Search Results (20)

The rise of the Internet of Things (IoT) has made it possible to explore different types of communication, such as underwater IoT (UIoT). This new paradigm allows the interconnection of ships, boats, coasts, objects in the sea, cameras, and animals that require constant monitoring. The use of sensors for environmental monitoring, tracking marine fauna and flora, and monitoring the health of aquifers requires the integration of heterogeneous technologies as well as wireless communication technologies. Aquatic mobile sensor nodes face various limitations, such as bandwidth, propagation distance, and data transmission delay issues. Owing to their versatility, wireless sensor networks support remote monitoring and surveillance. In this work, an architecture for a general packet radio service (GPRS) wireless sensor network is presented. The network is used to monitor the geographic position over the coastal area of the Gulf of Mexico. The proposed architecture integrates cellular technology and some ad hoc network configurations in a single device such that coverage is improved without significantly affecting the energy consumption, as shown in the results. The network coverage and energy consumption are evaluated by analyzing the attenuation in a proposed channel model and the autonomy of the electronic system, respectively. Full article

Based on Life Cycle Assessment (LCA) and ISO standards, we compared the global environmental sustainability (ES) of two technologies that process the organic fraction of municipal solid waste (OFMSW) in Mexico. The first technology was a biorefinery (BRF) known as HMEZSNN-BRF (abbreviation for Hydrogen-Methane-Extraction-Enzyme-Saccharification/Nanoproduction Biorefinery); it produces the gas biofuels hydrogen (H) and methane (M), organic acids (E), enzymes (Z), saccharified liquors (S), and bionanobioparticles (BNBPs) in a nanoproduction stage (NN). The second technology was incineration with energy recovery (IER). An LCA was performed with a functional unit (FU) of 1000 kg of OFMSW. The BRF generates 166.4 kWh/FU (600 MJ) of net electricity, along with bioproducts such as volatile organic acids (38 kg), industrial enzyme solution (1087 kg), and BNBPs (40 kg). The IER only produces 393 net kWh/FU electricity and 5653 MJ/FU heat. The characterization potential environmental impacts (PEIs) were assessed using SimaPro software, and normalized PEIs (NPEIs) were calculated accordingly. We defined a new variable alpha and the indices σ-τ plane for quantifying the ES. The higher the alpha, the lower the ES. Alpha was the sum of the eighteen NPEIs aligned with the ISO standards. The contributions to PEI and NPEI were also analyzed. Four NPEIs were the highest in both technologies, i.e., freshwater and marine ecotoxicities and human non-carcinogenic and carcinogenic toxicities. For the three first categories, the NPEI values corresponding to IER were much higher than those of the BRF (58.6 and 8.7 person*year/FU freshwater toxicity; 93.5 and 13.6 marine ecotoxicity; 12.1 and 1.8 human non-carcinogenic toxicity; 13.7 and 13.9 human carcinogenic toxicity, for IER and the BRF, respectively). The total α values were 179.1 and 40.7 (person*yr)/FU for IER and the BRF, respectively. Thus, the ES of IER was four times lower than that of the BRF. Values of σ = 0.592 and τ = −0.368 were found; the point defined by these coordinates in the σ-τ plane was located in Quadrant IV. This result confirmed that the BRF in this work is more environmentally sustainable (with restrictions) than the IER in Mexico for the treatment of the OFMSW. Full article

The application of fuzzy logic to environmental impact assessment (EIA) provides a robust method to address uncertainties and subjectivities inherent in evaluating complex environmental systems. This is particularly relevant in ocean renewable energy projects, where predicting environmental impacts is challenging due to the dynamic nature of marine environments. We conducted a comprehensive literature review to identify the types of impacts currently being investigated, assessed, and monitored in existing marine energy conversion projects. Based on these foundations, we developed both traditional and fuzzy mythologies for EIA. The fuzzy logic methodology approach allows for the incorporation of uncertainties into the assessment process, converting qualitative assessments into quantifiable data and linguistic levels and enhancing decision-making accuracy. We tested this fuzzy methodology across four types of ocean energy devices: floating, submerged, fixed to the ocean floor, and onshore. Finally, we applied the methodology to the EIA of a marine energy project in the Cozumel Channel, Quintana Roo, Mexico. The results demonstrate that fuzzy logic provides a more flexible and reliable evaluation of environmental impacts, contributing to more effective environmental management and sustainable development in marine renewable energy contexts. Full article

