Marine Zones Research Articles

Heterotrophic activities of neustonic and planktonic bacterial communities in an estuarine environment (Ria de Aveiro)

The uppermost millimeter of the water column, the surface microlayer (SML), hosts bacterial communities (bacterioneuston) with potential metabolic adaptations to this unique physical and chemical environment. Hydrolysis and monomer incorporation by bacterioneuston and bacterioplankton communities in the estuarine system, Ria de Aveiro, was investigated and compared during a 2-year survey. The study was conducted at two contrasting sites, typifying the marine and brackish water characteristics of the estuary and with different sources, amounts and composition of organic matter. In the marine zone, bacterioneuston showed higher rates of hydrolysis and lower rates of monomer incorporation than bacterioplankton, whereas in the brackish water zone, neustonic and planktonic microbial communities showed similar activity rates. This pattern may result from the different degree of surface organic and inorganic matter enrichments, which reflect site-specific characteristics, such as hydrodynamics and sources of organic matter composition. In general, the estuarine SML environment favors polymer hydrolysis, but inhibits monomer utilization, in comparison with the subsurface layers. However, the differences between the two communities tend to decrease as autotrophic and heterotrophic activities increase in the brackish-water area.

Establishing an Ecologically Coherent Network of Marine Protected Areas in English Waters: What Does the Designation of Marine Conservation Zones under the Marine and Coastal Access Act 2009 Add to the Picture?

Establishing marine protected areas (MPAs) is a key conservation strategy to safeguard marine biodiversity from anthropogenic pressures. Designing MPAs is, however, not a simple task due to the complexity and fluidity of marine social-ecological environments. How best can we plan MPAs in such environments with no well-defined social and natural boundaries and in a way that is procedurally just? This article attempts to consider these issues, focusing on the ongoing UK legal efforts in establishing an ecologically coherent network of MPAs under section 123 of the Marine and Coastal Access Act 2009. The network is to be made up of European marine sites, Ramsar sites, the marine component of Sites of Special Scientific Interest and marine conservation zones (MCZs), a new type of MPA established under section 116 of the Marine and Coastal Access Act 2009. The designation criteria of MCZs are considered in detail and compared with those of other marine protected sites to understand what MCZs are adding to existing MPAs designated under European and international law. The article also grounds the legal discussion by critically considering the ongoing implementation of the MCZs' designation.

English

An attempt was made to study the benthic biodiversity in Pichavaram mangrove ecosystem, Southeast coast of India. Monthly (duplicate) sampling was done in 3 stations, (Station I - fresh water zone, Station II - core mangrove zone and Station III - marine zone) for a period of one year from January 2008 to December 2008. As many as 22 species of benthic macro fauna were recorded in the study area (16 species of polychaetes, 4 species of crustaceans and 2 species of molluscs). The population density varied between 394 and 23,888 number/m2. The species diversity was ranged from 1.52 to 3.87; species richness was from 1.24 to 4.09 and species evenness from 0.71 to 0.96. The maximum diversity was recorded in Station II and minimum in I. As observed in the conventional indices, the values of taxonomic and phylogenetic diversity were also more in Station II compared to Stations I and III. K- Dominance curve drawn paralleled the trend of diversity indices. Cluster and MDS showed the similarity in faunal composition stations within the zones. Key words: Mangroves, benthos, biodiversity, polychaetes.

A multiproxy study between the Río de la Plata and the adjacent South-western Atlantic inner shelf to assess the sediment footprint of river vs. marineinfluence

