Critical Environmental Factors in Offshore Wind–Hydrogen Projects: Uruguay’s Exclusive Economic Zone

Abstract

Green hydrogen is a promising solution for decarbonizing emission-intensive sectors, with its production through offshore wind energy offering viable opportunities. This study presents a preliminary assessment of the main environmental factors potentially affected by offshore wind and green hydrogen projects in Uruguay’s Exclusive Economic Zone (EEZ), where such developments pose environmental challenges that require evaluation, particularly given the limited prior research in Uruguay and Latin America. Through a comprehensive review of international literature and national technical data, the study identifies key interactions between project activities and the physical, biotic, and anthropic environmental components during the development, construction, and operational phases. Using cross-reference matrices and impact categorization, the analysis highlights that activities such as foundation installation, submarine cable deployment, and offshore electrolysis could significantly affect the seabed, underwater noise levels, water quality, and marine biodiversity. The biotic and physical environment were found to be the most frequently impacted. To contextualize these findings, technical information specific to Uruguay’s EEZ was reviewed to identify the most vulnerable regional environmental factors. The results offer a science-based foundation to support early-stage environmental assessments and guide sustainable offshore energy development in the region.

1. Introduction

The growth of renewable energy and the transition to a low-carbon economy have driven the development of new technologies for the generation and storage of clean energy. Among these solutions, green hydrogen has emerged as a viable alternative for the decarbonization of energy-intensive sectors. Hydrogen, the most abundant element in the universe [1], is a lightweight gas with a high energy density, making it an attractive energy carrier. However, storage and transportation pose significant challenges because of its low volumetric density and tendency to leak through conventional materials. In its gaseous state, hydrogen must be compressed to pressures of up to 700 bar or liquefied at −253 °C to facilitate transport, which implies considerable energy consumption and requires specialized infrastructure [1].

The production of green hydrogen is based on water electrolysis using electricity from renewable sources, allowing for the avoidance of CO₂ emissions associated with conventional hydrogen production methods, such as natural gas reforming [2]. Integrating this technology with offshore wind energy represents a key opportunity for the development of large-scale sustainable solutions. Offshore wind energy, unlike its onshore counterpart, is installed in bodies of water, mainly oceans, allowing it to harness stronger and more consistent winds, improving power generation efficiency. In terms of installed capacity, modern offshore wind turbines can exceed 16 MW, with rotor diameters of up to 250 m. There are already prototypes reaching 20 MW, which significantly enhances wind energy capture compared to onshore turbines, whose typical capacities range between 2 and 9 MW [3].

To better understand wind energy, it is essential to consider wind dynamics and its interaction with the Earth’s surface. Wind energy originates from the kinetic energy of the wind, which is driven by solar radiation and the Earth’s rotation [4]. This phenomenon results in different wind scales, ranging from global atmospheric circulation systems to local winds influenced by terrain topography and surface roughness. Most usable wind energy is found in the atmospheric boundary layer, which is the part of the atmosphere closest to the Earth’s surface, where wind turbines can efficiently capture the available energy [5].

As air moves over the Earth’s surface, it is subject to friction and terrain roughness, slowing its movement near the ground. As it rises, it moves away from the direct influence of the terrain, experiencing less friction and, therefore, moving at higher speeds. This is why wind energy projects aim to increase turbine heights to capture higher wind speeds [6].

The development phase of an offshore wind farm is a complex process involving multiple studies and assessments to ensure the project’s technical, economic, and environmental feasibility. According to BVG Associates [7], this phase includes the concession of marine space, geophysical and geotechnical seabed studies, wind resource assessment, metocean analysis, and the corresponding environmental impact assessment. Uruguayan regulations, through Law 16.466 [8] and Decree 349/005 [9], require Prior Environmental Authorization (AAP), which involves conducting many detailed studies including those on marine fauna, air quality, underwater acoustics, and benthic ecosystems, among others. Technologies used for data collection include side-scan sonars, multibeam bathymetry, and cone penetration tests (CPTs) for seabed characterization [7]. Additionally, floating LiDAR systems, meteorological towers, and metocean buoys are implemented to evaluate wind speeds and ocean conditions, crucial for optimizing wind farm design and minimizing environmental impacts.

Regarding turbine foundation types, there are fixed and floating structures. Fixed foundations include monopiles, gravity-based foundations, and jacket structures, while deep-water projects use floating platforms such as Spar, semi-submersible, and tension-leg platforms (TLPs) [10]. The choice of foundation type directly impacts the economic and structural feasibility of the wind farm, as well as the stability of the turbines and the durability of the infrastructure [11]. These structures must withstand not only wind loads but also hydrodynamic forces from waves and ocean currents, requiring high-strength materials and advanced anchoring systems [11].

The electrical infrastructure is a key component for system efficiency and stability, enabling the transmission of generated energy to onshore substations. The medium-voltage subsea cable network connects wind turbines in a ring system, facilitating energy transmission to the offshore substation. These cables are corrosion-resistant, feature galvanized steel mechanical shielding, and integrate fiber optics for data transmission and monitoring [12]. For high-voltage transmission, offshore wind farms use AC (alternating current) or DC (direct current) systems, with DC being more efficient over long distances due to lower Joule effect losses. The installation of these cables requires specialized cable-laying vessels and remotely operated vehicles (ROVs) for seabed placement, minimizing navigation interference and marine life disruption [13].

