Northern Coast Of Brazil Research Articles

Prediction of the potential Brazilian distribution for invasive mollusc Melanoides tuberculata (Müller, 1774), including a new record from Northern Coastal Region

The freshwater snail Melanoides tuberculata (Müller, 1774) native from Africa and Asia, recently spreads out over the world. Records of invasive species are extremely important, because it helps in future invasions mitigation. Here, we report for the first time the occurrence of M. tuberculata in a protected area of Northern Brazilian Coast and use predictive distribution modeling to know the potential Brazilian distribution for this species. The gastropod M. tuberculata were collected in the municipalities of Tutóia and Santo Amaro - Maranhão State. According to the results of the predictive map distribution for Brazil, the regions with the highest susceptibility are the northeast, southeast and midwest. Preciptation of month and Isothermalithy were de variables that most contribute to the species’ potential distribution. This species presented high to medium suitability of occurrence in 32 national protected areas. Futher studies are recommended to monitor the growth and dispersion, in order to determine its real impact.

Variation in macrobenthic community of vegetated and unvegetated habitats in a macrotidal estuary of northern Brazilian Amazon coast

Variation in macrobenthic community of vegetated and unvegetated habitats in a macrotidal estuary of northern Brazilian Amazon coast

New occurrences, mean infestation intensity and prevalence of parasitic isopods (Isopoda, Cymothoida, Bopyridae) associated with Macrobrachium amazonicum (Decapoda, Palaemonidae) from the mouth of the Amazon River.

The Amazon prawn or Macrobrachium amazonicum (Heller, 1862) is widely distributed in South America, occurring in the Orinoco and Amazon rivers, and forms an important source of income for riverside families. This prawn hosts crustacean ectoparasites of the genus Probopyrus (Giard & Bonnier, 1888) (Bopyridae) that infest its gill cavity. The aim of the present study was to report new occurrences of Probopyrus in Amazon prawns caught in the Amazon River. Macrobrachium amazonicum prawns were collected between May 2017 and April 2018, and again from July 2021 to May 2022 in the regions of Ilha de Santana and Rio Mazagão, state of Amapá, Brazil. Among the 5,179 prawn specimens caught, 133 were parasitized by the ectoparasites Probopyrus pandalicola (Packard, 1879), Probopyrus bithynis (Richardson, 1904), Probopyrus floridensis (Richardson, 1904) and Probopyrus palaemoni (Lemos de Castro & Brasil Lima, 1974). These occurrences of P. floridensis and P. palaemoni in M. amazonicum were the first records of this on the northern coast of Brazil. These four ectoparasites are not limited to specific host species or genera, as observed in this study, which reports four species of Probopyrus infesting M. amazonicum.

Opportunistic sightings of manta rays on Brazil's Amazon Coast.

Little is known about the ecology and distribution of mobulid rays along Brazil's extensive coastline. Here we report opportunistic sightings of manta rays (Mobula cf. birostris) in the Brazilian Amazon estuaries and the Great Amazon Reef System. These sightings consist of manta ray individuals stranded in tide pools, caught in artisanal fisheries, and footage obtained with a submersible. Future investigations on the spatial, temporal, and environmental drivers of manta rays' distribution on the northern Brazilian coast and the threats posed by fishing gear are warranted.

A new species of Thaisella (Neogastropoda: Muricidae) from the northern Brazilian coast

A new species of Thaisella (Neogastropoda: Muricidae) from the northern Brazilian coast

Ecological notes and occurrence of Astrangia solitaria (Le Sueur, 1817) (Cnidaria: Astrangiidae) for the Northern Brazilian Coast

Ecological associations are widely reported in literature, covering several levels in the trophic chain or with different species interaction. However, the epibiosis between coral and gastropod species is still rarely observed in Brazil. Therefore, herein we report the epibiosis between the coral species Astrangia solitaria (Le Sueur, 1817) and the gastropod Turbinella laevigata Anton, 1838, additionally, extending the distribution of A. solitaria from the northern Brazilian coast (State of Amapá). The species were collected as bycatch fauna during commercial fishing operations along the continental shelf of Amapá, under the supervision of Center for Research and Management of Fisheries Resources of the North Coast (CEPNOR). This paper increases the northernmost record of A. solitaria and expands its epibiosis interaction with T. laevigata.

