant species identification was performed on the field, and those species of which the identification was difficult, were brought to the laboratory for proper identification according to APG III.
 Results: 19 species, including two Pteridophytes and 17 Angiosperms, belonging to 19 families and 12 orders were identified. The site of Molondo was the most diversified with 15 plant species, followed respectively by the sites of Mipongo (13 species), Japon (12 species) and Kingabwa (07 species). The plant species Ludwigia abyssinica A. Rich., Ipomoea aquatica Forsk, Eichhornia crassipes (Mart), Pistia stratiotes L, Echinochloa pyramidalis (Lam) and Salvinia molesta D.S. Mitchell were present in all four prospected sites. E. pyramidalis and E. crassipes constitute a serious threat for the environment and are source of erosion/loss of aquatic biodiversity. Physiologically, these species form a mono-specific carpet and eliminate native or autochthonous species of aquatic flora.
 Conclusions and Suggestions: The invasion of alien species is a consequence of human activities and a concern, as it affects all sectors of society. These plants can alter, disrupt, and degrade many ecosystem services like the disturbing of habitats and the alteration of the environmental and biological conditions around them. They can also reduce light and diversity of native aquatic plant species. Controlling invasive alien species is thus a challenge for the Congolese society. Political decision-makers are therefore invited to take appropriate measures for managing and protecting the local aquatic flora and valorize the invasive plants as potential medicinal remedy.

English

The current anarchic exploitation of Marcusenius fish in the Malebo Pool located in the Congo River stands as a threat of extinction to certain species, while the ecology of most of them are hardly known. This study aims at evaluating the impact of environmental factors on the distribution of Marcusenius fish caught in six fishing stations in the Malebo Pool. Canonical correspondence analysis of environmental factors classified the stations into two groups, which differ in vegetation formation, bottom substrates, water current velocity, pH, suspended particles and in dissolved oxygen. Thus, the five stations located upstream and in the middle of the pool are characterized by low water current velocity, slightly acidic pH, bottom substrates composed of silt, plant debris, clay, silt and sand. The predominant Echinocloa and Eichhornia plant formations found in these sites provide shelter, food sources and impact on the distribution and abundance of seven Marcusenius species in Malebo pool. The rocky substrate of Kinsuka station associated with the plant formation dominated by Ledermanniella and Pennisetum, and a high-water current constitute a habitat that is not favourable for Marcusenius species.   Key words: Abundance, ecology, flora, Marcusenius, fishing, substrate, Malebo Pool.

Contribution to the Knowledge of Freshwater Shrimps (Crustacea, Decapoda) and Their Spatial Distribution in the Malebo Pool (Congo River), R.D Congo

Background and Objective: Crustaceans play a considerable role in the ecological process of aquatic ecosystems, acting at different trophic levels as herbivores, detritivores, predators and prey and constitute an important source of animal protein for humans and livestock. This study investigated the diversity of shrimp from the left bank of the Malebo Pool in the Congo River.
 Study Area: Five sampling campaigns were organized from July 2020 to August 2021 in six sites (Ngamanzo 1, Ngamanzo 2, Kinkole 1, Kinkole 2, Kinsuka 1 and Kinsuka 2) in the Malebo Pool, the terminal part of the middle Congo River.
 Methods: Shrimp samples were collected using dip nets and creels during the experimental fisheries. Physical parameters were measured monthly in situ at six sites. Chemical parameters were assessed using an ultraviolet atomic spectrophotometer. Systematic identification of shrimp was done using appropriate systematic identification keys. The structure of the shrimp populations was studied using several ecological indices.
 Results: A total of 1422 shrimp specimens were sampled. These individuals belonged to three different species (Caridina africana Macrobrachium dux and Macrobrachium sollaudii), two genera (Caridina and Macrobrachium) and two families (Atyidae and Palaemonidae). Shanon and Weaver's diversity index values ranged from 0 to 1.3 indicating that the shrimp fauna is not diverse in Malebo Pool. These species are better represented at Ngamanzo 1, Ngamanzo 2 and Kinkole 2. Redundancy analysis (RDA) showed that environmental variables such as dissolved oxygen level, conductivity, water temperature, transparency, water flow velocity, plant debris, aquatic plants and canopy strongly influence taxonomic diversity across sites.
 Conclusion: The results obtained showed that the shrimp fauna is rich and diversified in the studied part of the Malebo Pool in the Congo River and, these organisms are essential in maintaining the ecological balance in this aquatic ecosystem.

