Northwestern Coast Research Articles

Assessment of electricity production and coastal protection of a nearshore 500 MW wave farm in the north-western Portuguese coast

Wave energy can contribute towards the “green” energy transition, but complementary applications like coastal protection are equally pertinent. However, viable commercialization should entice large wave energy farms of significant capacity, which may raise conflicts with coastal industries and/or protected areas. Such matters are addressed in this paper's numerical case study of a dual wave farm for a nearshore Portuguese site. It incorporates two parks of 75 bottom-fixed oscillating flap units, each. The farm's configuration, orientation, layout, and rating were evaluated for varying wave conditions and water levels, based on a statistically representative clustering technique. The farm's location was selected to minimize marine space conflicts. The numerical modelling was executed with SNL-SWAN, from which it was found that a staggered configuration – “W” – would yield better results than an aligned configuration – “III”. The “shadowing” effect of one park onto the other was equally observed, but with limited impact. Greater farm unit spacing and rated power benefited the annual energy production, with values of nearly 345 GWh/yr being achieved. However, the capacity factors were generally greater for lower power ratings, as pondered mean values varied between 0.078 (3.332 MW) to 0.144 (1 MW). Wave power absorption ratios between wave farms and cumulative standalone units (q-factors) were always below 1, pointing towards a destructive interference pattern. Important significant wave height reductions were observed (above 30 %, at times), albeit increments were punctually identified near two shallow water areas. Lastly, increasing the tidal level did not impact the farm's performance considerably, but benefited the nearshore impact.

Bioaccumulation Patterns of Trace Elements in Jellyfish (Crambionella orsini and Cassiopea andromeda) from Northwestern Coastal Waters of the Persian Gulf

Trace element pollution in the Persian Gulf originates from industrial activities, urbanization, shipping, and oil extraction, leading to accumulation in sediments, water, and marine life such as jellyfish. This study investigated trace element bioaccumulation in two jellyfish species, Crambionella orsini and Cassiopea andromeda, across different locations. Jellyfish samples were collected from the Mahshahr and Dilam ports, and their trace element concentrations were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The study revealed no significant differences in trace element concentrations between C. orsini and C. andromeda. However, levels of copper, iron, manganese, and nickel were significantly higher in specimens from Mahshahr compared to those from Dilam. No significant differences were observed for cadmium, mercury, vanadium, tin, magnesium, and selenium across sites. Lower concentrations of lead, arsenic, zinc, and cobalt were found in C. orsini from Dilam compared to Mahshahr. Additionally, the study found no significant correlation between trace element concentrations in the water and their accumulation in jellyfish bodies. These findings offer valuable insights into the distribution and bioaccumulation of trace elements in jellyfish populations across different marine environments in the Persian Gulf.

Saltwater intrusion simulations in coastal karstic aquifers related to climate change scenarios

Coastal zones are crucial ecosystems supporting significant biodiversity and pertinent socio-economic activities. However, anthropogenic development contributes to socio-environmental complexities, particularly public water supply threats caused by climate change. This research presents a case study on the north-western coast of Yucatan, Mexico, which models potential saltwater intrusion in groundwater for multiple projections of sea level rise and recharge change due to climate change and its implications for the public water supply of the regional population and ecosystem. For this purpose, a previously calibrated and validated numerical model is employed, adapting its boundary conditions, keeping its calibrated hydrogeologic parameters, and considering the 2040 and 2100 climate change projections. Simulation results show that under these projections, significant saltwater intrusion may occur, reducing freshwater thickness due to increased salinity in groundwater and a loss of freshwater sources resulting from brackish-saline wedge intrusion. These scenarios are of particular concern as freshwater in this coastal region is the main source for public water supply and for freshwater input in coastal ecosystems. Moreover, this study underscores the susceptibility of karstic aquifers to salinization, especially in the face of rising sea levels, given their unique hydrogeological characteristics and substantial responsiveness to marine forcings. In spite of the uncertainties in global climate change predictions, this study enhances our understanding of the dynamics of these unique aquifers, and presents future saltwater intrusion projections that offer valuable technical insights to design and implement pertinent and resilient coastal aquifer management strategies.

