bluuebunny/crossref_metadata_2025 huggingface dataset:
TTT-Diagram of Intermetallic Phases Formation in Heat-Resistant Titanium Alloys
Authors: Popova Maria A. , Popov A.A.
Published: September 2017

The silicides and aluminides particles precipitation in near α-and two-phase (α + β) titanium – alloys has been investigated. It is shown that in Ti-Al-Si-Zr alloys three different types of particles are precipitated: (Ti,Zr)5Si3 (S1), (Ti,Zr)6Si3 (S2), (Ti,Zr)2Si (S3). The types of precipitated particles depend on the heat treatment modes and an alloying elements ratio. The investigation of silicide particles influence on the mechanical properties of the alloys has shown that silicides S1 reduced viscosity characteristics. While silicides S2 and S3 were found to reduce the heat resistance due to the depletion of solid solution by Al and Si and to impede the formation of α2 - phase particles. Microstructural investigation has been performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The orientation relationships between silicides and matrix phase were identified by electron diffraction. Based on obtained results the schematic TTT-diagram of intermetallic phases formation has been suggested.
Morphology of Nanostructured TiO2 Surfaces for Biomedical Implants Developed by Electrochemical Anodization
Authors: Strnad Gabriela , Portan Diana , Jakab-Farkas Laszlo , Petrovan Cecilia , Russu Octav
Published: September 2017

Ti6Al4V alloy is widely used for biomedical implants, and the modification of its surface, at nanoscale level, is a method to enhance its osseointegration. We modified the Ti6Al4V surface, with an initial micro rough topography, by using electrochemical anodization in 1M H3PO4 + 0.5 wt% HF electrolyte, and anodization potential of 20 V. By using short anodization duration, 5 min, or 15 min, the oxide layer presents a nanoporous morphology, and do not cover the entire surface. At an anodization time of 30 min, our results demonstrate the synthesis of continuous, highly ordered nanotubular TiO2 layer (diameter of nanotubes: 25-90 nm, thickness of the layer: 350-450 nm), superimposed over a micro rough topography, the oxide layer exhibiting a good adherence to the substrate, coherence and no brittleness. Anodization time of 2 hours provides the results very similar with those obtained at 30 min in terms of nanotubular layer topography, but some drawbacks appear in terms of surface coverage and continuity of the layer.
Phenotypic and Functional Characterization of Circulatory, Splenic, and Hepatic NK Cells in Simian Immunodeficiency Virus–Controlling Macaques
Authors: Vargas-Inchaustegui Diego A. , Helmold Hait Sabrina , Chung Hye Kyung , Narola Jigna , Hoang Tanya , Robert-Guroff Marjorie
Published: September 2017

NK cells are key components of the immune system because of their rapid response potential and their ability to mediate cytotoxic and immunomodulatory functions. Additionally, NK cells have recently been shown to persist for long periods in vivo and to have the capacity to establish immunologic memory. In the current study, we assessed the phenotype and function of circulatory and tissue-resident NK cells in a unique cohort of SIV-controlling rhesus macaques that maintained low to undetectable levels of viremia in the chronic phase of infection. By contrasting NK responses of these macaques with those observed in SIV-noncontrolling and uninfected macaques, we aimed to identify markers and activities of NK subpopulations associated with disease control. We show in this article that most differences among NK cells of the three groups of macaques were observed in tissue-resident cells. Although SIV infection resulted in NK cell dysfunction, double-negative NK cells and those expressing CXCR3, NKG2D, and IL-18Rα were associated with viremia control, as was Ab-dependent cytotoxic function. Our results suggest several novel targets for therapeutic intervention.
Setting the stage for multi-spectral acoustic backscatter research
Authors: Brown C J , Beaudoin J , Brissette M , Gazzola V
Published: September 2017

The establishment of multibeam echosounders (MBES) as a mainstream tool in ocean mapping has facilitated integrative approaches towards nautical charting, benthic habitat mapping, and seafloor geotechnical surveys. The combined acoustic response of the seabed and
the subsurface can vary with MBES operating frequency. At worst, this can make for difficulties in merging results from different mapping systems or mapping campaigns. At best, however, having observations of the same seafloor at different acoustic wavelengths allows for increased discriminatory
power in seabed classification and characterization efforts. Here, we present results from early trials of a multispectral multibeam system (R2Sonic 2026 MBES) in the Bedford Basin, Nova Scotia. In this system, the frequency can be modified on a ping-by-ping basis, which can provide multi-spectral
acoustic measurements with a single pass of the survey platform. We demonstrate how this capability provides improved seafloor discrimination at this site based on the different frequency responses and seafloor sediment characteristics. These innovations offer tremendous potential for application in
the area of seafloor geological and benthic habitat mapping.
Using a commercial drone for mapping ecological phase shifts on the coral reefs of Southern Faafu Atoll, Republic of the Maldives
Authors: Fallati L , Marchese F , Savini A , Corselli C , Zapata Ramirez P
A , Galli P
Published: September 2017

