Atlantic Coastal Waters Research Articles

Analysis of Amphora ostrearia var. minor Grunow, a blooming marine diatom (Bacillariophyceae) in French Atlantic coastal waters and its transfer to the genus Tetramphora

A marine amphoroid diatom, responsible for blooms in 2011 and 2019 in French Atlantic waters was studied using morphology and molecular phylogeny. The highest cell concentrations were reached in the region of Marennes Oléron on 19 August 2011 and were related to a greyish discolouration of gills of oysters and mussels. It was identified as Amphora ostrearia var. minor Grunow, based on morphological characteristics. To ensure the correct identification, type material was re-investigated, using the type slide n° 142 (Cleve & Möller 1878. Diatoms. Part II. Esatas Edquists Boktryckeri, Upsala: 49–108) that enabled us to establish the identity of the taxon. Plastid morphology corresponded to Mereschkowsky’s type 8 amphoroid chloroplast, a feature typical for the genus Tetramphora Mereschkowsky. Results of a phylogenetic analysis inferred from a concatenated alignment including the nuclear marker SSU and the chloroplast rbcL indicated that A. ostrearia var. minor was positioned inside the monophyletic clade Tetramphora (Mereschkowsky) Stepanek & Kociolek. This, together with the morphological data, necessitated a transfer of A. ostrearia var. minor Grunow to the genus Tetramphora (Mereschkowsky) Stepanek & Kociolek. In addition, the genetic distances (p-values) from SSU–rbcL sequences were estimated among the species of Tetramphora including T. ostrearia, the generitype. These revealed that the divergence between Tetramphora ostrearia (Brébisson) Mereschkowsky and its variety minor was higher than the mean value within species of the genus. As a consequence, the studied taxon is raised to the species level as Tetramphora minor (Grunow) Nézan, comb. et stat. nov. Toxin analysis of four strains of T. minor revealed the absence of domoic acid production. Pigment analysis of T. ostrearia revealed a high fucoxanthin production, similar to other amphoroid species.

Killer whales habitat suitability in the Iberian Peninsula and the Gulf of Biscay: Implications for conservation

This study addresses existing gaps in our understanding of the ecology of killer whales by investigating their habitat use dynamics in the Atlantic coastal waters of North Africa, the Iberian Peninsula, and the Gulf of Biscay. Despite previous research on their distribution during the Atlantic Bluefin tuna migration in the Strait of Gibraltar and adjacent waters, substantial knowledge gaps persist, particularly regarding their movement patterns beyond these regions and seasonal variations in habitat use. Utilizing killer whale occurrence records from 2020 to 2023 and considering environmental factors influencing prey presence, we employed seasonal spatial distribution models. MaxEnt models exhibited robust predictive performance, emphasizing distance to shore, depth, and sea surface temperature as key factors influencing killer whale habitat suitability. Spatial distribution patterns reveal a peak in coastal waters of the southern Iberian Peninsula and North Africa during winter and spring, with a significant shift northward and expansion during summer and autumn towards the Gulf of Biscay. This expansion suggests a broader distribution of killer whales in the Northeast Atlantic during warmer months, encompassing a diverse range of habitats. The research underscores a substantial interaction (47%) between killer whales and recreational vessels, posing concerns for both the killer whales and maritime safety. This study provides valuable insights on killer whale habitat use in the Atlantic waters from North Africa to the Gulf of Biscay, thereby supporting conservation and management efforts in the region.

