This article addresses the changing regulatory environment for ship recycling. Often criticized for dire health and safety conditions at breaking destinations in the Global South, our contribution considers ship recycling as a potential future source for secondary steel in green transformations. It represents an analysis of ongoing changes in the regulatory framework, i.e. entry into force of the Hongkong Convention, EU's attempts to revise its directive on the topic, the Basle Convention on hazardous waste, and the manifold pledges for net zero. Together, this can be characetrised as a tremendous shift in incentives for shipping industry. We will share a state-of-the-art assessment with an outlook. Furthermore, we did an initial assessment of steel stocks based on publicly available data, and a local case study. Here, we assess the capability of Bremen, a city in Northern Germany, to gain a relevant future market share. Our results indicate the future market is significant, roughly equivalent to the entire current US car fleet in terms of steel stocks, and the ability to act locally depends on a variety of critical factors, including political will, entrepreneurial capital, and space requirements. The latter is also part of an ongoing PhD thesis on the topic (Anja Binkofski).

The contribution concludes with an outlook on the importance of such a development for a 'blue economy' at international scales, the transition towards ‘net zero steel’ and provides a perspective on future research needs.

We did a paper on the topic (ERL 2023) and have continuously updated since, including presentations at the European Commission and at the ShipRecycling Lab2.0. We are also in close contact with others from Brasil, Bangladesh, India, etc, industrial stakeholders, and colleagues from EU projects.

How to cite: Bleischwitz, R.: Shipping regulations at a turning point - dismantling ships as contribution to a blue economy, net zero and raw materials security, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-508, https://doi.org/10.5194/oos2025-508, 2025.

As the global maritime sector advances towards decarbonisation, alternative fuels such as biofuels, hydrogen, and ammonia are increasingly being considered to reduce greenhouse gas (GHG) emissions. However, these fuels pose unique environmental risks, particularly in cases of accidental spills. This study investigates whether the current international legal framework—comprising conventions like MARPOL and the United Nations Convention on the Law of the Sea (UNCLOS)—is sufficient to mitigate and repair environmental damage from spills of these alternative fuels, given that no specific international agreements directly address this issue.

The analysis draws on the complex interplay between maritime law and environmental protection, highlighting that MARPOL’s primary focus has been on regulating traditional pollutants, which limits its applicability to newer fuel types whose chemical properties and ecological impacts vary significantly. According to research by Hsieh and Felby, approximately 70% of fuels in maritime operations must transition to low-carbon alternatives to meet International Maritime Organization (IMO) decarbonisation targets, yet safety data on these new fuels is scarce. Thus, an incident involving such fuels could create challenges for damage quantification, risk assessment, and cleanup protocols (Hsieh & Felby, 2017).

In terms of liability and enforcement, UNCLOS provides a general framework for pollution control, conferring responsibility primarily to flag and coastal states. However, the unique characteristics of alternative fuels, such as ammonia’s toxicity or hydrogen’s flammability, highlight the limitations of existing port and coastal state powers under Articles 211 and 218, which were developed and construed with conventional pollutants in mind (UNCLOS, 1982). Additionally, the IMO’s non-binding guidelines, while useful, do not hold the weight of enforceable international law, leaving significant enforcement gaps when spills involve non-traditional fuels.

This study also considers the “ocean implementation gap” as outlined by Hinds, referring to the lack of inter-agency cooperation among UN organizations tasked with ocean governance, which impedes the development of cohesive regulations for alternative fuel risks. There is a need for fostering UN inter agency cooperation due to their capacity for supporting maritime environmental safety projects (Hinds, 2003). There is also a need for increasing capacity development and ocean research. For instance, only a few initiatives, such as the GreenVoyage2050 project, address the safe use of alternative fuels, leaving major safety concerns unaddressed, as Tandros notes, in terms of fire and explosion risks (Tandros et al., 2023).

In conclusion, while MARPOL and UNCLOS provide foundational frameworks for pollution control, they are not fully equipped to handle the emerging risks associated with alternative fuel spills. The paper recommends establishing legally binding international standards and promoting inter-agency cooperation to bridge the implementation gap. Addressing these regulatory gaps is essential to advancing maritime sustainability and ensuring that the transition to low-carbon fuels does not inadvertently heighten environmental risks.

