MUSSELp Funding from NSF

Evolution in a Vortex: An Inventory of the Fishes and Mollusks of the Lower Congo River Rapids

From Malebo Pool near the twin Congolese capitals of Kinshasa and Brazzaville, the Lower Congo River passes through the gorges of the Crystal Mountain region, dropping 280 m in elevation enroute to the Atlantic Ocean 350 km downstream. In this short stretch are found some of the most spectacular rapids on Earth, and a rich but poorly studied aquatic fauna. The proposal is to undertake a collaborative biotic survey of this poorly known region, concentrating on an inventory of freshwater fishes and their parasitic freshwater mussels. Other mollusks and selected aquatic invertebrates will be collected and worked up by the team and other authorities, enabling as complete a census of fish, mollusks and other invertebrates as possible. The region is logistically challenging, but preliminary field visits, in-country collaborators, and ongoing analysis of remotely sensed satellite data allow precise mapping of the rapids along the Congo mainstream, as well as providing information on the relative accessibility by road and by foot necessary to plan an effective collection strategy and identify priority areas for sampling. A central component of the collaboration between the American Museum of Natural History and Academy of Natural Sciences is educational outreach and student training; not only of American students and public, including a post-doctoral position, but also of Congolese researchers and students. The work will include faculty and students from the universities of Kinshasa (Democratic Republic of Congo) and Brazzaville (Republic of Congo), in the field and also by funding them to visit New York and Philadelphia to engage in ongoing training and collaborative research on this survey.

Intellectual merit. — The extraordinary hydrology of the Lower Congo represents a biohydrological model system for exploring underlying patterns of aquatic species richness and endemism in the region. With large collections of specimens and tissues it will be possible for the first time to use molecular phylogeographic methods to address some of the pressing questions concerning the evolutionary history and ecological interactions of aquatic organisms in the Lower Congo rapids as well as providing critical biodiversity data for conservation planning and global freshwater biodiversity assessments. It is hypothesized that the intermittent rapids mediate dispersal of organisms within the Congo mainstream, and may function as engines of diversification, driving allopatric speciation at a fine scale. Geospatial analyses and the specimens gathered will allow the team, and others, to investigate an array of evolutionary questions. Analysis of the structure of molecular variance across populations of species and among members of clades within and between rapids, based on multiple mitochondrial and nuclear loci will test the diversification hypothesis by revealing fine-scale patterns of gene connectivity, or a lack thereof. Additionally many of the Lower Congo River taxa will be incorporated into ongoing higherlevel phylogenetic studies thereby filling critical sampling gaps and enhancing resolution at the continental levels of analysis.

Broader impacts. —The spectacular and poorly known location of the Lower Congo River and the biological richness it harbors, combined with the growing threats to the region make this a compelling focus for scientific exploration and inventory in Africa. The projects freshwater focus brings an additional opportunity to underscore the tremendous importance of freshwater habitats as highly fragile reservoirs harboring extraordinary concentrations of biodiversity. A synergistic collaboration between US and Congolese scientists with potential to build lasting infrastructure and capacity support in Congo, and advancing training opportunities for US students in African biodiversity is proposed. Besides scientific papers on mollusk and fish biodiversity, evolution and biogeography for the community of systematic biologists interested in African faunas, the project provides other points of entry to data and synthesized results. Foremost among these will be an web site including an integrated geospatial database of taxonomy, fish-mussel/host-parasite relationships, specimen records and images for the species collected and those legacy records deposited in collections around the world. The web site will also serve to disseminate interactive taxonomic keys, integrating results in a context of greatest use to students, ecologists, conservation biologists and resource managers. By utilizing both traditional publication media, and the World Wide Web, the work will have a broad impact, indeed.

Non-technical abstract #1

This abstract is also available from NSF.

A grant has been award to Dr. Daniel Graf of the Academy of Natural Sciences in collaboration with Melanie Stiassny of the American Museum of Natural History to survey the diversity of freshwater mollusks (clams and snails) in the Lower Congo River of Western Africa. These organisms are of interest to biologists not only because they have interesting evolutionary histories but also as intermediate hosts of disease-causing parasites. The lowest reach of the Congo is punctuated by numerous powerful rapids, and it is expected that these cataracts constitute barriers to aquatic dispersal and therefore contribute to the endemic diversity of the area. Through sampling expeditions to the Lower Congo, the specimens collected for this research can be used to test hypotheses of evolutionary relationships and biogeographic processes, both at the population level and among species on a continent-wide scale. The result will be a clearer understanding of the origin and maintenance of biological diversity in western Africa. The data and conclusions generated by this research will not only be made available through traditional media but will also take advantage of modern means of dissemination, especially the internet (http://www.mussel-project.net/). An important component of the internet presence for this project will be the use of powerful database technology to provide searching and browsing interfaces into the data and conclusions, with multiple points of entry. The target audience for this research is not only scientists and conservation officials; these results will also serve teachers, students and all members of the public interested in better understanding their world. Besides providing a novel scientific perspective on an interesting, important but poorly known fauna, this study will also serve to train up-and-coming biologists including Congolese faculty and students through hands-on research experience.

Non-Technical Abstract #2

This abstract is also available from NSF.

A grant has been award to Dr. Melanie Stiassny and Robert Schelly of the American Museum of Natural History in collaboration with Dr. Daniel Graf of the Academy of Natural Sciences to study the diversity of aquatic organisms, particularly the fishes and freshwater mussels, of the Lower Congo River in west-Central Africa. The spectacular and poorly known location of the Lower Congo River and the biological richness it harbors, combined with the growing threats to the region make this a compelling focus for scientific exploration and inventory in Africa. In the study region the Lower Congo River is punctuated by some of the most spectacular rapids on Earth and the extraordinary hydrology of the river represents a model system for exploring underlying patterns of aquatic species richness and endemism. With large collections of specimens and tissues gathered in this study it will be possible for the first time to use molecular techniques combined with the latest developments in remote sensing technology to address some of the pressing questions concerning the evolutionary history and ecological interactions of aquatic organisms in the Lower Congo rapids as well as providing critical biodiversity data for conservation planning and global freshwater biodiversity assessments. For millions of Congolese living along the Lower Congo the health of these freshwater systems, and of the diverse communities of organisms that reside in them are of major importance. Increasing urbanization and agricultural activities have resulted in significant habitat destruction, yet the impacts of these factors on the region's freshwater fishes has not previously been studied or documented. In addition to basic survey and inventory a central component of the collaboration between the American Museum of Natural History and Academy of Natural Sciences is educational outreach and student training; not only of American students and public, but also of Congolese researchers and students. The project represents a synergistic collaboration between US and Congolese scientists with potential to build lasting infrastructure and capacity support in Congo, and advancing training opportunities for US students in African biodiversity. This award is cofunded by the Office of International Science and Engineering.