This study addresses the need to implement sustainable alternatives in marine vessels, particularly in vulnerable environments, highlighting the potential of biofuels as a viable option for the transition towards renewable energy. The objective of the research was to evaluate the interest and perception of tourism service providers in Los Cabos, B.C.S., Mexico, regarding the alternative use of biofuels in their vessels. A total of 56 random surveys were applied and validated, and the results were as follows: 92% consider fuel to be their largest operational cost, 84.6% acknowledge that their activities impact the environment, and 80% are aware of biodiesel biofuel. Notably, more than 94% expressed interest in learning how to produce biodiesel and in using it as an alternative in their operations, while 95% believe that the use of biofuels could be a positive differentiating feature for their businesses, contributing to an eco-friendlier service. This introductory assessment is crucial as it highlights the importance of understanding the willingness of key stakeholders before adopting new technologies. It concludes that there is strong interest in exploring and adopting sustainable alternatives, reinforcing the need for further research to provide viable solutions, promoting a circular economy and fostering sustainable tourism in alignment with the Sustainable Development Goals. Full article

Although the literature on Sustainable Development Goals (SDGs) is vast worldwide, studies in Mexico focusing on Marine Renewable Energy (MRE) and SDGs are only beginning to emerge. Despite this academic gap, Mexico has signed up for the United Nations SDGs, which include producing clean and affordable energy and reducing CO₂ emissions to slow global warming. The country is, therefore, committed to implementing measures to help achieve these goals. This study is the first multidisciplinary analysis performed at a national level in Mexico, aimed at identifying sites for efficient Marine Renewable Energy (MRE) production while considering socioeconomic needs, environmental risks, and societal acceptance of the new technologies. We first calculated the energy potential from nearshore winds, waves, marine currents, and offshore thermal gradients. The results show that electricity needs are greater in the 11 states where levels of marginalization are highest. The production of MRE is feasible in three of these regions. However, because Mexico is home to significant natural coastal ecosystems and protected species, care is necessary to produce electricity while protecting Mexico’s megadiversity. Social perception of the use of MRE is variable: the inhabitants of some locations are willing to accept the new technologies, whereas those in others are not. MRE production in Mexico is feasible but will face environmental and social issues that must be addressed before deploying new devices in the oceans. Full article

Ocean energy sources are a promising source of energy. However, simulating a hydrokinetic farm with multiple units requires significant computational resources, while physical experimentation on site is expensive. Therefore, the scientific challenge is to develop analytical and experimental tools that consider real aspects of areas with generation potential in a controlled laboratory environment. This paper presents a theoretical and experimental tool for analysing the interconnection of a hydrokinetic energy farm comprising 20 generation units. The test bench is a Power Hardware in the Loop type, consisting of one physical prototype generator to scale and 19 discrete averaged models operating in real-time. The system allows generators to interact through an amplifier, emulating the impact of power injection in a small electrical network. This is based on the variability of the marine resource, specifically the current velocities in the Cozumel-Mexico channel. Unlike other publications, the most significant contribution of this work is a complete feasible emulation of a marine current plant interconnected to an electrical grid, where the objective is to have a global analysis of the operation of each generation unit and the impact of the interconnection as a whole, considering that such information is of utmost importance for the execution of future projects of power generation from the sea. Full article

