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1.
Environ Res ; 252(Pt 2): 118977, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38649017

RESUMO

Seafood is an essential protein source for coastal communities. However, they can accumulate heavy metals from human activities which could pose a potential health risk to consumers. In this study, we investigated the distribution, bioaccumulation, trophic transfer and potential human health risk of heavy metals in sediments, shell and fin fish collected from the Escravos Estuary in southern Nigeria. Heavy metals (Ni, Cd, V, Pb and Cu) in sediments, periwinkles and tongue soles from the two study sites were lower than the permissible limits for fishery products. The metal distribution in fish tissues was in the decreasing order of liver > gills > muscles > gonads > rest of the fish. Moderate to high BSAF (>1) was reported for Cd, Pb and Cu. All the studied metals, except Pb, showed evidence of biomagnification from periwinkle to tongue sole. The estimated daily intake (EDI) and hazard ratio (HR) for metals in periwinkles from both study sites were lower or within the USEPA reference doses (RfD) for the respective daily intake and HR value < 1, except for Cd, V and Pb for children. In contrast, EDI values in the muscle of tongue soles were higher than the RfD values for heavy metals except for Ni and Pb, whereas HR values > 1 except for Ni, Cd and V. In the whole fish, EDI and HR values were disproportionately high in both study sites with higher values reported for children. This study provides the first insights on the trophic transfer and risk assessment of heavy metals from petroleum and gas operations impacting the Escravos Estuary and the implications to public health.


Assuntos
Estuários , Metais Pesados , Alimentos Marinhos , Poluentes Químicos da Água , Metais Pesados/análise , Medição de Risco , Animais , Poluentes Químicos da Água/análise , Alimentos Marinhos/análise , Humanos , Peixes/metabolismo , Nigéria , Contaminação de Alimentos/análise , Monitoramento Ambiental , Sedimentos Geológicos/química , Sedimentos Geológicos/análise , Cadeia Alimentar
2.
Ecol Evol ; 14(3): e11133, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38505183

RESUMO

Sea turtles are critical components of marine ecosystems, and their conservation is important for Ocean Governance and Global Planet Health. However, there is limited knowledge of their ecology in the Gulf of Guinea. To fill this knowledge gap, this study presents the first integrative assessment of green and hawksbill turtles in the region, combining nesting surveys over 9 years and telemetry data, to offer insights into these population dynamics, and behaviours, including nesting preferences, morphological and reproductive parameters, diving patterns and inter-nesting core-use areas. Both green and hawksbill turtles are likely making a recovery on São Tomé, potentially driven by sustained conservation efforts. There are preliminary indications of recovery, but we interpret this cautiously. Coupled with satellite tracking, this study estimated that 482 to 736 green turtles and 135 to 217 hawksbills nest on the beaches of São Tomé. Their movements overlap significantly with a proposed Marine Protected Area (MPA), which suggests they may be well placed for conservation if managed appropriately. However, the presence of artisanal fisheries and emerging threats, such as sand mining and unregulated tourism, highlight the urgent need for robust management strategies that align global conservation objectives with local socioeconomic realities. This study significantly enhances our understanding of the ecology and conservation needs of the green and hawksbill turtles in the Gulf of Guinea. The insights gleaned here can contribute to the development of tailored conservation strategies that benefit these populations and the ecosystem services upon which they depend.

3.
Heliyon ; 9(1): e13047, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36747934

RESUMO

This study applied ocean models data from Copernicus Marine Environment Monitoring Service (CMEMS) in assessing the impacts of the trends in key ocean parameters on the primary production of the Gulf of Guinea (GoG). Trend analyses, from 1993 to 2020, were done using linear regression and Mann-Kendall significance test methods to ascertain inter-annual and inter-seasonal variations and check the significance of the trends, respectively. Results affirm that temperature, salinity, nutrients, and oxygen play significant roles in the primary production of the GoG. Also, parameters such as temperature, salinity, chlorophyll-A, net primary production, phosphate, and dissolved oxygen have been experiencing increases between the study duration while silicate and nitrate have been declining in the GoG. However, there are regions and years with contrary values to the average trends. The varying level of significance of the trend showed that the impacts of the climate on the primary production of the GoG vary basin-wide.