Green hydrogen production from offshore wind energy relies on water electrolysis technologies, primarily alkaline electrolysis (AEL), proton-exchange membrane (PEM), and solid oxide electrolysis (SOE). AEL technology is the most mature and cost-effective, with 70–80% efficiency, but has limitations in responding to renewable energy variability [2]. PEM technology, on the other hand, provides higher flexibility and faster response times, making it suitable for offshore wind farms, though its higher investment cost is due to the use of noble metal catalysts [14]. SOE technology is an emerging alternative with potential efficiencies of 90–100% but remains in development, facing challenges related to high-temperature material durability [15].

Uruguay is actively evaluating offshore wind energy for green hydrogen production in the Exclusive Economic Zone (EEZ), recognizing its maritime energy potential. In 2022, the Ministry of Industry, Energy, and Mining (MIEM) launched the Green Hydrogen Roadmap, including the H2U Offshore initiative, led by ANCAP (Administración Nacional de Combustibles, Alcohol y Portland, Uruguay’s national oil and energy company), which aimed at promoting offshore wind-based green hydrogen projects. The Uruguayan government has authorized ANCAP to auction four maritime areas for offshore wind farm installation, with a potential capacity of 3 GW to produce 200,000 tons of green hydrogen per year [16].

The EEZ of Uruguay was defined by the United Nations Convention on the Law of the Sea (UNCLOS) in 1982 [17]. It covers an area of 142,166 km², extending up to 200 nautical miles from the baselines established in Article 14 of Law No. 17.033. This maritime space, along with the Uruguayan continental margin, is vital from hydrodynamic, topographic, ecological, and economic perspectives.

Uruguay has sovereign rights to explore and exploit both living and non-living resources within the EEZ, including economic activities such as energy production. The sustainable management and use of the zone’s resources, along with the protection and preservation of biodiversity and the marine environment, are fundamental.

This study aims to identify the environmental factors potentially affected by offshore wind-to-hydrogen projects within Uruguay’s Exclusive Economic Zone (EEZ). It considers physical, biotic, and anthropic components to determine which environmental factors are most likely to be impacted. Additionally, it seeks to inform the prioritization of environmental protection and mitigation measures in the early stages of project development. This work provides a preliminary technical basis for environmental decision-making in a context where no similar assessments have yet been conducted in Uruguay or the broader region.

Environmental factors are defined as the specific attributes of the environment that may be subject to alteration due to human interventions [18]. For the purpose of this study, these factors are classified under three main environmental components:

• Physical Component: Includes seabed and soil characteristics, ambient noise levels, surface water quality, air quality, surface water temperature and hydrochemistry, and pressures on natural resources.
• Biotic Component: Covers fauna (e.g., plankton, benthos, nekton, fish, birds, reptiles, marine mammals, and cephalopods) and flora (e.g., aquatic vegetation and coastal plant communities).
• Anthropic Component: Encompasses human-related aspects such as landscape, fishing activities, maritime navigation, and terrestrial and marine traffic.

Given the scale and novelty of these projects in the region, this analysis seeks to contribute a structured and science-based approach to anticipate potential interactions with the environment. The insights derived here aim to support future impact assessments and regulatory planning, promoting the sustainable development of offshore renewable energy initiatives in Uruguay.

2. Methodology

A bibliographic review was conducted focusing on offshore wind projects and green hydrogen at the international level, encompassing scientific literature and technical reports published between 2012 and 2024. Articles were selected that described activities associated with the development, construction, and operational phases of offshore wind farms and green hydrogen projects and related these activities to the categories of impact on the affected environmental components.

It is important to note that a specific evaluation of environmental impacts requires the inclusion of elements such as frequency, intensity, and environmental context in order to propose effective assessment and mitigation measures. This level of analysis is beyond the scope of this study as the primary objective was to provide a general identification of the most relevant environmental impacts and the most affected environmental factors within the EEZ in Uruguay for projects of this nature.

For this initial assessment, each potential activity (e.g., foundation installation, dredging, and offshore electrolysis) was identified, along with its frequency of occurrence and potential interaction pathways with the environment (e.g., noise, sediment disturbance, and maritime traffic). Cross-reference tables were then developed to link activities and processes with associated impacts, environmental components, and factors, enabling the classification of impact frequency and the magnitude of the affected environmental factors. The reference tables that served as the basis for this cross-referencing and impact classification are included in Appendix A, providing detailed traceability of the input data used to construct the diagrams and synthesize the results.

Subsequently, the relationship between each project activity and its potential effects on the environmental components was identified, as well as the possible environmental impacts during the different phases of the project lifecycle: development, construction, and operation. The environmental impacts were then analyzed based on their degree of incidence, identifying those with the greatest potential to cause significant effects during each project phase.