How to cite: Maltese Zuffo, M., Moraes Neves, A. F., Duleba, W., and Duleba Marques, I.: Assessing International Legal Frameworks for Environmental Damage from Alternative Fuel Spills: Gaps and Future Directions for Maritime Decarbonisation., One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1393, https://doi.org/10.5194/oos2025-1393, 2025.

The maritime sector is experiencing a profound transformation, driven by the development, testing, and implementation of diverse low/zero-emission solutions. However, substantial challenges to achieving net-zero shipping persist, including high costs and limited infrastructure for alternative fuels, as well as notable regional disparities in decarbonisation commitments, technological advancement, and adoption rates across the industry.

The upcoming OECD report, The role of shipbuilding in maritime decarbonisation: impacts of technology developments and policy measures (2025), provides an in-depth analysis of the shipbuilding and marine equipment sector’s capacity to support maritime decarbonisation through advancements in ship design and construction for low/zero-emission fuels and propulsion systems. This report leverages comprehensive data from major shipbuilding nations, applying quantitative analysis alongside insights from company reports, policy documents, and interviews. It examines production capacities, research and development (R&D) trends, and policy frameworks influencing the development and adoption of alternative fuels and propulsion technologies in the pursuit of low/zero-emission shipping.

Building on the report’s insights, the proposed presentation offers original and extensive findings for session T9-2 in the following areas:

Regional shipbuilding and marine technology capacity for alternative fuels and propulsion: The report assess industry capacity in major shipbuilding regions, studying newbuild and retrofitting capabilities in relation to alternative fuel adoption. It examines significant regional disparities in capacities for alternative fuel capable vessel construction between leading countries, with China and South Korea together accounting for almost 90% of the global alternative fuel orderbook in CGT— and other economies. An additional focus is placed on engine design and manufacturing capacity for alternative fuel-capable engines.

Innovation trends in low/zero-emission ship design and propulsion systems: The report analyses trends in low-carbon innovation, with a focus on annual patent activity related to low/zero-emission marine technology and ship design. It highlights recent trends in patenting in low-carbon maritime technologies, identifying key areas where innovation has slowed or increased and examining the types of technologies that are prioritised across regions. This is linked to analysis on where investment and policy support might stimulate renewed R&D, particularly in propulsion system advancements and ship designs optimised for alternative fuels.

Comparative analysis of maritime decarbonisation policies: The report provides a comparative analysis of decarbonisation policy measures across 25 maritime nations—spotlighting key shipbuilding economies in East Asia, Southeast Asia, South Asia, Europe, North America and South America. By mapping policy target areas, instruments, and support measures, it assesses how different national policy frameworks shape industry decarbonisation efforts. The report also examines trends in Green Shipping Corridors and agreements between shipowners, ports, and energy producers to create integrated supply chains for alternative fuels.

How to cite: Berger, E. and Daniel, L.: The role of shipbuilding in maritime decarbonisation: impacts of technology developments and policy measures , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-749, https://doi.org/10.5194/oos2025-749, 2025.

Aligned with the International Maritime Organization's (IMO) aim to lower greenhouse gas emissions, the use of Wind-Assisted Ship Propulsion (WASP) in maritime transport is gaining increased attention. The study and optimization of WASP remain challenging due to complex physics and the high number of parameters involved. This includes interactions between aerodynamics, hydrodynamics, and structural dynamics, which require advanced multi-physics modeling. Additionally, numerous factors must be optimized, from design and control parameters to route selection, all within the variable maritime environment. Addressing these challenges demands multi-model approaches and multi-criteria optimization methods to maximize energy efficiency effectively. In this context, the laboratories of Ecole Navale, IFREMER, ENSM, and ENSTA Bretagne are collaborating on several research projects, with a selection of two thematic studies presented here.

The first study is carried out as part of the SHIVA and SAWASP projects, jointly led by Ecole Navale, IFREMER and ENSTA Bretagne. The goal of these projects is to optimize the hydrodynamic performance of innovative, fully electric, Vertical-Axis Propellers (VAPs) and their optimal use in conjunction with a wind-assisted ships. To achieve this, the SHIVA project implements a multi-criteria optimization of the propeller blade-pitching laws, utilizing multi-fidelity numerical and experimental surrogate models. These optimizations enable the determination of a set of optimal pitch laws for different operating points of the propeller. In the SAWASP project, a 6-meter wind-assisted ship equipped with VAPs is developed to study the optimal aerodynamic-hydrodynamic coupling. In particular, the energy gains from using VAPs as the main propulsion system, generating a lateral anti-drift force, are studied. The use of Reinforcement Learning (RL) methods to maintain optimal ship operation performance at sea, as an uncertain environment, is also part of this project.