4.
Data Brief ; 45: 108623, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36426077

RESUMO

The ubiquity of microplastics in coastal environments and marine ecosystems is a significant concern because they have a strong affinity for organic contaminants. This paper presents the first reported data on hydrophobic organic contaminants (HOCs) and microplastics particles (MPs, 1-5 mm) in lagoon and beach sediments along the Gulf of Guinea coastline (SE Atlantic). Sampling was carried out between August and November 2019. Ten sites were designated for each location, and sediment samples were taken along three transects: high waterline, drift waterline, and current waterline. Sediment samples were extracted through density floatation procedure and sieving. Primary data on polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) associated with MPs are provided, as well as detailed information on sampling coordinates, plastic types, and their relative abundance. Refer to the research publication ``Microplastics and associated organic pollutants in beach sediments from the Gulf of Guinea (SE Atlantic) coastal ecosystems'' (Fred-Ahmadu et al., 2022) for detailed discussion and interpretation of the reported data.

5.
PeerJ ; 10: e13942, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36281365

RESUMO

The monitoring of the N'Kossa offshore oil and gas fields in the Republic of Congo allowed us to assess the ecological traits of two polychaete species belonging to Sigambra (Annelida, Pilargidae). Sigambra parva occur in very low densities in all bottoms, except the most impacted, where it is totally absent; it is an undescribed species that reached >4,000 ind/m2 in hydrocarbon-enriched sediments. Their distribution patterns are compared with those of other polychaetes, showing a range of affinities for hydrocarbon-enriched sediments in the N'Kossa region. Our results suggest that S. parva would be a representative of the original local fauna, while the species associated with artificial hydrocarbon-enriched sediments, including the other Sigambra, six more polychaetes and a bivalve, could be natively associated with natural hydrocarbon-enriched sediments, using the former as alternative habitats and as dispersal stepping stones. This ecological segregation, together with a careful morphological and morphometric analyses led us to describe the latter as a new species, namely Sigambra nkossa sp. nov. Moreover, morphometric analysis allowed us to discuss on the taxonomic robustness of the key morphological characters of S. nkossa sp. nov., as well as to emend the generic diagnosis of Sigambra to accommodate the new species.


Assuntos
Anelídeos , Bivalves , Poliquetos , Animais , Ecossistema , Congo
6.
Proc Natl Acad Sci U S A ; 119(35): e2201871119, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35994649

RESUMO

The stability of widespread methane hydrates in shallow subsurface sediments of the marine continental margins is sensitive to temperature increases experienced by upper intermediate waters. Destabilization of methane hydrates and ensuing release of methane would produce climatic feedbacks amplifying and accelerating global warming. Hence, improved assessment of ongoing intermediate water warming is crucially important, especially that resulting from a weakening of Atlantic meridional overturning circulation (AMOC). Our study provides an independent paleoclimatic perspective by reconstructing the thermal structure and imprint of methane oxidation throughout a water column of 1,300 m. We studied a sediment sequence from the eastern equatorial Atlantic (Gulf of Guinea), a region containing abundant shallow subsurface methane hydrates. We focused on the early part of the penultimate interglacial and present a hitherto undocumented and remarkably large intermediate water warming of 6.8 °C in response to a brief episode of meltwater-induced, modest AMOC weakening centered at 126,000 to 125,000 y ago. The warming of intermediate waters to 14 °C significantly exceeds the stability field of methane hydrates. In conjunction with this warming, our study reveals an anomalously low δ13C spike throughout the entire water column, recorded as primary signatures in single and pooled shells of multitaxa foraminifers. This extremely negative δ13C excursion was almost certainly the result of massive destabilization of methane hydrates. This study documents and connects a sequence of climatic events and climatic feedback processes associated with and triggered by the penultimate climate warming that can serve as a paleoanalog for modern ongoing warming.