First Molecular Identification of a Goussia Parasite from a New World Invasive Blenny.

Introduced or invasive fish are susceptible to new parasites but can simultaneously carry infectious parasites from their native range towards new hosts. Screening these parasites is key to address the health of fish populations and spread of diseases. In this study, we sequenced a Coccidia parasite, for the first time from the blenny Omobranchus sewalli, introduced in the northern coast of Brazil with an Indo-Pacific origin. Only one individual was infected, its genetic sequence matched (over 99%) with two lineages of undetermined species, belonging to the genus Goussia, sequenced from three marine fish species (Mulloidichthys flavolineatus, Lutjanus kasmira, and Selar crumenophthalmus) in Hawaii. Phylogenetic analysis suggests considerable differentiation between the Goussia detected and other Goussia spp. sequenced from North Atlantic marine fish, thus we cannot exclude the possibly that this parasite was carried by O. sewalli from its native Indo-Pacific range.

Shark bycatch of the acoupa weakfish, Cynoscion acoupa (Lacèpede, 1801), fisheries of the Amazon Shelf

In recent years, the populations of many shark species have been depleted drastically around the world. In the present study, we analyzed the shark bycatch in the monthly landing data of the acoupa weakfish (Cynoscion acoupa) gillnet fisheries of the state of Pará, on the northern coast of Brazil, between January 1995 and December 2007. Based on 4,659 landings, we estimated that a total of 1,972.50 tons of shark were taken as bycatch during the study period. The acoupa weakfish fisheries operate on the Amazon Shelf, an important fishing ground, and we analyzed the shark landings in relation to the Amazon River Discharge anomaly (ARD) and the climatic variability in the Atlantic Ocean. We applied cross-correlation, cross-wavelet, wavelet coherence, and redundancy analysis techniques to the analysis of the data time series. The shark bycatch landings peaked between 1998 and 2000, a period associated with an increase in fishing effort by the acoupa weakfish fisheries, in particular during the dry season of the Amazon basin. The cross-correlation analysis indicated that shark landings were associated with Sea Surface Temperatures (SSTs), the characteristics of the wind, and the Atlantic Multidecadal Oscillation (AMO), while the fishing effort of the acoupa weakfish fisheries was associated with the meridional wind component, the AMO, and the ARD. The cross-wavelet and coherence wavelet analyses indicated that environmental variability was linked systematically with shark landings and acoupa weakfish fishing effort. We observed a phase change in this signal between 1998 and 2000, due to a strong and persistent La Niña event. Despite the resistance from the fishing industry, development and deployment of devices designed to reduce bycatch should be incentivized in order to reduce the unintentional capture of endangered species such as sharks. The findings of the present study highlight the importance of a continuous and accurate fishery database, and the need for continuous fishery statistics to ensure adequate management practices. Adequate public fishery management policies must be implemented urgently to guarantee the survival of shark species, with the effective participation of all the actors involved in the process, including managers, researchers, and fishers.

Does dredging activity exert an influence on benthic macrofauna in tropical estuaries? Case study on the northern coast of Brazil

Does dredging activity exert an influence on benthic macrofauna in tropical estuaries? Case study on the northern coast of Brazil

Morphological identification of Skrjabinisakis Mozgovoi, 1951 (Nematoda: Anisakidae) in Kogia sima (Cetacea: Kogiidae) from Brazilian waters.

New morphological, morphometric and scanning electron microscopy data of a nematode of the family Anisakidae, recovered from a specimen of Kogia sima, a cetacean that died off the northern coast of Brazil, are presented in this paper. Morphological features such as the violin-shaped ventricle and short and equal spicules, as well as the distribution of post-cloacal papillae and specificity for the definitive host (Kogiidae cetaceans) demonstrate similarity to Skrjabinisakis paggiae. This research records Kogia sima and S. paggiae on the estuarine coast of Pará, northern Brazil.

