Atlantic Ocean Coast Research Articles

Halogenated natural products and anthropogenic persistent organic pollutants in chokka squid (Loligo reynaudii) from three sites along the South Atlantic and Indian Ocean coasts of South Africa

Chokka squid (Loligo reynaudii) from three sites along the South African coast were analyzed for halogenated natural products (HNPs) and anthropogenic persistent organic pollutants (POPs). HNPs were generally more than one order of magnitude more abundant than POPs. The most prevalent pollutant, i.e. the HNP 2,3,3′,4,4′,5,5′-heptachloro-1′-methyl-1,2′-bipyrrole (Q1), was detected in all chokka squid samples with mean concentrations of 105, 98 and 45 ng/g lipid mass, respectively, at the Indian Ocean (site A), between both oceans (site B) and the South Atlantic Ocean (site C). In addition, bromine containing polyhalogenated 1′-methyl-1,2′-bipyrroles (PMBPs), 2,4,6-tribromophenol (2,4,6-TBP, up to 28 ng/g lipid mass), polybrominated methoxy diphenyl ethers, MHC-1, TBMP and other HNPs were also detected. Polychlorinated biphenyls (PCBs) were the predominant class of anthropogenic POPs. PCB 153 was the most abundant PCB congener in chokka squid from the Indian Ocean, and PCB 138 in samples from the South Atlantic Ocean and between both oceans.

Seasonal and diurnal trends of surface refractivity in a tropical environment using ground-based automatic weather stations

The seasonal and diurnal trends of surface refractivity were derived using International Telecommunication Union Radio assembly model (ITU-R P.453-13) in two locations of entirely different vegetation characteristics in Nigeria. Atmospheric refractivity is a function of temperature, pressure as well as humidity. These meteorological variables were applied to the model to compute the refractivity parameter. Atmospheric refraction or refractivity is a key component in radio wave propagation. Real-time measurement data from a network of ground-based automatic weather station (AWS) installed at 3 m height were used and the monthly trends of surface refractivity at both stations (Lagos and Anyigba) were derived; the trends showed a month-to-month variability signifying the dynamic nature of the Earth’s atmosphere. The monthly trends in both stations show high refractivity values in the rainy months and low refractivity values in the dry months. A drop in refractivity value was observed in Lagos in the month of August, due to the cessation in rainfall as a result of a phenomenon referred to as August break. The diurnal variations were also determined and results obtained showed that the lowest refractivity value in the dry season observed in Lagos is higher than the highest refractivity value in rainy season observed in Anyigba. This is attributed to the fact that Lagos is located along the coast of the South Atlantic Ocean, therefore, the monsoon has a direct influence on its atmosphere, while Anyigba is an inland station with a mixture of savannah vegetation. Overall, the diurnal variations show high values in the morning and evening hours and low values in the afternoon hours in both seasons in Anyigba, while in Lagos we observed a surprising result, such as a rise in refractivity value at pre-noon and a post-noon drop. This unacquainted observation is probably due to excessive precipitation in the area caused by the influence of massive emissions from the South Atlantic Ocean, these emissions are mainly a result of the trapped heat due to warming of surface water.

Responses by Atlantic Ghost Crab (Ocypode quadrata) Populations to Hurricane Impacts on a Texas Beach: A 10-Year Study

The Atlantic ghost crab (Ocypode quadrata) is a widely distributed predator and scavenger along Atlantic Ocean and Gulf Coast beaches. A long-term study was initiated on the Bolivar Peninsula of Texas in 2006 to assess the impact of human activity on ghost crabs. Line transects were used to determine crab burrow arrangement at a high-impact site and a low-impact site. Differences were found between the two sites in number of active burrows per transect, burrow density, the diameter of burrow openings, burrow distance to the high-water line, and nearest-neighbor distances. In Fall 2008, Hurricane Ike struck the study sites. Re-examinations of the sites in 2010 showed changes in ghost crab burrows. The high-impact site experienced a decline in human activity – beach width increased by > 50%, the number of burrows/transect tripled, and nearest-neighbor distances decreased by one-third. The hurricane also reshaped the low-impact site on the western tip of the peninsula as beach width decreased by two-thirds, burrow density increased by sevenfold, and nearest-neighbor distances decreased by one-half. Sampling in 2012, 2014, and 2016 show that some of the physical characteristics of the beach gradually returned to near pre-hurricane status. However, reduced beach space at the low-traffic site remained, with higher burrow density and reduced crab size persisting 8 years after the hurricane, and the post-storm reduction in human traffic in the high-impact site has maintained higher burrow density there even as traffic increased. Monitoring the ecological impact of hurricanes is of growing importance as global climate change could lead to increased frequency and severity of tropical storms.

