Pollution and Foraging Behavior of Pied Kingfisher Ceryle rudis in Bujumbura Bay of Lake Tanganyika, Burundi: Conservation Implications

Lake Tanganyika is threatened by overfishing, deforestation, climate change and water pollution. Very few studies have investigated the effects of pollution on semi-aquatic communities such as aquatic birds. This study investigates the effects of pollution on the foraging behavior of pied Kingfisher Ceryle rudis in the Bujumbura bay of Lake Tanganyika. We use data on foraging behavior of this bird species collected in 2002 as background and data collected over two periods during which we assessed change in water environmental parameters. The sampling site is located in the littoral zone next to the channel mouths that collect rainfall and wastewater from Bujumbura city. The results show a change in the number of observations of foraging pied kingfishers during the course of the day with a significantly lower number of observations in the morning than in the study carried out in 2002. The most frequent foraging behavior also changed from direct dives in 2002 to repeated hovering before diving in 2016. These changes could be accounted for by pollution as the water parameters data collected during the same time periods reveal an increase in turbidity while dissolved oxygen levels dropped. Increased turbidity may have caused reduction of visibility of these visual predatory birds. Attention should be given to measures toward alleviation of pollution of Lake Tanganyika for the conservation of semi-aquatic communities which are members of this deep and ancient lake ecosystem

Les poissons du bassin de la rivière Ulindi, à l’Est de la République Démocratique du Congo : revue de la littérature

Cette revue de la littérature sur les poissons du bassin hydrographique de la rivière Ulindi à l’Est de la République Démocratique du Congo a été réalisée dans le but d’avoir une idée sur l’état des connaissances actuelles de son ichtyofaune en vue de définir les orientations pour leurs études ultérieures dans cette région non encore prospectée en profondeur et dont la plupart des rivières se trouvent actuellement menacées par des activités anthropiques. Cette étude présente une vue globale des rivières du Bassin de la rivière Ulindi avec une liste systématique non exhaustive d’environ 31 espèces de poissons appartenant à 17 genres, 9 Familles et 4 ordres, basée sur la méta-analyse des différentes études taxonomiques de l’ichtyofaune du Bassin de la Rivière Ulindi, réalisées depuis l’époque coloniale du Congo-Belge jusqu’en 2019. Les résultats de cette étude constituent une aide-mémoire pour les services publics en charge de la gestion de l’environnement dans la gestion de la biodiversité ichtyologique de cet écosystème à intérêt socio-économique considérable dans la région, d’une part et une liste de contrôle aux scientifiques pour des études ultérieures.Mots clés : Ichtyofaune, Ulindi, République Démocratique du Congo, revue de la littérature, liste de contrôle.   English Title: Fishes from the Ulindi river basin, East of the Democratic Republic of Congo: review of the literatureThis review of the literature on fish in the Ulindi river basin in the east of the Democratic Republic of Congo was carried out with the aim of gaining an idea of the state of current knowledge of its fish fauna in order to define guidelines for their further studies in this region not yet explored in depth and most of the rivers of which are currently threatened by anthropogenic activities. This study presents a global view of the rivers of the Ulindi river basin with a non-exhaustive systematic list of approximately 31 fish species belonging to 17 genera, 9 Families and 4 orders, based on the meta-analysis of the various taxonomic studies of the ichtyofauna of the Ulindi river basin, carried out since the colonial times of the Belgian Congo until 2019. The results of this study constitute a baseline for the public services in charge of environmental management in the management of the ichthyological biodiversity of this ecosystem with considerable socio-economic interest in the region, on the one hand and a checklist to scientists for further studies.Keywords: Ichtyofauna, Ulindi, Democratic Republic of Congo, literature review, checklist. &nbsp

Reproduction de Bagrus bajad (Fabricius, 1775, Bagridae) du Lac Albert, Bassin du Nil, République Démocratique du Congo (RDC)