First record of the genus Togula (Gymnodiniales, Dinophyceae) and of the species T. jolla for the South-West Atlantic coastal waters

In the framework of a phytoplankton and biotoxin monitoring program implemented since 2008 in marine coastal waters of the Buenos Aires Province (Argentina), a gymnodinioid, photosynthetic dinoflagellate was isolated from a sample collected in Santa Teresita, establishing the strain LPCc007. The strain was identified as belonging to the psammophilic genus Togula by light microscopy based on the following distinctive characters: morphology of the cell dorso-ventrally flattened, and course of the cingulum, highly asymmetric, descending, with its ends displaced by about one to two thirds of the total length of the cell and joined by an oblique intercingular groove. The comparative morphological analysis between the motile vegetative cells of the isolated strain and the three species of the genus described to date, did not reveal significant differences that would allow it to be determined at a specific level. Instead, the pattern of development of longitudinal grooves on the hypocone of cells about to undergo mitosis observed in strain LPCc007, perfectly agrees with that described for T. jolla as a differential character. The morphological identification was consistent with LSU rDNA (D1-D2) based phylogeny that showed the sequence aggregation in the T. jolla clade. This is the first report of the genus Togula and the species T. jolla from Argentina and the South-West Atlantic Ocean coastal waters.

Detection of different Betanodavirus genotypes in wild fish from Spanish Atlantic coastal waters (Galicia, northwestern Spain).

The nervous necrosis virus (NNV; genus Betanodavirus) is an aquatic pathogen that is responsible for a neurological disease affecting marine fish. Despite its almost worldwide distribution, global warming could favor the spread of NNV to new areas, highlighting the importance of conducting epidemiological surveys on both wild and farmed marine fish species. In this study, we assessed NNV prevalence in wild fish caught along the Galician Atlantic coast. In total, 1277 fish were analyzed by reverse transcription real-time polymerase chain reaction. Twenty two (1.72%) of those fish tested positive for NNV, including two species in which the pathogen had not yet been reported. The reassortant RGNNV/SJNNV (red-spotted grouper NNV/striped jack NNV) was detected in 55% of NNV-positive individuals, while the remaining 45% harbored the SJNNV-type genome. Moreover, from European Pilchard Sardina pilchardus and Atlantic Mackerel Scomber scombrus, we isolated four reassortant strains that carried amino acid mutations at key sites related to NNV-host interaction.

Effects of projected wave climate changes on the sizing and performance of OWCs: a focus on the Mediterranean and Atlantic European coastal waters

Reliable estimations of the Annual Energy Production (AEP) achievable with a certain Wave Energy Converter (WEC) are among the fundamental elements for a sound evaluation of the related Levelized Cost of Energy (LCOE) that plays a crucial role in the investment decision-making process. The lack of reliability in estimates of the device productivity can be a result of the uncertainty in the assessment of the available wave energy resource since the geometry of the device which maximizes the AEP is dependent on the specific wave climate at the foreseen installation site.
 The Climate Data Store of the Copernicus Climate Change Service delivers projections of the wave climate along the 20 m bathymetric contours of the whole European coastlines, covering the period 2040-2100, under two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5) [1].
 This work addresses the effect of such long-term wave climate changes on the optimal sizing and performances of Oscillating Water Column (OWC) WECs to be installed along the Atlantic European coastline, expanding a previously published work in which the Mediterranean coastline was investigated [2]. The capture width of the OWC WEC under different wave conditions is computed using an empirical model [3] capable of predicting the device performance with acceptable accuracy and limited computational time.
 The results show that the optimal geometry of the OWC WEC varies significantly in the different geographical locations, and that the long-term changes in the wave energy resource could cause a slight modification of the optimal geometry in each potential installation site. The AEP of the OWC WEC in the projected wave climate scenario can be significantly different compared to the present one, potentially contributing to reducing the LCOE of this wave energy conversion technology in some geographical locations.
 REFERENCES:
 [1] Caires, S., Yan, K., 2022. Ocean surface wave time series for the European coast from 1976 to 2100 derived from climate projections. (Accessed on Feb. 2022) DOI: 10.24381/cds.572bf382. Copernicus Climate Change Service (C3S) Climate Data Store (CDS)
 [2] Simonetti, I., Cappietti, L., 2023, Mediterranean coastal wave-climate long-term trend in climate change scenarios and effects on the optimal sizing of OWC wave energy converters, Coastal Engineering, 173, 104247.
 [3] Simonetti, I., Cappietti, L., Oumeraci, H., 2018. An empirical model as a supporting tool to optimize the main design parameters of a stationary oscillating water column wave energy converter. Appl. Energy 231, 1205–1215.