The second study is conducted within the framework of the SOMOS project, jointly managed by ENSM and ENSTA Bretagne. The project's goal is to create and validate a set of numerical tools, that allow for rapid and precise assessment of the energy efficiency of wind-assisted ships. For the purposes of this study, a modular and comprehensive ship motion solver is formulated as an optimal control optimization problem, to evaluate, compare, and optimize energy performance. Such an approach is very complex to implement and, depending on the fidelity-level used, may require very high modeling costs. This is why most research efforts focus on specific aspects of the broader problem, often overlooking the coupling of maritime routing, ship motion analysis, and the optimization of control parameters along the planned sea route. The present work provides an innovative approach for the calculation of optimized trajectories for wind-assisted ship, by both considering the ship's maneuvering capabilities and the optimization of ship control and/or design parameters. In contrast to conventional routing methods, the proposed approach achieves high computational efficiency and relies on direct multiple shooting methods to determine optimal ship control parameters (RPM, rudder angle, etc.) and design variables (rotor Flettner or sail positioning, rudder area, etc.) along the sea route, satisfying the constraints of complying with the ship's equations of motion.

How to cite: Sacher, M., Leroux, J.-B., Podeur, V., Guilcher, P.-M., Nême, A., Jochum, C., Clement, B., Hauville, F., Becker, F., Augier, B., Germain, G., Merino Laso, P., and Vanhorick, C.: Optimization and Multi-Model Approaches for Maximizing Ship Decarbonization, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-607, https://doi.org/10.5194/oos2025-607, 2025.

The French Oceanographic Fleet (FOF) is one of the largest oceanographic fleets in the world. Its ability to operate at great depths and its global coverage make it an essential tool for ocean sciences. To prepare for the renewal of the FOF, a global and collective foresight process has been undertaken in 2023 and 2024.

We identified strong expectations for the FOF around major scientific challenges: (i) understanding the role of the ocean as a regulator in the climate system and the profound changes that are taking place; (ii) reconstructing paleoclimates based on marine sedimentary archives; (iii) geological and geophysical knowledge of the oceanic crust; (iv) the diversity of living organisms and biogeochemical cycles; (v) the impact of human activities on the ocean. These major scientific challenges call for the FOF to be deployed throughout the world's oceans, particularly in certain regions that are more sensitive to changes and in areas that already benefit from long-term scientific monitoring.

To carry out this ambitious programme, the FOF's capacity will have to be consistent with France's ambitions for ocean sciences. At the crossroads of technological prospects and scientific needs, several path for evolution of ships and facilities have been identified. We must continue to renew the fleet of coastal, mid-shore and deep-sea vessels. They are essential facilities for deploying subsea systems, sampling the water column or the sea bed, and carrying out in situ work. Coastal and oceanic unmanned surface vehicle (USV) will also provide additional support. Giving access to the deep seas, the renewal of underwater equipment will be particularly marked by the modernisation of the 6000 m HOV Nautile and ROV Victor

The FOF will also have to improve its processes in terms of access to infrastructure, anticipation in the geographical positioning of ships and the programming of missions and also enhance the use of data. Strengthening European and international partnerships will also be essential in order to optimise the displacement of vessels in remote areas.

But neither can the FOF imagine its future without considering to reduce its environmental footprint. The FOF emits around 43,000 tCO2 per year. Fuel accounts for 71% of these emissions. Decarbonising the FOF is a huge challenge that can only be met by combining changes in practices and ships design. We advocate that future deep-sea oceanographic ships should be hybrid and make extensive use of wind propulsion especially for transits. Without waiting for these new types of vessels, there are a number of levers that can reduce the carbon footprint: dockside electricity, reducing vessel speed and introducing biofuels. Strict application of these measures could lead to a 20% reduction in emissions by 2030. From 2030 onwards, decarbonisation will have to be stepped up as new ocean-going hybrid vessels enter the fleet. There is therefore a vital interest in rapidly building a first ‘decarbonised’ deep-sea ship, successor to the R/V L'Atalante, in order to preserve the potential for deep-sea operations and to allow the FOF to reach a significant decarbonisation milestone.