Taphonomic feedback, paleoecology, and ostracod biostratigraphy of the Oligocene-Miocene carbonate deposits in the onshore Pará-Maranhão Basin, Northern Brazil

The Oligocene-Miocene carbonates of the Bragantina Platform are represented by densely fossiliferous rocks, which overlay the basement of the Northern Brazilian coast. Outcrop-based stratigraphy analysis combined with petrography, taphonomy, paleoecology, and ostracod biostratigraphy was carried out in the eight (8) m-thick of the Neogene mixed carbonate-siliciclastic succession exposed mainly in the Atalaia Beach. This outcrop is the classical exposure of the Pirabas Formation, generally overlaid by the siliciclastic deposits of the middle Miocene Barreiras Formation. The taphonomic signature in the last carbonate beds of this sedimentary succession indicates intense storms as autogenic processes succeeded by rapid allogenic burial by Barreiras’ deposits. These processes caused death, disarticulation, and accumulation of the benthic communities in the shallow platform, forming a coquina substrate (Taphofacies 1). During a low-energy period, shell-gravel-dwelling individuals represented mainly by Turbinella tuberculata and Mercenaria prototypa colonized this carbonate hardground (Taphofacies 2). Forced regression of Barreiras’ siliciclastics caused a fast shift of continental facies over coastal carbonate zones. The rapid burial culminated in the death of benthic communities creating a geochemical environment propitious for the pyritization of shells, leaves, and trunks (Taphofacies 3). The ostracod biozonation formed by the Cytherella stainforthi biozone and by the Quadracythere brachypygaia, Jugosocythereis pannosa, and Neocaudites macertus sub-biozones support the paleoenvironmental interpretation, chronocorrelation with the Caribbean units and confirm the Miocene age for this carbonate succession. Although taphonomic, paleoecologic, and biostratigraphic studies were carried out in a unique occurrence of the Pirabas Formation. These high-resolution stratigraphy analysis allowed the discovery of the details of this burial event that led to the shutdown of carbonate fabric on the Eastern Amazon Coast.

Multi-Sensor Remote Sensing of Intertidal Flat Habitats for Migratory Shorebird Conservation

Many species of shorebirds migrate long distances from their overwintering grounds in the southern hemisphere to breeding grounds in the northern hemisphere. The coastal intertidal zone, consisting of sand and mud flats exposed at low tide and covered at high tide, is heavily used as a migratory stopover or overwintering habitat. Understanding the spatial distribution of sediment types at these stopover sites is a critical step for understanding habitat use by shorebird species. Due to their importance as overwintering and stopover habitat for the imperiled western Atlantic subpopulation of the shorebird, the red knot (Calidris canutus rufa), as well as other migratory shorebirds, the northern coast of Brazil between Pará and Maranhão, and Bahía Lomas in northern Tierra del Fuego, Chile, were selected for further investigation as to the applicability of remotely sensed characterization of the intertidal flat habitats. Examination of the Landsat 8 multispectral reflectance and Sentinel-1 SAR backscatter reveals that sand and mud represent endmembers at opposite ends of a continuous gradient in feature space. While remotely sensed data can be used to discriminate between mud and sand intertidal types, the spectral relationships varied between the two very different geographic locations. The inclusion of both multispectral and radar sensing imagery can lead to important insights about the physical properties of the sediment that would be omitted by using one data source alone. Spectral unmixing techniques in Google Earth Engine were used to map the intertidal zone into general sediment classes spanning the gradient (i.e., mud, sandy mud, muddy sand, and sand). Comparison of the mapped outputs with field reference data suggests that mapping of mud- vs. sand-dominated areas can be accomplished with reasonable accuracy (overall accuracy of 75%).

Accelerated migration of mangroves indicate large-scale saltwater intrusion in Amazon coastal wetlands.

