MARINE ENVIRONMENTAL LAW AND CURRENT ISSUES

I. INTRODUCTION

Oceans are of indispensable importance for balancing the climate system, conserving biodiversity, international transport, energy production, fisheries, tourism, and the economic life of coastal communities. However, the marine environment is exposed to diverse but often interconnected pressures such as ship discharges, oil and chemical spills, terrestrial waste, plastics, wastewater, agricultural pollution, atmospheric emissions, seabed activities, overfishing, and climate change.

The transboundary nature of marine pollution makes it impossible to resolve the issue solely through the domestic laws of states. Pollution originating in a state's land territory or maritime jurisdiction can reach the coasts of other states or areas outside its national borders through currents, atmospheric transport, and the movement of living organisms. Therefore, at the heart of marine environmental law lies the balance between states' right to utilize their own natural resources and their obligation to protect the marine environment and avoid harming other states.

Marine environmental law is not merely about compensation and liability rules to be applied after pollution occurs. Today, the main aim of this branch of law is to prevent environmental damage before it happens, to assess risks using scientific methods, to apply the precautionary principle, to ensure that the polluter bears the costs, and to facilitate information sharing and cooperation between states.

This study will examine the conceptual foundations of marine environmental law, major international regulations, state obligations, ship and land-based pollution regimes, principles of legal liability, and current issues such as plastic pollution, climate change, decarbonization of maritime transport, and deep-sea mining.

II. CONCEPTUAL FRAMEWORK OF MARINE ENVIRONMENTAL LAW

Maritime environmental law is the entirety of national, regional, and international legal rules aimed at protecting the seas and coastal areas, and preventing, reducing, and controlling marine pollution. This field is closely related to international maritime law, environmental law, administrative law, criminal law, commercial law, and liability law.

The 1982 United Nations Convention on the Law of the Sea defines marine pollution as the direct or indirect release of substances or energy into the marine environment by humans, resulting in or likely to result in harmful consequences such as damage to living resources, endangerment of human health, obstruction of maritime activities, deterioration of the usability of seawater, or reduction of the opportunities offered by the sea.

This definition does not limit pollution solely to the discharge of solid or liquid waste into the sea. Heat, noise, greenhouse gases, radioactive materials, the transport of invasive species, and other effects arising from technological activities can also be considered within the scope of marine environmental pollution when the conditions are met.

One of the fundamental characteristics of marine environmental law is the need for the holistic protection of the marine ecosystem. While the source of pollution—whether land-based, ship-based, air-based, pipeline-based, coastal facility-based, or seabed-based—can affect the legal regime, the resulting environmental consequences often converge on the same ecosystem. Therefore, instead of fragmented regulations focusing solely on the source of the pollutant, integrated management models that consider the marine basin and coastal areas together are needed.

III. FUNDAMENTAL PRINCIPLES OF MARINE ENVIRONMENTAL LAW

A. The Prevention Principle

The principle of prevention forms the basis of environmental law. Since it is often impossible to completely remedy environmental damage once it has occurred, states and operators are primarily obligated to prevent the damage from occurring in the first place.

Even if it is possible to clean up an oil spill or rehabilitate a contaminated coastline, it may not be possible to completely eliminate the effects of extinct species, damaged breeding grounds, or heavy metals accumulating on the seabed over many years. Therefore, permits, inspections, technical standards, risk analysis, and emergency response plans constitute the tools of the prevention principle.

Article 194 of the UNCLOS requires states to take all necessary measures to prevent, reduce, and control pollution of the marine environment from any source. States are also obliged to ensure that activities under their jurisdiction or control do not cause harm to other states and their environment, and that pollution does not spread beyond the areas where they exercise sovereign rights.

B. The Precautionary Principle

The precautionary principle states that the fact that a scientific link between an activity and environmental damage has not been fully proven does not constitute a justification for delaying protective measures.

There are significant scientific uncertainties, particularly regarding deep-sea mining, the effects of microplastics on human health, ocean acidification, and the impact of new technologies on marine ecosystems. In such cases, waiting for definitive proof of harm can lead to irreversible consequences.

The precautionary principle does not require the prohibition of all economic activities. The principle necessitates a scientific assessment of risks, examination of alternatives, phased permission, monitoring, and, if necessary, restriction or suspension of activity.

C. The Polluter Pays Principle

The polluter pays principle aims to ensure that the costs incurred in preventing, controlling, cleaning up, and mitigating the damage from environmental pollution are borne by the individual causing the pollution, rather than by society as a whole.

In the context of marine pollution, this principle forms the basis for demanding compensation from the responsible party for cleanup costs, damage to natural resources, losses in fishing and tourism, damage to coastal facilities, and necessary rehabilitation expenses.