How to cite: Simon, M., David-Beausire, C., and Lefort, O.: Shaping the future of the French oceanographic fleet, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-331, https://doi.org/10.5194/oos2025-331, 2025.

Amphitrite, a spin-off from the French École Polytechnique and CNRS, presents The Ocean Bulletin, an innovative ocean data and voyage planning platform designed to advance the reliability and precision of oceanic and meteorological data for maritime transport. Integrating cutting-edge satellite observations with real-time AI data fusion, The Ocean Bulletin offers high-resolution forecasts of ocean currents, waves, and wind conditions. We fuse data from satellite infrared, visible, and altimetric sensors, as well as from the pioneering SWOT mission, which enables for the first time kilometer-scale resolution forecasts of currents and waves.

Through pilot tests with leading shipping and chartering companies, we have validated our ocean current and wave models by analyzing vessel speed logs and data from specialized onboard sensors as well as fuel gains and CO2 emission reductions by conducting voyage optimization. Notably, through our participation in the Statsraad Lehmkuhl oceanographic campaign that will reach Nice during the One Ocean conference, we will use VMADCP and Wave Sensor measurements to further validate our AI models.

The Ocean Bulletin is a user-centric tool, built collaboratively with ship captains and maritime professionals to ensure operational relevance and ease of use, facilitating daily decision-making for safer, more efficient voyages. Optimizing route at the fine scale,  by catching favorable currents and avoiding extreme wave conditions can enable fuel and CO2 emission reductions of up to 10% added to the gains of traditional weather routing.

For more information, visit www.ocean-bulletin.com.

How to cite: Moschos, E., Larroche, I., Dupont, A., and Stegner, A.: The Ocean Bulletin : Harnessing Fine-Scale Ocean Data via Satellites & AI for Optimal Ship Routing, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1116, https://doi.org/10.5194/oos2025-1116, 2025.

How to cite: Zygarlowska, E., Dumard, C., and Rochut, B.: Ensemble weather routing solutions towards safety and decarbonisation of maritime transport , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1040, https://doi.org/10.5194/oos2025-1040, 2025.

Air pollution particles generated by the incomplete burning of fossil fuels can be dispersed in the atmosphere or fall in the soil, being transported to aquatic environments by deposition or river currents. [1] The dissolved fraction of BC is composed of a set of heterogeneous pyrogenic compounds. Dissolved Black Carbon (DBC), a soluble part of BC (0.2 μm – 0.7 μm), consists exclusively of polycondensed aromatic molecules. [2] In the marine environment, zooplankton can modify the physicochemical characteristics of pollutants in the water column (e.g., by absorption, transformation, and elimination), playing an important role in the biomagnification of pollutants in food webs. The knowledge about the interactions between zooplankton and anthropogenic pollutants is still scarce. [3,4] In this study, we used two-photon confocal microscopy and our recent advances in the optical characterization of Particulate (PBC) and Dissolved Black Carbon to identify them in copepods collected in the Bay of Toulon, France, in vivo. We incubated the copepods after the sea sampling with a typical PBC concentration of coast regions and high anthropogenic activity. The images obtained revealed the localization of the particles in the digestive tract of the animals, confirming their ingestion by these marine species after 48h of incubation. The identification was made by the previous PBC and DBC fluorescence emission characterization. Inside of the copepods the signal ressembly of the DBC particles who are knowing to be toxic and highly dangerous. Next steps include the investigation of DBC toxicity effects in copepods and their chemical transformation.

1- Wagner, S., Jaffé, R., & Stubbins, A. (2018). Dissolved black carbon in aquatic ecosystems. Limnology And Oceanography Letters, 3(3), 168–185. -https://doi.org/10.1002/LOL2.10076

2- MARTINOT, P. L. et al. Assessing the bioavailability of black carbon-derived dissolved organic matter for marine heterotrophic prokaryotes. Science of the Total Environment, v. 901, p. 165802, 2023. DOI: 10.1016/j.scitotenv.2023.165802.

3- ZIYAADINI, M. et al. Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay. Marine Pollution Bulletin, v. 107, n. 1, p. 408–412, 2016. DOI: 10.1016/j.marpolbul.2016.02.045.

4- THIRUNAVUKKARASU, S.; HWANG, J. S. Genotoxic effects of marine pollutants on coastal meso-zooplankton populations – a mini-review. Marine Pollution Bulletin, v. 205, 2024. DOI: 10.1016/j.marpolbul.2024.116548.