Assuntos
Aquecimento Global , Camada de Gelo , Metano , Camada de Gelo/química , Metano/química , Oxirredução , Água/química
7.
Mar Pollut Bull ; 182: 114006, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35939935

RESUMO

Almost everywhere in the marine ecosystem contains microplastics. Although their environmental contamination is a global problem, relatively little is known about their distribution and abundance in the Gulf of Guinea. This study looked at the spatial dynamics of microplastics in the sea surface water off the coast of Ghana. Four chosen areas were found to have non-variable concentrations ranging from 1.14 to 2.79 particles m-3 using a self-constructed Low-Tech Aquatic Debris Instrument (LADI) trawl (333 µm mesh). The most abundant shapes were fragments and pellets, while the most common colors were colored and transparent particles. The polymer types found in the microplastics selected for investigation using Fourier Transform Infrared spectroscopy in Attenuated Total Reflectance mode (ATR-FT-IR) were Polypropylene, Polyethylene, and Polystyrene. These results provide an important baseline on microplastic pollution along the Ghanaian coast suggesting the LADI trawl as an accurate quantitative sampling tool for microplastics from sea surface water.


Assuntos
Microplásticos , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental/métodos , Gana , Plásticos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
8.
Sci Total Environ ; 813: 152650, 2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-34954167

RESUMO

The pervasive existence of microplastics (MPs) and toxic metals is raising environmental and health concerns. Plastics are essentially a complex mixture of chemicals, but exposure to the aquatic environment increases their complexity through contaminant desorption/sorption. The aim of this study was to establish baseline data on the elemental occurrence and distribution of potentially toxic and geochemical metals/metalloids in microplastics 1-5 mm and mesoplastics (> 5 mm - 1 cm) along designated coastlines of the Gulf of Guinea (Nigeria) in addition to enabling more comprehensive ecotoxicological risk assessment. The concentrations of twenty-six metals: aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), selenium (Se), sodium (Na), silicon (Si), silver (Ag), strontium (Sr), thallium (Tl), titanium (Ti), vanadium (V), and zinc (Zn), associated with beach MPs, pristine, and lagoon plastics were determined after extraction in 10% nitric acid and analysis using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The distribution of MPs was variable, with 3680 particles identified along the drift and high waterlines across designated shoreline locations. The beach MPs were dominated by polyethylene (PE), polypropylene (PP), and polystyrene (PS), whereas lagoon-sourced plastics were characterized by polyethylene terephthalate (PET), polystyrene (PS), and polyurethane (PUR). Metal concentration was higher when associated with foam plastic (PS, PUR, PEVA) compared to hard plastic (PE, PP, PET) samples. The results showed that all samples had slightly elevated Al, Fe, Mn, and Zn concentrations, suggesting potential sorption interactions and plastic additive influences. Notably, foam MPs had a stronger affinity for metals. This study emphasizes the critical role of microplastics in serving as vectors for toxic metals. Except for Cd, pollution indices such as the potential contamination index (PCI), hazard quotient (HQ), and modified hazard quotient (mHQ) indicated low severity contamination of beach and lagoon MPs by heavy metals. However, considering long-term accumulation of sorbed metals, their potential toxicity to marine biota may be considerable.


Assuntos
Metaloides , Metais Pesados , Monitoramento Ambiental , Guiné , Metais Pesados/análise , Microplásticos , Plásticos
9.
Zookeys ; 1126: 1-54, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36763062