Once the main environmental impacts and the affected components were identified, a cross-analysis was conducted with the environmental factors associated with each component to determine which factors would be impacted by each environmental effect. Figure 1 presents the flowchart of the methodology adopted for identifying the most affected environmental factors.

This structured methodology is used to identify and classify environmental factors associated with different types of study activities (environmental studies, metocean, and geotechnical studies). In Figure 2, the diagram illustrates the linkage between these activities and the environmental impacts they generate (such as habitat alteration, increased noise levels, or fauna mortality) for the development phase. These impacts are grouped into categories of affected factors—biotic, physical, and anthropic—and are ultimately connected to specific environmental receptor components (such as marine fauna, water quality, or landscape).

During the development phase, the activities predominantly affect the biotic and physical components, with notable interactions such as disturbance to marine fauna, alteration of marine habitats, increased noise levels, and impacts on water and air quality. Within the biotic component, marine fauna and seabirds are the most frequently linked environmental factors, while in the physical component, sound pressure levels, water quality, and air quality appear as recurrently impacted. The anthropic component is less represented at this stage, with limited but traceable effects on navigation and landscape.

Among the activities assessed for the construction phase, the installation of foundations for wind turbines emerges as one of the most impactful. This activity involves direct intervention in the seabed, leading to disturbances of benthic habitats, increased underwater noise levels, and degradation of water quality due to sediment resuspension. Recent studies also highlight adverse effects on marine mammals, including avoidance behavior and temporary displacement from construction areas. Additional relevant impacts are associated with the installation of submarine cables and offshore electrolysis plants, which may alter substrate conditions, pose risks to navigation, and contribute to localized emissions during construction. As shown in Figure 3, the physical component registers the highest frequency of impacts, particularly on the seabed, water quality, and sound pressure levels. However, it is important to note that although many of these impacts are categorized under the physical component, they often result in secondary effects on the biotic component, especially marine fauna and ecosystems. For the anthropic component, notable impacts are observed on landscape, fisheries, and maritime traffic, emphasizing the importance of considering interactions between infrastructure deployment and human uses of the marine space.

In Figure 4, the operational phase of offshore wind–hydrogen projects reveals a broader distribution of environmental impacts across all three environmental components. The physical component remains the most frequently affected, with impacts such as increased noise levels, temperature rise, vibration disturbances, and potential air and water quality degradation linked to the continuous operation of electrolyzers, compression systems, and desalination plants. However, the biotic component also registers significant interactions, particularly due to collision risks for seabirds, disturbances to marine fauna, and electromagnetic fields. The formation of new ecosystems is also identified as a potential biotic outcome during long-term operations. The anthropic component is impacted through increased maritime traffic, logistics congestion, and risks to fishing activities, highlighting the need to address human-use conflicts in marine space planning. Activities such as desalination, electrolyzer operation, and hydrogen storage stand out as key sources of both physical and anthropogenic impacts during this stage.

After identifying the main environmental factors affected by this type of project at the international level, a cross-analysis was conducted with the environmental factors present in Uruguay’s Exclusive Economic Zone (EEZ). This included a review of existing technical information relevant to the area. The objective was to determine which factors are most likely to be impacted in the regional context, considering the specific biophysical and socio-environmental characteristics of the country. This approach provides an initial, regionally grounded perspective on potential impacts and helps inform future detailed assessments and strategic environmental planning; the main results are presented in the Section 3.

Although the methodology used is not a standard method for environmental impact assessment, it was aligned with established impact identification frameworks. It integrates tools such as impact matrices, categorization of environmental factors, lifecycle analysis of the project (by phases), and interaction pathways. Established methods, including the Leopold Matrices and adaptive management models, were incorporated to enable a preliminary identification of environmental impacts.

The use of data from international studies facilitated the development of a comprehensive and adaptable evaluation, providing validated results applicable to other regions. This serves as a critical foundation for more detailed analyses in subsequent stages.

Identification of the Exclusive Economic Zone of Uruguay

Uruguay’s Exclusive Economic Zone (EEZ) spans over 140,000 km² [19], with depths ranging from continental shelf areas to slope zones and deep oceanic floors. The area represents a particularly complex and dynamic environmental setting, resulting from the interaction of physical, biological, and anthropogenic factors, as well as the confluence of continental and oceanic water masses. The physical environment is influenced by a series of oceanographic processes, including hydrodynamics, temperature and salinity gradients, the circulation of various ocean currents (such as the Brazil and Malvinas currents), and the system’s hydrochemistry, according to studies conducted by ANCAP in 2014 [17].

In terms of water quality and physicochemical conditions, the EEZ shows significant spatial and temporal variability. Seasonal variations have been reported in turbidity, pH, total dissolved solids, dissolved oxygen levels, and nutrient concentrations—parameters that are highly relevant for evaluating the health of the marine ecosystem. Marked stratification of oxygen and nutrients has also been identified, as well as variability in chlorophyll concentrations, particularly near the mouth of the Río de la Plata, indicating high productivity in certain coastal and slope regions.