The Republic of the Maldives is a Small Island Developing State with a unique geographic configuration: an archipelago composed of more than 1100 islands surrounded by coral reefs, grouped into a chain of atolls in the Indian Ocean. The one-metre elevation of
most of the atolls' islands makes the Maldives one of the countries highly vulnerable to the impacts of climate change. Maldivian islands are carbonate landforms, totally composed of biogenic sediments produced by the surrounding coral reef. Healthy coral reefs are thus essential for the survival of
the Maldivian islands due to their capacity to keep up with rising sea-level. Nevertheless, the Maldivian coral reefs are threatened by anthropic and climatic issues and during April and May 2016 they faced a massive coral bleaching followed by extremely high rates of mortality.
In our study, we collected high resolution images using a commercial drone (DJI Phantom 4) along different sector of reefs surrounding inhabited, uninhabited and resort islands of the Southern Faafu Atoll. The acquired data were processed in order to map the extension and the composition of shallow
lagoons habitat, from the beach to the reef crest. Comparing these new results with habitat maps realized using satellite images databases from 2011 to 2016 (RapidEye, Sentinel 2 and LandSat8) and field data (snorkelling and diving transects), we were able to create habitat change maps and correlate
these changes to environmental disturbances. In addition, high resolution images (1.5 cm/pixel) were collected in situ, at selected locations, in order to create a 3D model of shallow reef communities using structure from motion photogrammetry technologies. These 3D optical models will be used as
the first step of a three year monitoring campaign designed to observe the 3D structural complexity changes of the reef after the 2016 bleaching event.
The whole study will focus on the integration of multi-scale maps to investigate, on a multi-temporal scale, ecological and geomorphological shifts in the study area and to figure out relationships with human activities (agriculture, land reclamation, new infrastructure) and pressures related to
global climate change.
Fit for purpose approaches to seabed mapping; developing a tool box
Authors: Green S , Cooper R , Lark M , Dove D , Stewart H
Published: September 2017

The British Geological Survey (BGS) is recognised as a national and international leader in characterising the geological nature of the seabed and shallow sub-seabed, from developing novel methodologies, to research and applied science. The BGS, often working
together with academics and industry-based scientists, are perpetually active in innovating new data processing and interpretation techniques, including remote-sensing and statistical protocols, automatic feature-detection algorithms, and database solutions.
There is no one-size-fits-all approach for seabed mapping, and standardisation of the flow from multibeam echosounder (MBES) data to interpretation and map production, remains an elusive goal. Numerous factors must be considered in determining the most appropriate approach for substrate mapping.
These include the planned end user, mapping objective, scale, data quality, and geological context. A crucial step in the mapping process is to take account of these variables, and determine the most suitable mapping methodology.
Considering these conditions, this study elucidates the decision-making process behind the selection of a mapping technique and illustrates the application of a variety of approaches to produce maps for a range of end users. The relative merits and caveats to these outputs are considered, with a
particular focus on the requirements of different end users.
Quantifying macro-scale geomorphological changes post-Hurricane Sandy and Hurricane Joaquin at Assateague Island utilizing bathymetric mapping techniques
Authors: Haulsee K
Published: September 2017

Assateague Island is a barrier island complex that stretches 37 miles along the Atlantic coast of Maryland and Virginia. The island's location along the eastern seaboard makes for a highly dynamic system that not only changes over long temporal scale through
longshore transport and sea level transgression/ regression, but also over short seasonal scales due to strong currents and storm events such as Hurricane Sandy in late October 2012 and Hurricane Joaquin in October 2015. Geologically speaking, both hurricanes gave us a rare opportunity to quantify
large spatial scale sea-floor changes over a short temporal scale because of the vast amount of energy that moved through the region in 2012 and 2015. This coastal geomorphological study will aim to quantify the macro-scale changes that took place over time by utilizing data collected via
bathymetric sea-floor mapping surveys that took place in 2011 and 2014. The first data set was collected by the Maryland Geological Survey pre-Hurricane Sandy (2011), using a Versar single-beam echosounder. This will be compared to multi-phase bathymetric data that was collected by the University of
Delaware utilizing an Edgetech 6205 multi-phase echosounder (2015). Comparing these two data sets allows us to measure large spatial scale changes over a short temporal scale. This will aim to quantify the amount of substrate changes and overall sediment movement based off each storm event. This
study will have implications for quantifying near shore sand resource movement during storm events.
Scour evolution around a vibrating monopile in cohesive beds
Authors: Hendry J A , Dix J K , Thompson C E L , Whitehouse R J S , Harris J M
Published: September 2017