Study of the population structure of decapod crustaceans in the Pool Malebo in Kinshasa (DR Congo)

The study of the population structure of crustaceans was undertaken during the period from June to September 2019, in the Pool Malebo. A total of 467 individuals were collected. These specimens were divided into 3 families, 3 genera and 4 species. Several biotic indices were used to study the structure of the population on the one hand, and its diversity on the other. Gross abundance, relative frequency, species richness, diversity of Shannon-Weaver and equitability of Piélou were calculated. The evaluation of these indices in the different stations showed that there is a parallelism between them. The highest gross abundance of crustaceans in the Pool Malebo was observed in M. sollaudiis (224 individuals which accounted for 47.9% of the total abundance. It was followed by C. africana, C. togoensis and Soudanautes sp. which accounted for 145, 59 and 39 individuals respectively, i.e. 31.1%, 12.6% and 8.3 of the total catch. The distribution of crustaceans is largely influenced by the physical and chemical quality of the water (dissolved oxygen, temperature, pH, conductivity, nitrate, etc.).

Ecological Characterization of Invasive Alien Species and Associated Abiotic Factors of Three Islands in the Pool Malebo in Kinshasa, Democratic Republic of the Congo

Nowadays, invasive alien species are causing more and more environmental problems in several water bodies around the world, in Africa and in the Democratic Republic of the Congo. In October 2020, a floristic inventory was carried out around three islands of the Congo River (Molondo, Mipongo and Japon) at the Pool Malebo in Kinshasa. The study focused on the identification and behavior of alien species along with associated abiotic factors in the Malebo Pool of the Congo River in Kinkole, Kinshasa.
 The study used a simple random sampling design to select different sites where samples were collected after a direct observation. We collected invasive species in the middle of the Congo River and to achieve that, we used canoe depending on the location of each site. Recorded species were classified either alien species or invasive alien species according to the status in the study region. The identification of collected species was performed according to APG III. Seeing the way these species invade the environment and how they disturb the ecology of rivers, the physico-chemical characteristics of waters were measured between 8:00 am and 3:00 pm with the appropriate electronic probe for each parameter. For each parameter, the comparison between the sites was carried out using the ANOVA test with XLSTAT 2013 software.
 The findings show that 19 species have been identified as invasive alien species out of which, four were dominant, namely Echinochloa pyramidalis, Eichhornia crassipes, Salvinia molesta and Pistia stratiotes. Considering the physico-chemical parameters, no significant differences were observed for the temperature (F=0.42 and p=0.66), conductivity (F=1.55 and p=0.25) and turbidity (F=2.28 and p=0.14) for the three sites. While the pH (F=4.98; p=0.026; LSD=0.361), dissolved oxygen (F=12; p=0.001; LSD=3.65) and salinity (F=4.06; p= 0.04; LSD= 1.69) showed significant variation in the three sites. The formation of vegetation groups around these islands in the Congo River at the Pool Malebo in Kinshasa would also be justified by the influence of these parameters.

Temporal Variability of Sediments, Dissolved Solids and Dissolved Organic Matter Fluxes in the Congo River at Brazzaville/Kinshasa

For three decades, the solid and dissolved fluxes of the Congo River have been regularly monitored on a monthly basis, despite 12 years of deficiencies (1994–2005). Two programs successively carried out these follow-ups: PEGI/GBF (1987–1993) and SO HYBAM (2006–2017), upstream and downstream, respectively, of the Malebo Pool near Brazzaville, the main hydrometric station of the Congo River. The objective of this study is to examine the temporal dynamic of TSS, TDS and DOC, to explore how these descriptors change over time. Comparison with the two time programs will shed more light on how these descriptors are related to discharge. Afterward, we then find a relationship between total TSS in the water column and that measured in surface for eventual estimation of TSS by remote sensing. In the last decade, compared to the PEGI/GBF period, the discharge of the Congo River was mainly marked by a 4% increase, leading to a significant change on TDS and DOC behaviors. The TSS was quite stable (from 8.2 and 9.3 t km−2 yr−1) due to the low physical erosion well known in this region. The TDS concentrations decreased slightly, by a simple dilution effect. However, the mineral dissolved fluxes (from 11.6 and 10.1 t km-2 yr-1) due to the chemical weathering and atmospheric inputs still predominate over the solid fluxes. Therefore, there was no radical change in the monthly geochemical regime of Congo River Basin (CRB) during these last 30 years. Contrariwise, the DOC concentration marking the biogeochemical processes significantly increased, from 9.0+/−3.0 mg L−1 to 12.7+/−5.0 mg L−1, due to more flooding events in the central part of the CRB. The change for the DOC fluxes is more relevant, with an increase of 45% between the two studied periods, from 11.1 × 106 to 16.2 × 106 t yr−1. This highlights the continuous and actual importance of the “Cuvette Centrale” in the heart of the CRB for dissolved organic matter transport by the Congo River.