Saltwater intrusion can dramatically transform coastal ecosystems, changing vegetation and impacting wildlife and human communities who rely on these natural resources. This phenomenon is difficult to measure over large and remote areas but can be inferred from changes in the distribution of salt-tolerant vegetation, such as mangroves, observable from satellite imagery. The northern coast of Brazil has the largest continuous mangrove forest in the world and very low human occupation. Even so, saltwater intrusion and changes to the coastline have been reported in this region, with potential consequences for mangrove carbon storage and for local livelihoods, but this has not been quantified due to the remoteness of the area. This study measured changes in mangrove distribution along the Northern Brazil coast in the state of Amapá, covering ca. 15,000 km2, over the last 38 years using Landsat satellite imagery. We found that mangrove area in this region is highly dynamic, with significant gains and losses occurring over the study period, but with an overall net gain of 157 km2. Mangroves have been systematically expanding inland and this growth has accelerated close to the shoreline and at the head of tidal channels in the last two decades, indicating rapid and large-scale saltwater intrusion in this region. This phenomenon is likely driven by sea level rise, which also accelerated in this region in recent decades, but anthropogenic impacts such as buffalo grazing may also play an important role.

New Insight Into the Reproductive Biology and Catch of Juveniles of the Lutjanus purpureus in a Portion of the Great Amazon Reef System Off the Northern Brazilian Coast

The Southern red snapper, Lutjanus purpureus, is a valuable economic resource, especially in international market. However, no recent data are available on the reproductive biology of this species in Brazilian waters, in particular, the stock found on the Amazon reef. The present study evaluated the population structure and reproductive biology of L. purpureus, and the volume of the catch of juveniles taken by the local commercial fisheries. A total of 923 specimens were analyzed, of which, 577 were female and 346 male (sex ratio: 0.6:1; p < 0.05). The analysis of the gonadosomatic index (GSI) and the distribution of maturation stages indicated that the males and females are able to reproduce throughout the year, however the reproductive peak occurs simultaneously with the increase in the water discharge of the Amazon River. The spawning females were registered in the study area, indicating that L. purpureus does not perform long distance reproductive migrations, different from the previously proposed. The Fork length at first sexual maturation (FL50) was estimated to be 35.2 cm in the males and 32.1 cm in the females. The high frequency of juveniles (< FL50) captured by the commercial snapper fleet using longlines (33.67% of the total catch) and traps (42.1%) indicates the poor selectivity of the fishing gear used by the snapper fleet, which may contribute to the accelerated depletion of the L. purpureus stock. Although the results of this study show a catch percentage of juveniles >50%, it is still a significant percentage of juveniles that are being caught due to little or no guidance and enforcement of fishing gear to ensure compliance with current legislation. Considering the data presented in this study and the current situation of declining fish stocks of L. purpureus, an assessment is recommended for the inclusion of the species in the IUCN Red List of Threatened Species, which is currently a species categorized as “vulnerable” in the Brazilian Red List.

Brazil Wave Climate from a High-Resolution Wave Hindcast

A detailed climatology of ocean wind waves in the South Atlantic Ocean, based on ERA-5 reanalysis and in a higher-resolution wave hindcast (ERA-5H), both developed by the European Centre for Medium-Range Weather Forecasts, is presented. The higher resolution of the wave fields in the ERA-5H (22 km) allowed for a better description of the wind sea and swell features compared to previous global and regional studies along the Brazilian coast. Overall, it is shown that swell waves are more prevalent and carry more energy in the offshore area of the study area, while wind sea waves dominate the nearshore regions, especially along the northern coast of Brazil. The influence of different climate indices on the significant wave heights patterns is also presented, with two behavioral groups showing opposite correlations to the North Atlantic Oscillation and Southern Annular Mode than to the Southern Oscillation Index. The analysis of the decadal trends of wind sea and swell heights during the ERA-5H period (1979–2020) shows that the long-term trends of the total significant wave height in the South Atlantic Ocean are mostly due to swell events and the wave propagation effect from Southern Ocean storms.

Genetic Structure of the Mangrove Killifish Kryptolebias hermaphroditus Costa, 2011 (Cyprinodontiformes: Aplocheiloidei) Supports A Wide Connection among its Populations.