With the advent of Offshore Wind Farms (OWF), energy security of many countries has the potential to progress towards self-sustainability. Early stages of offshore turbine installation took place in nearby post transgressional shallow sands. These locations were
preferentially developed given their relative ease of installation, maintenance and supportive knowledge of granular soils. Fuelled by increased power generation with larger scale, and concerns of noise pollution and displeasing aesthetics, more recent stages of OWF development are entering deeper
water. Cohesivity is commonly encountered within these environments of fine grained soils and consolidated tills. With little knowledge of scouring implications these sites are often over engineered, from calculations based on parameters orders of magnitudes too conservative.
This paper will discuss offshore cohesive soils and the initiation of floc erosion at critical bed stresses defined through geotechnical analysis dictating the temporal evolution of scour. Moreover, this study examines the potential impact of vibration, which at present is unknown, but is
hypothesised to provide a critical plane of weakness directly adjacent to the monopile.
Using ArcGIS and MATLAB the cohesive bed locations are assessed. By extracting field CPT obtained from BGS, and the Marine Data Exchange, seabed parameters are chosen. These parameters are then scaled to a flume located at the University of Southampton and 4D photometry adopted for analysis of the
spatial and temporal variation of the scour geometry. We evaluate the degree to which the turbine excitation affects the structure stability of the emplaced monopile and compare the effect on the seafloor bathymetry. These results are evaluated relative to Offshore Wind Farm field studies in the UK
and in the East China Sea.
Seabed geodiversity of the Baltic Sea
Authors: Kaskela A M , Kotilainen A T
Published: September 2017

Geodiversity describes the variability of the geological characteristics over a certain area. It includes e.g. geological and geomorphological features and their assemblages. Geodiversity has an intrinsic value, it provides several abiotic ecosystem services, and
is associated with the biodiversity and long-term conservation of the marine environment.
We have analyzed geodiversity patterns on a glaciated epicontinental basin, the Baltic Sea. The analysis aimed to locate geodiversity hotspots and draw conclusions on contributing processes. Geodiversity was assessed in a GIS environment based on broad-scale datasets on seabed substrates,
structures, and bedrock. Geodiversity was measured with three parameters: patchiness, richness and geodiversity index. Geodiversity patterns were compared with variables, which were considered to reflect geological processes under seabed conditions. The aim of the analysis was to visualize broad
scale geological characteristics of the seafloor environment and to provide science-based knowledge for the ecosystem based management of the Baltic Sea. This presentation will describe the seabed geodiversity distribution of the Baltic Sea and discuss the linkages between geodiversity and various
geological processes.
The analysis used seabed data provided by EMODnet program among others. The study was partly funded by the SmartSea project of the Strategic Research Council of the Academy of Finland (grant no. 292 985).
Delineation of significant benthic areas in eastern Canada using kernel density analysis and species distribution models
Authors: Kenchington E , Beazley L , Lirette C , Murillo F J , Guijarro J
Published: September 2017

The Canadian Policy for Managing the Impact of Fishing on Sensitive Benthic Areas developed by the Department of Fisheries and Oceans Canada (DFO) in 2009 defines Significant Benthic Areas in DFO's Ecological Risk Assessment Framework as "significant areas of
cold-water corals and sponge dominated communities".
Kernel density estimation (KDE) was applied to research vessel trawl survey data to create modelled biomass surfaces for corals and sponges. From these, an aerial expansion method was applied to identify significant concentrations of these taxa across eastern Canada. The borders of the areas so
identified were refined using species distribution models that predict species presence-absence and/or biomass, both incorporating environmental data. We present such predictive models produced using a random forest (RF) machine-learning technique. A suite of between 54 and 78 environmental
predictor variables from different data sources were used. Occurrence models performed well in general with cross-validated AUC (Area Under the Receiver Operating Characteristic Curve) values over 0.8 in most of the cases. Biomass models provided diverse results depending of the taxa and region
studied. The biomass models were compared with Generalized Additive Models (GAM), which produced comparable results to random forest, although the fewer assumptions required for RF made this method more convenient.
These results have been used to identify significant concentrations of corals and sponges in eastern Canada, an essential first step in the identification of Sensitive Benthic Areas to ensure Canadian fisheries are conducted in a manner that supports marine conservation and sustainable resource use
within and outside Canada's 200 nautical mile exclusive economic zone.
Habitat mapping and assessment in Atlantic Outer Continental Shelf wind energy areas
Authors: Kentner V , Guida V , Johnson D , Brink J
Published: September 2017

The Bureau of Ocean Energy Management (BOEM) is working with the National Oceanic and Atmospheric Administration (NOAA) Fisheries to conduct a comprehensive study of eight wind energy areas (WEAs) located along the Northwest Atlantic Outer Continental Shelf (OCS)
from North Carolina to Massachusetts. The purpose of the study is to assess the current state of the WEAs and determine their suitability for the development of wind turbines.
To assess each WEA, NOAA NEFSC has compiled data from a variety new and existing data sources. The data collected includes high-resolution bathymetry from multibeam sonar (2m) and microtopography from side scan sonar (cm level), physical sediment samples from USGS and visual analysis of imagery from
HabCam IV and SMAST camera pyramid, CTD scans, benthic infauna samples from sediment samples, and epifauna from trawls. The compiled data will serve as a comprehensive benthic habitat database that can be used as a baseline for evaluating impacts within the WEAs and across the entire OSC. The goal
of this study is to create a comprehensive habitat assessment of each WEA including establishing relationships between physical and biological features in an effort to describe habitat distributions.
This study is utilizing several techniques to assess the habitats within the WEAs. We are applying the coastal and marine ecological classification standard (CMECS) to describe and classify the biological communities and the ecosystems within the WEAs. We are conducting various interpolations of the
sediment compositions and grain size analysis to characterize the seafloor. We are also mapping multidimensional habitat features in 3D by combining benthic sediment and community data with the ranges of salinity and temperature across depth as well as across time. This assessment can be used in
modeling habitat suitability for fisheries stocks and ecosystem assemblages. When combined, these techniques give insight into the environmental and community interactions in each wind energy area, providing area-specific overviews of marine habitat characteristics and vulnerability to wind
energy-related development in WEAs for consideration by BOEM and offshore wind developers.
Differences in hydroacoustic backscatter signals and epifauna growth in a stony and coarse grain habitat ("Helgolaender Steingrund", German Bight, North Sea)
Authors: Kohlmorgen L R , Coers S , Bischof K , Kröncke I , Bartholoma A
Published: September 2017