The biotic environment, in turn, is characterized by notable ecological richness and biodiversity. The EEZ hosts highly diverse communities of plankton (bacterioplankton, phytoplankton, zooplankton, and ichthyoplankton) and benthos, with key species such as cyanobacteria, diatoms, copepods, anchovy larvae, polychaetes, and echinoderms. There is also an abundant nektonic community, including commercially important bony and cartilaginous fish, cephalopods (squid), sea turtles, pelagic birds, and marine mammals such as dolphins, sperm whales, and humpback whales. Many of these species are migratory, endemic, or classified as threatened, and several zones within the EEZ have been identified as ecologically valuable areas due to their function as feeding, breeding, or nursery habitats [17].

From an anthropogenic perspective, Uruguay’s EEZ also experiences intense human activity, particularly related to both industrial and artisanal fisheries. Key target species include hake, croaker, squid, and tuna species, harvested using methods such as bottom trawling, longlining, and purse seining. This activity is distributed throughout the EEZ but is especially concentrated along the continental slope, where oceanographic conditions favor high-value pelagic species. In addition, there is significant maritime traffic in the Río de la Plata and coastal areas, as well as existing infrastructure such as submarine cables.

This intricate network of physical, biotic, and anthropogenic factors makes the EEZ a zone of high ecological sensitivity and strategic economic importance. Therefore, any large-scale industrial development—such as offshore wind energy or green hydrogen production projects—must carefully consider an updated baseline environmental conditions. These ecosystems host species that play key roles in the food chain and support commercial fishing activities. Within the EEZ, several protected areas stand out, including the following [20]:

• Restingas del Pez Limón: An essential habitat for benthic species of ecological interest.
• Pozo de Fango: A highly productive area where commercial species such as hake are concentrated.
• Breeding Zones: Critical for the conservation of juvenile fish and cephalopods.

Based on this analysis, a delimitation of the EEZ was carried out to identify areas suitable for project construction. A significant technological limitation exists for fixed turbine foundations, which can only be installed at depths of 60–80 m [10]. Floating foundations can reach greater depths, but their high costs may render projects economically unfeasible. Therefore, areas with depths exceeding 100 m were excluded, leaving only zones from the country’s coastline to Region 1, as indicated in Figure 5, as feasible for development. Protected areas were also excluded from consideration. The delimitation accounted for major merchant shipping routes, fishing zones, and other relevant spatial constraints. As shown in Figure 5, a safety buffer of approximately 50 km was maintained between the coastline and the feasible development zone (shown in green), with red lines indicating the buffer margins. This precaution aims to minimize potential impacts on coastal activities such as artisanal fishing, tourism, and nearshore navigation. The feasible area lies within Region 1 of Uruguay’s continental shelf, where water depths remain below 100 m and conditions are favorable for fixed-bottom turbines. This initial delimitation serves as a strategic reference for future planning and will require refinement through more detailed technical, environmental, and regulatory assessments.

3. Results

3.1. Development Phase

The results obtained from the analysis of impact tables indicated that the development phase will have a significant effect on the biotic environment, particularly on environmental factors of the EEZ related to marine fauna. There will also be a moderate impact on the physical environment, specifically on the seabed and water quality, while the anthropic environment will experience occasional logistical disruptions. These findings are summarized in Figure 6, which illustrates the relationship between the environmental components and their interaction with specific factors or activities present in the EEZ. The anthropic component highlights human-related activities like fishing and natural resource exploitation, with varying degrees of impact. The biotic component shows a strong influence across all categories, including marine mammals, birds, and plankton, indicated by intense red bars. The physical component reflects the significance of factors like hydrochemistry, water temperature, and sound pressure levels, with a moderate-to-low impact. The intensity of the colors (from light pink to dark red) represents the magnitude of influence or relevance, where darker tones indicate the most impacted components and lighter tones the less affected ones. However, even the less affected components, shown in lighter shades, must not be overlooked as they still play a crucial role in the overall environmental balance.

• Disturbance to marine fauna due to geophysical and geotechnical studies: The results indicate that the methods used for seabed characterization (e.g., airgun seismic surveys and high-resolution geophysical studies) [21,22] generate low-frequency, high-intensity sound waves that can cause stress or injuries in marine mammals and fish [23]. Notable impacts include potential physical damage (barotrauma and swim bladder impairment) and behavioral changes (e.g., avoidance of survey areas) in bony fish species, as well as disturbances to cetaceans and marine turtles [24].
• Localized alteration of the seabed and benthic habitats: The installation of measurement buoys and wind towers during the early phases may involve minor drilling and anchoring, which can displace sediments and affect benthic species (e.g., polychaetes and crustaceans) [25]. Although these localized disturbances are not typically extensive, they become significant if they occur in ecologically sensitive areas or breeding grounds for commercial species (e.g., hake and croaker).
• Increased maritime traffic and associated risks: The need for inspection vessels and technical personnel increases maritime traffic in the study area, raising the risk of collisions with marine mammals and turtles, as well as accidental fuel spills [26]. Additionally, this increased traffic may temporarily interfere with coastal and offshore fishing activities, potentially generating socioeconomic tensions.