Le Bagrus bajad figure parmi les espèces des poissons très pêchées dans les cours d’eau tropicaux d’Afrique dont les informations sur la reproduction sont rares. Quelques paramètres de reproduction de Bagrus bajad du Sud-ouest du Lac Albert ont été étudiés durant cette recherche. Les échantillons ont été collectés entre décembre 2019 et décembre 2020 au moyen des éperviers, des palangres et des filets maillants de maille standard (20,2, 25,4 et 30,5 mm). Au total, 520 spécimens dont 283 femelles et 237 males ont été étudiés. Les informations sur le sex-ratio, le stade de maturité sexuelle, le rapport gonadosomatique, le rapport hepathosomatique, la fécondité et le facteur de condition ont été analysés. L’étude a révélé l’égalité entre les mâles et les femelle parmi les individus, même si les femelles étaient supérieurs aux mâles (1: 0,84; p-value<0.05). Tous les poissons étudiés ont présenté tous les stades de maturité sexuelle (I, II, III, IV, et V). Les matures (III, IV et V) ont une plus grande proportion (III, IV et V) par rapport aux immatures (I et II). Les mâles ont une taille de première maturité sexuelle de 43.5 cm contre 44 cm pour les femelles. Les valeurs mensuelles des indices gonadosomatiques et celles des stades gonadiques macroscopiques prouvent que B. bajad a trois périodes de fraie au cours de l’année : (i) Janvier-Avril ; (ii) Juin-Août et (iii) Octobre-Novembre alternées par une période d’un mois de repos en mai, septembre et décembre. La fécondité absolue est de 525 à 34440 ovocytes mais n’est pas significativement corrélées avec la longueur totale (R2=0,002) et le poids (R2=0,12). Les connaissances de la présente étude constituent une base fondamentale pour assurer la surveillance des risques d’épuisement du stock potentiel cette espèce et orienteront les décideurs à développer des politiques et stratégies efficaces garantissant l’exploitation et la conservation rationnelle de cette espèce.   Bagrus bayad is one of the highly fished fish species in tropical African rivers for which information on reproduction is scarce. Some reproduction parameters of B. bayad from the southwest of Lake Albert were studied. The samples were collected between December 2019 and December 2020 using cast nets, longlines, and standard mesh gillnets (20.2, 25.4, and 30.5 mm). A total of 520 specimens including 283 females and 237 males were examined. Information on sex ratio, stage of sexual maturity, gonadosomatic ratio, hepatosomatic ratio, fecundity, and condition factor was analyzed. The study revealed equality between males and females among individuals, although females were superior to males (1:0.84; p-value<0.05). All fish investigated showed all stages of sexual maturity (I, II, III, IV, and V). The mature (III, IV and V) have a greater proportion (III, IV and V) compared to the immature (I and II). Males have a size at first sexual maturity of 43.5 cm against 44 cm for females. The monthly values of gonadosomatic indices and those of macroscopic gonad stages show that B. bajad has three spawning periods a year: (i) January-April; (ii) June-August and (iii) October-November, alternated by a one-month rest period in May, September, and December. Absolute fecundity varies between 525 and 34440 oocytes but is not significantly correlated with total length (R2=0.002) and weight (R2=0.12). Knowledge from this study constitutes a fundamental basis for ensuring the monitoring of the risks of depletion of the potential stock of this species and will guide decision-makers in developing effective policies and strategies guaranteeing rational exploitation and conservation of this species

Slaughter weight rather than sex affects carcass cuts and tissue composition of Bisaro pigs

Carcass cuts and tissue composition were assessed in Bisaro pigs (n=64) from two sexes (31 gilts and 33 entire males) reared until three target slaughter body-weights (BW) means: 17 kg, 32 kg, and 79 kg. Dressing percentage and backfat thickness increased whereas carcass shrinkage decreased with increasing BW. Slaughter weight affected most of the carcass cut proportions, except shoulder and thoracic regions. Bone proportion decreased linearly with increasing slaughter BW, while intermuscular and subcutaneous adipose tissue depots increased concomitantly. Slaughter weight increased the subcutaneous adipose tissue proportion but this impaired intramuscular and intermuscular adipose tissues in the loin primal. The sex of the pigs minimally affected the carcass composition, as only the belly weight and the subcutaneous adipose tissue proportions were greater in gilts than in entire males. Light pigs regardless of sex are recommended to balance the trade-offs between carcass cuts and their non-edible compositional outcomes.Work included in the Portuguese PRODER research Project BISOPORC – Pork extensive production of Bísara breed, in two alternative systems: fattening on concentrate vs chesnut, Project PRODER SI I&DT Medida 4.1 “Cooperação para a Inovação”. The authors are grateful to Laboratory of Carcass and Meat Quality of Agriculture School of Polytechnic Institute of Bragança ‘Cantinho do Alfredo’. The authors are members of the MARCARNE network, funded by CYTED (ref. 116RT0503).info:eu-repo/semantics/publishedVersio