The number of built structures on the seabed, such as shipwrecks, energy platforms, and pipelines, is increasing in coastal and offshore regions. These structures, typically composed of steel or wood, are substrates for microbial attachment and biofilm formation. The success of biofilm growth depends on substrate characteristics and local environmental conditions, though it is unclear which feature is dominant in shaping biofilm microbiomes. The goal of this study was to understand the substrate- and site-specific impacts of built structures on short-term biofilm composition and functional potential. Seafloor experiments were conducted wherein steel and wood surfaces were deployed for four months at distances extending up to 115 m away from three historic (>50 years old) shipwrecks in the Gulf of Mexico. DNA from biofilms on the steel and wood was extracted, and metagenomes were sequenced on an Illumina NextSeq. A bioinformatics analysis revealed that the taxonomic composition was significantly different between substrates and sites, with substrate being the primary determining factor. Regardless of site, the steel biofilms had a higher abundance of genes related to biofilm formation, and sulfur, iron, and nitrogen cycling, while the wood biofilms showed a higher abundance of manganese cycling and methanol oxidation genes. This study demonstrates how substrate composition shapes biofilm microbiomes and suggests that marine biofilms may contribute to nutrient cycling at depth. Analyzing the marine biofilm microbiome provides insight into the ecological impact of anthropogenic structures on the seabed. Full article

Urban infrastructures serve as the backbone of modern economies, mediating global exchanges and responding to urban demands. Yet, our comprehension of these complex structures, particularly within diverse socio-political terrain, remains fragmented. In bridging this knowledge gap, this study delves into “boundary objects”—entities enabling diverse stakeholders to collaborate without a comprehensive consensus. Central to our investigation is the hypothesis that oceanic infrastructural developments are instrumental in molding the interface of urban, industrial, and energy sectors within marine contexts. Our lens is directed at the Gulf of Mexico, which is distinguished by its industrial depth and expansive marine grid. We highlight the Gulf Intracoastal Waterway’s (GIWW) paramount role in regional movement and the ecological facets of practices such as dredging, which is vital for transport and coastal conservation. A striking revelation of our study is the transformation of offshore structures in the Gulf into vibrant marine habitats. Emphasizing the intertwined nature of marine infrastructures, we denote oceans as pivotal platforms for impending urban expansion, especially as land resources wane. Our research aspires to validate the role played by oceans as a nexus in the urban–industrial–energy fusion. Full article

Accurate and reliable wave forecasting is crucial for optimizing the performance of various marine operations, such as offshore energy production, shipping, and fishing. Meanwhile, predicting wave height and wave energy is crucial for achieving sustainability as a renewable energy source, as it enables the harnessing of the power of wave energy efficiently based on the water-energy nexus. Advanced wave forecasting models, such as machine learning models and the semi-analytical approach, have been developed to provide more accurate predictions of ocean waves. In this study, the Sverdrup Munk Bretschneider (SMB) semi-analytical approach, Emotional Artificial Neural Network (EANN) approach, and Wavelet Artificial Neural Network (WANN) approach will be used to estimate ocean wave parameters in the Gulf of Mexico and Aleutian Basin. The accuracy and reliability of these approaches will be evaluated, and the spatial and temporal variability of the wave field will be investigated. The available wave characteristics are used to generate hourly, 12-hourly, and daily datasets. The WANN and SMB model shows good performance in the daily prediction of the significant wave height in both case studies. In the SMB model, specifically on a daily time scale, the Nash–Sutcliffe Efficiency (NSE) and the peak deviation coefficient (DC_peak) were determined to be 0.62 and 0.54 for the Aleutian buoy and 0.64 and 0.55 for the Gulf of Mexico buoy, respectively, for significant wave height. In the context of the WANN model and in the testing phase at the daily time scale, the NSE and DC_peak indices exhibit values of 0.85 and 0.61 for the Aleutian buoy and 0.72 and 0.61 for the Gulf of Mexico buoy, respectively, while the EANN model is a strong tool in hourly wave height prediction (Aleutian buoy (NSE_EANN = 0.60 and DC_peakEANN = 0.88), Gulf of Mexico buoy (NSE_EANN = 0.80 and DC_peakEANN = 0.82)). In addition, the findings pertaining to the energy spectrum density demonstrate that the EANN model exhibits superior performance in comparison to the WANN and SMB models, particularly with regard to accurately estimating the peak of the spectrum (Aleutian buoy (DC_peakEANN= 0.41), Gulf of Mexico buoy (DC_peakEANN = 0.59)). Full article