Estimation of bacterio‐, picophyto‐ and nanophytoplankton abundance in the Middle Caspian Sea by flow cytometry

Aim. For the first time, flow cytometry has been used to study the structure and functional characteristics of bacterio‐, pico‐ and nano‐ phytoplankton in the Middle Caspian during the bloom period in early September 2022.Water samples were taken at different horizons (from the surface to the bottom layer) at a series of stations along the western coast of the Caspian Sea on the border between its northern and central parts to quantitatively assess heterotrophic bacterioplankton, picophyto‐ and nanophy‐ toplankton. Sampling was undertaken in early September 2022 under summer hydrological conditions with water surface temperatures ranging from 24.7°C to 26.7°C. Sample analysis was performed using flow cytometry.Extremely high concentrations of picophytoplankton (up to 1.8×105 cells/mL), probably of Synechococcus picocyanobacteria, were detected off the northwestern coast of the Middle Caspian. Very high values of nanophytoplankton abundance (up to 1.6×105 cells/mL), dominated by small flagellates, were also found. A clear spatial uncoupling of pico‐ and nanophytoplankton was revealed. Maximum levels of nanophytoplankton were confined to the area of intensive phytoplankton blooming with high concentrations of chlorophyll a, while picophytoplankton reached peak abundance further south, outside this area. The influence of the thermocline on the vertical structure of microbial communities was detected. The concentrations of picophytoplankton and the proportion of physiologically active HNA‐bacteria decreased sharply under the thermocline.The results obtained indicate the leading role of the smallest phototrophs in the Caspian pelagial and emphasise the need for further comprehensive studies of Caspian microbial communities using modern methods.

2D nonlinear inversion of DC resistivity measurements, a case study; southeastern part of Ras El Dabaa, Northwestern coast, Egypt

The southern Mediterranean coast suffers from limited water resources as a result of exploitation of water supply, population growth, and climate change. Spatial lineaments and Seawater Intrusion (SWI) were detected at the southeast portion of Ras El Dabaa, on Egypt’s northwest coast, using the direct current resistivity (DCR) method. The Vertical Electrical Sounding (VES) data were acquired using Schlumberger array along four profiles and inverted both independently and jointly, aiming to obtain Two Dimensional (2D) geoelectrical images. The results of the one Dimensional (1D) inversion of VES data at each profile were stitched to form pseudo-2D sections on which the resistivity values and aquifer thickness in the southwest of the region appeared to be generally increasing, indicating a potential improvement in water quality.However, the results did not fully image the lateral variation but focused on the horizontal boundaries of the subsurface. On the contrary, the results of 2D inversion of the same data sets successfully managed to provide images that depicted resistivity distribution in both lateral and vertical directions. The detected sets of lineaments and fractured zones within the oolitic limestone and fossiliferous limestone units control the occurrence of groundwater in the region. The 2D inversion scheme revealed a low resistivity zone that indicated the presence of SWI and/or the dissolution of marine salts from the marine limestone bedrock of these aquifers in the northern portions of the studied area. Additionally, analysis of the 2D apparent porosity section shows how aquifers are connected by secondary porosity, which is defined by structures that resemble channels. The current approach offers valuable structural information for future planning and development of such complex geological coastal locations, taking into consideration the vulnerability of the groundwater system.

Characteristics of sublittoral vegetation at the northwestern coast of the Japan Sea based on the concept of adaptive zone

Characteristics of sublittoral vegetation at the northwestern coast of the Japan Sea based on the concept of adaptive zone