3.2. Construction Phase

The results show that during the construction phase, the physical environment (water quality and seabed) experiences the most intense impacts, with highly significant effects on the biotic environment, particularly marine fauna. The anthropic environment is impacted in terms of logistics, temporary fishing restrictions, and congestion in port areas. However, after conducting a cross-analysis of the impacts on environmental factors, it becomes evident that the most affected factors overall are related to the biotic environment, as shown in Figure 7.

• Intense underwater noise generation: The use of hydraulic hammers for driving monopiles or anchoring foundations for offshore wind turbines and platforms generates very high acoustic peaks, affecting marine mammals, fish, and cephalopods within a radius that can reach tens of kilometers [11] in the EEZ. This noise is exacerbated in areas with hard seabeds, where higher impact force is required, and is further compounded by noise from dredging and intensive ship traffic [23].
• Water quality alteration and sediment suspension: Dredging for the installation of submarine cables and excavation of foundations disturbs fine sediments and contaminants deposited on the seabed, increasing turbidity and potentially releasing heavy metals [25]. In high-productivity environments, turbidity alteration has been observed to impact photosynthesis and primary productivity, thereby affecting trophic networks (plankton–nekton).
• Port congestion and waste generation: The transport of large components (foundations and wind turbines) and equipment for electrolysis plants exerts significant pressure on ports, requiring large-scale storage and logistics spaces [11]. Construction generates volumes of solid waste (packaging materials, welding remnants, etc.) and liquid waste (oils and lubricants), which, in the absence of proper management protocols, could leak into the marine environment.

3.3. Operation Phase

During the operational phase, the results reveal a coexistence of possible positive effects (such as the formation of artificial reefs) and negative effects (such as bird mortality, continuous noise, risks of hydrogen leaks, and brine discharges). Water quality, sea birds, and marine fauna remain the most vulnerable factors, exacerbated by maintenance-related maritime traffic and the presence of electrolysis infrastructure. Figure 8 illustrates the environmental factors most affected by significant impacts identified during the operational phase.

• Collision risks with wind turbines and infrastructure: Seabirds, particularly migratory species, are at risk of colliding with wind turbine blades under conditions of low visibility or strong winds [27]. Marine mammals and reptiles face collision risks with maintenance vessels, which typically operate throughout the entire lifespan of the wind farm [26].
• Acoustic disturbances and continuous vibrations: Although the operational noise of wind turbines is lower than during construction, low-frequency underwater emissions persist, potentially affecting the communication and behavior of marine mammals [24]. Additionally, electrolysis, compression, and hydrogen storage systems generate additional mechanical noise, which propagates through the structures of the platforms.
• Brine generation and management: If the electrolysis process is implemented offshore, seawater desalination is required, producing brine with high ionic concentrations that can increase local salinity when discharged [28]. International studies suggest that implementing diffusers and staggered discharge plans can mitigate the impact. However, in areas with limited circulation, this brine could harm benthic biota and reduce oxygen availability.
• Creation of artificial reefs: Submerged structures—such as fixed and floating foundations, as well as anti-erosion coverings—provide hard surfaces for invertebrate colonization, potentially aiding the regeneration of certain communities [24]. In areas with restricted fishing, fish tend to aggregate around these new habitats, increasing local biodiversity and creating refuge zones [25]. This impact is not always beneficial as it could also lead to an increase in invasive species populations that may alter the ecosystem.

4. Discussion of Results

4.1. Vulnerability of the Biotic Environment and Impact Synergies

The findings indicate that the biotic environment is one of the most affected components throughout the entire project lifecycle (development, construction, and operation). For instance, during the development phase, the use of seismic and geophysical prospecting technologies generates impulsive noises that can harm marine mammals and fish [23]. Subsequently, during the construction phase, the installation of monopile foundations using hydraulic hammers exposes whales and dolphins to intense acoustic impulses over distances of tens of kilometers [24]. These results align with studies from the North Atlantic and the North Sea, where marine mammal populations have been observed to temporarily or permanently abandon their feeding areas due to cumulative noise [11].

During operation, the offshore wind farms pose significant risks to seabird populations, primarily through collision mortality and habitat displacement. Turbine height, rotor blade length, and increased tip speeds, combined with ambient marine noise, can hinder birds’ ability to detect and avoid turbines, increasing the likelihood of collisions—especially for large, migratory species such as albatrosses and petrels [27], both present in the EEZ. Additionally, birds may alter their foraging and migration routes to avoid wind farm areas, which can result in increased energy expenditure and reduced breeding success [24]. Studies indicate that offshore turbines may affect a broader area than the immediate project footprint, with avoidance behavior observed up to 800 m from turbines in some species [27]. The potential for cumulative impacts is heightened when projects intersect key migratory corridors or high-biodiversity regions, such as Uruguay’s EEZ, where protected and vulnerable seabird species are distributed throughout the area.