RESUMO

A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus) is described from Príncipe Island, São Tomé and Príncipe (Gulf of Guinea, Africa). This species was discovered for science in 2016, although suspicions of its occurrence gained traction from 1998, and testimonies from local people suggesting its existence could be traced back to 1928. Morphometrics, plumage colour and pattern, vocalisations, and molecular evidence all support the species status of the scops-owl from Príncipe, which is described here as Otusbikegila sp. nov. Phylogenetic analyses suggest that this species descended from the first colonisation of the Gulf of Guinea islands, being sister to the clade including the mainland African Scops-Owl O.senegalensis, and the island endemics Sao Tome Scops-Owl O.hartlaubi and Pemba Scops-Owl O.pembaensis. The most diagnostic trait in the field is its unique call which, curiously, is most similar to a distantly related Otus species, the Sokoke Scops-Owl O.ireneae. The new species occurs at low elevations of the old-growth native forest of Príncipe, currently restricted to the south of the island but fully included within Príncipe Obô Natural Park. Otusbikegila sp. nov. takes the number of single-island endemic bird species of Príncipe to eight, further highlighting the unusually high level of bird endemism for an island of only 139 km2.


ResumoDescrevemos uma nova espécie de mocho-de-orelhas ou kitóli (Strigiformes: Strigidae: Otus) da Ilha do Príncipe, São Tomé e Príncipe (Golfo da Guiné, África). Esta espécie foi descoberta para a ciência apenas em 2016, embora suspeitas da sua existência tenham ganho força a partir de 1998, e testemunhos de habitantes locais sobre a sua ocorrência já estarem documentados em 1928. A morfometria, a cor e padrão da plumagem, as vocalizações e dados moleculares demonstram que esta população de mocho no Príncipe é uma espécie nova, que foi batizada de mocho-do-príncipe (lista mundial) ou kitóli-do-príncipe (nome nacional), Otusbikegila sp. nov. As análises filogenéticas indicam que esta espécie descende da primeira colonização das ilhas do Golfo da Guiné, sendo irmã do clado que inclui o mocho-d'ore­lhas-africano O.senegalensis, do continente, o mocho-de-são-tomé (ou kitóli-de-são-tomé) O.hartlaubi e o mocho-de-pemba O.pembaensis, ambos endémicos das ilhas que lhes dão o nome. No campo, a característica mais diagnóstica é o seu canto único que, curiosamente, é mais parecido com o da espécie de Otus mais afastada, o mocho-de-sokoke O.ireneae. A nova espécie ocorre nas zonas baixas da floresta nativa do Príncipe, atualmente restrita ao sul da ilha, mas totalmente inserida no Parque Natural do Obô do Príncipe. Otusbikegila sp. nov. eleva o número de espécies de aves endémicas restritas ao Príncipe para oito, sublinhando ainda mais o nível extremamente elevado de aves endémicas para uma ilha de apenas 139 km2.

10.
J Fish Biol ; 98(4): 1120-1136, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33314115

RESUMO

Anthropogenic factors that negatively impact reef fishes can include changes in life-history patterns of fisheries-targeted species. Understanding these impacts on growth and population age structure is essential in the management of exploited populations of fishes. This is the first study to directly compare age and growth for a major fisheries species between east and west populations of a transatlantic reef fish. The main goal of this study was to document age and growth in grey triggerfish Balistes capriscus from coastal waters of Ghana in the Gulf of Guinea (GOG) and compare those with the previous growth studies from that region and with the western Atlantic population. A secondary objective of this study was to evaluate the use of otoliths to age triggerfish and to provide a preliminary comparison with spine-derived age estimates. The results obtained from this study provided an updated understanding of the growth and age structure of the eastern B. capriscus population in GOG. The authors documented that shifts in population attributes occurred for B. capriscus after its major decline in abundance. The differences in physical and biotic characteristics of the East and West Atlantic regions and the differences in collection methods of samples make direct comparisons of growth parameters difficult. Nonetheless, overall differences in maximum sizes and ages were apparent; the western Atlantic population had a larger maximum size and older maximum age. The authors also documented that sagittal otoliths can be used to provide age estimates for triggerfish species, and otoliths as an ageing structure had better between-reader precision compared to dorsal spines.