Proxies of terrigenous versus marine input (Al and Ti, Fe/Ca and Ti/Ca ratios), origin of organic matter (δ13C, δ15N and C/N ratio), productivity (Corg; Nt; CaCO3, P, Ca, and Ba content; and Ba/Al and Ba/Ti ratios), hydrodynamics (grain size, mean diameter and sorting) and biological records of the main features of the environment (benthic foraminifera assemblage distribution) were used to assess the sediment footprint of river vs. marine influence along the salinity gradient between the Rio de la Plata (RdlP) estuary and the adjacent South Western Atlantic Shelf. These criteria permitted characterisation and interpretation of the sedimentary processes influencing transition between three known environments: tidal river, estuarine and marine zones. Increases in sand and clay content at the transition between tidal river and proper estuarine zones indicate resuspension/deposition processes associated with the maximum turbidity zone (MTZ). The MTZ was also characterised by an increase in mixed organic matter content indicated by stable carbon and nitrogen isotope values, an increment in productivity proxies (Corg, Nt and CaCO3) and the substitution of the Miliammina fusca assemblage (brackish environments) for the Ammonia tepida assemblage (estuarine environments). The transition between estuarine and marine environments was characterised by a sharp (up to 99%) increase in sand content, reflecting the progradation of modern RdlP sediments toward relict continental shelf sediment. C/N values typical of the marine environment, decreased trace element concentrations and the distribution of the Buliminella elegantissima assemblage (a more marine assemblage) also highlight the marine environment. This paper is particularly important as a tool both to better understand sedimentological dynamics in salinity fronts (along the shelf sediment of large estuaries) and to elaborate more precise palaeoenvironmental and palaeoceanographic reconstructions.

Phytoplankton Communities in a Coastal Site of Natural Reserve “Lake of Tarsia-Mouth of River Crati”-Northern Ionian Sea, Calabria (Italy)

Our work was aimed to study the phytoplankton communities in two coastal sites placed in Natural Reserve “Lake of Tarsia-Mouth of river Crati” in Northern Ionian Sea-Calabria (Italy). This zone represents a wetland area of high natural interest populated by different organisms (animals and plants) living in a transitional ecosystem characterized by a great biodiversity. The sampling was performed in two different seasonal periods (summer and autumn 2012) and in two different sites (marine site vs fluvial one). Different algal genera/species were recognized and analyzed by Utermohl inverted microscope method and also qualitative and quantitative measures of biomass were performed. The results showed that the dominant group was the Diatoms with exclusive species in such periods in both the sampling sites; we also observed the presence of genera and/or species of potentially toxic algae (Pseudo-nitzschia sp., Alexandrium taylori, Prorocentrum micans, Skeletonema sp.), mostly in summer. Complessively, the phytoplankton biomass was always higher in marine site than in the fluvial site. The results were also processed considering the context of the chemical-physical parameters (such as temperature, pH, salinity, nutrients). The high concentration of the nutrients N and P in such periods indicated a state of meso-eutrophic waters both in the proximity of river site as well as in the marine zone. The data represent the first contribution to the knowledge of the phytoplankton structure in this area, which results in a very variable environment with a high recovery capacity.

Characterization of copper sulfides formed in MEMS connections by atmospheric corrosion in indoor of electronics industry of arid and marine environments

Copper sulfides formed in micro electrical connections are very observed frequently in manufacturing areas of the electronics industry in arid and marine environments as whiskers or dendrites. This is generated by drastic variations of relative humidity (RH) and temperature levels in indoor of these industrial plants, which originates the corrosion phenomena and the deterioration and deformation of electrical ways where are conducted the electrical current of Micro Electromechanical Systems (MEMS). MEMS are fabricated in isolated and clean rooms of the electronics industry where are strict rules with specific for the control of microclimates to avoid the corrosion process. In these rooms are filters with high control to detect diminutive and finite particles and gases which promotes the electrochemical process. This added to the severe changes in some periods of the year, of humidity and temperature in outdoor of companies, affect the microclimates of the clean rooms, originating the condensation, which generates the visible or invisible thin films in the copper surfaces of micro electrical connections of MEMS and causing the corrosion. For this reason a study of characterization of sulfur compounds was made to identify the type of corrosion process generated with the climatic factors mentioned, and with the concentration levels of sulfurs that penetrate by holes and air condition systems principally to indoor of the electronics industry. This research shows results of the uniform corrosion in marine zones as in the cities of Tijuana and Ensenada and the pitting corrosion in arid environments as the Mexicali city from 2010 to 2011. The technique used to analyze the copper sulfides as corrosion products was the Scanning Electron Microscopy (SEM) with information organized in graphs and tables and also a MatLab simulation was made to determine in a short future the corrosion rate of this electrochemical phenomenon to measure the grade of deterioration of the MEMS connections and have the precaution necessary to prevent the corrosion process.