Wind energy production mainly depends on atmospheric conditions. The atmospheric stability can be described through different parameters, such as wind shear, turbulence intensity, bulk Richardson number, and the Monin–Obukhov length. Although they are frequently used in micrometeorology and the wind industry, there is no standard comparison method. This study describes the atmospheric stability of a coastal region of Yucatan, Mexico, using these four parameters. They are calculated using six-month data from a meteorological mast and a marine buoy to determine atmospheric stability conditions and compare their results. The unstable atmospheric condition was predominant at the site, with an 80% occurrence during the measurement period, followed by 12% in neutral and 6% in stable conditions. Wind speed estimations were performed for each atmospheric stability scenario, and the variation in the energy produced was derived for each case. Unstable atmospheric conditions deliver up to 8% more power than stable conditions, while neutral conditions deliver up to 9% more energy than stable conditions. Therefore, considering a neutral state may lead to a considerably biased energy production estimation. Finally, an example calculation indicates that atmospheric stability is a crucial parameter in estimating wind energy production more accurately. Full article

Analysis of the omnidirectional energy spectrum from storm wave measurements provides valuable parameters for understanding the specific local conditions that wave energy converters would have to withstand. Partitioning the energy spectrum also helps to identify wave groups with low directional spread propagating in the direction of the dominant waves of the more energetic wave systems. This paper analyzes the partition of the Hurricane Wilma energy spectrum using single-point measurements obtained in shallow water. Hurricane Wilma generated simultaneous crossing wave systems with different significant wave heights and steepnesses. The maximum estimated significant height among the wave groups was 5.5 m. The corresponding height of the partitions and the omnidirectional energy spectrum were 11.0 m (swell) and 12 m, respectively. While linear superposition was the main mechanism responsible for driving the wave groups, at times, modulational instability produced nonlinear wave groups. This is a new finding, since modulational instability is usually considered an open-sea phenomenon. For shorelines with multidirectional wave groups, submerged and semi-submerged devices should be designed to account for changes in wave direction and wave height, although under extreme hurricane conditions, energy harvesting might have to be sacrificed for the benefit of device integrity. Full article

Environmental risks and vulnerabilities in coastal regions include the massive deposits of brown algae of the genus Sargassum in regions such as the Caribbean, Gulf of Mexico, and northern Brazil. Efforts have been made to turn this problem into an opportunity by seeking new uses for this biomass in the sectors of food, agriculture, health, biofuels, bioremediation, and civil construction. Thus, this study aimed to produce quantitative data for different end-of-life scenarios of the Sargassum algae, seeking for potential applications of this macroalgae in the civil construction sector. For this purpose, we conducted a life cycle assessment (LCA) study of the Sargassum algae, in its natural destination, and evaluated its potential impact. This evaluation was then compared to the possible impacts of alternatives to their end of life, such as landfill disposal, drying and grinding to use as fibers or particles, burning the biomass to generate energy and fly ash, using a consequential LCA and the indicators of the ReCiPe 2016 method. For each of the proposed scenarios, the functional unit of 1 kg of the three types of unprocessed Sargassum algae that are found in the Brazilian deposits (natans I, natans VIII, and fluitans) was considered separately, and also for a composition that is closer to that found in the Brazilian deposits (50% fluitans, 15% natans I, and 35% natans VIII). The results for both natural decomposition scenarios demonstrated a dominant contribution to the categories of impact for climate change, marine eutrophication, and land use, thus justifying the search for new initiatives for the use of the algae. The burning process showed a significant contribution to most of the indicators, with emphasis on the massive generation of particulate, inherent to the biomass burning process; however, it showed a reduction in the magnitude of climate change emissions from around 47% to less than 2%. Finally, the proposed scenario of processing Sargassum biomass to obtain particles presented prevalence of magnitude for potential impact in most of the proposed indicators, due to the processes with high electricity consumption, but keeping climate change emissions’ relative reduction from 47% to 6%. Thus, new studies may further investigate the potential of application of these materials in different products and components of civil construction. Full article