Assuntos
Envelhecimento/fisiologia , Distribuição Animal/fisiologia , Recifes de Corais , Tetraodontiformes/fisiologia , Animais , Oceano Atlântico , Tetraodontiformes/crescimento & desenvolvimento
11.
Zootaxa ; 4771(1): zootaxa.4771.1.1, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33055633

RESUMO

The actual diversity of Terebellides (Annelida; Trichobranchidae) in the South East Atlantic Ocean remains largely unknown. Only two species have been reported to date, T. stroemii Sars, 1835 and T. jorgeni Hutchings, 2007. The revision of specimens collected during the Atlantide and Galathea oceanographic cruises in the Atlantic coast of Africa, along with new materials obtained during monitoring surveys off Gabon, Congo and Angola, has allowed us to describe seven new species: T. augeneri sp. nov., T. congolana sp. nov., T. fauveli sp. nov., T. kirkegaardi sp. nov., T. longiseta sp. nov., T. nkossa sp. nov. and T. ramili sp. nov. Moreover, the type material of Terebellides stroemii var. africana Augener, 1918 is redescribed and the variety raised to species. All taxa are morphologically characterised and compared with species described or reported in world seas, particularly from the Atlantic Ocean. The presence of T. stroemii in Africa and the validity of the thoracic uncini as taxonomic character is discussed and a key to all species of Terebellides described from the South Atlantic Ocean is provided.


Assuntos
Anelídeos , África Ocidental , Distribuição Animal , Animais
12.
Zootaxa ; 4786(3): zootaxa.4786.3.2, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-33056471

RESUMO

The present study deals with two species new to science, as well as several new records in the closely related alpheid shrimp genera Salmoneus Holthuis, 1955 and Deioneus Dworschak, Anker Abed-Navandi, 2000, based on material collected at various localities in the tropical western and eastern Atlantic Ocean. In the western Atlantic, Salmoneus inconspicuus sp. nov. is described based on material from the Caribbean coast of Panama, Cuba, French Antilles and (with some doubts) Bermuda. The new species has been previously reported from the eastern Caribbean Sea as S. teres Manning Chace, 1990, a closely related species so far known only from Ascension Island in the central Atlantic. Salmoneus camaroncito Anker, 2010 is reported from the Caribbean coast of Mexico, for the first time since its original description. Salmoneus carvachoi Anker, 2007 is reported from Colombia and southeastern USA, representing a new record of the species for each of these countries. Salmoneus depressus Anker, 2011 and Salmoneus setosus Manning Chace, 1990 are reported for the first time from Cuba and Panama, respectively. In addition, these two species, as well as Salmoneus wehrtmanni Anker, 2010, are reported from new localities in Mexico. In the eastern Atlantic, Salmoneus saotomensis sp. nov. is described based on a single specimen from São Tomé Island in the Gulf of Guinea. The new species is characterised by the somewhat enlarged minor cheliped and is compared to all other Atlantic species presenting this feature. Deioneus sandizelli Dworschak, Anker Abed-Navandi, 2000 is reported from São Tomé Island, for the first second time since its original description based on the Cape Verde type material. The characters separating Deioneus and Salmoneus are reassessed. The new evidence shows that these two genera are distinguished by only one morphological feature known to be variable in at least one non-related alpheid genus. However, in view of the increasing morphological heterogeneity in Salmoneus, it seems more appropriate to retain Deioneus as a valid genus for it may represent a distinct clade that also includes several other species currently placed in Salmoneus.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais , Animais , Oceano Atlântico
13.
Environ Sci Pollut Res Int ; 27(34): 42530-42555, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32705561