Additionally, the overlap of impacts (noise, vibrations, and increased maritime traffic) can exacerbate the vulnerability of fauna. While each disturbance on its own might be considered moderate, the cumulative effect of continuous alterations (e.g., closely spaced construction phases) often leads to changes in the distribution and reproduction patterns of species [29]. Therefore, strategic planning is required to stagger these activities over time to reduce simultaneous exposure.

The increase in noise levels is identified as one of the main and most concerning impacts. During the installation of foundations, a significant increase in underwater noise levels is expected, especially during the development and construction phases of the project. The use of technologies such as hydraulic hammers for monopile driving generates high-energy, impulsive sounds with rapid rise times that propagate through the water column and marine substrate, reaching levels exceeding 220 dB re 1 µPa at 1 m [23]. This type of noise can induce hearing damage in marine mammals at short distances and alter their behavior over ranges of up to several tens of kilometers [30].

During the geophysical and geotechnical survey phase, airguns that generate low-frequency sounds (50–400 Hz) with peak levels of up to 175 dB are used, which can sensorially affect bony fish, cephalopods, and marine reptiles such as turtles. In addition, these sounds can induce physiological stress in invertebrates, altering their immune responses [31].

In the operational phase, although the noise is continuous and lower in intensity than during construction, acoustic emissions persist from wind turbines, compression systems, and submarine cables. While operational noise from wind turbines is estimated to be 10–20 dB lower than that of vessels in the same frequency range, it can still be detected over several kilometers and may contribute to cumulative acoustic pressure in the ecosystem [32]. Infrasonic emissions generated by wind turbines should also be considered as they may affect sensitive species such as whales and migratory birds [33].

Mitigation measures and recommendations include the following: (a) Use of pingers, which emit deterrent acoustic signals prior to pile driving to displace marine mammals from the area, thereby reducing the risk of permanent hearing damage [11]. (b) Deployment of bubble curtains, created by perforated hoses releasing compressed air, which form a barrier of bubbles that attenuates underwater sound. Their efficiency, however, may vary depending on current strength and bubble rise rate [11]. (c) Jet propulsion systems, which have been shown to reduce injuries and mortality in marine turtles compared to conventional propellers and may offer benefits to other aquatic species as well [26].

4.2. Alterations to the Physical Environment and Ecosystem Consequences

Water quality impacts represent a critical environmental concern throughout both the construction and operational phases of offshore wind-to-hydrogen projects. During the construction phase, activities such as dredging, seabed excavation, and accidental releases of fuels or chemicals significantly increase turbidity and can introduce hazardous substances into the marine environment. These disturbances compromise water clarity, reduce light penetration, and affect photosynthesis in phytoplankton—thereby altering the base of the marine food web [11,25]. The installation of foundations and trenching for submarine cables can resuspend fine sediments and change local sediment dynamics, which negatively impacts benthic organisms such as polychaetes and echinoderms. Furthermore, antifouling paints and maintenance activities may release chemical pollutants that degrade water quality and pose ecotoxicological risks [26].

In the operational phase, vessel traffic contributes to water quality degradation through ballast water discharge, bilge water, and wastewater. These discharges may contain invasive species, pathogens, and nutrients that disrupt ecosystem balance and increase the risk of eutrophication [26]. A major water-related impact stems from the desalination process required to supply high-purity water for PEM electrolyzers. This process produces large volumes of concentrated brine, which, when discharged back into the sea, increases local salinity and density, creating stratification that inhibits vertical mixing and oxygen exchange in the water column. This, in turn, can severely impact marine life, particularly benthic fauna such as shellfish, crustaceans, and demersal fish [28].

The brine discharge can also contain residual metals like copper—commonly used in heat exchangers for its anti-corrosive properties—which may accumulate in marine ecosystems and become toxic if not properly managed. In addition, the desalination process often involves chemical additives for membrane cleaning and pre-treatment, which may enter marine waters through effluents if not adequately treated [34].

To mitigate these issues, several measures are recommended:

• The implementation of brine diffuser systems designed through site-specific hydrodynamic modeling can promote rapid dilution and dispersion of high-salinity effluents, minimizing localized impacts and protecting benthic habitats [28]. In the context of Uruguayan regulation, where effluent dilution is restricted, controlled return of brine through a regulated outfall system may be a viable alternative.
• Installing robust wastewater treatment systems aboard vessels and onshore facilities is essential for removing pollutants before discharge.
• Strict chemical management protocols must be enforced for the safe storage, handling, and disposal of maintenance-related substances used in electrolyzers and offshore turbines.
• Brine mining technologies can be explored to recover valuable salts and reduce the environmental load of salinity waste [35].
• Continuous environmental monitoring programs should be established to assess real-time changes in water quality parameters and guide adaptive management actions. Baseline ecological surveys are also key to understanding site-specific sensitivities and tailoring mitigation accordingly.

4.3. Interactions with the Anthropic Environment

The construction and operation of this projects may significantly affect local fisheries, maritime traffic patterns, and operational safety. Construction activities and the associated increase in vessel traffic can disrupt fishing operations by limiting access to traditional fishing grounds and degrading marine habitats. Hydrodynamic changes caused by construction may affect larval dispersion, alter primary and secondary productivity, and impact benthic communities [25].