Controls on the erosion of the continental margin of southeast Brazil from cosmogenic 10Be in river sediments

The Atlantic Ocean coast region of southeast Brazil contains two coast-parallel mountain ranges (the Serra do Mar and Serra da Mantiqueira) generated by tectonic activity pulses tens of millions years after the main continental rift event occurred around 120 Ma. Although the short-term erosion rates for the region are established, the relative importance of the factors controlling erosion is poorly constrained. We combine new and published catchment-averaged erosion rates (n = 48) using in situ-produced 10Be concentrations in quartz from river sediments to establish the regional erosion pattern. The river catchments are (i) escarpment topography, (ii) high-altitude low-relief and (iii) mixed topography, which record how escarpment fronts are migrating inland. Ocean-facing coastal escarpment catchments of the Serra do Mar (ε = 18–53 m/Ma) can be eroded approximately twice as fast as continent-facing escarpment catchments in the Serra do Mar and Serra da Mantiqueira (ε = 7–24 m/Ma). The correlation between the normalized channel steepness index (ksn) and slope angle indicates that river incision and hillslope erosion processes combine to maintain the high relief. The Serra do Mar catchments define a mean slope angle threshold indicating that landslides are the dominant erosional process when slope angles in excess of ~30°. Tectonic activity is low and plays no significant role in driving erosion. A first-order relationship between erosion rate and precipitation-temperature across the region implies that climate plays a key role in soil production, river incision and in triggering erosional processes. Although the high topographic relief is a pre-condition for the occurrence of significant erosion, the climatic condition is the outlining factor of the regional variation in erosion rates.

First confirmed record of Branchiomma luctuosum (Annelida: Sabellidae) in marinas of southern Spain

Event Abstract Back to Event First confirmed record of Branchiomma luctuosum (Annelida: Sabellidae) in marinas of southern Spain Alejandro Fernández Romero1*, Juan Moreira Da Rocha2 and Jose Manuel Guerra-García1 1 University of Seville, Spain 2 Autonomous University of Madrid, Spain Introductions and spread of Non-Indigenous species (NIS) are one of the greatest threats to marine biodiversity around the world. One of the most investigated NIS is the fan worm Branchiomma luctuosum (Grube, 1870). Its type locality is in the Red Sea and has been later reported as a NIS in the Mediterranean Sea for the first time by Bianchi (1983). Since this finding, a dynamic non-stop invasion process has been recorded along the whole Mediterranean basin, from Turkish to Spanish coasts. In fact, B. luctuosum has been recently included in the list of the 100 worst invasive alien marine species in the Mediterranean Sea due to 1) its high densities in artificial and natural habitats, 2) ability to growth in nutrient-enriched water, 3) strategies of anti-predation, 4) ability to simultaneous hermaphrodite reproduction and 5) high capacity to outcompete other filter feeding organisms. However, in spite of its ability to successfully colonize new environments, its presence has not been confirmed yet on the European Atlantics coasts. The present study is within the framework of a project whose main objective is the characterization of the macrofaunal community associated with artificial structures in marinas. A total of 8 marinas were sampled along the Bay of Cádiz between September and October 2018. B. luctuosum was present in six of them being associated to the vertical surface of floating pontoons, very close to the water surface and usually in small aggregates. Some specimens have been detected associated to the fouling of ships hull; therefore, such finding involves the first evidence of its occurring in these biotopes. Anyway, all of them have been located on a few recreational ships with an obvious lack of maintenance. Thus, larval transport within water ballast generated by shipping traffic is probably the main introduction vector in the Atlantic Ocean coasts. To explore its invasion dynamics in these new colonized habitats, a monitoring program has been initiated aiming to 1) determining the presence and population densities of B. luctuosum both in marinas and natural habitats in the Atlantic coast of southern Spain and Portugal, 2) quantifying the biomass (wet weight) of B. luctuosum populations in comparison to other sessile species of the fouling on floating pontoons, and 3) describing the epibiont major taxa on tubes and aggregates of B. luctuosum. The present study represents the first documented record of B. luctuosum for the Atlantic marinas of the Iberian Peninsula. We also warn about its successful spread and establishment in these new environments along the east Atlantic Ocean. More studies are needed to understand the consequences of this invasion on the biodiversity of the Atlantic communities. Keywords: Branchiomma luctuosum, Marine invasions, Marinas, Southern Spain, Bay of Cádiz, Fouling community, Polychaeta Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019. Presentation Type: Poster Presentation Topic: Global Change, Invasive Species and Conservation Citation: Fernández Romero A, Moreira Da Rocha J and Guerra-García J (2019). First confirmed record of Branchiomma luctuosum (Annelida: Sabellidae) in marinas of southern Spain. Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00064 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Apr 2019; Published Online: 27 Sep 2019. * Correspondence: Mr. Alejandro Fernández Romero, University of Seville, Seville, Spain, afernandez66@us.es Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Alejandro Fernández Romero Juan Moreira Da Rocha Jose Manuel Guerra-García Google Alejandro Fernández Romero Juan Moreira Da Rocha Jose Manuel Guerra-García Google Scholar Alejandro Fernández Romero Juan Moreira Da Rocha Jose Manuel Guerra-García PubMed Alejandro Fernández Romero Juan Moreira Da Rocha Jose Manuel Guerra-García Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Búsqueda de primers y optimización de técnicas para la determinación de marcadores de ADN microsatélites en langostino argentino (Pleoticus muelleri)