Human Endoparasites Present in the Digestive Tracts of Two Species of Cichlidae Fish: Oreochromis Niloticus (Linnaeus, 1758) and Tilapia Tholloni (Sauvage, 1884) Caught in the Malebo Pool (Congo River), D.R. Congo

Parasitic diseases of fish are very rarely highlighted in comparison with certain parasitic diseases transmitted to humans through animals or plants such as echinococcosis, bilharziasis or fasciolosis. The aim of this study is to provide knowledge on endoparasites of the human digestive tract that also infest the digestive tracts of two species of Cichlidae fish: Oreochromis niloticus Linnaeus, 1758 and Tilapia tholloni Sauvage, 1884 caught in the Congo River (Malebo Pool). Microscopic observations were made on 42 specimens of O. niloticus fish and 42 of T. tholloni. The results obtained showed that the digestive tracts of fish Oreochromis niloticus host 8 species of parasites grouped in 6 genera, 6 families, 4 classes and 2 branches. The species belonging to the phylum Nemathelminths branch were more abundant (58.8%) than Plathelminths (41.2%). Species Trichurus trichiura (23.5%), Ascaris lumbricoides (20.6%), Strongyloides stercoralis (14.7%), Schistosoma haematobium and Schistosoma intercarlantum (11.8%) were the most frequently observed. On the other hand, microscopic analyses of the digestive tract of Tilapia tholloni revealed the presence of five species of parasites belonging to 3 branches, 4 classes, 4 families and 4 genera. Nemathelminthes (58.3%) and Plathelminthes (25%) are the most represented phylum than Amoebians (16.7%). Enterobius vermicularis (33.3%), Trichocephalus trichuris (25%), Schistosoma haematobium (20.8%) and Entemoeba hystolica (16.7%) were frequently observed. These results confirm the presence of endoparasites in congolese freshwater fish. This information is important in setting up a strategy to protect fish and consumers against these pathogens.

Floristic Inventory of Invasive Alien Aquatic Plants Found in Some Congolese Rivers, Kinshasa, Democratic Republic of the Congo

Aim: To identify invasive aquatic alien plant species found in the Pool Malebo and some rivers in Kinshasa city, their behavior as well as their socio-economic impacts.
 Study Design: The study used a combination of purposive sampling and simple random sampling in order to select different sites where samples were collected.
 Place and Duration of Study: This study was carried out in different rivers (Pool Malebo system (Kinkole, Kingabwa), and N'sele, Funa and Lukaya rivers) of Kinshasa city in Democratic Republic of the Congo. The Pool Malebo is located along the Congo River. This was conducted between March and October 2013.
 Methodology: The collection was performed after a direct observation. The location of collection depended on sites, at Kingabwa and Kinkole, we collected invasive species in the middle of the Congo river and to achieve that, we used canoe. While at N’sele, Lukaya and Funa rivers, samples were collected at the edges. The collection took place in the morning between 7 and 11 am. Recorded species were classified either alien species or invasive alien species according to the status in the study region. The identification of collected species was carried out according to APG III. Seeing the way these species invade the environment and how they disturb the ecology of rivers, the physico-chemical characteristics of waters were measured between 7:00 and 11:00 am with the appropriate electronic probe for each parameter. For each parameter, the comparison between the sites was carried out using the ANOVA test with XLSTAT 2013 software.
 Results: Out of 151 specimens collected, 35 species have been identified of which 19 species as alien were identified and 4 proved to be invasive alien species, namely: Eichhornia crassipes, Echinochloa pyramidalis, Ludwigia peploides and Pistia stratiotes. These invasive species are used by farmers as livestock feed and also as green manure for different agricultural and farming activities, As to the physico-chemical characteristics, no significant differences were observed for the temperature and the turbidity in various sites while the pH and conductivity, there was a highly significant difference between different sites. The hydrology of these rivers is seriously disturbed due to the presence of these invasive alien species. These species constitute a serious threat in the erosion of aquatic biodiversity in the removal of native species in the formation of floating monospecific dense mats as observed.
 Conclusion: The invasion of alien species is a consequence of human activities and a concern, which affects all sectors of the society. It constitutes a true challenge for ecologists, economists, social scientists, agricultural engineers, environmentalists and other in order to develop and implement strong risk analysis frameworks and environmental impact assessments.