Analysis of the environmental state of the Sarata River in Odesa Region

The relevance of the study is dictated by the need to preserve the water resources of southern Ukraine and ensure their good environmental condition. In the context of military operations, Odesa Region plays a key role in providing the country with agricultural products because of significant damage incurred to agricultural lands of Mykolaiv and Kherson Regions in the course of military actions. Hence the role of irrigation and the need to restore and modernize irrigation systems are growing. One of fresh water reservoirs of Odesa Region is Sasyk reservoir (artificially created as part of the estuary) which accumulates fresh water supplied from the Danube. The Kogylnyk and the Sarata rivers flow into the northern part of the reservoir and can worsen its hydroecological condition. The subject of the study: pollution of the rivers across North-Western Black Sea Coast by chemicals. The object of the study: the environmental state of the Sarata River. The study is aimed at assessing the environmental state and environmental risks of chemical pollution of the Sarata River. The water quality assessment was performed based on a modified version of water pollution index (WPI). Biogenic substances (ammonium nitrogen, nitrite nitrogen, nitrate nitrogen) were identified as the main pollutants. The content of chlorides and sulfates is also significant. The assessment of the pollution risks by biogenic substances is based on calculations of the statistical probit function. The source materials of the research include hydrochemical observations made by the State Agency of Water Resources of Ukraine for the period from 2007 to 2023 in the upper reaches of the Sarata River - village of Miniailivka (94 km from the mouth, near the border with Moldova) and in the lower reaches of the Sarata River - village of Bilolissya (14.3 km from the mouth). The analysis of probability of exceeding the MPC for fishery use indicated that, in terms of nitrite ions and nitrate ions, such probability is higher in the upper basin than in the lower one. According to other indicators, the probability of exceeding the MPC by pollutants is either almost the same or slightly increased in the lower reaches. The assessment of water quality according to the modified WPI (dissolved oxygen, BOD5, ammonium, nitrite and nitrate ions, phosphates) showed that the water quality in the Sarata River mainly belongs to the "moderately polluted" and "polluted" classes. According to the environmental risk indicators, it was established that the possibility of a "high" risk of contamination by biogenic substances does prevail. Its probability is 52.9% for the upper reaches and 60% for the lower reaches. The "high" level of class IV pollution (ER=0.60-0.79) corresponds to an "unsatisfactory" environmental condition. The probability of achieving the class of a "good" environmental condition (class II, ER=0.20-0.39) is quite small: 17.6% in the upper reaches and only 6.67% in the lower reaches. Thus, the Sarata River belongs to such rivers, the natural properties of which underwent significant changes as a result of sewage delivery from "Sarata Komunservis" utility enterprise, settlement of Sarata. Contaminated waters are unsuitable for drinking, household and sports purposes, as well as for fish farming. The quality of the Sarata River's water has a negative impact on the environmental state of Sasyk reservoir.

Integrated Impact of Olive Mill Wastes and Semi-Circular Bunds on Soil Properties and Rainwater Harvesting Efficiency in Egypt’s Northwestern Coastal Zone

ABSTRACT The productivity of olive in the northwestern coastal zone of Egypt is significantly constrained by drought and low organic matter in the soil. This study addresses these challenges by exploring the synergistic effects of olive mill wastes (OMW) application and micro-catchment water harvesting techniques on soil properties, runoff, moisture storage, and rainwater harvesting efficiency. Field experiments were conducted over two winter seasons, employing different micro-catchment structures (semi-circular and triangular bunds) and OMW applications. The results revealed that the integration of semi-circular bunds with OMW application (T4) substantially increased rainwater harvesting efficiency by 67.7% and 46.4% in the first and second seasons, respectively. Additionally, T4 and T5 exhibited reduced runoff by 47.8% and 41.3% in the first season and 49.4% and 38.9% in the second season, respectively. T4 significantly enhanced soil organic matter, soil macronutrients (N, P, and K), and micronutrients (Fe, Mn, Zn, and Cu) compared to the control (T1). The study highlights the effectiveness of T4 in improving soil moisture, reducing soil erosion, and enhancing soil fertility. This integrated approach involving OMW application within a semi-circular bund as a water harvesting system proves to be a promising strategy for sustainable olive cultivation in arid conditions.

Soil thematic mapping as the base for agricultural development in the Northwestern Coast, Egypt

Soil thematic mapping as the base for agricultural development in the Northwestern Coast, Egypt

SEISMOGENIC ZONE OF CAPE SHARTLAY (LAKE BAIKAL): SPECIFIC FEATURES OF STRUCTURE, DISPLACEMENTS AND RUPTURE GROWTH

Seismogenic deformations of Cape Shartlay represent a very young fault system on the northwestern coast of Lake Baikal. Their study is providing an important opportunity to measure earthquake magnitudes, to identify areas where earthquakes are more likely to occur, and to estimate the probability of earthquake occurrence as applied to seismically active Baikal region. In this connection, the present work was aimed at characterizing in detail the structure, displacements, and reconstruction of the rupture propagation model. The study is based on photogrammetric processing and interpretation of the unmanned aerial survey data, as well as on morphostructural analysis of the displacement profiles and georadiolocation (GPR) data. It has been found that seismogenic ruptures of Cape Shartlay formed under prevailing extension conditions during no less than two earthquakes with magnitudes Mw≥7.0, Ms≥7.2. Seismic rupture propagation was primarily northward. The main rupture with displacement amplitude of more than 2 m contributed 39 to 93 % to the total surface displacement depending on the amount of dislocations on the transverse profile. It is shown that the length of a certain rupture increased almost instantaneously, then displacements along some of the ruptures stopped. A significant elongation of ruptures is primarily due to their merging. The present-day seismogenic zone is highly permeable. According to the tectonophysical model of formation of inner structure of the fault zone, the development of the seismogenic rupture system of Cape Shartlay corresponds to the late disjunctive stage. This means that the rupturing process in this segment of the North Baikal fault may not have stopped yet, and the lack of large earthquakes in the instrumental record implies the accumulation of stress in its southern part. The obtained results provide an opportunity to reconstruct the development of large fault zones by studying the displacement profiles and, therefore, to localize more precisely the places where future earthquakes may occur.