First survey of metallic distribution in zooplankton from a south Moroccan area

The Moroccan Southern Atlantic coast is mainly influenced by upwelling, Saharan dust and anthropogenic micropollutant input. These factors contribute to increasing the availability of metal elements in waters. To differentiate human impact from natural variability, knowledge of background concentrations of metals and their fluctuations in bioindicator organisms such as zooplankton is important. This work aims to determine the levels of metals elements (Zn, Mn, Pb, Cu, Cd, Cr, Co, Ni, Li, As, Sr, U, Fe and Ba) in zooplankton along the southern area of the Atlantic coast of Morocco. Zooplankton samples were collected in the summer (July 2013) and autumn (December 2013) at 27 stations from Sidi Ifni to the south of Dakhla. All stations were located on transects perpendicular to the coast. The analysis of metal elements in zooplankton was determined by ICP–MS. The results revealed that in all transects, metal concentrations were below the regulatory limits. Metal enrichments were observed in the south and decreased gradually to the north. This study can be used as baseline data for the metal contents of zooplankton in Moroccan South Atlantic coastal water. A comparison to worldwide reported data on zooplankton did not reveal any suggestions on increased metal presence in the area investigated.

Twenty‐year trends of Centropages typicus (Copepoda, Calanoida) reproduction, feeding, population abundance and structure in the Gulf of Naples (Western Mediterranean Sea)

AbstractCentropages typicus is a temperate calanoid copepod occurring in Atlantic and Mediterranean coastal waters, where its reproductive biology and population dynamics are well‐known. C. typicus has also been suggested as a key species for monitoring the impact of environmental changes on copepod secondary production. The aim of this study is to investigate the seasonal and interannual reproductive (egg production and egg hatching success) and feeding (fecal pellet production) traits, population abundance and structure (sex ratio) of C. typicus over a 20‐year period at the Long‐Term Ecological Research site MareChiara (LTER‐MC) in the Gulf of Naples (Central Tyrrhenian Sea, Western Mediterranean Sea), identifying specific trends and patterns. At a seasonal scale, egg production and hatching success were tightly linked with maxima in February–March, driving the juvenile and adult springtime population peaks but showing a poor correlation with phytoplankton abundance, pointing to an omnivorous diet. At a multiannual scale, an observed decrease in the population is backed up by a reduction in egg production, despite an increase in hatching success. The results of this study provide new elements to comprehend the links between C. typicus functional traits, population dynamics, and environmental factors and highlight the importance of running LTER series to monitor the trends in natural environments.

Characteristics of wave energy resources on coastal waters of northeast Taiwan

Hourly measurements of wave data for 10–14 years from four field stations were analyzed to evaluate wave energy resource characteristics in medium wave power potential coastal waters of northeast Taiwan. Spectral parameters, resource index, and constitutive energy periods were discussed. Time series of water surface displacement in each hour for three consecutive years at two stations were first adopted to obtain period transferring coefficient Cep of 0.86–0.87 for JONSWAP's peak enhancement factor γ of 1.5–1.6. The derived average wave energy scatter maps characterized indices of monthly and seasonal variations and highlighted the effects of typhoon and higher potentials by monsoons with increasing waves from NE. Comparisons with previous numerical simulations on sites offshore northeastern coasts pointed out slightly higher energy potentials at present field stations suggesting field measurements being vital for resource assessment. From energy scatter maps of two representative geographical zones, 15 and 16 top-ranked bin conditions were selected to display concentrations on constitutive energy periods from 6 s to 10 s. Similar selections were applied to foreign energy resources in Pacific and Atlantic coastal waters to show major energy potentials at higher latitudes concentrated on constitutive period ranges by 2 s longer.