Consumer Preferences Toward Marine Tourism Area

The marine zone tourism is growing attracting more tourists. Pramuka Island is marine conservation area enriched with marine biodiversity in coral reefs and other natural resources. To develop this potential tourist destination, a customer-based marketing program is required to attract domestic and foreign tourists. The main vision is to understand tourist preferences for marine tourism activities and facilities. A research was conducted on Pramuka Island as a well-known marine tourism zone. The objective was to determine the key tourist preferences for marine tourism destination. Research methods utilized Cochran Q test and Conjoint analysis where the primary data were obtained from tourist respondents. The result showed that there was a tourist preference based on the five attributes considered most important, namely tourism activities, tourist attractions, types of accommodation, food and souvenirs types. This study provided marine tourism destination management with useful guidance for broader implications of the implementation of marketing programs and tourism attraction. Moreover, the results of this study consolidated the learning of a variety of academic and industrial research papers in particular for the measurement of customer preferences towards marine tourism destination.

Microbial oceanography of anoxic oxygen minimum zones.

Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, contributing to major losses of fixed nitrogen as dinitrogen (N(2)) and nitrous oxide (N(2)O) gases. Anaerobic microbial processes, including the two pathways of N(2) production, denitrification and anaerobic ammonium oxidation, are oxygen-sensitive, with some occurring only under strictly anoxic conditions. The detection limit of the usual method (Winkler titrations) for measuring dissolved oxygen in seawater, however, is much too high to distinguish low oxygen conditions from true anoxia. However, new analytical technologies are revealing vanishingly low oxygen concentrations in nitrite-rich OMZs, indicating that these OMZs are essentially anoxic marine zones (AMZs). Autonomous monitoring platforms also reveal previously unrecognized episodic intrusions of oxygen into the AMZ core, which could periodically support aerobic metabolisms in a typically anoxic environment. Although nitrogen cycling is considered to dominate the microbial ecology and biogeochemistry of AMZs, recent environmental genomics and geochemical studies show the presence of other relevant processes, particularly those associated with the sulfur and carbon cycles. AMZs correspond to an intermediate state between two "end points" represented by fully oxic systems and fully sulfidic systems. Modern and ancient AMZs and sulfidic basins are chemically and functionally related. Global change is affecting the magnitude of biogeochemical fluxes and ocean chemical inventories, leading to shifts in AMZ chemistry and biology that are likely to continue well into the future.

Coastal Water Quality Protection

This chapter is for the Second Edition of Coastal and Ocean Law, published by the American Bar Association's Section on Environment, Energy, and Resources. It comprehensively reviews the application of the Clean Water Act in the coastal and at sea. For example, the chapter details the regulatory significance of the Act's recognition of three marine zones -- the territorial sea, the contiguous zone, and the ocean -- and explains how the Clean Water Act applies to discharges from non-military ships, vessels of the Armed Forces, and floating craft as well as land-based sewage discharges and discharges from offshore oil and gas platforms. The Second Edition version of this chapter also highlights developments in this area of law since 2006. For example, the chapter highlights the EPA's newest (2012) National Coastal Condition Report. Moreover, it details the relatively rapid change in the law governing ballast water and other discharges from ships, examines the Chesapeake Bay multi-state TMDL and the litigation over the dead zone in the Gulf of Mexico, and examines states' increasing use of the Act's No Discharge Zone provisions, especially California's 2012 establishment of its entire coastline as a No Discharge Zone.