Relationship between skin and body condition in three species of baleen whales.

The assessment of free-ranging cetacean health through the study of skin conditions using photographs has gained prominence in recent years. However, little attention has been given to the relationships between cetacean skin conditions, species, and body condition. To explore this relationship among baleen whale species along the northwestern coast of Spain, we employed a non-invasive method involving photograph analysis. In this study, we examined skin conditions (including injuries, epizoites and ectoparasites, pigmentation disorders, skin lesions, and anatomical malformations) and body condition (overall physical contours and form, as an indicator of nutritional status and health) in 3 species of whales (blue, fin, and minke whales). This methodology facilitated the identification of 29 subcategories of distinct skin conditions and an assessment of body condition over a 5 yr period (2017 to 2021). In our study, we present evidence linking hypopigmentation, protruding pieces of tissue, and tattoo-like lesions to 'Poor' body condition in the 3 baleen whale species. Fin whales exhibited a higher susceptibility to mottling (prevalence = 17.7%), while blue whales were more prone to starbursts (prevalence = 90.5%). Additionally, we found a significant relationship between skin condition diversity and individual body condition. Our findings contribute valuable information to the broader understanding of the health status of baleen whales. Further investigations are necessary to delve into the etiology of the documented skin conditions and their potential implications for individual survival. This study serves as a foundation for ongoing research aimed at advancing our comprehension of these findings.

The problem of the attribution of burials of medieval nomads on the territory of the ukrainian steppe on the example of three burials from the Novosilsky kurgan complex

The article is devoted to the problem of attributing monuments of medieval nomads from the Ukrainian steppe in the period of X-XIV centuries on the example of three burials from the Novosilsky Kurgan group located in the North-Western Black Sea coast. The attribution of such burials is problematic for the archaeology of Ukraine. The number of modern studies on this topic is rather small, which is determined by the somewhat biased attitude of scientists towards the monuments of medieval nomads of the 10th-14th centuries as those left by a certain homogeneous community, as evidenced by the still used term "late nomads". However, such a strong generalization does not reflect reality. During the Middle Ages, the steppe of Ukraine was replaced one after another by waves of multi-ethnic nomads who migrated here from Central Asia. The ethnic diversity of the Pechenegs, Torks, Cumans, and the Central Asian peoples who came with the Mongols, but also their similarities, including the significant similarity of funeral rites, made it difficult to attribute and identify features for certain ethnocultural groups and chronological periods. The purpose of this paper is to trace possible solutions to this problem. Modern technologies can also help with this - namely, 3-D modelling of artefacts from burials, which allows us to learn the detailed parameters of each object and visualize it in high resolution. For this work, three 3-D models were created - one object from each burial site, which will be characterized in the paper. The models also perform an important task of preserving cultural heritage, because unfortunately, since 2014, because of the armed aggression of the Russian Federation, nomadic monuments from the medieval steppe of Ukraine have been destroyed.

Evaluation of the ecological risks on green macro-algae spp. (Ulva fusciata) at the north western coast of Egypt, using neutron activation technique

The study used the radio-analytical technique (Neutron Activation Analysis), besides the other advanced chemical technique, which was inductively coupled plasma mass spectroscopy (ICP-MS), in order to evaluate the bioaccumulation factor (BF), of different trace elements inside the collected green macro algal samples. The results showed that BF results were based on the algal selectivity of each analyzed trace element. The study recommended the using of Ulva fasciata, as a bio-filter of nuclear cooling water system (mitigation tool), due to its selective absorption ability for certain trace elements such as; Th, Cs &Sr.