Spatio-temporal structure of fish communities Mochokidae (Ostariophysi, Siluriformes) in the Malebo Pool, Congo River (Democratic Republic of the Congo)

At the level of Malebo Pool of the River Congo, ecological studies of Mochokidae fish communities are non-existent. This study was carried out monthly from July 2009 to October 2010, and bimonthly from March 2011 to August 2013 through experimental fishing in seven lotic and lentic stations to specify the spatio-temporal structure of these relatively abundant fish. Multivariate analysis (Canonical Redundancy Analysis) of Mochokidae stands and their habitats show segregation of species between lotic and lentic areas. The lotic habitats (Nganda Mabanga and Ile Mimosa) are colonised by species such as Chiloglanis congicus, Euchilichthys guentheri, Synodontis brichardi, Synodontis longirostris and Synodontis ornatipinnis that are located in rocky substrates with high current speed. Lentic habitats (Ngamanzo-Japon-Mipongo-Molondo-Kingabwa complex) are colonised by other species such as Synodontis acanthomias, S. decorus, S. alberti, S. notatus, S. congicus, S. caudalis, S. soloni, S. pleurops, S. nummifer and S. contractus that live in muddy and sandy substrates with submerged vegetation and weak current. The study aims to contribute towards better management and conservation of the aquatic ecosystem, specifically the habitat of the Mochokidae species, in light of the negative impacts of human developments in the Democratic Republic of the Congo.

Environmental Influences on Fish Species Distribution in the Musolo River System, Congo River Basin (Democratic Republic of the Congo, Central Africa)

Ichthyofaunal distribution was studied in the Musolo River system, a small affluent tributary of the Congo River flowing into Pool Malebo (Democratic Republic of the Congo). Twelve ecological stations were sampled, of which eight were located in the Musolo main-channel and four in the Fushi River, a principal tributary of the Musolo. Each station was sampled four times over a two-year period, with fishing techniques following standardized methods utilizing dip and cast nets, and nine environment variables were measured at each station. Fifty-three fish species belonging to 36 genera and 16 families were collected with the Alestidae, Distichodontidae, Cichlidae, Cyprinidae, Mormyridae, and Mochokidae being the most diversified. Redundancy Analysis with forward selection coupled with Monte Carlo permutation tests (499 permutations) identified total dissolved solid (25.8%) and altitude (24.4%) as accounting for 50.2% of total variance (p < 0.05). The contribution of the two first axes was significant (F = 3.41; p = 0.004). Species richness increases from upstream to downstream. In general, the high value of Shannon’s diversity (1.07-2.67) and Equitability (0.62-0.96) indices at all sites, indicates that the examined stretch of the Musolo River system is in good ecological health, despite its location adjacent to the megacity of Kinshasa.

Riverbank Erosional Features in the Stanley Pool of the Congo River and Some Geotechnical Classifications of the Sands

The Stanley Pool, an almost circular island about thirty kilometers in diameter, crossed by the Congo River, is subject to diversified erosion of its riverbanks. This study highlights description using geotechnical particle size distribution analysis of soils of the shoreline that make up the shoreline. Three critical areas of the island were examined to characterize the origins of these erosion phenomena. The results obtained show that the soil materials are mostly sands with very fine or fine grains characteristic of very unstable soils. The morpho-sedimentological characteristics of the areas studied show that these soils are plastic (with a Plasticity Index between 15 percent and 19 percent). The presence of water, action of currents or groundwater flow easily destabilize the materials that make up the riverbank and cause the fines to creep (Collapse of sandy riverbanks, Landslide of sandy riverbanks, …).