Virginia Game Fish Tagging Program: A Nontraditional Data Source for Fisheries Management

Since 1995, the Virginia Game Fish Tagging Program (VGFTP) has collected data for recreationally important marine fishes in cooperation with skilled volunteers. These trained anglers tagged more than 380,000 fishes since 1995 and contributed data regarding fish movement and site fidelity patterns of species captured and released in the Chesapeake Bay and Atlantic coastal waters. Over time, the VGFTP has become an important source of data for fishery managers and program data are included in stock assessments for species such as Cobia Rachycentron canadum. Best management practices from the VGFTP show that cooperative science programs that collect data for management should have mandatory hands‐on training with quality control mechanisms in place for submitted data. Further, fishery managers, statisticians, and stakeholders should work together to identify the data needs for statistical viability before volunteers start collecting information. Finally, data objectives and project results should be shared with the stakeholders who collected the data, in addition to fishery managers.

Circles in the sea: annual courtship "torus" behaviour of basking sharks Cetorhinus maximus identified in the eastern North Atlantic Ocean.

Groups of basking sharks engaged in circling behaviour are rarely observed, and their function remains enigmatic in the absence of detailed observations. Here, underwater and aerial video recordings of multiple circling groups of basking sharks during late summer (August and September 2016-2021) in the eastern North Atlantic Ocean showed groups numbering between 6 and 23 non-feeding individuals of both sexes. Sharks swam slowly in a rotating "torus" (diameter range: 17-39 m), with individuals layered vertically from the surface to a maximum depth of 16 m. Within a torus, sharks engaged in close-following, echelon, close-flank approach or parallel-swimming behaviours. Measured shark total body lengths were 5.4-9.5m (mean LT : 7.3m ± 0.9s.d.; median: 7.2m, n= 27), overlapping known lengths of sexually mature males and females. Males possessed large claspers with abrasions that were also observed on female pectoral fins. Female body colouration was paler than that of males, similar to colour changes observed during courtship and mating in other shark species. Individuals associated with most other members rapidly (within minutes), indicating toroidal behaviours facilitate multiple interactions. Sharks interacted through fin-fin and fin-body contacts, rolling to expose the ventral surfaces to following sharks, and breaching behaviour. Toruses formed in late summer when feeding aggregations in zooplankton-rich thermal fronts switched to non-feeding following and circling behaviours. Collectively, the observations explain a courtship function for toruses. This study highlights northeast Atlantic coastal waters as a critical habitat supporting courtship reproductive behaviour of endangered basking sharks, the first such habitat identified for this species globally.

Interactions between American lobster (Homarus americanus) and salmonid aquaculture in the Canadian Maritimes

Salmonid aquaculture occurs in coastal Atlantic waters around the Canadian Maritimes and can overlap with the American lobster ( Homarus americanus) fishery, the most profitable fishery in the region. There has been debate around whether there is potential for salmonid aquaculture to negatively affect the fishery that has been heated in both the scientific community and public news media. This review and resultant commentary explore the developing research approaches used in the Canadian Maritimes to examine known and inferred interactions between these two important industries. We re-examine some inferences of previous research and identify low-oxygen environments and improper use of therapeutants as having the greatest potential to adversely affect lobsters, although there are knowledge gaps. We further discuss the implications of whether localized lobster displacement from a farm area would have any measurable impact on the lobster fishing industry as a whole, using examples from Nova Scotia, Canada. In most instances, existing regulatory compliance addresses the drivers that have the largest potential to adversely impact lobster.

