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Scientific fishing programmes were carried out between 1979 and 2013 in several West African estuarine, coastal and lagoon ecosystems. Batrachoides liberiensis represented only 5.2% of the occurrences, of which the majority were recorded in the Sine Saloum estuary. This originality makes it possible to use this population to characterise certain features of the biology and ecology of this little described species. B. liberiensis was recorded in waters with a salinity of 25–46, transparency of 1–3.5 m, at depths of 2–10 m. It was particularly abundant in areas at a distance of 15–35 km from the mouth. The water temperature did not appear to be a determining factor for this species. The sex ratio of the population, whose total length ranged from 10 to 371 mm, was in favour of females (87%) with an estimated size at first maturity of 189 mm (total length). The parameters of the length-weight relationship were estimated at K = 1.0009*10−5 and b = 3.097. The diet of B. liberiensis consisted mainly of molluscs and crabs, present in respectively, 53.6% and 50.7% of the stomach contents analysed.

In West African tropical estuaries, such as the Saloum Delta (Senegal), mangroves provide specific socio-economic functions including various natural food resources for local human populations. Mangrove-habitat loss is therefore of great concern, in terms of conservation and management, and highlights the need to study West African mangrove under human-induced pressures. Based on data from 2007-2008, this study aimed to establish a conditions report for two of the main Southern West Senegal mangroves areas: the Sine Saloum and the Petite Côte. We assessed the influence of environmental variables and human-induced pressures (i.e. shellfish harvesting and heavy metals (potentially toxic elements, PTEs)) on infaunal community structure and functions through trait-based approaches. Reflecting for example changing seasons and hypersaline events, the Saloum environmental variables and their temporal dynamics greatly impacted infaunal communities in the subtidal zone. In the intertidal area, closer to anthropogenic disturbances, pressures related to human activities took precedence over environmental variables in explaining infaunal community structure. Shellfish harvesting resulted in a significant decrease (p < 0.05) in total macrofaunal abundance (933.79 ± 626.34 ind m−2 in unexploited stations compared to 140.92 ± 71.99 ind m−2 in exploited stations; mean ± SE) in addition to a decline in biomass and taxonomic richness. Intertidal species composition was affected by both shellfish harvesting and PTEs. PTEs were also associated with a significant decrease in functional diversity and particularly with a change in macrofaunal living habits. The combination of an RLQ and fourth-corner analysis highlighted a significant association between feeding modes and sediment grain size in both tidal areas. This study provides a needed deeper understanding of the unintended effects of human activities on infaunal communities and their functioning, in a highly valuable system for huma

Marine spatial planning and management processes are important tools for environmental and resource management, providing effective frameworks for considering environmental, social, cultural, institutional and economic variables within a common biogeographic context. The Akanda National Park (ANP) in Gabon, almost exclusively constituted by mangroves, is part of a green belt of protected areas around the capital city of Libreville. The creation of the ANP is considered as an essential tool for the ecosystemic management of fisheries in Mondah Bay, playing nursery function for several exploited fish species. However, this role has never been documented in the mangroves of Gabon. The aim of this study is to describe the spatial and seasonal variability of fish assemblages, to assess ANP mangrove role as a nursery for fish juveniles. Fish sampling was carried out at four different sites in the four hydroclimatic seasons in Gabon using trammel gillnets with different mesh size (10, 27 and 40 mm). Fifty-nine fish species mainly estuarine and marine, first and second level predators were collected whatever the season and the site. The numerically dominant species were Pseudotolithus elongatus, Pellonula leonensis and Parachelon grandisquamis (48% of the total number of individuals), whereas P. elongatus, Chrysichthys nigrodigitatus and Plectorhinchus macrolepis represented the main biomasses (55%). The predominance in the catches of immature individuals of many species of commercial interest and in particular, P. elongatus, P. grandisquamis, C. nigrodigitatus, Eucinostomus melanopterus, Neochelon falcipinnis and Polydactylus quadrifilis, which dominate the community, highlights the importance of Akanda mangrove as a nursery for the juveniles of these species. The results of our study are a first step in understanding the fish communities of a Gabon marine protected area, which can support the decision making management plans, zonation and initiate a monitoring program for