However, the polluter pays principle does not give a person the right to pollute the environment by paying a certain fee. The obligation to prevent pollution remains. Compensation and financial liability do not replace preventive obligations; they complement them.

D. The Principle of Not Causing Transboundary Harm

While states have the right to freely regulate activities within their own territories and jurisdictions, they are obliged to ensure that these activities do not cause serious environmental damage to the territories of other states or to the international arena.

This principle requires that sovereignty be considered in conjunction with environmental responsibility. A state's right to exploit its natural resources is not independent of its obligation to protect the marine environment. The UNCLOS recognizes the right of states to exploit their natural resources within the framework of their own environmental policies; however, it regulates this right together with the obligation to protect and conserve the marine environment.

E. Environmental Impact Assessment

Environmental impact assessments are required for activities that are likely to cause significant pollution or serious and harmful changes in the marine environment.

According to Article 206 of the UNCLOS, States are obliged to assess, to the extent possible, the potential impacts of planned activities within their jurisdiction or control when there are reasonable grounds to believe that such activities could cause significant pollution or serious harmful changes to the marine environment.

Environmental impact assessment should not be merely a formality for a permit. It should also evaluate the cumulative impacts of the project, alternative locations and methods, emergency scenarios, impacts on climate change, and post-activity monitoring studies.

F. Obligation to Cooperate and Provide Information

The transboundary nature of marine pollution necessitates global and regional cooperation among states. Article 197 of the UNCLOS requires states to cooperate at a global or regional level to protect the marine environment.

When a state learns that the marine environment is at imminent risk of damage or has been damaged by pollution, it must notify likely affected states and relevant international organizations without delay.

This obligation is particularly important with regard to oil tanker accidents, underwater pipeline damage, nuclear or chemical material transport, and transboundary coastal facilities.

IV. PROTECTION OF THE MARINE ENVIRONMENT IN INTERNATIONAL LAW

A. United Nations Convention on the Law of the Sea

Part XII of the UNCLOS is devoted to the protection and conservation of the marine environment. Article 192 of the Convention explicitly stipulates that states have a general obligation to protect and conserve the marine environment.

This general liability covers pollution from ships, land-based sources, the atmosphere, seabed activities, discharge of waste into the sea, and facilities used in the marine environment.

The UNCLOS not only imposes on states the duty to prevent pollution within their own countries, but also the obligation to prevent the transfer of pollution from one area to another or the transformation of one type of pollution into another. For example, sinking a pollutant to the seabed using chemicals does not eliminate the pollution, but rather transfers the risk of harm to another environmental setting.

B. MARPOL Convention and Ship-Generated Pollution

The primary international regulation for preventing marine pollution from ships is the International Convention for the Prevention of Pollution from Ships (MARPOL). MARPOL sets technical and operational standards for oil, hazardous liquids, packaged hazardous materials, wastewater, litter, and air pollution from ships.

Article 211 of the UNCLOS also stipulates that states shall establish international rules and standards for the prevention of pollution from ships through competent international organizations. Regulations adopted by flag states for ships flying their flag should not be less effective than generally accepted international rules.

The MARPOL regime considers the ship's design, construction, equipment, operation, waste records, fuel quality, and port waste reception facilities together. Thus, the aim is not only to penalize illegal discharges but also to reduce the technical and operational risks that lead to pollution from the outset.

C. Land-based Pollution

A significant portion of marine pollution originates from land-based sources such as rivers, sewage systems, agricultural runoff, industrial facilities, coastal cities, and waste disposal sites.

Article 207 of the UNCLOS requires States to adopt national regulations to prevent, reduce and control land-based pollution, including pollution from rivers, estuaries, pipelines and discharge structures into the sea. These regulations should, in particular, aim to minimize the release of persistent, toxic and harmful substances into the marine environment.

Controlling land-based pollution is more difficult than controlling ship-based pollution. This is because pollution can originate from numerous small sources, and establishing a link between the point at which the pollutant reaches the sea and its initial source can be challenging. Therefore, river basin management, wastewater treatment systems, agricultural policies, and coastal planning are integral parts of marine environmental law.

D. Regional Protection Systems

The geographical, ecological, and economic characteristics of the seas differ from one another. Therefore, in addition to global agreements, regional agreement systems have been developed.

Turkey is a signatory to the Barcelona Convention for the Mediterranean Sea and the Bucharest Convention for the Black Sea. These regional arrangements foresee common obligations regarding the prevention of marine pollution, the reduction of land-based pollutants, the establishment of special protection areas, cooperation in emergencies, and the implementation of regional monitoring programs.

The importance of regional cooperation is particularly evident in enclosed and semi-enclosed seas. In seas such as the Marmara Sea, the Black Sea, and the Mediterranean Sea, where water exchange is limited or where there is a dense coastal population, measures taken unilaterally by a single state may not be sufficient.