How to cite: Ferreira Vicente, M. L., Blanchet, J., Jamet, J.-L., Jamet, D., Gontijo Guimarães, F. E., Mounier, S., and Hajjoul, H.: Identification and Characterization of Dissolved Black Carbon and Its Interactions with Zooplankton, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-428, https://doi.org/10.5194/oos2025-428, 2025.

The current climate change, pollution, and biodiversity crises highlight the urgent need to develop effective conservation measures for wildlife and their habitats. The Mediterranean Sea is home to some of the busiest traffic lanes globally, accounting for approximately 30% of international commercial shipping activity. These high volumes of maritime traffic pose a substantial threat to the resident, endangered sub-population of fin whales, with significant conservation and welfare concerns arising from both lethal and sub-lethal collisions and noise pollution. In 2023, the International Maritime Organization (IMO) designated a Particularly Sensitive Sea Area (PSSA) in the North-Western Mediterranean Sea, following a joint proposal from France, Italy, Monaco, and Spain. This designation acknowledges the significant adverse effects of vessel strikes on the region’s fin and sperm whales, highlighting the need for targeted conservation measures to mitigate these threats. This PSSA encompasses the existing Spanish ‘Cetacean Migration Corridor’ and the ‘Pelagos Sanctuary’, as well as the ‘North-Western Mediterranean Sea, Slope and Canyon System’ Important Marine Mammal Area (IMMA). Substantial understanding of fin whale distribution and habitat use is available for the NW Mediterranean Sea. However, knowledge of the species regional movement ecology (e.g., through the use of biologging technology), critical to support mitigation and management efforts, particularly in relation to vessel-strikes, remains limited. In this context, we assess the habitat use of endangered Mediterranean fin whales in the newly established PSSA. During four field seasons (2021–2024), 15 fin whales were equipped with satellite transmitters – including 11 SPOT and 4 Fastloc GPS tags, all in the LIMPET configuration – during their spring-summer aggregation in the Corso-Liguro-Provençal and the Balearic Basins. Hidden Markov Models (HMM) and Utilization Distributions (UD) were used to identify foraging behavior, revealing that individuals were consistent in their use of seasonal core feeding grounds, many of which occurred in areas with no explicit protected status. Based on the overlap between shipping routes and whale habitat, our research highlights how fin whales do not avoid areas of intense maritime traffic. This, alongside a potentially limited repertoire of avoidance responses to incoming traffic, makes Mediterranean fin whales particularly susceptible to collision risk. Our findings show that the recently established PSSA encompasses the entirety of the movements of the tracked fin whales across the study period, except for one individual who left the study area. These findings underscore the need for a mandatory vessel speed reduction rule to 10-13 knots to be adopted among the Associated Protective Measures (APM), in addition to other recommended voluntary measures already in place within the PSSA.

How to cite: Panigada, V., Nowacek, D. P., Pierantonio, N., and Panigada, S.: Habitat use of Mediterranean fin whales in the recently established North-Western Mediterranean Particularly Sensitive Sea Area, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-708, https://doi.org/10.5194/oos2025-708, 2025.

The global shipping industry plays a critical role in international trade, but its environmental impact extends beyond greenhouse gas emissions to include underwater noise pollution. As ships navigate the world's oceans, the noise generated by their engines, propellers, and hulls creates a persistent soundscape that can have far-reaching consequences for marine life. In response, the Noise Ship Index (NSI), developed by Quiet-Oceans, is a pioneering tool designed to assess and rate the underwater noise emissions of individual vessels.

This paper examines the relevance and need for a dedicated index, detail the proposal made through the Noise Ship Index (NSI), as well as the benefits it offers to various stakeholders within the maritime supply chain, including shipowners, maritime service providers, ports, and charterers.

The NSI framework, structured around four key pillars (Management & Empowerment, Diagnosis, Reduction, and Achievement), is discussed in detail, along with the scoring system and award levels that incentivize and recognize progress in reducing underwater noise.

The paper also highlights the crucial role that the financial sector and insurance industry can play in promoting the widespread adoption of the NSI through initiatives such as preferential financing, incorporation into ESG criteria, and adjustments to insurance premiums. Finally, the authors present policy recommendations to effectively address underwater noise from shipping and support the implementation of the Noise Ship Index, including the development of regulatory frameworks, incentive mechanisms, and enhanced monitoring and enforcement.