This study provides length-weight relationships (LWR) that had not yet been reported for four fish species belonging to four different families: Chrysichthys johnelsi Daget, 1959, Cynoglossus senegalensis (Kaup, 1858), Citharichthys stampflii (Steindachner, 1894) and Pseudotolithus typus, Bleeker, 1863. Data were collected in the Fatala estuary, republic of Guinea, each month between January 1993 and March 1994, using alternately a purse seine net (length 250 m, height 20 m, 14 mm side mesh) and gillnets (side mesh sizes of 10, 12.5, 15, 15.5, 20, 22.5, 25, 30, 35 and 40 mm). For each fish specimen, fork or total length and total weight were measured with precision to 0.1 cm and 0.1 g respectively. A wider size range, compared to the size range available in FishBase, was obtained for Pseudotolithus typus. The present study also provides a new maximum total length for Citharichthys stampflii. The determination coefficient (r²) between length and total body weight ranged between 0.958 in Citharichthys stampflii and 0.989 in Cynoglossus senegalensis. The allometric coefficient b varied from 2.9552 (Chrysichthys johnelsi) to 3.7288 (Citharichthys stampflii). The value of LWRs for the four fish species should assist fisheries scientists and managers to complement their further studies of population parameters to improve management decisions in Fatala estuary and, more widely, in West Africa.

Throughout the world, biodiversity and nature's contributions to people are under threat, with clear changes evident. Biodiversity and ecosystem services have particular value in Africa– yet they are negatively impacted by a range of drivers, including land use and climate change. In this communication, we show evidence of changing biodiversity and ecosystem services in Africa, as well as the current most significant drivers of change. We then consider five plausible futures for the African continent, each underlain by differing assumptions. In three out of the five futures under consideration, negative impacts on biodiversity and ecosystem services are likely to persist. Those two plausible futures prioritizing environment and sustainability, however, are shown as the most likely paths to achieving long term development objectives without compromising the continent's biodiversity and ecosystem services. Such a finding shows clearly that achievement of such objectives cannot be separated from full recognition of the value of such services.

Length-weight relationships (W = aLb) were estimated for 5 fish species, the pearl stingray Fontitrygon margaritella (Compagno & Roberts, 1984), the West African spadefish Chaetodipterus lippei (Steindachner, 1895), the East Atlantic African spadefish Ephippus goreensis (Cuvier, 1831), the law croaker Pseudotolithus senegallus (Cuvier, 1830) and the Guinean sole Dagetichthys cadenati (Chabanaud, 1948). Fishes were collected during several scientific fishing surveys using purse seine (length 250 m, height 20 m, 14 mm mesh size) and beach seine (180 m length, 9 m height and 25 mm mesh net) conducted from April 1990 to October 2012 in the Sine Saloum estuary, Senegal. They were weighed to the nearest g and measured to the nearest mm (disc width for Fontitrygon margaritella and total length for the 4 other species). The values of parameter b in the LWR equations varied from 3.048 (Chaetodipterus lippei) to 3.274 (Dagetichthys cadenati) and the coefficient of determination (r²) varied between 0.969 (Fontitrygon margaritella) and 0.998 (Chaetodipterus lippei). In addition, new maximum lengths are proposed for Fontitrygon margaritella, Chaetodipterus lippei and Dagetichthys cadenati.