V. LIABILITY AND COMPENSATION IN MARINE POLLUTION

Article 235 of the UNCLOS stipulates that states are responsible for fulfilling their international obligations regarding the protection of the marine environment and that their liabilities may arise under international law. States must also establish within their own legal systems swift and adequate remedies for damages caused by marine pollution caused by natural or legal persons under their jurisdiction.

The liability regime for marine pollution damages varies depending on the source of the pollution. Damages from oil tankers, bunker fuel pollution, transport of hazardous materials, coastal facilities, and land-based activities may be subject to different international and national regulations.

One of the most important issues in terms of liability is determining the extent of the damage. The traditional approach has focused on cleanup costs and economic losses. However, modern environmental law recognizes that compensation should also be given for the loss of natural resources and ecosystem services.

Pollution of a coastline results not only in the cost of cleaning the beach itself. Fishing activities can be disrupted, tourism revenues can decrease, breeding grounds for aquatic life can be damaged, and the ecosystem's capacity to regenerate can be severely impaired for a long time. Therefore, ecological rehabilitation costs and temporary losses of natural resources should also be considered when calculating environmental damage.

In Türkiye, the Environmental Law No. 2872 and the Law No. 5312 on the Principles of Emergency Response and Compensation for Damages in Cases of Marine Pollution by Oil and Other Harmful Substances are of significant importance in terms of marine pollution.

Under Law No. 5312, coastal facilities are obligated to prepare emergency response plans and obtain liability insurance. Response to oil or chemical spills is carried out within the framework of the relevant law and its implementing regulations.

VI. CURRENT MARINE ENVIRONMENTAL PROBLEMS

A. Plastic and Microplastic Pollution

Plastic pollution is one of the most significant global problems facing the marine environment today. Due to their durable structure, plastics remain in nature for a long time, breaking down into smaller particles over time and transforming into microplastics and nanoplastics.

Plastic waste can be ingested by marine life, causing entanglement and suffocation, and can enter the food chain. Microplastics can be found not only on the sea surface but also in coastal sands, the water column, the seabed, and in living tissues.

The most challenging legal aspect of plastic pollution is that the problem is linked to the entire life cycle of the product. Simply prohibiting the dumping of waste into the sea is not enough. Plastic production, design, packaging, consumption, collection, recycling, export, and waste management must all be regulated together.

In line with the United Nations Environment Assembly's 2022 resolution, negotiations are underway to prepare a legally binding global document on plastic pollution, including in the marine environment. At the INC-5.3 session held in February 2026, administrative matters such as the presidential election were discussed, but substantive negotiations did not take place, and the process was postponed to subsequent sessions.

At the heart of the global plastics deal discussions are limiting production, reducing single-use plastics, regulating chemical additives, financing, support for developing countries, and decision-making procedures.

B. Climate Change and Ocean Conservation

Climate change affects the marine environment in various ways. These effects include increased sea surface temperature, ocean acidification, oxygen depletion, melting glaciers, rising sea levels, coastal erosion, and changes in the distribution of marine species.

One of the most important consequences of climate change from the perspective of maritime law is the question of whether greenhouse gas emissions can be considered as marine pollution.

In its advisory opinion of May 21, 2024, the International Tribunal for the Law of the Sea assessed the obligations of states under the UNCLOS regarding the effects of climate change on the marine environment. The Tribunal reached a unanimous decision, stating that damage to the marine environment caused by climate change can be addressed under the Convention.

This approach represents a significant development in applying general obligations regarding the protection of the marine environment to climate change. It strengthens the view that states should not only fulfill their commitments under the Paris Agreement but also exercise due diligence in protecting the marine environment under UNCLOS.

Climate change is also affecting the future of maritime zones. Rising sea levels are causing changes in baselines and the land areas of small island states, creating new debates about the legal stability of territorial waters, EEZs, and continental shelf boundaries.

C. Greenhouse Gas Emissions from Maritime Transport

International maritime transport is a cornerstone of global trade but also a significant contributor to greenhouse gas emissions. Therefore, improving the energy efficiency of ships and switching to low- or zero-carbon fuels has become a crucial issue in maritime environmental law.

The IMO's 2023 Greenhouse Gas Strategy aims to achieve zero net greenhouse gas emissions from international maritime transport by around 2050. The strategy includes interim targets for 2030 and 2040, as well as targets for the share of zero or near-zero emission fuels and technologies by 2030.

As of January 1, 2023, the Energy Efficiency Current Ship Index, along with an annual operational carbon intensity indicator and rating, has become mandatory for ships. Under these regulations, ships can receive an energy efficiency rating from A to E.