Discovery of dinosaur footprints in the Stanley Pool Formation of Gabon

ABSTRACT Stanley Pool is a Cretaceous continental formation which outcrops Southeast of Gabon to Congo. The current investigations performed in this continental formation in Gabon just revealed seven dinosaur footprints on pieces of argillites flags. The analysis of these more or less well preserved footprints highlights three morphotypes. Morphotype 1 comprises footprints 1, 2, 3 and 4 of the same shape but of different sizes. These footprints belong to tridactylous dinosaurs. Morphotype 2 comprises footprints 5 and 6 whose shape is oval. They would correspond to sauropods. Finally morphotype 3 only represented by the footprint 7 consists of four fingers. This well-preserved footprint would belong to a tetradactylous dinosaur. This major discovery is the first record of dinosaurs in Gabon. It strengthens the knowledge of dinosaurs palaeoichnology in Africa.

Henry Morton Stanley and Emin Pasha: New Historical Sources for Heart of Darkness

Henry Morton Stanley and Emin Pasha:New Historical Sources for Heart of Darkness Jeffrey Meyers (bio) In 1885, Emin Pasha, the German-born, Turkish-titled governor of Equatoria—the southernmost province of the Egyptian Sudan, on the upper reaches of the Nile—had acquired an enormous treasure of ivory, worth as much as £60,000, but was cut off from the outside world. The Moslem rebel who called himself the Mahdi, or Messiah, had captured Khartoum, killed the governor of the Sudan, General Charles Gordon, and publicly exhibited his severed head. The British explorer and adventurer Henry Morton Stanley (1841–1904) had achieved international fame in 1871 by finding a distinguished medical missionary in Central Africa and greeting him with the understated query, "Dr. Livingstone, I presume?" He wanted to repeat this astonishing achievement by rescuing Emin Pasha. From 1879 to 1884, Stanley had been the principal agent in developing King Leopold II's privately owned and notoriously brutal Congo Free State, which was seventy-six times larger than his Belgian kingdom. Stanley explored the vast region, built roads, launched steamships, and duped the local chiefs into signing, with an X, extortionate treaties in a language they could not understand. Stanley could have taken the more direct route from British East Africa. But King Leopold, whose greed was insatiable, insisted that Stanley, still under contract to the king, take the longer and more dangerous west-to-east route along the Congo River. The king hoped to seize more unknown territory and even absorb Equatoria itself. Stanley and his ten British officers started out in Cairo in January 1886, stopped in Zanzibar to pick up hundreds of Arab porters, and sailed around the Cape of Good Hope. He entered the Congo at the quaintly named Banana, situated on the coast and at the mouth of the river, then trekked through the primeval jungle to Boma, Matadi, and Leopoldville, next to the widening of the river at a place he'd previously named Stanley Pool. For the next thousand miles, from Stanley Pool to Stanleyville, near the seven cataracts at Stanley Falls, he navigated the river by steamboat, which had been carried in sections and reassembled for the journey. Stanley began with more than 700 men and lost more than 500. [End Page 77] The expedition suffered from the burning climate, heavy burdens, exhausting marches, lack of food, near starvation, numerous desertions, virulent disease, hostile tribes, and frequent deaths. Stanley had left a severed head hanging from a tree to warn the Africans not to resist his depredations when he came back. Arthur Jephson, one of Stanley's gentlemanly officers, developed an intense loathing for the river: "One hates it as if it were a living thing—it is so treacherous & crafty, so overpowering & relentless in its force & overwhelming strength" (Liebowitz 171). Jephson wrote that when two of his African followers were wounded in battle and clearly dying, they "looked at me with doglike eyes, like suffering animals. And I felt sickeningly sorry for them & awfully choky" (Liebowitz 116). Stanley masked commercial rapacity as a mission of mercy and made efficient use of the Maxim gun that could shoot 330 rounds a minute. As Hilaire Belloc wrote of British firepower, "Whatever happens we have got / The Maxim gun and they have not" (Belloc, IV). Stanley burned villages, killed unarmed Africans, inflicted severe lashings, beat some porters to death, executed deserters, captured Africans, sold them as slaves, and served them as human sacrifices to starving cannibals. The man-eaters removed the internal organs of their victims, stuffed them with bananas and barbecued them over a fire. Jephson also reported, with grisly detail, "Opposite my hut is a large dead bough stuck in the ground & garnished with skulls & bones, some of them are not picked clean, the natives had not eaten all the meat off them" (Liebowitz 121). The British saw cannibal feasts as the essence of primitive barbarism and justification for conquest, though many myths and plays suggest that this custom had also been practiced in ancient Greece. In The Iliad, Homer wrote that Achilles had a tremendous desire to carve up Hector's flesh and devour it: "I wish only that my...