Long-term monitoring of heavy metals in Chilean coastal sediments in the eastern South Pacific Ocean

Concentrations of seven metals (Al, Cd, Cu, Fe, Pb, Ni, Zn) were determined in 256 surface sediment samples, collected between May 2006 and November 2009, from 15 stations at the mouth of the Itata River and its adjacent marine zone (central-southern Chile) as part of an environmental monitoring program. The objectives of the work were to: (i) establish baseline metal concentrations in the sediments of the area and (ii) identify tendencies in the spatial and temporal distribution of the metals in these marine sediments. Concentrations were highest in the north zone of the Itata River mouth (stations E2C, E13C) for all the metals and at the stations farthest offshore from the mouth (E4, E6) for Cu, Fe, Pb, and Ni. The ranges in those concentrations were lower than those reported in other studies performed along the Chilean coast and lower than those observed in most other coastal systems around the world. Based on results of the indices used (geoaccumulation index, enrichment factor), the coastal sediments were not measurably elevated above natural levels.

Age and fine-scale marine growth of Atlantic salmon post-smolts in the Northeast Atlantic

Abstract Jensen, A. J., Ó Maoiléidigh, N., Thomas, K., Einarsson, S. M., Haugland, M., Erkinaro, J., Fiske, P., Friedland, K. D., Gudmundsdottir, A. K., Haantie, J., Holm, M., Holst, J. C., Jacobsen, J. A., Jensås, J. G., Kuusela, J., Melle, W., Mork, K. A., Wennevik, V., and Østborg, G. M. 2012. Age and fine-scale marine growth of Atlantic salmon post-smolts in the Northeast Atlantic. – ICES Journal of Marine Science, 69: 1668–1677. Surface trawls were conducted over a large area of the Northeast Atlantic in 2002, 2003, 2008, and 2009 to collect samples of Atlantic salmon (Salmo salar) post-smolts during their marine feeding migration (n = 2242). The dominant smolt age of wild post-smolts was 2 years, followed by 1- and 3-year-old fish, and a few 4-year-old fish. The average rate of circulus formation in the marine zone of scales was estimated to be 6.3 d circulus−1. Both the age structure and the number of marine circuli in the scales suggest that the majority of the post-smolts originated in rivers in southern Europe. Applying intercirculi distances in scales as a proxy variable of growth rate suggests that putative marine growth rates varied among years, with the fastest growth rates in 2002 and the slowest growth rates in 2008. Further, the first marine intercirculi distances were narrowest in 1-year-old smolts, successively increasing with smolt age, indicating that growth rates during the first period at sea were lowest for salmon of southernmost origin. Growth indices are linked to prevailing environmental and biological conditions.

Exposure Test of FRP-Reinforced Concrete Structure in Temperate Marine Tide Zone

Through exposure test of FRP-reinforced concrete member in littoral test area of temperate marine zone, the durability and constructional measures of FRP-reinforced concrete structure are investigated. The test results show that FRP shell on the surface of FRP-reinforced concrete member is effective in avoiding wave flush, freezing and thawing damage, preventing chloride ion corrosion and improving durability. On the other hand, reliable measures should be taken to protect concrete structures with no FRP shell on the surface. Based on above, the provided reference for evaluation durability of FRP-reinforced concrete structure, and proper constructional measures for FRP-reinforced concrete structure are presented.

Spatial Dynamics and Expanded Vertical Niche of Blue Sharks in Oceanographic Fronts Reveal Habitat Targets for Conservation

Dramatic population declines among species of pelagic shark as a result of overfishing have been reported, with some species now at a fraction of their historical biomass. Advanced telemetry techniques enable tracking of spatial dynamics and behaviour, providing fundamental information on habitat preferences of threatened species to aid conservation. We tracked movements of the highest pelagic fisheries by-catch species, the blue shark Prionace glauca, in the North-east Atlantic using pop-off satellite-linked archival tags to determine the degree of space use linked to habitat and to examine vertical niche. Overall, blue sharks moved south-west of tagging sites (English Channel; southern Portugal), exhibiting pronounced site fidelity correlated with localized productive frontal areas, with estimated space-use patterns being significantly different from that of random walks. Tracked female sharks displayed behavioural variability in diel depth preferences, both within and between individuals. Diel depth use ranged from normal DVM (nDVM; dawn descent, dusk ascent), to reverse DVM (rDVM; dawn ascent, dusk descent), to behavioural patterns where no diel differences were apparent. Results showed that blue sharks occupy some of the most productive marine zones for extended periods and structure diel activity patterns across multiple spatio-temporal scales in response to particular habitat types. In so doing, sharks occupied an extraordinarily broad vertical depth range for their size (1.0–2.0 m fork length), from the surface into the bathypelagic realm (max. dive depth, 1160 m). The space-use patterns of blue sharks indicated they spend much of the time in areas where pelagic longlining activities are often highest, and in depth zones where these fisheries particularly target other species, which could account for the rapid declines recently reported for blue sharks in many parts of the world's oceans. Our results provide habitat targets for blue shark conservation that may also be relevant to other pelagic species.