Length-weight relationships (LWR) were measured for 20 fish species collected during scientific fishing surveys conducted from April 1990 to October 2012 in the Sine Saloum estuary, Senegal, using purse seine and beach seine. The number of individuals collected varied according to the species, from 10 (Hemicaranx bicolor) to 777 (Carlarius latiscutatus). Fish length ranged from 4.5 cm total length (Sphoeroides marmoratus) to 130.0 cm total length (Sphyraena afra). The values of parameter b in the LWR equations (W = aLb where W is weight (g) and L is length (cm)) varied from 2.687 (Hemicaranx bicolor) to 3.334 (Citharichthys stampflii). The coefficient of determination varied between 0.953 (Sphoeroides marmoratus) and 0.996 (Sphyraena afra). The length-weight relationship has never been studied before in Sine Saloum estuary for 13 fish species (Carlarius parkii, Batrachoides liberiensis, Caranx senegallus, Hemicaranx bicolor, Trachinotus teraia, Elops senegalensis, Lutjanus goreensis, Citharichthys stampflii, Psettodes belcheri, Dagetichthys lusitanicus, Sphyraena afra, S. guachancho and Sphoeroides marmoratus). This study provides LWRs that are not available in FishBase (Froese and Pauly, 2020) for 14 species (Carlarius latiscutatus, C. parkii, Batrachoides liberiensis, s Caranx senegallus, Hemicaranx bicolor, Cynoglossus senegalensis, Fontitrygon margarita, Plectorhinchus macrolepis, Pomadasys perotaei, Lutjanus goreensis, Citharichthys stampflii, Psettodes belcheri, Dagetichthys lusitanicus and Sphoeroides marmoratus). It also provides new information for size ranges that are not specified for LWRs in FishBase for 5 species (Ephippion guttifer, Elops senegalensis, Pseudotolithus senegalensis, P. senegallus and Sphyraena afra). In addition, new maximum lengths are presented for Plectorhinchus macrolepis and Citharichthys stampflii. The parameters obtained from this study provide new information for the species studied and will be useful for proper fish population ma, Les relations tailles-poids (RTP) ont été estimées pour 20 espèces de poisson collectées au cours des missions de pêches scientifiques effectuées d’avril 1990 à octobre 2012 dans l’estuaire du Sine Saloum, Sénégal, avec comme engin de pêche la senne tournante coulissante et la senne de plage. Le nombre d’individus par espèce variait entre 10 (Hemicaranx bicolor) et 777 (Carlarius latiscutatus). La taille des poissons variait entre 4,5 cm de longueur totale (Sphoeroides marmoratus) et 130,0 cm de longueur totale (Sphyraena afra). Les valeurs du paramètre b de l’équation de la RTP [W = aLb, où W est le poids (g) et L la taille (cm)] variaient de 2,687 (Hemicaranx bicolor) à 3,334 (Citharichthys stampflii). Le coefficient de détermination variait entre 0,953 (Sphoeroides marmoratus) et 0,996 (Sphyraena afra). La RTP n’a jamais été étudiée auparavant pour 13 espèces de poissons (Carlarius parkii, Batrachoides liberiensis, Caranx senegallus, Hemicaranx bicolor, Trachinotus teraia, Elops senegalensis, Lutjanus goreensis, Citharichthys stampflii, Psettodes belcheri, Dagetichthys lusitanicus, Sphyraena afra, S. guachancho et Sphoeroides marmoratus) dans l’estuaire du Sine Saloum. Cette étude fournit des informations sur les RTP qui n’existent pas encore dans FishBase (Froese et Pauly, 2020) pour 20 espèces (Carlarius latiscutatus, C. parkii, Batrachoides liberiensis, Caranx senegallus, Hemicaranx bicolor, Cynoglossus senegalensis, Fontitrygon margarita, Plectorhinchus macrolepis, Pomadasys perotaei, Lutjanus goreensis, Citharichthys stampflii, Psettodes belcheri, Dagetichthys lusitanicus et Sphoeroides marmoratus). Elle fournit aussi des gammes de taille qui ne sont pas spécifiées dans FishBase pour la relation taille-poids de 5 espèces (Ephippion guttifer Elops senegalensis, Pseudotolithus senegalensis, P. senegallus et Sphyraena afra). En outre, de nouvelles tailles maximales sont présentées pour Plectorhinchus macrolepis et Citharichthys stampflii. Les paramètres obtenus

Length-weight relationships (LWRs) were estimated for 19 fish species sampled from two artificial reservoirs (Manantali and Selingue) in Mali: Brycinus leuciscus, B. macrolepidotus, B. nurse, Chrysichthys auratus, C. nigrodigitatus, Coptodon zillii, Distichodus brevipinnis, D. rostratus, Hemichromis fasciatus, Hydrocynus forskahlii, Labeo coubie, L. senegalensis, Lates niloticus, Mormyrus rume, Sarotherodon galilaeus, Schilbe intermedius, S. mystus, Synodontis schall, S. sorex. The fish were collected between June 2002 and October 2003 during three experimental fishing campaigns using gillnets deployed overnight. All fish were measured (total length) to the nearest mm and weighed to the nearest g (total weight). Coefficients of determination of the LWRs (r²) were mostly high (> 0.9). The values of the allometry coefficient b ranged from 2.651 (Chrysichthys auratus) to 3.270 (Brycinus leuciscus). This study provides new information about LWRs of two fish species, which have been published but are not yet available in Fishbase (Distichodus brevipinnis and Mormyrus rume)., Les relations longueur-poids (RLP) ont été estimées pour 19 espèces de poissons échantillonnées dans deux lacs artificiels (Manantali et Sélingué) au Mali : Brycinus leuciscus, B. macrolepidotus, B. nurse, Chrysichthys auratus, C. nigrodigitatus, Coptodon zillii, Distichodus brevipinnis, D. rostratus, Hemichromis fasciatus, Hydrocynus forskahlii, Labeo coubie, L. senegalensis, Lates niloticus, Mormyrus rume, Sarotherodon galilaeus, Schilbe intermedius, S. mystus, Synodontis schall, S. sorex. Les poissons ont été collectés entre juin 2002 et octobre 2003 au cours de trois campagnes de pêche expérimentale utilisant des filets maillants déployés pendant la nuit. Tous les poissons ont été mesurés (longueur totale) au mm près et pesés au g près (poids total). Les coefficients de détermination (r2) étaient pour la plupart élevés (> 0,9). Les valeurs du coefficient d’allométrie b étaient comprises entre 2,651 (Chrysichthys auratus) et 3,270 (Brycinus leuciscus). Cette étude fournit de nouvelles informations sur les relations longueur-poids de deux espèces de poissons qui ont été publiées mais ne sont pas encore renseignées dans Fishbase (Distichodus brevipinnis et Mormyrus rume).