There are a variety of methods used to observe stony and coarse grain habitats. Many of these, like video recordings by scuba divers, in situ recordings of macrofauna and photographic documentation, are expensive and complex. For geological analysis, grab samples
are quite common, but represent just a small range of the actual habitat. Quantitative sampling of macrofauna is difficult. Thus is it important to develop new methods that are less expensive and can cover larger areas.
This study presents the first results of a combination of side-scan sonar data and drop camera records to study the presence and absence of macrofauna as well as the sediment grain size distribution in a stony and coarse grain habitat in the "Helgolaender Steingrund".
The "Helgolaender Steingrund" is a stony and natural coarse grain habitat of ~159 ha, 11 km east-northeast of Helgoland island in the German Bight (North Sea). It is included in the Flora-Fauna-Habitat guidelines and is part of the German Natura 2000 areas. Sampling was carried out during three
different cruises from May to August 2016 with RV "SENCKENBERG".
Side-scan sonar and drop camera records show a quite heterogeneous habitat. Several areas comprising of different living communities were correlated to sediment grain size. Larger organisms, such as the European lobster (Homarus gammarus), the brown crab (Cancer pagurus) and the edible sea urchin
(Echinus esculentus) were identified. Additionally, a cover of Bryozoan species such as Flustra foliacea and Alcyonidium diaphanum could clearly be discerned.
In conclusion, the drop camera and side-scan sonar proved to be reliable methods for the analysis of stony and coarse grain habitats such as the "Steingrund". Further analysis on the gathered data has yet to be done.
Effects of projected climate change induced changes in wind patterns on the spatial distribution of blue mussels
Authors: Kurvinen L , Sahla M , Virtanen E , Westerbom M , Ekebom J
Published: September 2017

The projected changing climate is expected to have impacts on sea temperatures and salinities. In addition, wind patterns are projected to shift. Although projections are uncertain, noticeable changes in wind directions and patterns have already been recorded in
the Baltic Sea, due to changing climate during the past decades.
Wave exposure is one of the most important environmental factor controlling blue mussel (Mytilus trossulus) distribution and densities. Higher exposure keeps e.g. sedimentation at a lower level, which is beneficial for the species. Sea surface wave exposure is determined by wind power and direction,
additionally by below surface topography. In the northern Baltic Sea, south-western winds prevail. It is assumed that blue mussels occur at higher densities on the exposed western and south-western sides of islands, islets and reefs.
The blue mussel is a key species providing several ecosystem services, such as removal of organic nutrients by filtering water and being the main food source for many Baltic flagship species. So it is of great ecological interest to try to predict how, and where, this species will manage in the
changing environment.
The blue mussel data used in this study has been collected by diving, mainly within the Finnish Inventory Program for the Underwater Marine Environment (VELMU) and samples collected 2011-2015 were included. For this study, we started by running a distribution model for blue mussel densities, using
wave exposure models produced with current wind data, in combination with other relevant environmental predictors. We ran models using exposure, produced with changed wind patterns, some of which follow predictions, while some are more extreme. The aim was to see how the pattern of occurrence
changes in the fragmented archipelago of southern Finland and to see if there are significant shifts in occurrences within current protected area boundaries and if currently implemented MPAs
Results show decreasing mussel densities with shifts towards northerly winds. Also changes in locations occurred, but these shifts might not be relevant for the planning of large MPAs, if the areas include a wide range of possible exposures. On the other hand, decreasing densities might affect the
way the species provides its ecosystem services.
Multiscale geomorphological classification of the seafloor in an active continental volcanic setting - Bay of Plenty, New Zealand
Authors: Lamarche G , Guntz M , Mackay K , Pallentin A , Rowden A
Published: September 2017