The significance of Ruzizi Delta: Rusizi Burundian Delta and Ruzizi Congolese Delta, in the Great Lakes Region, for the Conservation of Birds

ABSTRACT The significance of the Ruzizi Delta: Rusizi Burundian Delta (RBD) and Ruzizi Congolese Delta (RCD), in the Great Lakes Region for bird conservation was investigated from April 2019 to November 2021 in five sites of the RBD and five sites of the RCD. The investigation was conducted by direct observation on transects counts, counting points and on bird species recognition routes using binoculars and two telescopes. Travels were facilitated by the motorized fiberglass boat and the double cabin field vehicle of the Centre for Research in Hydrobiology (CRH) in Uvira, Democratic Republic of Congo (DRC). At the end of our investigations, we drew up the list of 490 species divided into 84 families and 18 orders. The following groups were listed: (i) 359 species of resident birds, of which 74 (21%) were recorded in the RCD, 148 (41%) in the RBD and 137 species (38%) were recorded both in the RCD and the RBD; (ii) 131 migrant bird species, of which 24 (18%) were recorded only in the RCD, 44 (34%) in the RBD and 63 species (48%) were recorded both in the RCD and the RBD; (iii) 176 water bird species, of which 26 (15%) were only recorded in the RCD, 49 (28%) in the RBD and 101 (57%) were recorded both in the RCD and the RBD; (iv) 238 (49%) Ramsar bird species for the criteria A1, A2, A3, A4i, A4ii and A4iv, among them, 29 (12%) species were only recorded in the RCD, 107 ( 45%) in the RBD and 102 species (43%) recorded in both the RCD and the RBD; (v) 21 species (4%) of birds with IUCN (International Union for Nature Conservation) status, of which only one species (Limosa limosa, Black-tailed Godwit) was recorded only in the RCD, 13 (62%) were only recorded in the RBD and 7 species (33%) were recorded both in the RCD and the RBD; Finally, the research pinpointed 60 newly recorded bird species in the Ruzizi Delta, of which four 4 (7%) were recorded only in the RCD, 37 (61%) in the RBD and 19 species (32%) were recorded in both the RCD and the RBD. The sustainability of all these species and their groups in the Ruzizi Delta requires the protection of the wetlands of the Ruzizi Congolese Delta as a community reserve and potential Ramsar site which will be submitted by the Congolese Institute for Nature Conservation (ICCN) to the Ramsar Secretariat for designation as a Ruzizi Congolese Delta Ramsar site. Keywords: Significance of the Ruzizi Delta; Ruzizi Congolese Delta; Rusizi Burundian Delta; Bird conservation; Great Lakes region. References Bashonga, A. B., Sande, E., Kahindo, C., & Ntakimazi, G. (2023). Checklist of the Bird Species from the Ruzizi Delta, Northern End of lake Tanganyika, in Burundi and the Democratic Republic of Congo. Biolife 11 (2);115-129. Chimatiro, S., & al, e. (2021). The African Great Lakes Regional Food System; the contribution of fisheries- the case of small pelagic fishes. A Discussion Paper. . Penang Malaysia: World Fish & Natural Resources Institute (NRI), 43 pages. www.fish.cgiar.org 23/8/2023. Cousin, P. H., Sinclair, L., Alain, J. F., & Love, C. E. (1993). Larousse & Collins Pratique; Dictionnaire Francais-Anglais/Anglais-Francais Voyages-Correspondance, 70000 mots et expressions. Londrs-Glasgow: Harper Collins Publishers, No 9 782850 36 140 1, 358 pages. Demey, R., & Louette, M. (2001). Democratic Republic of Congo. In Fishpool L.D.C.& Evans M.I eds Important Bird Areas in Africa:Priority Sites for Conservation. Pisces Publications and BirdLife International, 199-218. Dowset, & Dowset-Lemaire. (1993). A contribution to the Distribution and Taxonomy of Afrotropical and Malagasy birds Tauraco Research Report . Liège, Belgium.: Tauraco Press, Jupille No. 5 pp195-204. Fishpool, L., & Evans, M. (2001). Important Bird Areas in Africa and Associated Islands, Priority Sites for Conservation. Newbury and Cambridge, UK: BirdLife International, 1144 pages. www.birdlife.net. Gaugris, Y. (1979). Les oiseaux aquatiques de la plaine de la basse Rusizi (Burundi) (1973-1978). Belgium: l’Oiseau et la Revue française d’ornithologie, volume 49 n° 21:33-153. Guggisberg, C. (1986). Birds of East Africa. Supra Safari Guide No 6 Volume II. Nairobi: Mount Kenya Sundries, 196 pages. Guggisberg, C. (1988). Birds of East Africa. Supra Safari Guide No 6 Volum I. Nairobi: Mount Kenya Sundries, 198 pages . MEEATU, Ramsar, C., & WWF. (2014). Atlas of Burundi's four Ramsar sites: Location and Resources. Bujumbura, Burundi: Ministry of Water, Environment, Land Use Planning and Town Planning (MEEATU), 44p. Nkezabahizi, L., & Bizimana, D. (2008). Burundi’s Important Bird Areas, Status and Trends. Bujumbura-Burundi: Association Burundaise pour la protection des Oiseaux, 58 pages. Nkezabahizi, L., & Manirambona, A. (2011). Burundi’s Important Bird Areas Status and Trend 2010. London: BirdLife International & RSPB (Royal Society for the Protection of Birds (UK), 36 pages