The Kryptolebias marmoratus species group is composed of the only three vertebrate species that lack females. These species present only males and simultaneously hermaphroditic individuals; that are able to reproduce by allogamy, with males, or by autogamy, performing self-fertilization and generating clones of themselves. The proportion of males is variable among those species and even among their populations. Kryptolebias hermaphroditus has the smallest proportion of males. Indeed, no males have been recorded in most known populations. This is a mainly autogamous species, with small populations having a disjunct distribution along the eastern and northern coast of Brazil. Species presenting such adaptations would be expected to have an elevated rate of genetic population structure, reflecting any barriers that obstruct gene flow between populations. Partial sequences of the mitochondrial cytochrome c oxidase I (COI) gene from 335 individuals were sampled to perform a population analysis. Only a single haplotype of COI, widely distributed throughout all the sampled populations, was recovered for K. hermaphroditus. Here we hypothesize that the high degree of communication within populations is probably the main biological feature leading to this pattern.

Carapace width/length-weight relationships for portunid crabs (genus Callinectes Stimpson, 1860) in northern Brazilian mangrove estuaries

Carapace width-carapace length (CW/CLRs), carapace width-weight (CW/WRs), and carapace length-weight (CL/WR) relationships are presented for the portunid species Callinectes bocourti A. Milne Edwards, 1879, Callinectes danae Smith, 1869, and Callinectes ornatus Ordway, 1863 from the northern coast of Brazil. A total of 85 crabs were collected between May and October 2015 in intertidal zones of the Caeté, Pirabas and Salinas estuaries. All species had strong relationships between measurements with a coefficient of determination (r 2) ranging between 0.97 and 0.99. The variable most strongly related to CW was CL with 99 % of the variability provided by C. ornatus. These relationships are a useful tool for field ecologists to estimate length and/or mass of portunid species, and it is not necessary to euthanize the organism to collect body measurements. Additionally, this study describes the first reference of CW/CLRs and CL/WRs for these portunid species in the region. The Callinectes species in Amazon estuaries are still poorly studied, and there is a need for monitoring their stocks due to its importance for artisanal fishery. The present data are important for supplying biological information required for an adequate management of this fishery.

Modelling the dynamic response of shallow methane hydrates to simultaneous sea level and bottom water temperatures variations since the last glacial maximum on the Amazon Deep-Sea Fan, Brazil

In marine sediments, methane hydrate can occur within the methane hydrate stability zone (MHSZ), which extends from the seafloor to a certain depth below it, within which the conditions of pressure and temperature are such that allow their formation and stability. Variations in sea level and in bottom water temperatures (BWTs) have opposite effects on the stability zone: a sea level rise leads to higher hydrostatic pressure, which tends to enlarge the MHSZ, while an increase in temperature tends to shrink it, and vice-versa. When the MHSZ shrinks, methane hydrate dissociates, releasing water and gaseous methane into the sediment pores. If the gaseous methane reaches the seafloor, it will be released into the ocean. In this study, we use numerical modelling to investigate the dynamic response of shallow methane hydrates at 550, 575, 600, 625, 650, 700 and 750 m water depth (mwd), on the Amazon Deep-Sea Fan, Equatorial Atlantic Ocean (near the northern coast of Brazil), to simultaneous sea level and BWTs increases, since the Last Glacial Maximum (LGM) up to the present. These water depths lie on the feather edge of the MHSZ, where hydrates are most sensitive to pressure and temperature perturbations. The results suggest that the methane hydrate stability decrease caused by the BWTs increases has completely overcome the increase in stability owing to sea level increase, for 550 and 575 mwd. For these two water depths, the MHSZ disappeared in the models and all the hydrate initially present has dissociated. The modelling results indicate that gaseous methane started to be released into the ocean at ca. 17,500 y BP for 550 mwd and at ca. 16,000 y BP for 575 mwd. For the other water depths considered, hydrate stability decrease caused by the BWT increase has only partly overcome the increase in stability due to pressure increase, so that the MHSZs have shrank, but have not totally disappeared in the models. Gaseous methane was released into the ocean from ca. 14,000 y BP to 7000 y BP for 600 mwd. For 625, 650, 700 and 750 mwd, no gaseous methane has been released into the ocean. Methane release amounts and flowrates are maximum limits for each depth, as no methane consumption processes, such as anaerobic oxidation, are modeled in this study.