The use of GIS in the exploitation of rainwater running in the region from Fouka to Ras Alam al-Rum in the northwestern coast of Egypt

The use of GIS in the exploitation of rainwater running in the region from Fouka to Ras Alam al-Rum in the northwestern coast of Egypt

A High-Resolution Digital Bathymetric Elevation Model Derived from ICESat-2 for Adam’s Bridge

This data descriptor elaborates the details of a high-resolution digital bathymetric elevation model generated for the region, namely, Adam’s Bridge, which encompasses a chain of shoals between Rameswaram Island, off the southeastern coast of Tamil Nadu, India, and Mannar Island, off the northwestern coast of Sri Lanka. The proposed dataset has taken advantage of the photon penetrability in the shallow waters by the green laser of ICESat-2 LiDAR to derive the seabed topography. Seafloor depths from ~0.2 million geolocated photons of ICESat-2 for the study area were accrued and interpolated to generate a 10 m digital bathymetric elevation model. Adam’s Bridge, an isthmus and submerged reefal assemblage in shallow and super-shallow waters, is a feature of scientific curiosity. Our dataset has the potential to enhance the understanding of Adam’s Bridge structure by providing substantial information to reconstruct its evolution.

An Analysis of Hybrid Renewable Energy-Based Hydrogen Production and Power Supply for Off-Grid Systems

Utilizing renewable energy sources to produce hydrogen is essential for promoting cleaner production and improving power utilization, especially considering the growing use of fossil fuels and their impact on the environment. Selecting the most efficient method for distributing power and capacity is a critical issue when developing hybrid systems from scratch. The main objective of this study is to determine how a backup system affects the performance of a microgrid system. The study focuses on power and hydrogen production using renewable energy resources, particularly solar and wind. Based on photovoltaics (PVs), wind turbines (WTs), and their combinations, including battery storage systems (BSSs) and hydrogen technologies, two renewable energy systems were examined. The proposed location for this study is the northwestern coast of Saudi Arabia (KSA). To simulate the optimal size of system components and determine their cost-effective configuration, the study utilized the Hybrid Optimization Model for Multiple Energy Resources (HOMER) software (Version 3.16.2). The results showed that, when considering the minimum cost of energy (COE), the integration of WTs, PVs, a battery bank, an electrolyzer, and a hydrogen tank brought the cost of energy to almost 0.60 USD/kWh in the system A. However, without a battery bank, the COE increased to 0.72 USD/kWh in the same location because of the capital cost of system components. In addition, the results showed that the operational life of the fuel cell decreased significantly in system B due to the high hours of operation, which will add additional costs. These results imply that long-term energy storage in off-grid energy systems can be economically benefited by using hydrogen with a backup system.

The distribution of macroalgae in the Aceh north-western coastline

Abstract Macroalgae are polyphyletic multicellular plants that generally inhabit the littoral zone of the seashore. Aceh Province has a coastline stretching along the east, north and west ends of Sumatra Island; thus, various macroalga species may be found. This research aims to study the distribution of macroalga species at four locations on the north-western side of Aceh, including three sites in Aceh Besar District (Lhoknga, Lange, and Ujung Pancu Beaches) and one site in Banda Aceh City (Ulee Lheue Beach). Sampling was done across 50 meters of the seashore and 1 meter towards the sea. The sampling was conducted using a 1×1 meter quadrant transect method with sampling points every 10 meters. The morphology determination shows that five species of macroalga grew at Lhoknga Beach, namely Valoniopsis pachynema, Halimeda opuntia, Turbinaria decurrens, Sargassum plagiophyllum, and Padina australis. Lange Beach had three macroalgae species: Chaetomorpha linum, Laurencia obtusa, and Sargassum plagiophyllum. Meanwhile, Ujung Pancu Beach has four macroalga species: Halymenia durvillei, Turbinaria decurrens, Ulva lactuca and Sargassum plagiophyllum. At Ulee Lheue Beach, five species were found: Gracilaria edulis, Caulerpa taxifolia, Hypnea musciformis, Padina australis, and Acanthophora spicifera. In total, 13 macroalga species were distributed on Aceh’s north-western coast.