Detailed knowledge of the physical and biological conditions of the seafloor is key to the development of economic, environmental and cultural activities in the marine environment. Full coverage information on substrate and benthic habitat relies almost
exclusively on acoustic remote-sensed data provided by multibeam echosounders, subsequently ground-truthed using visual observations and physical sampling. Predictive habitat mapping provides a means to develop models of seafloor habitat in regions where only acoustic data are available.
The diverse geomorphology and benthic ecology in the Bay of Plenty makes the area a useful case study for developing regional and local models of benthic habitat: water depths range 0 - 3300 m with geomorphological features including channel, canyons, seamounts and ridges at a variety of scales.
Active geology is demonstrated by the intense seismicity, dense fault network, and ubiquitous submarine volcanic activity that results in venting hydrothermal fluids at, for example, the Calypso vent fields. This environment provides habitat for benthic communities, whose structure and distribution
can be expressed at a variety of scales.
Multiscale seafloor topography classification is strongly dependent on the quality of the bathymetric data. In this study we combined multibeam echosounder (MBES) data from a variety of systems, data collected on transit, and dedicated scientific and hydrographic surveys, with data from the New
Zealand national bathymetry model derived from historic and modern single-beam echosounder (SBES) data for areas without MBES coverage.
We integrated marine geological and oceanographic information in Benthic Terrain Models of the Bay of Plenty and the Calypso vent fields, i.e. at regional and local scales using the ESRI ArcGIS Benthic Terrain Modeler (BTM) tools, with a modified classification catalog to suit the highly variable
terrain of the Bay of Plenty. Classification of the geomorphology was based on a number of morphometric parameters (e.g., slope, Bathymetric Positioning Index, curvature, rugosity) derived from the bathymetry gridded at 25 m for the region, and 5 m for the Calypso vent fields.
A 13 geomorphological class catalogue was used that differentiated large (broad slopes, basins) and local (knolls, narrow ridges/valleys) scale features. Seventy-seven percent of the 25,000 km2 study area is broad flat, the remainder is dominated by local ridges and narrow depressions.
Ground-truthing data will enable us to associate biological observations to each class, and predict benthic habitat in region where no observations exist.
Mapping and monitoring temperate intertidal habitats: an object-based approach
Authors: Lightfoot P , Scott C , Polunin N , Fitzsimmons C
Published: September 2017

Intertidal habitat maps are needed at both fine and coarse scales to monitor change and inform conservation and management, but current methods of field survey and expert interpretation of aerial imagery can be time-consuming and subjective. Object-based image
analysis (OBIA) of remote sensing data is an increasingly employed method for producing habitat or land cover maps. Users create automated workflows to segment imagery, creating ecologically meaningful objects which are then classified based on their spectral or geometric properties, relationships
to other objects and contextual data.
Our research evaluates the potential of OBIA and remote sensing data for planning, managing and monitoring temperate intertidal Marine Protected Areas. We developed and tested OBIA workflows for interpreting ultra-high resolution imagery collected by an unmanned aerial vehicle (UAV) to map
intertidal habitats at two thematic scales, comparing the accuracy, consistency and reproducibility of three supervised classification approaches. To evaluate the change-detection capability of OBIA in the intertidal environment, we developed and compared two OBIA methods for quantifying change in
extent and distribution of habitats from freely available aerial and LiDAR time series data.
This talk will present and discuss our findings. We demonstrate that OBIA offers robust methods of mapping intertidal habitats from ultra-high resolution UAV imagery (mean accuracy 83.4% ± 3.8%) and lower resolution aerial and LiDAR imagery (mean accuracy 71.4% ± 1.6%) and
of detecting change at different levels of sensitivity. Developed in partnership with the responsible monitoring authorities, OBIA methods could integrate ecological knowledge and remote sensing data as a basis for cost-effective intertidal monitoring protocols, providing solutions both for
large-scale rapid assessment and more targeted, detailed surveys.
Development of a new acoustic mapping method for eelgrass using a multi-beam echo-sounder
Authors: Norton A R , Dijkstra S J
Published: September 2017

Eelgrass plays important roles in temperate coastal ecosystems, including as primary producers and as habitat for many species. The distribution and health of eelgrass beds are also sometimes used as a bio-indicator for water quality. The deepest edges of
eelgrass beds are especially vulnerable to water quality issues because of the pre-existing light limitation with increasing depth due to natural light attenuation. However, the deep edges of beds are also often the most difficult to delineate with satellite and aerial imagery often used for
large-scale seagrass mapping programs; the use of aerial imagery for mapping eelgrass beds is also sometimes hindered by turbidity issues common in estuarine environments. We are in particular developing methods to determine and map the maximum depth limit ('deep edge'), percent cover, functional
type (i.e., macroalgae or eelgrass) and canopy height of the beds using water column backscatter data from a multi-beam echo-sounder because these characteristics are difficult to obtain using existing optical and acoustic methods. Water column data was collected using an Odom MB1 sonar in 2014 and
2015 over a variety of vegetated sites in New Hampshire and Massachusetts, selected to represent a range of conditions: dense/sparse eelgrass, long/short eelgrass, mixed macroalgae and eelgrass, eelgrass on muddy or hard substrates, etc. The data processing workflow will look at both echo and
terrain characteristics to determine the presence and characteristics of vegetation. In addition to sonar data, drop camera data was collected, and data from a regional aerial mapping program also exist for comparison. Initial data analysis shows good agreement between drop camera and sonar
detections, and patches as small as 1m2 and as short as 20 cm are detectable.
Remote sensing assessment of seaweed resources in western Ireland
Authors: Rossiter T , Casal G , Furey T , McCarthy T , Stengel D
B
Published: September 2017