Un estudio explorativo de los Sistemas Convectivos de Mesoescala de México

Se analizan los sistemas convectivos de mesoescala (SCM) en México, para lo cual se emplearon imágenes infrarrojas de satélite meteorológico durante un año. En el periodo de análisis fueron identificados 548 SCM, con un máximo en julio y un mínimo en enero y febrero. La variación mensual de los SCM es consistente con la variación mensual de la precipitación sobre el área de estudio. Las zonas con mayor número de SCM son las llanuras costeras del sur del Golfo de México, la península de Yucatán y la zona marítima frente a las costas del Pacífico Sur. Hay zonas con máximos o mínimos estacionales de SCM, que reflejan eventos climáticos intraestacionales como el monzón de Norteamérica y el periodo de canícula. La duración promedio de los SCM es de siete horas alcanzando hasta 10 horas en otoño. En general, los SCM inician su desarrollo al anochecer y se disipan a la medianoche. Un aspecto interesante es que el movimiento de los SCM es de este a oeste durante los meses de mayor precipitación (mayo a octubre) y de oeste a este en el resto del año, lo que es un reflejo del patrón de circulación dominante en México en esos periodos.

Simulating Study of Atmospheric Corrosion of Galvanized Steels: Influence of Zinc Rusts on the Formation of β-FeOOH Rust Particles by Aerial Oxidation of Aqueous FeCl2 Solution

To simulate the corrosion of galvanized steel in a marine zone, steel rust of β-FeOOH particles was prepared by aerial oxidation of aqueous FeCl2 solutions containing ZnCl2 and zinc rusts such as Z...

Ecological Baseline Survey: North of Ras Laffan to South of Ar Ruwais - Coastal & Marine Zone

Abstract Qatar has experienced great change in its infrastructure, continuous upgrading of its major industrial cities, of its network of roads and highways and major construction and development along its coastline in particular the eastern coastline. These activities can all have an impact on the marine life and terrestrial wildlife, vegetation and floristic composition. One strip of coastline on the north-eastern section of Qatar remains in parts virgin land and the coastal zone is considered a least impacted zone. A baseline survey was commissioned to record all physical/chemical and biological data of the Qatar marine zone. This survey, representing field data collected between February and April 2010, encompassed a 35km long stretch of coastline and extended 20km offshore and as far inland as 1km, it also included Umm Tais Island and Al Jasasiya. The seabed and the water body were documented by video photography. Fish population was studied by deployment of fish nets. Mangrove forests were studied i...

Relation between bacterial activity in the surface microlayer and estuarine hydrodynamics

Bacterial communities of the surface microlayer (SML) of the estuary Ria de Aveiro (Portugal) were characterized in terms of abundance and activity during a 2-year survey at two sites with distinct hydrodynamic properties (marine and brackish water zones). The hydrodynamic conditions were simulated using a bidimensional numerical model and related to the microbiological observations. The pattern of variation of bacterial biomass productivity (BBP) was distinct between the two sampling sites. At the outer site, BBP was significantly lower at the SML, whereas at the inner site, it was significantly enhanced at the SML. Although the total bacterial abundance was similar in the SML and underlying water (UW), the fraction of cells attached to particles was significantly higher at the SML (two to three times). The integration of microbiological results with environmental and hydrological variables shows that strong currents in the marine zone promote the vertical mixing, inhibiting the establishment of an SML bacterial community distinct from that of UW. In contrast, in the brackish water zone, lower current velocities provide conditions for enhancing the bacterial activity in the enriched SML. Estuarine dynamics influence the distribution and activity of microorganisms at the SML and in the water column, with anticipated impacts for the carbon cycle in the estuarine environment.