The regulatory package, known as the IMO Net-Zero Framework, aims to combine a global fuel standard and an emissions pricing mechanism to gradually reduce the greenhouse gas intensity of marine fuels throughout their lifecycle. While the draft text was prepared for 2025, the meeting regarding the legally binding adoption process has been postponed to 2026.

The transition to alternative fuels also presents new environmental and legal risks. The safety of ammonia, hydrogen, methanol, biofuels, and electric propulsion systems, emissions in the production chain, infrastructure requirements, and the environmental impact of potential leaks must be evaluated separately.

D. Deep Sea Mining

The seabed and resources beyond national jurisdiction are, according to the UNCLOS, the common heritage of humanity. No state or private individual may claim sovereignty or ownership over this area. Activities related to resources are conducted within the framework of the International Seabed Authority system.

Deep-sea mining aims to extract resources such as polymetallic nodules, cobalt-rich crusts, and seabed sulfides. However, the effects of these activities on seabed ecosystems are not fully known.

Mining can cause physical disturbance of the seabed, formation of sediment clouds, noise and light pollution, destruction of living habitats, and disruption of carbon sequestration processes.

Article 145 of the UNCLOS requires the International Seabed Authority to adopt rules to ensure the effective protection of the marine environment against harmful effects that may arise from activities in the Area.

In deep-sea mining, the central legal debate centers on whether sufficient scientific information is available before commercial operation is permitted. According to the precautionary principle, scientific uncertainty should not be used to justify granting a permit if there is a risk of serious or irreversible harm.

E. Biodiversity Loss and Marine Protected Areas

Marine conservation cannot be achieved solely by preventing chemical or physical pollution. Overfishing, habitat destruction, invasive species, and climate change also place significant pressure on biodiversity.

Article 194 of the UNCLOS requires states to protect rare or fragile ecosystems and the habitats of extinct, threatened, or endangered species.

Marine protected areas aim to conserve biodiversity by restricting or regulating human activities in specific ecosystems. However, simply designating an area as a protected zone on a map is not enough. Effective monitoring, funding, scientific tracking, and enforcement mechanisms against violations are necessary.

F. Ghost Nets and Abandoned Fishing Equipment

Fishing nets lost or abandoned at sea can continue to catch fish, marine mammals, and birds for extended periods, leading to their deaths. This plastic-containing equipment also becomes a source of microplastics over time.

This issue lies at the intersection of fisheries law and waste law. It requires the marking of nets, reporting and recovery of lost equipment, and the establishment of free or cost-effective delivery systems at ports.

VII. LEGAL ASSESSMENT FROM Türkiye'S PERSPECTIVE

Türkiye's marine environmental policy exhibits a multi-layered structure consisting of the Environmental Law, Law No. 5312, coastal and port legislation, waste management regulations, marine tourism and fisheries legislation, and regional agreements.

The Ministry, the Coast Guard Command, port authorities, and metropolitan municipalities to which authority has been delegated may participate in monitoring illegal discharges from ships. The application of the provisions of the Environmental Law and administrative enforcement processes in maritime areas under Türkiye's jurisdiction are carried out according to the areas of responsibility of the relevant institutions.

However, focusing solely on ship inspections is insufficient in combating marine pollution. Integrated basin management should be implemented for municipal wastewater, industrial discharges, agricultural pollution, coastal development, and waste carried from rivers.

The mucilage problem in the Marmara Sea has demonstrated the need to consider land-based nutrient load, inadequate treatment, rising sea water temperatures, and limited water exchange together. Such events reveal the inadequacy of the classical approach to sanctions based on a single polluter or business.

One of the primary legal requirements for Turkey is that scientific monitoring results are more strongly reflected in the permitting and enforcement systems. New discharge permits should be restricted and existing permits should be re-evaluated in marine areas where pollution carrying capacity has been exceeded.

Furthermore, clear and predictable methods for calculating natural resource damages should be developed. Imposing administrative fines does not automatically ensure compensation for environmental damage. Cleaning costs, ecological rehabilitation, fisheries and tourism losses, and the reduction of ecosystem services should be claimed as separate items.

CONCLUSION

Marine environmental law is a dynamic field of law that strikes a balance between states' right to economically benefit from the seas and their obligation to protect marine ecosystems. UNCLOS (United Nations Convention on the Law of the Sea) imposes obligations on states to protect the marine environment, prevent all sources of pollution, prevent transboundary damage, assess environmental impacts, and cooperate internationally.

However, current challenges demonstrate that the existing legal system often evolves slower than the forms of pollution. Increased plastic production, the spread of microplastics, the effects of climate change on the oceans, ship decarbonization, and deep-sea mining all necessitate new regulations and more effective enforcement mechanisms.