The aim of this work is to develop an innovative and multi-disciplinary approach to assess the distribution and biomass of both intertidal fucoids (Ascoplyllum nodosum) and subtidal kelps (Laminariales) which are both of commercial and ecological importance in
Ireland. We look to address the current deficit of information about these Irish seaweeds, which will underpin sustainable resource development.
Aerial hyperspectral imagery is used to assess A. nodosum populations and will enhance species discrimination in a spatially and spectrally heterogeneous environment like the intertidal zone. Kelp habitat assessment will be done using a multibeam system (MBES) on a small vessel. Field surveys will
be used to ground-truth both A. nodosum and kelp distribution, evaluate morphology, and estimate biomass.
An aerial survey (July 2016) was conducted in western Ireland (Galway Bay) to survey A. nodosum using a Cessna 172 mounted with a Multispectral AIRINOV AgroSensor and a OCITM-U-1000 Ultra Compact Hyperspectral Imager. The flight plan was designed to cover as much of the intertidal zone as possible.
Field-based surveys have been conducted at multiple sites to match algal species presence, composition and biomass within the A. nodosum beds along with a field-radiometry survey, using a TriOS RAMSES radiometer, to construct a spectral library of species and substrate to classify the remote sensing
data. To improve the accuracy of the A. nodosum assessment, ground-truthing data are being collected on-foot, using a hand-held GPS device (Garmin Montana 600), to support the classification process by underpinning the selection of training areas.
We present a detailed methodology for assessing the spectral response of A. nodosum in relation to biological and physiological parameters in its habitat and the challenges associated with the discrimination between species of the same genus. Small drones offer very high resolution colour imagery
and will support the A. nodosum assessment by collecting ground-truthing data far more efficiently than on-foot methods.
High-resolution, habitat-suitability maps for the conservation and management of vulnerable marine ecosystems on the Louisville Seamount Chain, south Pacific Ocean
Authors: Rowden A A , Anderson O F , Georgian S E , Bowden D A , Clark M
R , Pallentin A , Miller A
Published: September 2017

Vulnerable marine ecosystems (VMEs) are ecosystems at risk from the effects of fishing activity or other kinds of disturbance, as determined by the vulnerability of their components (e.g., habitats, communities or species). Habitat suitability modelling is being
used increasingly to predict distribution patterns of VME indicator taxa in the deep sea (where data are particularly sparse), and the models are considered useful for marine ecosystem management.
The Louisville Seamount Chain is located within the South Pacific Regional Fishery Management Organisation (SPRFMO) Convention Area, and some seamounts are the subject of bottom trawling for orange roughy by the New Zealand fishery. The aim of the present study was to produce high-resolution,
habitat suitability maps for VME indicator taxa and VME habitat on these seamounts, in order to aid the design of within-seamount spatial closures to protect VMEs.
We used a multi-model habitat suitability mapping approach, based on bathymetric and backscatter data collected by multibeam echo sounder survey, and data for the stony coral and habitat-forming VME indicator species Solenosmilia variablis collected by towed underwater camera. Maps resulting from
our models showed that suitable habitat for this species is distributed around the summit-slope break of seamounts, and along ridges that extend down the seamount flanks. Only the flat, soft sediment summits are predicted to be unsuitable habitat for this stony coral species. We translated a
definition for stony coral-reef habitat into a Solenosmilia variablis abundance-based threshold in order to use our models to map this VME habitat. These maps showed that coral-reef occurred in small and isolated patches, with most of the seamounts predicted to be unsuitable habitat for this VME.
We discuss the implications of these results for spatial management closures on the Louisville Seamount Chain seamounts and the wider SPRFMO area, and future modelling improvements that could aid efforts to use habitat suitability maps for managing the impact of fishing on vulnerable marine
ecosystems.
Quality of image-based manganese nodule abundance assessment
Authors: Schoening T , Greinert J
Published: September 2017