By providing a standardized and transparent way to measure and reduce underwater noise, the NSI can drive industry-wide changes towards more sustainable and responsible maritime operations, ultimately contributing to the protection of marine ecosystems and the long-term viability of the shipping industry.

Keywords: Underwater noise, shipping, Noise Ship Index, marine environment, environmental impact, policy recommendations

How to cite: Folegot, T. and Baudin, E.: A new comprehensive index to address underwater radiated noise from ships., One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-344, https://doi.org/10.5194/oos2025-344, 2025.

Although the most important efforts towards undesired emissions and pollution reduction are focused on decarbonization and greenhouse gas emissions, the ocean noise pollution must not be relegated as of lesser importance. Existing evidence on ocean noise levels since mid-sixties of the past century report an incrementation rate of 3 dB per decade on average, inherently due to the increasing human ocean activity, i.e., maritime transportation. Also, URN impact on marine life is raising increasing concern, including the International Maritime Organisation. The last revision of its Guidelines for the Reduction of Underwater Radiated Noise from Shipping to Address Adverse Impact on Marine Life (IMO Ref. MEPC.1 / Circ.906) is a clear indicator, showing the path to follow.

For existing ships to advance in the implementation of URN reduction measures it is crucial to find a solution that fits well into already operating ships, as for new ships it is possible to include well known URN reduction techniques at the initial stages of the design and construction process.

For the estimation and control of the URN, the proposed method is based on the characterization of the several sources that that have a major contribution to the URN signature of a ship, i.e.,  propulsion system (engine and gears), propeller (both in non-cavitating and cavitating conditions) and other onboard machinery (generators, HVAC, etc.). The characterization was conducted by both onboard and outboard measurements (made in compliance with international standards such as IACS Rec. 176 and Bureau Veritas NR614) and resulted in the corresponding transfer functions for the several sources considered. The results show that an accurate estimation of the URN emitted by the ship can be obtained by measuring vibration levels at the selected onboard sources. The URN estimations can even be produced onboard in real-time using an extension to the Ni-CDS system, a non-intrusive onboard cavitation detection system, that already provides real-time information on the cavitation status of the propeller using accelerometers located nearby inside the hull, being cavitation the most contributing source to URN when occurring. Data analysis techniques merging URN estimations with knowledge on the operational status of the ship at the same time can provide insights and useful information for comprehensive URN management onboard, leading to lesser URN levels and thus, achieving the goals IMO is promoting.

How to cite: Beltrán Palomo, P., Baudin, E., Piqueras González-Tejero, L. A., Tesorero Moreno, M. A., García Méndez, R., and Molins Riera, S.: Ocean Noise Pollution Reduction, Onboard Underwater Radiated Noise (URN) Estimation and Management for the Existing Maritime Transportation Fleet, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1460, https://doi.org/10.5194/oos2025-1460, 2025.

The North-Western Mediterranean Sea is affected by intense human use (e.g., shipping, fishing, recreation, coastal urbanisation and industries, naval activities) which impacts on marine species survival. Marine mammal ecological and conservation science has made significant progress since the Pelagos Agreement came into force in 2002, and this now can inform better policies to be developed to mitigate such impacts, facilitating the well-being and recovery of Mediterranean marine mammals while allowing for the unavoidable human practices in the area to occur with the smallest possible environmental detriment. Within that context, conservation measures that generate multi-environmental benefits are to be explored and promoted, while also considering socio-economic impacts.

Shipping traffic has steadily increased in the Mediterranean over the past 50 years, as well as noise emissions, reported to have doubled between 2014 and 2019 in EU waters. The pressure it causes on marine mammals is assessed and identified at the EU, Barcelona Convention and IMO levels. Some measures, such as reduced vessel speed and others, have also been identified as generating multi-benefits by reducing greenhouse gas, ocean noise emissions and the risk of vessel strikes. Through ACCOBAMS’ support for regionally coordinated research and advocacy, such measures are more effectively promoted and implemented across member states.