RESUMO

Chemical contaminants are released from mining, domestic and industrial effluents into an aquatic environment. Sediments (n = 10) were collected with an Eckman grab at ten stations in the Densu Estuary for ecological risk assessment. The spatial distribution of organic characteristics and ecological risk of metals-zinc, lead, copper, mercury, iron, and manganese in sediment-were analyzed using standard methods. The organic parameters occurred in the ranges, as follows: % C, 0.76 to 2.05, % TN, 0.06 to 0.015; % TP, 0.44 to 1.38; and C/N, 12.31 to 34.81. The ranges of metal concentrations (mg/kg) were as follows: Fe, 201.10 to 720.90; Mn, 40.10 to 152.70; Zn, 7.3 to 158.3; Pb, 1.9 to 84.7; Cu 3.4 to 23.0; and Hg, 0.01 to 0.05. The mean concentration of metals in the sediment were Fe > Mn > Pb > Zn > Cu > Hg. The highest mean concentration of Fe suggested redox conditions in the Densu Estuary. There is a low contamination factor (CF) for five metals (Zn, Hg, Fe, Cu, and Mn) (CF < 1) to high contamination of Pb (3 < CF ≤ 6). The average Pb concentration was above local and geological backgrounds, suggesting an anthropogenic source of pollution from industrial and domestic effluents and agrochemicals. The sediment was extremely enriched by Pb (EF > 50) with a positive index of geoaccumulation (0 < Igeo ≤ 2) than other metals. There is considerable to a very high degree of contamination (DC) (3 ≤ DC ≥ 6) of metals in the sediment of Densu Estuary. The potential ecological risk index (≤ 40 PERI < 80) suggested a very low to moderate ecological risk of metal pollution. The study provides baseline knowledge on geochemical contamination in tropical estuarine systems for the development of effective chemical control strategies towards sustainable management of coastal waters.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Gana , Guiné , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análise
14.
Data Brief ; 31: 105755, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32529010

RESUMO

This article presents data on the occurrence and distribution of phthalate esters and metals associated with microplastics (MPs) (1-5 mm) collected from four beaches in the tropical Atlantic ecosystems, Nigeria, Gulf of Guinea. Information on microplastics extraction by density flotation with saturated NaCl and polymer identification with attenuated total reflectance infra-red spectroscopy (ATR-FTIR) is also provided. Analysis of six phthalate esters (PAEs) (dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DnBP), benzyl butyl phthalate (BBP), di (ethyl hexyl) phthalate (DEHP), and di n-octyl phthalate (DnOP)) associated with the microplastics by performed using Gas chromatography-mass spectroscopy (GC-MS). Metals including Ag, Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Si, Sr, Ti, Tl, V, and Zn were analysed by inductively coupled plasma-optical emission spectrometry (ICP-OES). The data present the separation of microplastics from sediment, extraction with cyclohexane/ethyl acetate (1:1, v/v) and 10% HNO3 for phthalate esters and metals, respectively, and the determination of target analytes concentrations. The compositional distributions of MPs and levels of carcinogenic and toxic metals and phthalate esters are presented. The dataset could be used for the evaluation of ecological risk associated with PAEs in the marine ecosystems.

15.
Environ Sci Pollut Res Int ; 27(26): 33373-33379, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32577960

RESUMO

Plastic pollution has enormous impacts on freshwater and marine ecosystem health, and it is one of the topmost environmental concerns of the current geological period (i.e. the Anthropocene). Thus, the goal of our study was to provide baseline information and bridge the information gap on the occurrence of microplastics (MPs) in African freshwater systems, using two tributaries of the Gulf of Guinea (Ogun and Osun Rivers) in Nigeria as a case study and three freshwater insect species of different feeding guilds as bioindicators. A total of 29 individuals of the insect species were chemically digested and subsequently analysed for MP presence under a digital microscope and a micro-Fourier-transform infrared (µFTIR) spectroscope. Collector-gatherers (Chironomus sp. and Siphlonurus sp.) recorded the highest MP load per gram wet weight, while the predatory Lestes viridis recorded the lowest. The highest diversity of polymers was recorded in Chironomus sp. of Ogun River, i.e. styrene ethylene butylene styrene, acrylonitrile butadiene styrene (ABS), chlorinated polyethylene, polypropylene (PP), and polyester, while two polymers each were recorded in Siphlonurus sp. (i.e. polyester and ABS) and L. viridis (i.e. polyester and PP) of Osun River. We conclude that collector-gatherers like Chironomus sp. and Siphlonurus sp. could be best employed as MP bioindicators in freshwater systems. However, their suitability as MP bioindicators should be further investigated in different freshwater ecosystems worldwide. Graphical abstract.