Manganese nodules are a marine mineral resource and are considered for deep sea mining operations. These nodules constitute an important element of the deep sea habitats they occur in and their abundance and size frequencies have an impact on occurring fauna.
Assessing the distribution of nodules is traditionally done with a combination of large-aerial hydro-acoustic mapping linked with ground-truthing by physical sampling. While hydro-acoustics provide large aerial coverage (km2/h) with low resolution (m/px), physical sampling provides low aerial
coverage (cm2/h) with high resolution (mm/px). To bridge these two separate data domains, optical imaging has successfully been applied as it provides medium aerial coverage (ha/h) and resolution (cm/px).
Extracting quantitative data from optical images is traditionally done by effortful manual image annotation. More recently, multiple automated and semi-automated image analysis algorithms have been proposed. These algorithms are usually tuned for one specific data set or use case. The application of
these algorithms to other optical imagery data sets is one necessity to prove their robustness. As manual annotations of manganese nodules are scarce and focus on nodule counts rather than exact nodule delineations, quantitative assessment of the quality of detection algorithms in the form of e.g.
precision and recall is not possible at the moment.
Apart from the within-data comparison, a link to the traditional sampling strategies is required. These strategies are the de-facto standard for aerial mapping of habitats and assessing seafloor substrate composition (including manganese nodules). In the case of physical sampling, statistic
variations in the natural nodule abundance can bias the sampling outcome. In the case of hydro-acoustic sampling, small-scale natural variations in abundance that are relevant to mining as well as habitat composition can be occluded due to the limited resolution. Using optical imaging as a bridge
technology enables to extract more robust nodule abundance data.
This presentation will include results on comparing different nodule detection algorithms, and will show the challenges in correlating physical sampling derived data with optical imagery data and shows potential applications for habitat assessment using the presented
algorithms.
Glacigenic debris-flows and down-slope gullies: evidence of a grounded ice margin during past glacials, South Shetland Trench, Antarctica
Authors: Stewart H A , Jamieson A J , Ó Cofaigh C , Bradwell T
Published: September 2017

The South Shetland Trench (SST) is located near the Antarctic Peninsula, around 100 km northwest, and parallel to, the South Shetland Islands. Although a number of studies examining glacial history have been undertaken in the Bransfield Strait located between the
South Shetland Islands and the Antarctic Peninsula to the south, the authors believe this is the first study of the seafloor glacial geomorphology, and recent glacial history of the SST. This paper presents initial results from a EUROFLEETS Expedition to the SST that took place in December 2015.
The Expedition collected three gravity cores, 3148 square kilometres of multibeam echosounder data and around 600 line kilometres of Topas sub-bottom data covering part of the southern flank and trench floor of the study area. Additional bathymetry data derived from the Global Multi-Resolution
Topography (GMRT) Synthesis (Marine Geoscience Data System www.marine-geo.org) comprising a multi-resolution global Digital Elevation Model (DEM) that includes processed multibeam bathymetry data (100 m resolution) where available and gridded seafloor depths (30 arc-second resolution) derived from
the General Bathymetric Chart of the Oceans (GEBCO www.gebco.net). These combined data reveal the study area, north of King George Island, on the southern flank of the SST to host a system of linear downslope gullies, glacigenic debris flows and glacigenic deposits.
Within the study area glacigenic debris flows are found to extend from the continental shelf break to the lower continental slope. Sub-bottom profiler data penetrated up to 150 ms below seafloor in places and reveal a stacked sequence of debris flows suggestive of a fluctuating ice front that was
grounded to, and retreated from, the shelf break on several occasions.
More than eleven individual gullies (and their tributaries) were imaged between 450 m and 3600 m water depth. The gullies are incised up to 250 m below the surrounding sea bed with internal slope angles locally exceeding 45° and were influenced by shallow transform faulting related to
subduction processes.
Downslope gullies have been observed on other glaciated margins such as the Scotian slope offshore Canada, Ross Sea Antarctica, north-western Barents Sea and West Shetland Margin offshore north-western UK. The gullies are inferred as being eroded by turbidity currents comprising cold, dense,
sediment-rich meltwater released from an ice front located at or near the continental shelf break.
Using AUV for sediment mapping - experiences from a MAREANO pilot project, Norway
Authors: Thorsnes T , Bjarnadottír L , Jakobsen F , Bellec V , Dloan M , Lagstad P , Olsen K
T
Published: September 2017

Sediment grain-size maps are an important product in their own right and a key input for habitat and biotope maps. National and regional mapping programmes are tasked with mapping large areas, and survey efficiency, data quality, and resulting map confidence are
important considerations when selecting the mapping strategy. Since 2005, c. 175,000 square kilometres of the Norwegian continental shelf and continental slope has been mapped with respect to sediments, habitats and biodiversity, and pollution under the MAREANO programme (www.mareano.no). At present
the sediment mapping is based on a combination of ship-borne multibeam bathymetry and backscatter, visual documentation using a towed video platform, and grab sampling.
We have now tested a new approach, using an Autonomous Underwater Vehicle (AUV) as the survey platform for the collection of acoustic data (Synthetic Aperture Sonar (SAS), EM2040 bathymetry and backscatter) and visual data (still images using a TFish colour photo system). This pilot project was
conducted together the Norwegian Hydrographic Service, the Institute of Marine Research (biology observations) and the Norwegian Defence Research Establishment (operation of ship and AUV).
The test site reported here is the Vesterdjupet area, offshore Lofoten, northern Norway. The water depth is between 170 and 300 metres, with sediments ranging from gravel, cobbles and boulders to sandy mud. A cold-water coral reef, associated with bioclastic sediments was also present in the study
area.
The presentation will give an overview of the main findings and experiences gained from this pilot project with a focus on geological mapping and will also discuss the relevance of AUV-based mapping to large-area mapping programmes like MAREANO.
How subsurface voxel modelling and uncertainty analysis contribute to habitat-change prediction and monitoring
Authors: Van Lancker V , Kint L , Montereale-Gavazzi G , Terseleer N , Chademenos V , Missiaen T , De Mol R , De Tré G , van Heteren S , van Maanen P P , Stafleu J
Published: September 2017