El langostino argentino (Pleoticus muelleri) se distribuye a lo largo de las costas del Océano Atlántico Sudoccidental, entre los 20º y 50º de Latitud S. En Argentina constituye en la actualidad uno de los recursos de mayor importancia para la actividad pesquera. El elevado valor comercial de este crustáceo en los mercados internacionales lo ha situado como uno de los principales productos de exportación pesquera argentina, representando una participación del 61% del total de exportaciones del sector, con un ingreso anual superior a los 1.200 millones de dólares estadounidenses.
 En la actualidad, se dispone para la especie de un estudio genético restringido a la zona sur de su distribución (entre los 42 y 47º de latitud S) y que analiza la diversidad de un segmento de ADN mitocondrial del gen COI, y otro que estudia la variabilidad genética del langostino P. muelleri en toda su área de distribución geográfica mediante el análisis de un fragmento de ADN mitocondrial correspondiente al gen región control (CR).
 Este trabajo tiene como objetivo evaluar marcadores moleculares microsatélites como información de base para el estudio poblacional en el langostino argentino.
 A partir de bibliografía se seleccionaron cuatro (4) primers que permitieron amplificar microsatélites en otras especies de la misma familia (Solenoceridae).
 Solo se han obtenidos resultados de amplificación a partir de un par de iniciadores (ZG-71). La secuenciación de estos fragmentos no permitió detectar la conservación de los microsatélites esperados para el desarrollo del marcador específico.

High-resolution observations on enrichment processes in the sea-surface microlayer

For decades, researchers assumed that enrichment of dissolved organic matter (DOM) in the sea surface microlayer (SML) is solely controlled by changes in the DOM concentration at this uppermost thin boundary layer between the ocean and the atmosphere. We conducted high-resolution observations of fluorescent-DOM (FDOM) at 13 stations in the coastal and open Atlantic Ocean to understand the enrichment processes. Results show that FDOM enrichment in the SML varied between 0.8 and 2.0 (in comparison to the concentrations in the underlying water; ULW), and FDOM enrichment is a common feature of the SML despite the varied distances to the terrestrial sources. At six stations, the FDOM concentration in the SML was less variable over the sampling period (>5 h) compared to FDOM concentrations in the ULW characterized with sudden changes. Even so we observed slightly lower enrichments with increasing wind speeds and solar radiation, changes in ULW concentrations forced the enrichment to change. In addition, we found evidences for the occurrence of photochemical degradation of FDOM in near-shore SML with implications on coastal carbon cycling. Overall, the results show that the processes leading to the enrichment of DOM in the SML are more complex than previously assumed. Given the importance of the organic-rich SML as a diffusion layer in the air–sea exchange of climate-relevant gases and heat, understanding the layer’s enrichment processes is crucial.