Once the tide recedes and leaves a significant amount of stranded seaweed on the coast, marine macroalgae pose a serious threat to the surrounding area. Through this work, we considered a large-scale application of stranded macroalgae in building construction. For the first time we studied the impact of incorporating Sargassum mitucum seaweed fiber in replacement of flax fiber used for a standard structural cob. Thus, cob specimens were elaborated and analyzed to evaluate their compressive and hygrothermal performances. It was found that the compressive strength and water vapor resistance factors of cob decreased with the algae content. Additionally, the obtained results showed that a cob made with Sargassum muticum algae presented better thermal (insulation and inertia) and hygroscopic properties than those of a cob made with a flax fiber. Indeed, the replacement of flax straw by algae lead to a reduction in the thermal conductivity by 38% when compared to the standard cob with 2.5% of flax straw fiber. Consequently, numerical simulation showed a reduction in the energy needs in buildings made with an algae-based cob when compared to those made with a flax-based cob. This study can contribute to a global environmental and economic issue, i.e., the valorization of brown algae on a large scale. Indeed, the worldwide knows the largest sea of sargassum algae extent measures over 8850 km². This huge mass of brownish algae is expanding every year, which now covers an area from Africa to the Caribbean. It weighs more than 20 million tons and extends from the Gulf of Mexico to the west coast of Africa. We show that stranded algae, which are considered as wastes, have the ability to improve the mechanical and hygrothermal performance of cob-based material. Full article

Environmental contaminants with chemical origins, such as organochlorine pesticides (OCPs) have major impacts on the health of marine animals, including sea turtles, due to the bioaccumulation of those substances by transference throughout the food chain. The effects of environmental pollution on the health of marine turtles are very important for management strategies and conservation. During recent decades, the south Gulf of Mexico and the Yucatan Peninsula have suffered from increasingly frequent disturbances from continental landmasses, river systems, urban wastewater runoff, port areas, tourism, industrial activities, pesticides from agricultural use, and other pollutants, such as metals, persistent organic pollutants (POPs) and hydrocarbons (from the oil industry activities), which contaminate water and sediments and worsen the environmental quality of the marine ecosystem in this region. In this study, we assessed the concentrations of OCPs in the blood and eggs of 60 hawksbill turtles (Eretmochelys imbricata) nesting at the Punta Xen turtle camp, and their effects on the nesting population’s reproductive performance: specifically, maternal transfer and embryonic development were analyzed. Hematologic characteristics, including packed cell volume, white blood cell count, red blood cell count, and haemoglobin levels, and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol and glucose, were also measured. The general health of the turtles in this study, as well as their levels of urea, serum creatinine, glucose, uric, acid, cholesterol, and triglyceride, fell within normal ranges and was similar to other normal values, which could indicate the turtles’ good energy levels and body conditions for nest-building activity, with all of the turtles able to successfully come ashore to nest. All the same, the obtained results also indicate that OCPs affect the nesting and reproductive performance of the hawksbill turtles, as well as their fertility and the development of the population of eggs and reproductive performance, specifically in terms of maternal transference and embryonic development. There were significant differences in the concentrations of OCPs (ΣHCHs and ΣDienes) between maternal blood and eggs, indicating that these chemicals are transferred from nesting females to eggs and, ultimately, to hatchlings. OCPs may, therefore, have an effect on the health and reproductive performance of hawksbill turtles, both in terms of their fertility and egg development. Conservation strategies need to be species-specific, due to differences in feeding, and address the reasons for any decline, focusing on regional assessments. Thus, accurate and comparable monitoring data are necessary, which requires the standardization of monitoring protocols. Full article

A spatial analysis was carried out to evaluate the compatibility of human activities and biophysical characteristics in the Mexican Caribbean Sea, in order to identify the most viable areas for energy generation from ocean currents and the areas where the population would most benefit from such energy projects. Of the study area, 82% have some form of protection legislation. Tourism is the main economic activity in the area and this is reflected in a wide range of activities and services that often overlap within the same spatial area. In the case study, the use of renewable ocean energies is seen as an important innovation to reduce fossil fuel dependency. These energies have the potential to meet the demands of the region. However, it is vital to seek for potential areas for this type of energy harvesting where the social, economic and environmental impacts would be minimal. The lack of marine policies and land-use planning processes in Mexico is a major obstacle in avoiding land use conflicts. Full article