For long-term predictions of geological resource quantity and quality, a voxel model was built for the subsurface of the Belgian part of the North Sea (Belgian Science Policy 'TILES'). The 3D voxels contain lithostratigraphic information over the entire data
volume (up to -70 m), but also sediment characteristics and a suite of sediment-dynamic parameters in the upper voxel (i.e., the seabed). Derivative data products include probability maps of sediment type and resource-suitability maps that reflect a combination of user-specific criteria.
From stakeholder consultation, it became clear that the model has numerous potential applications, provided that resolution requirements from very small-scale to large-scale can be met (e.g., assessing local aggregate quality, but also decision-making on long-term resource use). To accommodate these
varying needs, and also to enhance computational speed, voxel models were post-processed to vary the size of the voxels dependent on user demand. As such, data density, but also geological heterogeneity can steer the voxel size.
Uncertainty is parameterised to generate data products with confidence limits. Uniquely, the quality of each of the data fields in the databases is quantified in order to be propagated in the voxel model. Additionally, interpolation-related uncertainty, as well as uncertainty in the mapping of the
lithological class and stratigraphic uncertainty (i.e. the geological layer to which a so-called lithoclass belongs) is incorporated. Visualisation of these uncertainties is highly challenging, and is addressed through variation in the sizes of the voxels or through transparency.
An ample spectrum of benefits exists for habitat mapping. Firstly, the geology of the shallow subsurface is accounted for, being highly relevant in predicting and constraining habitat change in long-term projections of resource use. The approach is also pertinent to assist present-day seabed
mapping. Uncertainty mapping is critical to judge on the accuracy of seabed maps, and it assists in interpreting habitat changes within an envelope of natural variability, imposed by both the geological nature of the seabed and the highly dynamic sedimentary environment.
Mapping of the major morphologic features and seafloor sediments of the New Hampshire Continental Shelf using the Coastal and Marine Ecologic Classification Standard (CMECS)
Authors: Ward L , McAvoy Z , Nagel E
Published: September 2017

The New Hampshire continental shelf is extremely heterogeneous and includes extensive bedrock outcrops, sand and gravel deposits, and muddy basins. Many of the depositional features are glacial in origin and have been significantly modified by marine processes as
sea level fluctuated since the end of the last major glaciation. Glacial deposits (e.g., drumlins) on the shelf have been eroded, leaving very coarse lag deposits, while supplying sand to develop wave-formed features (shoals). Many of these features have positive relief standing above the seafloor,
lending evidence of their formation by waves and shallow water currents. Some of these deposits may represent significant sand and gravel deposits and have the potential for future use for beach nourishment and other efforts to build coastal resiliency.
Relatively recent high resolution multibeam echosounder (MBES) bathymetric and backscatter surveys have revealed features of the New Hampshire shelf and vicinity seafloor in exceptional detail that has not been previously described. Synthesis of the MBES bathymetry and backscatter (along with
bathymetric derivatives), coupled with an extensive archived database consisting of subbottom seismics, bottom sediment grain size data, and vibracores, were used to develop new surficial geology maps based on CMECS (partially supported by the Bureau of Ocean Energy Management). The new surficial
geology maps of the New Hampshire shelf produced in ArcGIS represent a major improvement over previous mapping efforts and provide ground truth for testing automated classification approaches. Presently, the CMECS maps are being refined and the classification of the geoforms expanded for paraglacial
environments. In addition, automated characterization and segmentation approaches using QPS Fledermaus Geocoder Toolbox Angle Range Analysis (ARA) and ESRI ArcGIS Spatial Analyst Tools are being evaluated.
Conformal invariance of dimer heights on isoradial double graphs
Authors: Li Zhongyang
Published: September 2017

An isoradial graph is a planar graph in which each face is inscribable into a circle of common radius. We study the 2-dimensional perfect matchings on a bipartite isoradial graph, obtained from the union of an isoradial graph and its interior dual graph. Using the isoradial graph to approximate a simply-connected domain bounded by a simple closed curve, by letting the mesh size go to zero, we prove that in the scaling limit, the distribution of height is conformally invariant and converges to a Gaussian free field.
Motivic Donaldson–Thomas invariants of some quantized threefolds
Authors: Cazzaniga Alberto , Morrison Andrew , Pym Brent , Szendrői Balázs
Published: September 2017

This paper is motivated by the question of howmotivic Donaldson–Thomas invariants behave in families. We compute the invariants for some simple families of noncommutative Calabi–Yau threefolds, defined by quivers with homogeneous potentials. These families give deformation quantizations of affine three-space, the resolved conifold, and the resolution of the transversal

A_n

-singularity. It turns out that their invariants are generically constant, but jump at special values of the deformation parameter, such as roots of unity. The corresponding generating series are written in closed form, as plethystic exponentials of simple rational functions. While our results are limited by the standard dimensional reduction techniques that we employ, they nevertheless allow us to conjecture formulae for more interesting cases, such as the elliptic Sklyanin algebras.