Concentration of heavy metals in edible fishes from Atlantic Coast of Muanda, Democratic Republic of the Congo

The present study aims to determine the levels of heavy metals in edible nine different commonly consumed fish species (Pseudotolithus elongatus, Pseudotolithus senegalensis, Cynoglossus senegalensis, Trichiurus lepturus, Galeoides decadactylus, Pentanemus quinquarius, Chrysichthys nigrodigitatus, Mugil curema, and Arius latiscutatus). Fishes were collected during August 2016 from five sites of West Atlantic Ocean Coast of the Democratic Republic of the Congo. Heavy metals (Cr, Cu, Zn, Ni, Sb, Cd, Pb, and Se) levels in fish muscle tissues were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) whereas Hg analysis was carried out using atomic absorption spectrophotometry (AAS). Metal concentrations varied considerably among sampling sites and fish species (P < 0.05), with maximum values (in mg kg−1 wet weight) of 1.00 (Cr), 2.69 (Cu), 29.90 (Zn), 4.25 (Ni), 0.09 (Sb), 0.59 (Cd), 0.09 (Pb), 1.05 (Se) and 1.21 (Hg). Except for Hg, metal concentration in fish was within the permissible levels set by Food and Agriculture Organization, European Union, and World Health Organization for human consumption. However, taking into account the antagonistic effect of Se on Hg, analyzed fishes might have the protection from Hg toxicity. Thus, the results imply that investigated fishes from study area can be considered as safe for human consumption.

Self-reported Well-being and Perceived Health Status of Women in Child-Producing Age Living in Rural Communities on the Atlantic Ocean Coast in Southwest Nigeria

Background: The health and well-being of women have not been studied extensively and had not been the major focus of policy fabricators and decision makers in Nigeria. It is imperative to explore the factors influencing health and the well-being of women in child-bearing age (WCBA). Methods: This study was cross-sectional and descriptive in nature. It used semi-structured questionnaires in 9 domains of age-group, marital status, parity, educational status, religion, occupation, income of respondent, income of husband and pregnancy state, to collect data on perceived health and wellbeing from 829 WCBA living on the Atlantic Ocean coastline in Lagos, Southwest Nigeria. Results: Majority of the surveyed women were aged 25- 34 years (406, 49.0%), ever married (660, 79.6%), have had 1-2 children (347, 41.9%), had attained secondary level of education (548, 66.0%) and were traders (472, 57.6%). In all, 252(30.4%) had no monthly income and only 15(1.2%) had the highest monthly income of over US$166.8. In comparison, 331(39.9%) and 67(7.6%) of respondents’ husbands had no income or had income of over US$166.8 respectively. Only 19(2.3%) perceived their well-being to be very poor while 70(8.4%) and 165(19.9%) respectively perceived it to be neither poor nor good or to be good. In all, 50(6.5%) respondents were very dissatisfied with their health compared to 254(30.6%) who were very satisfied with their health. Of those with no income, 31.6% and 48.0% respectively perceived their well-being to be very poor and their health status to be very unsatisfactory. In this group also 24.2% and 27.6% respectively perceived their well-being to be very good and their health status to be very satisfactory. Of those with income ≥US$166.8, 5.3% and 2.8% respectively perceived their well-being to be very good and health status to be very satisfactory. Significant relationships were observed between level of satisfaction with one’s health, age, woman’s income as well as pregnancy state. Discussion: The findings indicate that the experiences of well-being and health status of women in child-bearing age, living on the Atlantic Ocean coastline varied by age, marital status and educational status. A more robust study is needed to appropriately measure these variances among women, accommodate them in policies for better empowerment of women.