Assuntos
Plásticos , Poluentes Químicos da Água/análise , Animais , Ecossistema , Monitoramento Ambiental , Água Doce , Guiné , Insetos , Microplásticos , Nigéria
16.
Zookeys ; 930: 61-74, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32390748

RESUMO

During a soil zoological expedition to São Tomé and Príncipe in 2010 by the California Academy of Sciences, millipedes of the genus Globanus were collected. Samples of G. marginescaber (Karsch, 1884) and G. integer (Karsch, 1884) were recovered in addition to those containing a new species. Globanus drewesi sp. nov. is described and additional records, illustrations, and descriptive notes are given for the other two species. A key to all three species of the genus is provided, and a distribution map is presented. The monotypic genus Lobogonus Demange, 1971, which includes L. trilobatus Demange, 1971, from Sierra Leone, mainland western Africa, is revalidated and removed from synonymy under Globanus. Lobogonus is illustrated from a type specimen.

17.
Sci Total Environ ; 730: 139013, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32416503

RESUMO

Baseline microplastic pollution and the occurrence, spatial distribution and ecological risk of microplastic-sorbed phthalate esters (PAEs) in littoral sandflat sediments of the Gulf of Guinea were investigated. A total of 150 sediment samples were collected using a 0.5 × 0.5 × 0.2 m quadrant placed along designated high, drift and current waterlines at five (5) beaches. Analysis for 6 PAEs-sorbed to microplastics (MPs) was carried out using gas chromatography - mass spectrometry (GC-MS). Microplastic particles (1-5 mm) were identified visually and FTIR spectroscopy was also used for identification. The MPs distribution was variably heterogenous with a total of 3424 particles per m2 found within the drift and high waterlines across all sites. Results indicated fragments as the dominant microplastic type compared to pellets and fibres. Polyethylene terephthalate was the major polymer type and accounted for a weighted average of 41% of the total plastics, followed by polystyrene (28%), and polypropylene (21%). The ∑6PAEs concentration ranged from BDL to 164.09 mg/kg dw, dominated by di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DnBP), and dimethyl phthalate. The preliminary ecological risk assessment of PAEs in the microplastic fraction, RQmp, showed DEHP and DnBP may present medium to high biological risks to marine organisms, suggesting that future study of PAEs in total sediment versus the MP fraction might be useful to refine ecological risk assessments. Land-based anthropogenic activities are primary sources of MPs, whereas oceanographic peculiarities of the area constitute the major distribution driving force.