The impact of climate suitability, urbanisation, and connectivity on the expansion of dengue in 21st century Brazil

Dengue is hyperendemic in Brazil, with outbreaks affecting all regions. Previous studies identified geographical barriers to dengue transmission in Brazil, beyond which certain areas, such as South Brazil and the Amazon rainforest, were relatively protected from outbreaks. Recent data shows these barriers are being eroded. In this study, we explore the drivers of this expansion and identify the current limits to the dengue transmission zone. We used a spatio-temporal additive model to explore the associations between dengue outbreaks and temperature suitability, urbanisation, and connectivity to the Brazilian urban network. The model was applied to a binary outbreak indicator, assuming the official threshold value of 300 cases per 100,000 residents, for Brazil's municipalities between 2001 and 2020. We found a nonlinear relationship between higher levels of connectivity to the Brazilian urban network and the odds of an outbreak, with lower odds in metropoles compared to regional capitals. The number of months per year with suitable temperature conditions for Aedes mosquitoes was positively associated with the dengue outbreak occurrence. Temperature suitability explained most interannual and spatial variation in South Brazil, confirming this geographical barrier is influenced by lower seasonal temperatures. Municipalities that had experienced an outbreak previously had double the odds of subsequent outbreaks. We identified geographical barriers to dengue transmission in South Brazil, western Amazon, and along the northern coast of Brazil. Although a southern barrier still exists, it has shifted south, and the Amazon no longer has a clear boundary. Few areas of Brazil remain protected from dengue outbreaks. Communities living on the edge of previous barriers are particularly susceptible to future outbreaks as they lack immunity. Control strategies should target regions at risk of future outbreaks as well as those currently within the dengue transmission zone.

Better Alone Than in Bad Company: New Species of Caudofoveate Limifossorid (Mollusca, Aplacophora) Unravels Patterns of Distribution Hidden in the Deep Atlantic

Aplacophorans are common inhabitants of the deep-sea, where many places remain unexplored regarding their biodiversity. Filling a gap in knowledge about these animals from the South Atlantic, Scutopus variabilis sp. nov. (Caudofoveata, Limifossoridae) is described; further, species distribution modelling (SDM) was performed to elucidate the distribution patterns of Atlantic species of Scutopus. The type materials of S. megaradulatusSalvini-Plawen (1972) and S. chilensisSalvini-Plawen (1972), were examined and a search was performed for specimens of Scutopus held in museum collections. Scutopus variabilis sp. nov. has a slender and highly variable body form and a very distinct suture line is present midventrally. Two dominant types of trunk sclerites were observed by Scanning Electron Microscopy (SEM): one elongated with lateral margins slightly concave in medial portion, and another longer, with narrower base; its radula bears up to eight rows of heavily sclerotized teeth bearing 12–16 small denticles. The species occurs in a wide bathymetric range (40–1300 m), being more abundant at the edge between the continental shelf and upper slope. Outside the areas from where these samples were obtained, suitable areas for S. variabilis sp. nov. were found in the Southern Caribbean Sea (from where S. megaradulatus is recorded) and in the Brazilian Northern coast; the Gulf of Mexico and the Brazilian Northeastern coasts were found as unsuitable. Species of Scutopus appear to exhibit different patterns of geographical distribution: the European S. ventrolineatusSalvini-Plawen (1968) and S. robustusSalvini-Plawen (1970) are known as widely distributed, while non-European representants, the American S. megaradulatus, S. chilensis and S. variabilis sp. nov., and the Japanese S. schanderiSaito and Salvini-Plawen (2014) and S. hamatamiiSaito and Salvini-Plawen (2014) have more restricted distributions. However, clear and definite patterns of distribution of some of these species are probably blurred by sampling bias, for the European area is better studied. In the Atlantic, the SDM showed that species of Scutopus occur in a way that overlapping is minimized. Great sampling efforts combined with detailed descriptions based on SEM have revealed an interesting, abundant and up to now undescribed Brazilian deep-sea malacofauna.