Геодезическое обеспечение мониторинга береговой линии (на примере берега Атлантического океана Республики Бенин)

Геодезическое обеспечение мониторинга береговой линии (на примере берега Атлантического океана Республики Бенин)

Did the circum-Rodinia subduction trigger the Neoproterozoic rifting along the Congo–Kalahari Craton margin?

Early Neoproterozoic metaigneous rocks occur in the central part of the Kaoko–Dom Feliciano–Gariep orogenic system along the coasts of the southern Atlantic Ocean. In the Coastal Terrane (Kaoko Belt, Namibia), the bimodal character of the ca. 820–785 Ma magmatic suite and associated sedimentation sourced in the neighbouring pre-Neoproterozoic crust are taken as evidence that the Coastal Terrane formed as the shallow part of a developing back arc/rift. The arc-like chemistry of the bimodal magmas is interpreted as inherited from crustal and/or lithospheric mantle sources that have retained geochemical signature acquired during an older (Mesoproterozoic) subduction-related episode. In contrast, the mantle contribution was small in ca. 800–770 Ma plutonic suites in the Punta del Este Terrane (Dom Feliciano Belt, Uruguay) and in southern Brazil; still, the arc-like geochemistry of the prevalent felsic rocks seems inherited from their crustal sources. The within-plate geochemistry of a subsequent, ca. 740–710 Ma syn-sedimentary volcanism reflects the ongoing crustal stretching and sedimentation on top of the Congo and Kalahari cratons. The Punta del Este–Coastal Terrane is interpreted as an axial part of a Neoproterozoic “Adamastor Rift”. Its opening started in a back-arc position of a long-lasting subduction system at the edge of a continent that fragmented into the Nico Perez–Luis Alves Terrane and the Congo and Kalahari cratons. The continent had to be facing an open ocean and consequently could not be located in the interior of the Rodinia. Nevertheless, the early opening of the Adamastor Rift coincided with the lifetime of the circum-Rodinia subduction system.

Regional Acidification Trends in Florida Shellfish Estuaries: a 20+ Year Look at pH, Oxygen, Temperature, and Salinity

Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

Geology, biostratigraphy and carbon isotope chemostratigraphy of the Palaeogene fossil-bearing Dakhla sections, southwestern Moroccan Sahara

AbstractNew Palaeogene vertebrate localities were recently reported in the southern Dakhla area (southwestern Morocco). The Eocene sediment strata crops out on cliffs along the Atlantic Ocean coast. Vertebrate remains come from five conglomeratic sandstone beds and are principally represented by isolated teeth belonging to micromammals, selachians and bony fishes, a proboscidean assigned to ?Numidotheriumsp. and many remains of archaeocete whales (Basilosauridae). From fieldwork five lithostratigraphic sections were described, essentially based on the lithological characteristic of sediments. Despite the lateral variations of facies, correlations between these five sections were possible on the basis of fossil-bearing beds (A1, B1, B2, C1 and C2) and five lithological units were identified. The lower part of the section consists of rhythmically bedded, chert-rich marine siltstones and marls with thin black phosphorite with organic matter at the base. The overlying units include coarse-grained to microconglomeratic sandstones interbedded with silts, indicating deposition in a shallow-marine environment with fluvial influence. The natural remanence magnetization of a total of 50 samples was measured; the intensity of most of the samples is too weak however, before or after the first step of demagnetization. The palaeomagnetic data from the samples are very unstable, except for eight from three similar sandstone levels which show a normal polarity. Matched with biostratigraphic data on rodents, primates, the selachian, sirenian and cetacean faunas, the new carbon isotope chemostratigraphy on organics (1) refines the age of the uppermost C2 fossil-bearing bed to earliest Oligocene time and (2) confirms the Priabonian age of the B1 to C1 levels.