18.
Zootaxa ; 4742(1): zootaxa.4742.1.2, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32230389

RESUMO

Trindade and Martin Vaz (TMV) is a highly isolated, oceanic volcanic archipelago located approximately 1200 km off the Brazilian coast and about 4200 km away from the nearest African coast. It has been almost 70 years since the first sea star, "Astropecten sp.", was recorded from Trindade in 1951. In the following years (1955-1971; 2006) six sea star species were added to the archipelago's fauna. After that period, however, research on shallow water echinoderms has not been conducted in TMV and no further sea star species have been recorded from there since. From 2012 to 2019, 263 daytime SCUBA diving and intertidal samplings conducted at TMV yielded 91 lots of sea stars in 7 species: Linckia guildingi Gray, 1840; Oreaster reticulatus (Linnaeus, 1758); Astropecten aff. antillensis Lütken, 1859; Copidaster lymani A. H. Clark, 1948; Luidia alternata alternata (Say, 1825); Mithrodia clavigera (Lamarck, 1816); and Ophidiaster guildingi Gray, 1840. The last five species in this list represent new records to the archipelago, with C. lymani also being the first record of the species in the southwestern Atlantic. Five shallow water species previously known from TMV have not been observed in the present survey: Asterinides folium (Lütken, 1860), Astropecten brasiliensis Müller Troschel, 1842, Astropecten cingulatus Sladen, 1883, Linckia nodosa Perrier, 1875, and Ophidiaster alexandri Verrill, 1915. Twelve sea star species are currently known from shallow waters of TMV.                A list of all sea star species known from shallow waters (intertidal down to 100 meters) of the tropical southern-central Atlantic oceanic archipelagoes and islands (Ascension, Cape Verde, Fernando de Noronha, Gulf of Guinea, Rocas Atoll, Saint Helena, Trindade and Martin Vaz) with their gross distribution in the Atlantic Ocean was compiled in order to explore the existence of patterns of geographic distribution for the shallow water sea star species in the tropical southern-central Atlantic oceanic islands. It has been found that 44% of the species from TMV are of western Atlantic affinity, 33% amphi-Atlantic, and 22% circumtropical in distribution. No endemic sea star species are known from TMV to date. The even more remote Ascension (ASC) and Saint Helena (STH) are more of a mosaic than TMV. The ASC and STH fauna consist of 8 and 11 sea star species, respectively. Their endemic component totals to 25% and 27%, respectively. STH has more amphi-Atlantic and eastern Atlantic sea star species (27% each) than ASC (25% and 12.5%, respectively). Twenty-five percent of the sea star species in ASC are circumtropical in distribution, whereas no circumtropical species have been found in STH. The western Atlantic (WA) component comparatively to the eastern Atlantic (EA) one is of minor significance in STH (18% versus 27%, respectively), whereas the WA and EA components contribute equally to the taxonomic composition in ASC (12.5% each). However, patterns of faunal affinities in both islands are actually taxon-dependent.


Assuntos
Equinodermos , Estrelas-do-Mar , Animais , Oceanos e Mares
19.
Ecol Evol ; 7(11): 3645-3656, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28616162

RESUMO

Oceanic islands share several environmental characteristics that have been shown to drive convergent evolutionary changes in island organisms. One change that is often assumed but has seldom been examined is the evolution of weaker immune systems in island species. The reduction in species richness on islands is expected to lead to a reduced parasite pressure and, given that immune function is costly, island animals should show a reduced immune response. However, alternative hypotheses exist; for example, the slower pace of life on islands could favor the reorganization of the immune system components (innate vs. acquired immunity) on islands. Thus far, few island species have been studied and no general patterns have emerged. Here, we compared two immune parameters of birds from São Tomé and Príncipe islands to those of their close relatives at similar latitudes on the mainland (Gabon, West Africa). On islands, the acquired humoral component (total immunoglobulins) was lower for most species, whereas no clear pattern was detected for the innate component (haptoglobin levels). These different responses did not seem to arise from a reorganization of the two immune components, as both total immunoglobulins and haptoglobin levels were positively associated. This work adds to the few empirical studies conducted so far which suggest that changes in immune parameters in response to insularity are not as straightforward as initially thought.

20.
Acta Trop ; 171: 86-89, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28377219

RESUMO

Biological invasions have critical impacts on native biodiversity and human societies and especially on oceanic islands that are fragile and threatened ecosystems. The invasive tiger mosquito Aedes (Stegomyia) albopictus (Skuse, 1894) native to Southeast Asia has been introduced during the past 30 years almost everywhere in the world, including the Americas, the Pacific, Europe and Africa. It has been reported for the first time in the Gulf of Guinea in 2000, first in Cameroon, then in Bioko Island in 2003 and more recently in Gabon in 2007. Here we report the first record of Ae. albopictus on São Tomé Island. Although we cannot estimate precisely the year of introduction on São Tomé Island, it most likely arrived within the last 10 years. By sequencing the mitochondrial cytochrome c oxidase gene from individual adults, we detected three haplotypes already present in mainland Africa. More studies are needed to explore the dynamics of its expansion and competition with insular native mosquitoes.


Assuntos
Aedes/genética , Distribuição Animal , Aedes/classificação , Aedes/fisiologia , Animais , Camarões , Complexo IV da Cadeia de Transporte de Elétrons/genética , Gabão , Genes Mitocondriais , Haplótipos , Humanos , Ilhas , Especificidade da Espécie
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