Species such as corvina (Micropogonias furnieri) and hake (Merluccius hubbsi) may suffer stress, reproductive disruptions, or habitat displacement due to increased underwater noise. Maritime traffic related to material and personnel transport also raises the risk of vessel collisions and acoustic disturbances, affecting both marine life and human maritime activities. In the European Union, a 500 m safety zone is commonly enforced around construction sites to minimize these impacts [25].

Hydrogen production facilities present additional safety risks, particularly from fires or explosions. Hydrogen’s wide flammability range, low ignition energy, and tendency to cause material embrittlement require rigorous safety strategies, including proper facility design and emergency preparedness [34]. Establishing minimum safety distances based on fluid properties and component failure likelihood can mitigate potential consequences [36].

Mitigation Measures and Recommendations:

• Fisheries Coexistence Planning: Engage the fishing sector in early planning to minimize conflicts and ensure continued access where possible. Consider turbine spacing (800–1000 m) to allow passive fishing activities and vessel navigation [25].
• Navigation Restrictions: Implement regulated navigation and fishing exclusion zones during construction and operation phases to protect both marine fauna and project infrastructure.
• Ban on Bottom Trawling: Restrict bottom trawling in wind farm areas to reduce habitat disturbance and sediment resuspension while protecting subsea cables.
• Safety Protocols for Hydrogen: Adopt national codes and standards tailored to hydrogen technologies and assess safe distances from storage and production units using quantitative risk assessment [36].
• Stakeholder Engagement: Foster transparent dialogue and participatory processes with local fishers and maritime users throughout project design and implementation.

Another significant aspect of the anthropic environment is the potential congestion of ports and logistical routes, especially if multiple projects are developed simultaneously. The results indicate that the need for a large service port (60,000–70,000 m² for projects involving approximately 80 wind turbines) poses space availability challenges and may conflict with other port activities [11]. Furthermore, the social perception of changes to the marine landscape, though less frequent compared to biotic or physical impacts, remains a key factor for the acceptance of these projects [4].

4.4. Potential Positive Effects: Artificial Reefs and Economic Diversification

Despite the predominance of negative impacts, the creation of artificial reefs on support structures (fixed or floating foundations) could offer ecological opportunities by encouraging the aggregation of benthic species and increasing habitat complexity. Studies in the North Sea have shown that certain fish and crustacean species utilize these foundations as new zones for refuge and feeding [24]. Additionally, the prohibition of trawling around wind turbines could further enhance local repopulation. From a socioeconomic perspective, the operational phase generates specialized employment opportunities in wind turbine maintenance and electrolysis plant management [34]. This can boost coastal economies and create synergies with other sectors, such as tourism, provided that territorial planning is implemented to minimize potential conflicts [37].

4.5. Cumulative Impacts and the Need for Coordination

One of the most critical aspects is the lack of analysis regarding cumulative impacts when multiple projects are initiated simultaneously within the same EEZ. International studies demonstrate that fragmented permitting processes and the absence of marine spatial planning lead to underwater noise saturation, competition for space with fisheries, and overburdened port logistics [29]. While this study focuses on wind projects linked to green hydrogen production, the findings highlight the need to incorporate Strategic Environmental Assessment (SEA) approaches that consider the entirety of uses and pressures on Uruguay’s EEZ.

4.6. Recommendations and Future Vision

• Development of a Comprehensive Regulatory Framework

To enable the construction and operation of offshore wind and green hydrogen projects, Uruguay must develop a robust regulatory framework. This includes obtaining maritime space concessions, power generation permits, environmental authorizations, grid connection agreements, and licenses for hydrogen storage and related infrastructure. A fragmented permitting process with unclear responsibilities between authorities can lead to delays, uncertainty, and increased project risk. Countries like the UK and Denmark offer successful regulatory models, with Denmark implementing clear marine spatial planning, environmental standards, and competitive bidding, while the UK centralizes project area access through The Crown Estate and supports the sector via initiatives like the Offshore Wind Sector Deal [38]. The US has followed a marine spatial planning approach led by [22], ensuring compatibility with existing maritime uses. Uruguay is encouraged to adopt a One-Stop Shop (OSS) model—successfully used in Denmark and Costa Rica—to centralize and simplify permitting, improve inter-agency coordination, and enhance process transparency [39].

• Marine Spatial Planning (MSP)

Uruguay should initiate offshore development alongside a formal Marine Spatial Planning process. MSP is a strategic and integrative approach to coordinate maritime activities by allocating marine space while considering conflicting uses. GWEC and IRENA (2023) [39] recommend implementing MSP early in the permitting process to reduce risks and streamline approvals. MSP fosters collaboration among government bodies, conservation groups, energy developers, and community stakeholders. Global guidance has been provided by IOC-UNESCO and the EU, including the 2021 International Guide for MSP Implementation. Spain’s Offshore Wind Roadmap (2021) and its 2023 marine zoning decree exemplify how MSP can align infrastructure access, project siting, and marine use compatibility. For Uruguay, it is essential to include public consultations, particularly with fishers, from early planning stages and integrate cumulative impact assessments into spatial planning.