Climate control on late Holocene high-energy sedimentation along coasts of the northeastern Atlantic Ocean

Abundant sedimentological and geochronological data gathered on European sandy coasts highlight major phases of increased high-energy sedimentation in the North Atlantic Ocean during the late Holocene. Owing to an inconsistent use of the terminology, it is often difficult to determine whether studies have described storm-built or wave-built deposits. Both deposits can be identified by overall similar coarse-grained sedimentary facies, but may provide contradictory paleoenvironmental interpretations. The aim of this study is to address this issue, by analysing a set of published 14C ages recovered from wave-built sediment bodies of the Pertuis Charentais (France). Integration of 14C data highlights seven coarse-grained sedimentation pulses (CSPs) that reflect a synchronous increase in wave-induced sediment supply occurring around 2650, 2420, 1240, 970, 800, 650 and 450cal. yr B.P. CSPs can be matched with geochronological data published on other exposed sandy coasts of the western Europe. In first order, CSPs were preserved during phases of decreased storm activity and thus limited coastal erosion in the North Atlantic Ocean from 2700 to 2000 and from 1200 to 600cal. yr B.P. In second order, CSPs occurred during positive NAO and/or negative EA/WR peaks, which are known from previous studies to induce higher waves and to enhance wave-induced sediment transport in the Pertuis Charentais. Chronological boundaries of CSPs could be used as a diagnostic tool to differentiate storm deposits indicative of sudden, episodic very high-energy sedimentation from wave deposits resulting from the sustained action of above-average westerly winds blowing across the North Atlantic Ocean.

Chloromethane and dichloromethane in the tropical Atlantic Ocean

Chloromethane and dichloromethane were measured in the air of marine environment and in seawater during a cruise from the Port of Spain to Rio de Janeiro in the tropical Atlantic Ocean in April and May of 2009. Variation of chloromethane and dichloromethane concentrations was analysed as a function of latitude. There is no correlation observed between chloromethane and dichloromethane concentrations in the seawater suggest that they may not have a common oceanic source. In addition, a relation of concentrations, fluxes and sea surface temperature were studied to determine a dependency of concentrations and fluxes on sea surface temperature. Sea surface temperature does not show any significant effect on dichloromethane concentrations in surface seawater. Chloromethane and dichloromethane are supersaturated in the seawater during the cruise. This implies that the tropical Atlantic Ocean emits chloromethane and dichloromethane into the atmosphere. The tropical Atlantic Ocean mean fluxes of chloromethane and dichloromethane during the cruise were 150 nmol m−2 d−1 and 81 nmol m−2 d−1, respectively. The backward trajectory analysis revealed that the tropical Atlantic Ocean and African coast were primary and secondary source regions for chloromethane and dichloromethane respectively, during the Meteor cruise.

The oceanic influence on the rainy season of Peninsular Florida

AbstractIn this study we show that the robust surface ocean currents around Peninsular Florida, namely, the Loop and the Florida Currents, affect the terrestrial wet season of Peninsular Florida. We show this through two novel regional coupled ocean‐atmosphere models with different bathymetries that dislocate and modulate the strength of these currents and thereby affect the overlying sea surface temperature (SST) and upper ocean heat content. This study show that a weaker current system produces colder coastal SSTs along the Atlantic coast of Florida that reduces the length of the wet season and the total seasonal accumulation of precipitation over Peninsular Florida relative to the regional climate model simulation, in which these currents are stronger. The moisture budget reveals that as a result of these forced changes to the temperature of the upper coastal Atlantic Ocean, overlying surface evaporation and atmospheric convection is modulated. This consequently changes the moisture flux convergence leading to the modulation of the terrestrial wet season rainfall over Peninsular Florida that manifests in changes in the length and distribution of daily rain rate of the wet season. The results of this study have implications on interpreting future changes to hydroclimate of Peninsular Florida owing to climate change and low‐frequency changes to the Atlantic meridional overturning circulation that comprises the Loop and the Florida Currents as part of its upper branch.