Expected potential hemipteran vectors of Xylella fastidiosa bacterium in olive and vineyard groves of the Egyptian northwestern coast

Xylella fastidiosa was recently added to the list of threatening pathogens affecting more than 300 plant hosts. Hemipteran hoppers that feed on xylem have been documented as potential transmitters. Hemipteran hoppers, known vectors for plant pathogens via xylem feeding, pose significant risks to agriculture. Despite their role in transmitting diseases, comprehensive data on their species diversity, distribution, and seasonal patterns, particularly in critical agricultural zones, remain sparse. Hence, the current study was carried out at 14 sites (eight olive farms and six vineyards) during the 2021/2022 season to develop a comprehensive checklist of hopper species present on the Egyptian Northwestern Coast, including their seasonal and location distribution, to serve as a real roadmap supporting control strategies if the pathogen breaches Egyptian borders. Utilizing 560 yellow sticky traps, we collected data seasonally, resulting in the identification of 21 hopper species belonging to 14 genera within four families. Olive orchards harbored a higher number of hoppers compared to vineyards, with Empoasca decipiens being the most dominant species. Our findings provide a foundational checklist and highlight the importance of continued monitoring and detailed studies to support proactive control strategies against potential X. fastidiosa outbreaks. We used 560 yellow sticky traps at 10 traps per site (80 traps for olive orchards and 60 traps for the vineyard per season) throughout the study period. Traps were installed at two levels to catch hopper species harboring tree canopies and ground vegetation. Each trap was replaced every 7 days, and the collected trap sheets were sent to the laboratory for segregation and identification. The data revealed 21 hopper species belonging to 14 genera and 4 families, with cicadellid species being the most represented (14 species). Olive orchards harbored a higher number of hoppers than vineyards. Empoasca decipiens exhibited the highest dominance among the remaining species. Although summer sampling yielded the highest number of hopper species and trapped specimens, seasonal variation in the distribution pattern exhibited non-significant differences (F = 1.7 and P = 0.173). Ras El-Hekma had the highest species representation (21 species), whereas El-Negala had the highest species richness. The lowest species representation at the Barrani location had the highest abundance of caught specimens. Although there were fluctuations in the trapped specimens among the examined locations, statistical analysis revealed no significant differences (F = 0.67, P = 0.58). Cluster analysis revealed distinct groupings with different degrees of similarity for both seasonal and location distributions. The impact of trap height on the hopper capture pattern showed a biased tendency towards low traps. Diversity indices showed no significant differences between the examined locations. Although our results offer a foundation for potential control strategies against X. fastidiosa, further detailed studies are required to fill the knowledge gap regarding its suspected vectors. Such research will guide management strategies that can be applied in cases where this infectious bacterium crosses Egyptian borders.

TBE In Latvia

Aggregated data on TBE cases in Latvia are available from 1955,1 but serological testing for TBE began in the 1970s.2 Since TBE became notifiable in Latvia, epidemiological changes of disease incidence have been dramatic. Between 1990–2000 Latvia had the highest rates of TBE incidence in the world, ranging from 8 to 53 cases per 100,000 population.2 Although the incidence has decreased significantly in the past 10 years to about half – from 14.58/100,000 in 2010 to 7.86/100,000 in 2018 – Latvia still ranks very high among all countries in Europe with an annual incidence of 12.67/100,000 in 2022. The distribution of TBE cases in Latvia varies between different regions with the highest incidence usually registered near the northwestern coast.

Serodiversity, antibiotic resistance, and virulence genes of Vibrio parahaemolyticus in oysters collected in coastal areas of northwestern Mexico between 2012 and 2020

This study aimed to determine the prevalence of V. parahaemolyticus in oysters from the northwestern coast of Mexico and to identify the serotypes, virulence factors, and antibiotic resistance of the strains. Oyster samples were collected from 2012 to 2020 from the northwest coast of Mexico; biochemical and molecular methods were used to identify V. parahaemolyticus from oysters; antiserum reaction to determine V. parahaemolyticus serotypes, and PCR assays were performed to identify pathogenic (tdh and/or trh) or pandemic (toxRS/new, and/or orf8) strains and antibiotic resistance testing. A total of 441 oyster samples were collected and tested for V. parahaemolyticus. Forty-seven percent of oyster samples were positive for V. parahaemolyticus. Ten different O serogroups and 72 serovars were identified, predominantly serotype O1:KUT with 22.2% and OUT:KUT with 17.3%. Twenty new serotypes that had not been previously reported in our region were identified. We detected 4.3% of pathogenic clones but no pandemic strains. About 73.5% of strains were resistant to at least one antibiotic, mainly ampicillin and ciprofloxacin; 25% were multi-drug resistant. In conclusion, the pathogenic strains in oysters and antibiotic resistance are of public health concern, as the potential for outbreaks throughout northwestern Mexico is well established.