Organic matter characterization and distribution in sediments of the terminal lobes of the Congo deep-sea fan: Evidence for the direct influence of the Congo River

The terminal lobe complex of the Congo River submarine fan sits on the abyssal Atlantic plain, at 5000m water depth, 760km offshore from the river mouth estuarine area. While most rivers deliver particulate material to the continental shelf, particulate matter from the Congo River largely bypasses the shelf and is transported by turbidity currents through the Congo submarine canyon system. We determined the quantity and quality of the organic matter reaching the terminal lobe complex at five sites with marked morphological differences that may influence the distribution of organic matter. A suite of bulk geochemical (% OC, δ13Corg, δ15N, C: N), 137Cs and palynofacies analyses were done on cores collected from the terminal lobe area. These results were also compared to the composition of sediments collected upstream at the Malebo Pool (Congo River).Distal lobe complex sediments contain high amounts of terrestrial organic carbon (3–5wt.%) that is homogeneously distributed in surficial (22cm) and deeper sediments (580cm) silty–clay facies. Strongly altered soil-derived organic matter with well-preserved land plant detritus from the Congo River predominates. A terrestrial soil origin for the particulate load was confirmed by the elevated 137Cs activity in lobe sediments. The vertical distribution of the 137Cs signal suggests that there has been a massive arrival of terrestrial sediments since 1963, consistent with a turbiditic origin. From the locations surveyed, we estimate a maximum accumulation of terrestrial organic carbon of ca. 1kg OC m−2 y−1 for the distal lobe. However, transport modifies the organic matter both in terms of quantity and quality. Observed differences were attributed to preferential degradation of nitrogenous matter during diagenesis and to the addition of highly remineralized marine organic matter.Results from our temporal reference site (E) suggest that organic matter may be preserved in turbidite facies for thousands of years. The good preservation state of the accumulated organic matter shows that turbiditic lobe complexes should be considered as a sink for terrestrial organic carbon in the deep ocean.

Trace metal distributions in the sediments from river-reservoir systems: case of the Congo River and Lake Ma Vallée, Kinshasa (Democratic Republic of Congo).

The contamination of drinking water resources by toxic metals is a major problem in many parts of the world, particularly in dense populated areas of developing countries that lack wastewater treatment facilities. The present study characterizes the recent evolution with time of some contaminants deposited in the Congo River and Lake Ma Vallée, both located in the vicinity of the large city of Kinshasa, capital of Democratic Republic of Congo (DRC). Physicochemical parameters including grain size distribution, organic matter and trace element concentrations were measured in sediment cores sampled from Congo River (n = 3) and Lake Ma Vallée (n = 2). The maximum concentration of trace elements in sediment profiles was found in the samples from the sites of Pool Malebo, with the values of 107.2, 111.7, 88.6, 39.3, 15.4, 6.1 and 4.7mgkg(-1) for Cr, Ni, Zn, Cu, Pb, As and Hg, respectively. This site, which is characterized by intense human activities, is especially well known for the construction of numerous boats that are used for regular navigation on Congo River. Concerning Lake Ma Vallée, the concentration of all metals are generally low, with maximum values of 26.3, 53.6, 16.1, 15.3, 6.5 and 1.8mgkg(-1) for Cr, Ni, Zn, Cu, Pb and As, respectively. However, the comparison of the metal profiles retrieved from the different sampled cores also reveals specific variations. The results of this study point out the sediment pollution by toxic metals in the Congo River Basin. This research presents useful tools for the evaluation of sediment contamination of river-reservoir systems.