COASTAL OCEAN ACIDIFICATION IN BRAZIL: A BRIEF OVERVIEW AND PERSPECTIVES

This perspective paper aims at presenting the current knowledge on the processes of ocean acidification (OA) and coastal acidification (CA) in the Brazilian coastal ocean. We define and differentiate the processes of OA and CA: the first driven by the actual global increase of atmospheric carbon dioxide (CO2); the second driven by a combination of ocean uptake of atmospheric CO2 and other local/regional chemical additions or subtractions in aquatic ecosystems at the land-ocean interface. Regarding OA, we have centered our analysis on the data available for the main water masses along the Brazilian coast: South Atlantic Central Water (SACW), Tropical Water (TW), and Coastal Water (CW). The few data available for the shallow coastal waters (< 200 m depth) of the continental shelf reveal an increase in the anthropogenic component of the total dissolved inorganic carbon (DIC) pool in the SACW, with a decline in the ocean pH (over two decades; 1993-2013), and in the saturation state of calcium carbonate (CaCO3) minerals. We could not find OA trends for TW and CW because no data was available. Overall, the colder water masses (SACW, Plata Plume) have lower buffering capacity and simulations show that will potentially experience earlier negative OA impacts than the warmer waters masses (TW, Amazon Plume). Regarding CA, we have identified some local/regional studies investigating the carbonate chemistry in nearshore/estuarine ecosystems, particularly on the quantification of sources and sinks of CO2 , and determining short-term variabilities. Apparently, spreading coastal eutrophication in Brazil can enhances or reduces the process of OA, depending on the net ecosystem metabolism in combination with other chemical alterations. However, we could not find medium-long term acidification trends due to the limited data. There is a limited capacity to produce long time-series of carbonate chemistry parameters in key ecosystems and regions along the Brazilian coast. This lack of past information hinders and impairs the scientific community for identifying potential patterns of acidification along the Brazilian coast. We call for an urgent action in Brazil, with emphasis on the establishment of moored buoys/stations and/or scientific programs in the long term with continuous, real-time measurements of the main carbonate chemistry parameters.
 Keywords: ocean acidification, coastal acidification, coastal eutrophication, continental shelf, Southwestern Atlantic Ocean

Development of sensitive genotype‐specific quantitative polymerase chain reaction methods for detection of Phaeocystis globosa in the South China Sea

AbstractSince 1997, dense blooms of the alga Phaeocystis globosa have occurred in the South China Sea (SCS), and previous studies have revealed the co‐existence in this sea of two types of P. globosa cell characterized by different marker pigment profiles. However, owing to a lack of quantitative methods for the detection of different types of P. globosa cells, the dynamics of P. globosa blooms in the SCS are still poorly understood. In this study, on the basis of phylogenetic analysis of the mitochondrial atp8 (Mit atp8) gene and pigment profiles, the P. globosa strains from Pacific and Atlantic coastal waters were divided into four genotypes, of which Type I and Type IV strains co‐exist in the SCS. Furthermore, two genotype‐specific quantitative polymerase chain reaction (qPCR) methods were developed targeting the Mit atp8 gene for quantitative determinations of the densities of Type I and Type IV P. globosa cells. Both qPCR methods were reproducible, highly sensitive, and specific with a wide range of detection (from 30 to 1 × 108 cells L−1) for target P. globosa genotypes in the field, thereby facilitating the detection of low cell densities prior to bloom development, as well as high cell densities during bloom periods. Finally, the developed qPCR assays were successfully applied to determine the distribution patterns of Type I and Type IV P. globosa in the Beibu Gulf, a region of the SCS characterized by a high frequency of P. globosa blooms.

Declining Populations of Mytilus spp. in North Atlantic Coastal Waters—A Swedish Perspective

During the past 2–3 decades, the spatiotemporal distribution of Mytilus spp. in coastal waters of the North Atlantic has changed considerably. In general, reduced abundances of Mytilus are observed, but there is a great degree of local variation, and some areas are also experiencing recovery after declining events. In this review, hypotheses regarding the causes behind the changes are presented with focus on a Swedish perspective. Excessive exploitation of mussel banks combined with direct and indirect effects of climate change are most probably the main drivers of Mytilus spp. decline in large parts of the North Atlantic. On the Swedish west coast, the wild stocks have disappeared despite no overfishing. Paradoxically, they thrive in mussel farms and on other non-demersal substrates. Changes in predation from, for example, increased wintering populations of eiders (Somateria molissima; 10-fold) and green crabs (Carcinus maenas; 3-fold), alteration of natural substrates elicited by eutrophication, and exacerbated by climate change (increased sea surface temperature, precipitation and extreme weather events) are most likely the key factors for the decline. Most anthropogenic stressors may not be decisive by themselves, but combined effects can potentially be fatal to Mytilus spp. adults and larvae.