In addition, the rise in shipping traffic also increased the number of lethal collisions with cetaceans, significantly affecting the endangered fin and sperm whale Mediterranean sub-populations. This led to the recent establishment of the North-Western Mediterranean Particularly Sensitive Sea Area (PSSA) by the International Maritime Organization (IMO), which includes two recognized SPAMIs and MPAs. Associated Protective Measures (APM) include re-routing, reporting measures, and speed reduction and smart technology alerting ships of the presence of cetaceans. The application of these recommendations requires mapping of the critical habitats and fin and sperm whales’ density and fine-scale movements, and an increased effort on the robust assessment of the number of collisions from stranding programs. Robust data will allow to advocate for mandatory speed reduction (up to a maximum speed of 10 knots, following existing recommendations) and rerouting from the highest density areas. Quantitatively monitoring each vessel's compliance with the suggested measures within the PSSA boundaries is an essential step of an effective mitigation effort and will facilitate the robust assessment of the Associated Protective Measures.  By promoting a unified, regional response, ACCOBAMS, together with relevant stakeholders, can assist countries to ensure that these protective measures to reduce collision risk are consistently applied and monitored.

The Pelagos Sanctuary could be used as a laboratory to test recommendations at a large scale, become a pioneer area for meeting conservation objectives and draw conclusions on their effectiveness and inform decision-making at the IMO, the Barcelona Convention and the EU and its Member States, towards the implementation of the MSFD.

How to cite: Panigada, S., Entrup, N., Salivas, M., and Notarbartolo di Sciara, G.: Addressing underwater noise and vessel strikes mitigation to support conservation efforts within the North-Western Mediterranean Particularly Sensitive Sea Area, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1077, https://doi.org/10.5194/oos2025-1077, 2025.

Marine traffic is the main contributor to ocean noise at low frequencies, contributing to an observed increase of up to 10 dB over the few decades. It is predicted to further intensify over the coming decades and expand dramatically in the Arctic following new routes made accessible by global warming and sea-ice melt. Anthropogenic noise has a demonstrated impact on marine environment, through masking of intraspecific and interspecific communication, affecting predator-prey interactions hampering settlement cues and reducing threat (including vessel) detection, resulting in increased stress levels and reduction of habitat suitability. The St. Lawrence Estuary (eastern Canada) is a major shipping corridor linking the Great Lakes to the Atlantic Ocean, and home to 13 marine mammal species including Endangered Beluga whale and blue whale and Critically Endangered North Atlantic right whale. Understanding and reducing the acoustic footprint of maritime transport is critical to improve its cohabitation with the marine fauna.

The Marine Acoustic Research Station (MARS, www.projet/mars.ca/enwww.projet-mars.ca/en) is an applied research project focused on quantifying, understanding and attenuating traffic noise and its effects on marine life. An acoustic recording station was specifically designed to collect high-resolution measurements of the source levels radiated by a significant part of the commercial fleet operating in the St. Lawrence Seaway. The MARS observatory contributes to improving knowledge of the underwater noise emissions in the St. Lawrence Estuary through quantitative measurements, comprehensive analysis and modeling of ship noise. From our high-resolution source level database, we developed a source level model, tailored to the St. Lawrence fleet, to further understand, model and predict the acoustic footprint of traffic noise in the region, critical to conservation actions and traffic management.

Over the first three years of operation, we collected over 2500 source level measurements. A suite of autonomous onboard vibration sensors has been developed and deployed on 15 ships for comprehensive characterization onboard vibrations. Our observations provide quantitative information about the underwater noise generated by the St. Lawrence fleet to the government, for informed decisions regarding the establishment of source level limits. We also deliver quantitative feedback to shipowners regarding the contribution of each of their vessels to underwater noise, and we help raising awareness within their teams and identifying suitable attenuation solutions. Finally, the MARS team contributes to improve ship usage, modification and design to reduce noise emissions, through characterization of the mechanical processes, onboard the ships, related to noise generation, transmission, and radiation in the ocean.

The long-term operation of the MARS observatory offers a unique framework to advance scientific and technical knowledge regarding ship noise, and a robust measurement infrastructure to test and quantify the effects of noise mitigation solutions for individual vessels through successive measurements, as well as to monitor the fleet-wide effects of traffic management decisions and technology development over the years on the acoustic footprint of maritime transport.

How to cite: Cauchy, P., Mercure-Boissonnault, P., Mérindol, J., Perrier de la Bathie, C., Rabetoandro, F., Boujdi, S., Gauthier-Marquis, J.-C., Lafrance, S., and St-Onge, G.: Quantification, characterization and attenuation of the acoustic footprint of the maritime transport in the St. Lawrence seaway - The MARS observatory, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-204, https://doi.org/10.5194/oos2025-204, 2025.