Radar and optical mapping of surge persistence and marsh dieback along the New Jersey Mid-Atlantic coast after Hurricane Sandy

ABSTRACTThis study combined a radar-based time series of Hurricane Sandy surge and estimated persistence with optical sensor-based marsh condition change to assess potential causal linkages of surge persistence and marsh condition change along the New Jersey Atlantic Ocean coast. Results based on processed TerraSAR-X and COSMO-SkyMed synthetic aperture radar (SAR) images indicated that surge flooding persisted for 12 h past landfall in marshes from Great Bay to Great Egg Harbor Bay and up to 59 h after landfall in many back-barrier lagoon marshes. Marsh condition change (i.e. loss of green marsh vegetation) was assessed from optical satellite images (Satellite Pour l’Observation de la Terre and Moderate Resolution Imaging Spectroradiometer) collected before and after Hurricane Sandy. High change in condition often showed spatial correspondence, with high surge persistence in marsh surrounding the lagoon portion of Great Bay, while in contrast, low change and high persistence spatial correspondence dominated the interior marshes of the Great Bay and Great Egg Harbor Bay estuaries. Salinity measurements suggest that these areas were influenced by freshwater discharges after landfall possibly mitigating damage. Back-barrier marshes outside these regions exhibited mixed correspondences. In some cases, topographic features supporting longer surge persistence suggested that non-correspondence between radar and optical data-based results may be due to differential resilience; however, in many cases, reference information was lacking to determine a reason for non-correspondence.

Radular morphology of Zidona dufresnei (Neogastropoda: Volutidae) and an analysis of its variability along the distributional range

ABSTRACTThe radular morphology of Zidona dufresnei was studied by optical and scanning electron microscopy. We analysed the variability among and within three populations distributed along the southwestern Atlantic Ocean coast, considering the hypothesis that the isolation among populations favours adaptive phenotypic variation, which is also expressed at the radular level. Populations selected for this study differ in their maximum individual size, growth rate, size and age at maturity, and fecundity. This study provides the first analysis of the interpopulational variability of the radula of Zidona dufresnei and the first description of its morphology. Zidonia dufresnei exhibited a rachiglossate radulae composed of rows of tricuspid teeth (radular formula: 0+R+0). No differences in tooth shape among populations and sexes were observed. However, significant interpopulational differences in the height of the rachidian cusp and total length of the radula were detected. Specimens from San Antonio Bay showed the lowest values for all radular variables. Positive significant relationships between total shell length and the height of the rachidian cusp and total length of the radula were found, while the number of rows remained relatively constant regardless of size. The larger morphotypes had a longer radula because of an increase in the height of the rachidian cusp. No sexual dimorphism was observed in any morphometric variables of the radula. The results suggest that populations distributed along the Argentine Sea are homogeneous for radular morphology, despite the differences in life history traits, which may be linked to a similarity in feeding habits across populations.

Presence of giant tiger shrimp Penaeus monodon (Fabricius, 1798) in eastern Peninsula of Yucatan coast, Mexico

Giant tiger shrimp Penaeus monodon has been indicated as an invader on the western coast of Atlantic Ocean. We report the first record of P. monodon in the eastern Peninsula of Yucatan, Mexico. On October 14 and November 25, 2014, three giant tiger shrimps were caught in Rio Lagartos lagoon. The total lengths of the shrimp were between 210 and 290 mm and weighed between 111.6 and 200 gr. Further sampling and monitoring is required in other coastal lagoons in Yucatan state to assess the invasion area and the origin as well as the probable invasion route of this species.

Marcusenius desertus sp. nov. (Teleostei: Mormyridae), a mormyrid fish from the Namib desert

We critically compared Marcusenius specimens from the mouth of the Cunene River on the Namibia/Angola border, a harsh desert environment on the Atlantic Ocean coast virtually devoid of aerial insects with aquatic larvae which are an important food item, with Marcusenius multisquamatus Kramer & Wink, 2013 from the escarpment region of that same river, in a relatively rich and productive subtropical savannah environment. River mouth specimens were differentiated in morphology and electric organ discharges, as determined by ANOVA/MANOVA comparisons, principal component and discriminant analyses on morphological and electrophysiological characters, and genetics, including sequences of the mitochondrial cytochrome b gene, indicating reproductive isolation. Specimens from the river mouth differed from M. multisquamatus, their closest relatives, by having a shorter snout, a smaller eye diameter, and smaller nares separation. River mouth specimens were also differentiated from other, increasingly less-close relatives, such as M. altisambesi Kramer et al., 2007 from the Okavango River, Botswana, and from M. krameri Maake et al., 2014 from the Limpopo System, South Africa. We therefore designate the new species Marcusenius desertus sp. nov. for the Cunene River mouth population.