The atmospheric blocking influence over the South Brazil Bight during the 2013–2014 summer

The 2013–2014 summer in the Southeast Brazil region set records for negative precipitation anomalies and the highest sea surface temperatures. Such event was attributed to the anomalous presence of atmospheric blocking, which prevented the propagation of a cold front towards the Equator and the establishment of the South Atlantic Convergence Zone, two phenomena that regulate the precipitation regime in this area. These blocking episodes are relatively important to the climate in mid-latitudes, but the feedback of the coastal ocean is still poorly understood under these anomalous conditions. This paper investigates, from a numerical perspective, the impacts on the thermohaline properties and circulation in the South Brazil Bight (SBB). We found that enhanced shortwave radiation leads to intense surface heating and that the presence of northeasterly winds strengthens the coastal upwelling nearby Cabo Frio. The South Atlantic Coastal Waters, transported into the SBB, regulate the extreme heating in the northern half of the domain, while, in the southern half, the absence of cold waters leads to the development of a warm-water pool. The final thermohaline structure induced an enlargement and intensification of the northwestward currents south of São Sebastião Island. Between Ubatuba and Cabo Frio, in the northern half, the northeasterly winds developed an intense surface advection towards offshore, and in the northern region, compensated by an opposite advection, towards the coast. We conclude that the coastal ocean feedback could present extreme anomalous conditions during atmospheric blocking events, leading to impacts upon the thermodynamical properties. Further studies are needed to understand the impacts of these events on biogeochemical properties.

Does the Atlantic horse mackerel Trachurus trachurus (Teleostei: Carangidae) differentiate morphologically within the putative Moroccan-Saharan stock?

ABSTRACT To discriminate potential stock units of the Atlantic horse mackerel Trachurus trachurus within the putative Moroccan–Saharan stock, we investigated the morphological variation of this species from three fishing areas (from the north to the south: Larache, Safi and Dakhla) in the Moroccan Atlantic coastal waters. We used a geometric morphometric approach based on 30 truss measures derived from 14 landmarks in 165 fish specimens. We compared fish from three areas using a multivariate analysis including discriminant analysis and Procrustes technique. We found indications of at least two subunits: a differentiated subgroup in the north off Larache, probably a self-recruiting population or a locally adapted morphotype, and two overlapped subunits, respectively in the mid and southern Moroccan Atlantic coast off Safi and Dakhla. Examination of the contribution of each morphometric variable to canonical functions indicated that differences among samples seemed to be associated with morphological changes in the anterior and posterior parts of body, which may indicate adaptations to local environmental conditions and habitat use. Further investigations using other methods are needed to confirm the identified stock units. The present study and the obtained results on such a vulnerable declining small pelagic species are of great importance for fish stock assessment management and practice, but also have ecological and evolutionary implications related to local adaptations in fish populations that are under intense fishing pressure as an induced evolutionary selective force, which affects several adaptive traits.

Modeling investigation of the nutrients and phytoplankton dynamics in the Moroccan Atlantic coast: A case study of Agadir coast

Although the environmental status of the Moroccan Atlantic coastal waters has been researched in previous studies, there is still a lack of knowledge about its biogeochemical functioning. Especially for the Agadir coast where measurements are quite scarce, realistic ecological models can help identifying the key mechanisms driving fluctuations in such coastal areas. Here we implemented a three-dimensional (3D) coupled hydrodynamic-biogeochemical model in order investigate the time-space distribution of inorganic nutrients (NO₃, PO₄ and SiO₄), and their control on phytoplankton (diatoms, flagellates) biomass on the Agadir coast. Model performance was evaluated against satellite observations and climatology data. The model achieved satisfactory representation of the sea surface temperature, chlorophyll-a, and a reasonable agreement in the seasonal pattern of inorganic nutrients. Based on nutrient concentrations and their stoichiometric ratio; the study points to nitrate as the key factor controlling phytoplankton distribution (largely dominated by flagellates). Nitrate depletion occurs faster than phosphate and silicate, thus driving the area towards nitrogen limitation.