Background This paper describes a dataset of fish, crustacean and mollusc occurrences extracted from the “Experimental Fishing” section of the IRD's PPEAO information system. PPEAO stands for “Fish communities and artisanal fisheries of West African estuarine, lagoon and freshwater ecosystems”. This database contains information collected using two different methods: experimental fishing and surveys of the artisanal fisheries that exploit these ecosystems. The database is accessible at http://ppeao.ird.fr. New information The current dataset is available on GBIF.org at 10.15468/ra4voa. It comprises the occurrences of 314 fish, crustacean and mollusc taxa collected in experimental sampling surveys of different aquatic ecosystems in West Africa between 1979 and 2013. Different types of fishing gear were used including purse seines, gill nets and fyke nets. The taxa were identified by IRD scientists or by scientific partners well trained in systematics. Most taxa were identified at species level (97% of cases). This dataset is the result of 213 fishing surveys, 5,362 fishing hauls and 31,709 occurrences (28,428 of fish taxa and 3,281 of crustaceans and molluscs). The number of individuals per species and per haul is included and 80% of occurrences are geolocated.

Subcellular cadmium (Cd) partitioning was investigated in the liver of two marine fish species, the European sea bass Dicentrarchus labrax and the Senegalese sole Solea senegalensis, dietary exposed to an environmentally realistic Cd dose for two months followed by a two-month depuration. Cd exposure did not modify Cd cellular partitioning for either species, refuting the spillover hypothesis. Both species contained most of the Cd in the detoxifying fraction but displayed different handling strategies. Cd was largely bound to heat stable proteins (HSP) including metallothioneins (MT) in sea bass while Cd was more linked to metal rich granules (MRG) in sole. Whole liver concentrations and subcellular partitioning were also determined for essential elements. The greatest impairment of essential metal homeostasis due to Cd exposure was found in sole. These elements followed the Cd partitioning pattern, suggesting that they are involved in antioxidant responses against Cd toxicity. Cd consumption diminished sole growth in terms of body weight, probably due to lipid storage impairment. During the depuration period, the two species showed contrasting partitioning patterns, implying different pathways for Cd elimination from the liver. In sea bass, MT-bound Cd would be excreted through bile or released into blood, crossing the cell membrane via a protein transporter. In sole, MRG-bound Cd would be sequestered by organelles before being released into the blood via vesicular exocytosis. These distinct strategies in cellular Cd handling in the liver might account for differential sensitivity to Cd toxicity and differential Cd excretion pathways between the two marine fish species.

The status of marine biodiversity in the Eastern Central Atlantic (ECA), especially of coastal and pelagic fishes, is of concern owing to a number of threats including overharvesting, habitat loss, pollution, and climate change combined with inadequate policy responses, legislation, and enforcement. This study provides the first comprehensive documentation of the presence, status, and level of extinction risk, based on IUCN Red List assessment methodology, for more than 1800 marine species, including all taxonomically described marine vertebrates (marine mammals, sea turtles, seabirds, fishes); complete clades of selected marine invertebrates (sea cucumbers, cone snails, cephalopods, lobsters, reef-building corals); and marine plants (mangroves, seagrasses). Approximately 8% of all marine species assessed in the ECA are in threatened categories, while 4% are listed as Near Threatened, 73% are Least Concern, and 15% are Data Deficient. Fisheries and overharvesting are the biggest threats to living marine resources in the ECA, with 87% of threatened species across all taxonomic groups affected by both large- and small-scale targeted fisheries, excessive capture as by-catch, or unsustainable harvest. The results of this study will transform the current state of knowledge and increase capacity for regional stakeholders to identify and enact marine conservation and research priorities, as a number of species are identified as having high conservation and/or research priorities in the region. Through the process of marine species data collection and risk assessments conducted over the past 5 years, several key conservation actions and research needs are identified to enable more effective conservation of marine biodiversity in the ECA, including increased governance, multilateral collaboration, taxonomic training, and improved reporting of fisheries catch and effort.