• Promotion of Research and Baseline Studies

Scientific research is key to understanding the environmental and social impacts of offshore wind and hydrogen projects in Uruguay. The current data availability is limited, and baseline studies must be developed to support impact assessments. Developers should be required to share baseline data to enrich national datasets and improve transparency. Lessons from the UK and Europe emphasize site selection, design flexibility, robust baseline data collection, and digital databases for concessions and environmental conditions [40]. These measures enhance stakeholder engagement and reduce the risk of project rejection due to community concerns or knowledge gaps.

• Environmental Impact Assessment (EIA)

All offshore projects must undergo comprehensive Environmental Impact Assessments in accordance with international standards. These assessments must analyze environmental and social risks, include impact prevention and mitigation strategies, and identify sensitive or protected areas. Stakeholder participation should be integrated throughout the EIA process. In Europe, engagement is required from the initial research phases, while the US and Canada conduct consultations throughout the entire project lifecycle. Groups such as fishers, local communities, and indigenous populations must be included. Uruguay is encouraged to promote the use of sustainable technologies, such as efficient electrolysis and seawater-based hydrogen production. Environmental management systems should be designed to monitor and mitigate cumulative effects.

• Infrastructure and Logistics Development

Port infrastructure plays a critical role in offshore project logistics. Uruguay must assess and modernize its ports to accommodate turbine components, foundations, and hydrogen handling. International examples, like Denmark’s Esbjerg Port, demonstrate that port optimization can reduce project costs by up to 15 percent [41]. Site selection for ports should consider environmental and social criteria, avoiding sensitive or high-tourism areas. A strategic coastal mapping process is recommended, along with public–private partnerships (PPPs) to fund upgrades. Developers could be required to share infrastructure investment costs. The US offers additional best practices, with millions invested in port upgrades in Humboldt Bay, Massachusetts, and Rhode Island. Uruguay could replicate this model by developing pilot projects and a regulatory framework that supports offshore wind–hydrogen integration.

• Capacity Building and Skills Development

Uruguay should implement training and education programs to strengthen its workforce in offshore wind and hydrogen technologies. Despite strong onshore wind expertise, the country lacks experience in offshore systems. Training should target evaluators, permitting officers, and technical professionals, with an emphasis on digital and regulatory competencies. Partnerships between academia, regulators, and industry will be key. Uruguay could adopt digital permit platforms, such as those developed by WindEurope, AWS, and the World Economic Forum, to streamline documentation and improve transparency [39]. Investing in workforce development will enhance institutional capacity, reduce approval delays, and create new employment opportunities in the renewable energy sector.

5. Conclusions

The results highlight that marine fauna is particularly affected during all phases of an offshore project. Impulsive noise, vibrations, seabed changes, and continuous exposure to maritime infrastructure can disrupt feeding, migration, and reproduction patterns, necessitating mitigation measures integrated from the development phase.

Dredging, cable, and foundation installations, along with desalination for electrolysis, cause changes in turbidity, hydrodynamics, and the physicochemical composition of water. These modifications affect primary productivity and marine trophic networks, emphasizing the need for strict sediment control, pollutant management, and brine disposal.

The implementation of offshore projects demands large-scale ports, increased maritime traffic, and potential fishing restrictions. While the infrastructure creates opportunities for employment and technological innovation, it also poses logistical challenges and conflicts with sectors like commercial fishing. Early engagement with coastal communities and the development of spatial planning policies are crucial for social acceptance and project success.

Despite the observed negative impacts, the creation of artificial reefs on submerged structures can aid in benthic community regeneration and fish aggregation, especially with restrictions on aggressive fishing techniques like trawling. Additionally, green hydrogen production offers a pathway to decarbonization, attracting investment and fostering innovation.

The feasibility of these projects in Uruguay’s EEZ heavily depends on the effective implementation of mitigation measures and regulations, beginning at the development and research stages. Given the country’s vast oceanic resources and renewable energy expertise, there is substantial potential for development. However, this must be accompanied by a robust regulatory framework, continuous monitoring plans, and strict impact management to ensure long-term sustainability.

The analysis underscores the importance of assessing cumulative risks, particularly when multiple projects are planned simultaneously in the same region. Policies regulating underwater noise, brine disposal, and interactions with fisheries and maritime traffic are essential to ensure the ecological sustainability and economic viability of Uruguay’s wind–hydrogen industry.

Baseline studies and continuous monitoring are recommended, focusing on marine species mortality due to collisions, the effectiveness of acoustic mitigation techniques, and the optimal integration of desalination on offshore platforms. Such research will refine mitigation strategies and ensure the coexistence of green hydrogen projects with marine biodiversity and traditional coastal economic activities.

The adoption of an integrated regulatory framework, interinstitutional coordination, and specific mitigation measures is essential to align the socioeconomic benefits of offshore green hydrogen with the conservation of Uruguay’s EEZ marine ecosystems. This study provides a preliminary foundation for decision-making, demonstrating that these projects are feasible when approached from a holistic perspective of environmental management and sustainable development.