Lake Tanganyika : status, challenges, and opportunities for research collaborations

Abstract: Lake Tanganyika is one of the most important lakes in the world because it supports millions of people who rely on its resources and its exceptional biodiversity. However, the lake currently suffers from a range of anthropogenic stressors, including water pollution and sedimentation, resource, biodiversity decline, habitat loss (both physical and functional) and climate change. Past and current research has been limited and disparate, only allowing the scientific community to gather inadequate data required to make informed policy and management plans for this lake. Based on data and knowledge derived from scientific studies and field experiences by scientists and experts working in the Lake Tanganyika basin, this paper outlines past research, present gaps, and the opportunities for collaboration to generate scientific knowledge to inform positive policy and management strategies leading to the protection of Lake Tanganyika's ecological integrity. The results of this paper draw from independent short surveys, freshwater expert meetings, and formal and informal discussions carried out to identify and prioritize specific issues and threats that need to be addressed for the conservation of biodiversity and sustainable management of the Lake Tanganyika basin. After highlighting each issue or threat, the authors propose possible management interventions; the results of this work focus heavily on the need for enhanced specific research on many issues and a larger, multi-disciplinary, long-term monitoring program to collect comprehensive information on a host of variables that will ultimately assist relevant stakeholders and key agencies in addressing these issues and threats

Plastic debris in freshwater systems worldwide

Plastic debris is widespread in freshwater ecosystems, but a rigorous assessment of its global distribution has been hindered by a lack of comprehensive and comparable data. We performed the first standardized global survey of lakes to assess the quantity and type of plastics (>250μm). We included 38 lakes located in 23 different countries distributed across five continents, spanning different environmental gradients and varying levels of anthropogenic stress. All samples were collected by horizontal trawling of a plankton net and subsequently treated with hydrogen peroxide. We identified 9425 plastic particles, which were classified based on shape, color, and size. Polymer identification was carried out using Raman micro-spectroscopy. Our results showed that the concentration of plastics spanned four orders of magnitude (10-3-101 particles/m3). Fibers (49%) and fragments (41%) were the most frequently detected particles, suggesting a secondary origin of plastic contamination. The most commonly identified polymers were polyester (30%), polypropylene (20%), and polyethylene (16%), which are widely used in short life-cycle products and account for the majority of global plastic production. Further, we found that urban-related attributes of lakes/watersheds influenced the occurrence and type of plastics in lentic systems and larger and deeper lakes with higher retention times are accumulating plastic debris at higher concentrations.info:eu-repo/semantics/publishedVersio

Need for harmonized long-term multi-lake monitoring of African Great Lakes

To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multi-lake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries

Need for harmonized long-term multi-lake monitoring of African Great Lakes

To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multi-lake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries

Plastic debris in lakes and reservoirs

Plastic debris is thought to be widespread in freshwater ecosystems globally. However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging. Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 μm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris. Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services