Durability performance of a range of marine concretes and the applicability of the South African Service Life Prediction Model

The paper describes a study that examined and compared the potential durability performance of various geographically distinct South African marine concrete mix types. Mix proportions were designed at two water/binder ratios (0.40 and 0.55) for different material combinations of binder and aggregate types. Sampling was done at 28, 91 and 182 days. Durability performance was inferred from durability index (DI) tests that measure the resistance of concrete to ion, gas and fluid penetration. Comparison was made on the basis of regional concrete type, w/b ratio and mix constituents (binder and aggregate type). All the concrete mixes were further compared to plain CEM I control concrete mixes at each w/b ratio. Results indicate that low w/b ratio and blended binder concrete mixes have low penetrability characteristics. Aggregate type was seen not to have an appreciable influence on the transport properties of concrete. Across the range of geographically different mixes, it was found that with a given concrete grade and binder type, marine concrete mixes are practically comparable. This permits the existing Service Life Prediction Model to be more confidently applied for all marine zones in South Africa with possible application in other geographic regions following further research.

The inhabitants of the spring ice, under-ice water, and sediments of the white sea in the estuarine zone of the Severnaya Dvina River

The data on the supra-ice snow, ice, under-ice water, and benthic algal flora obtained in 2007–2008 by sampling in the estuary of the Severnaya Dvina River are analyzed. The river ice and under-ice water in the estuarine zone and in the channel part of the Severnaya Dvina differed greatly in the algal flora’s composition. The fresh water species never exceeded 8.6%, while the ice algae composed 90–96% of the total ice inhabitants’ biomass. In the under-ice water, this value did not exceed 58–64%. The bacteria in the ice composed not more than 2.5–10% of the total biomass, while, in the under-ice water, 36–49%. The shares of ciliates (0.04%) and nematodes (0.005–1.6%) in the total biomass were negligible. In the estuarine zone, the ice was inhabited mainly by nematodes (78% of the total biomass), while, in the river, their share decreased to 9%. The contribution of bacteria was 15% in Dvina Bay and increased to 61% in the river. The importance of algae in the snow was minor: 7% of the total biomass in the marine zone and 30% in the river region. High species diversity of the algal flora in the sandy and sandy-silty littoral grounds was revealed. The values of the total biomass of the bottom algal flora (0.38 g C/m2) were only two to three times lower than the values revealed in similar habitats in the summer. The epipelithic forms (0.15 g C/m2) dominated, being represented by 46 species of algae (49%). The shares of epipsammonic (0.12 g C/m2) and planktonic (0.11 g C/m2) species were almost equal to each other: 25 and 22 species, respectively (27 and 24%).

Expanding hybrid zone between Solea aegyptiaca and Solea senegalensis: genetic evidence over two decades

Several marine hybrid zones have been described and studied during the last years. Assessing the movements of extending hybrid zones is central to improve our understanding of evolutionary processes. We have re-examined the hybrid zone between Solea aegyptiaca and Solea senegalensis that was first described 22 years ago in northern Tunisia when introgressed S. senegalensis individuals were found in the Gulf of Tunis, whereas locally caught S. aegyptiaca were genetically pure. Six population samples harvested both inside and outside the area where the two fish species coexist were genotyped for allozymes and exon-primed intron length polymorphism. Both types of markers were congruent and revealed that introgression takes place indeed in both directions. A high introgression level (36.4%) in the Bizerta lagoon and much less outside indicate that this is the main area where hybridization occurs while introgression clines towards the south in S. aegyptiaca and towards the north in S. senegalensis plead in favour of the existence of a unimodal hybrid zone. The higher introgression level calculated in the current study (when compared to 16% reported formerly) and the newly found introgressed S. aegyptiaca in Bizerta lagoon seem to indicate that the genetic exchanges occurring between the two taxa are evolving and not stabilized yet.