Anthropogenic gadolinium in estuaries and tropical Atlantic coastal waters from Fortaleza, Northeast Brazil

Gadolinium-based contrast agents are worldly used for medical magnetic resonance imaging and are an emerging contaminant in natural waters. We investigated the dissolved fraction of Gd in coastal waters from Fortaleza city and observe positive Gd anomalies in the wastewater outfall area as well as in two local river estuaries indicating that the city is a significant source of anthropogenic Gd (Gdanth) to the ocean. Based on this synoptic study and on the conservative behavior of Gdanth we trace a highly concentrated sewage-based source which accounts for 2200 pmol kg−1 and to an annual discharge of 25 kg of Gd to the ocean. We also trace minor sources from the two rivers and estimate that the levels of wastewater dilution within freshwater prior to mixing with seawater accounted for 4.8%–14% of the Cocó River discharge and 1.4%–3.9% of the Ceará River discharge at the time of the sampling. Gd is consequently a suitable and promising tracer for water management and forensic purposes in Fortaleza. In order to guide the application of this method to other coastal waters impacted by metropolitan areas in the world, we propose a conceptual model for Gdanth behavior within salinity gradients and apply it to revisit previous studies.

Studying Submarine Geomorphology in an INFOMAR Priority Bay through the application of Remote Sensing Techniques

Bathymetric mapping in the coastal shallow water zone is a challenging and costly process using traditional survey methods. Because of this, much of this region worldwide remains uncharted and, therefore, is poorly understood. Multispectral satellite imagery has proven to be a practical alternative tool in predicting water depth in coastal zones, though influences on its performance and accuracy are not fully understood and vary according to local environmental conditions. This study explored the suitability of a satellite derived bathymetry (SDB) methodology in Irish Atlantic coastal waters. Using imagery captured at a range of spatial, spectral and temporal resolutions by the RapidEye and Landsat 8 satellites, we explored the correlation between performance, accuracy and image resolution, demonstrating that sensor wavelength is the key limiting factor in optical penetration of water and also accurate delineation of the gradient on the seafloor. We further applied this data in a study of submarine geomorphology in an INFOMAR priority bay. Although the SDB accuracy is insufficient for high accuracy bathymetry products, nevertheless, they are considered beneficial in a variety of other applications in sensitive disciplines such as environmental monitoring, seabed mapping, or coastal zone management.

Studying Submarine Geomorphology in an INFOMAR Priority Bay through the application of Remote Sensing Techniques

Bathymetric mapping in the coastal shallow water zone is a challenging and costly process using traditional survey methods. Because of this, much of this region worldwide remains uncharted and, therefore, is poorly understood. Multispectral satellite imagery has proven to be a practical alternative tool in predicting water depth in coastal zones, though influences on its performance and accuracy are not fully understood and vary according to local environmental conditions. This study explored the suitability of a satellite derived bathymetry (SDB) methodology in Irish Atlantic coastal waters. Using imagery captured at a range of spatial, spectral and temporal resolutions by the RapidEye and Landsat 8 satellites, we explored the correlation between performance, accuracy and image resolution, demonstrating that sensor wavelength is the key limiting factor in optical penetration of water and also accurate delineation of the gradient on the seafloor. We further applied this data in a study of submarine geomorphology in an INFOMAR priority bay. Although the SDB accuracy is insufficient for high accuracy bathymetry products, nevertheless, they are considered beneficial in a variety of other applications in sensitive disciplines such as environmental monitoring, seabed mapping, or coastal zone management.