The world’s oceans are facing significant threats, from chemical spillages to plastic pollution and loss of biodiversity. Global Insight reports on the steps being taken to protect them.

While there remain significant threats to our oceans and co-ordinating the appropriate international response proves challenging, there are, nevertheless, good reasons for optimism. Earlier this year, the Biodiversity Beyond National Jurisdiction Agreement – more commonly known as the High Seas Treaty – entered into force with the aim of safeguarding marine ecosystems. Meanwhile, work continues towards a UN treaty to address one of the most significant threats facing our oceans: plastic pollution.

Unsustainable fishing practices, loss of biodiversity and the dumping of toxic waste have threatened the world’s oceans for some time now. And, while there was already an existing body of international law designed to protect the marine environment, experts working in this area highlight gaps in the framework and issues of non-compliance that have tended to stymie these efforts.

For many years, the cornerstone of international legislation in this area has been the UN Convention on the Law of the Sea (UNCLOS), adopted in 1982 and in full effect from 1994. It focuses on the rights of states and their jurisdiction regarding maritime spaces, as well as how the oceans can be used peacefully and their resources managed.

Flaws in the system

The UNCLOS has a number of strengths. It has been ratified by 168 UN member states, as well as the EU, and provides a holistic framework for states to follow towards the protection and preservation of marine resources and the prevention of pollution. The Convention also includes dispute settlement measures through the International Tribunal for the Law of the Sea and the International Court of Justice.

However, compliance is uneven. For example, the ‘flag state principle’ provides less oversight in reality than was intended. This is the principle that grants the state whose flag is flown by a ship exclusive jurisdiction and overall responsibility for enforcing international maritime regulations regarding that vessel. While the principle aims to provide a single, consistent regulation for issues such as safety, pollution prevention and crew welfare, its effectiveness is challenged as nations with weak regulatory oversight allow ships to register with them. Those vessels are then able to take advantage of lax enforcement to avoid even basic rules. While some ports may take action against foreign vessels for violations in their zone, experts suggest this is not a long-term solution.

The London Dumping Convention doesn’t take account of microplastic waste, nor toxic pollutants. MARPOL, which is concerned with the reduction of oil spills and deliberate and/or harmful discharge by vessels into the sea, doesn’t cover land-based dumping, meanwhile. Iqbal says that both treaties mitigate harm, but ‘fail to completely capture […] the systemic nature of the level of oceanic degradation.’

The nature of certain treaties has prompted the creation of rules at local and regional level. For example, the UN Environment Programme (UNEP) Regional Seas Programme and the Barcelona Convention on protecting the Mediterranean Sea against pollution are more tailored to local ecosystems and threats, rather than addressing problems at an international level, which might allow for more regional cooperation. Their effectiveness is also weakened by a low level of participation and funding received from members, as well as by limited enforcement and often only voluntary compliance.

Andre Monette, a partner at Barnes & Thornburg, operating out of San Diego and Washington, says that, so far, the international treaties meant to protect the oceans have had ‘zero bite’. He says that countries are more likely to pursue companies and other states that pollute the seas and the environment in their own jurisdictions, rather than try to enforce any international obligations. In the case of pollution in international waters, for example, ‘very little is done to address the problem,’ he says.

Monette, a Council Member of the IBA Energy, Environment, Natural Resources and Infrastructure Law Section, believes compliance, as well as enforcement, would be boosted if the commitment to abide by the spirit of the law was attached to other mechanisms that had ‘meaning’, such as a bilateral trade agreement. ‘If these laws had proper economic impact, countries would be much more active than they have been,’ he says.

Governments taking unilateral action to protect waters in their own jurisdictions is an acknowledgment that coordinating internationally is difficult. In summer 2025, for instance, the UK government announced proposals to extend a ban on bottom trawling to a number of offshore protected areas; the practice involves dragging large fishing nets along the sea floor, damaging the environment and harming wildlife. It has, however, so far rejected an outright ban on bottom trawling. France, Greece and Sweden have also committed to taking action against the practice.

The landmark High Seas Treaty

Significantly, there have been recent efforts to make the UNCLOS more effective. By September 2025, the High Seas Treaty – an agreement under the UNCLOS that was formally adopted in 2023 – had reached the requisite 60 countries needed to sign and ratify it in order for it to enter force in January 2026. It’s a global, binding treaty and as the name suggests, it’s concerned with the ‘high seas’ – the roughly two-thirds of the ocean beyond any single country’s jurisdiction.

The treaty covers the exploitation of benefits from marine genetic resources – for example, plants in the ocean with scientific value – as well as area-based management tools. Such tools include the establishment of marine protected areas in the high seas, which the World Resources Institute describes as ‘typically clearly defined geographical spaces that are recognized, dedicated and managed, through legal or other effective means, to conserve marine biodiversity and ecosystem integrity’.

The High Seas Treaty represents ‘a landmark legal development,’ says Iqbal. She believes its main strength is ‘filling the vacuum that [the] UNCLOS left’ by creating a mechanism to protect marine areas across the ‘global commons’ – those domains containing shared resources outside the jurisdiction of any one nation. However, in some cases, there’s a gap between the aspirations found in the international legal framework and reality as countries pursue their own goals, often driven by economic concerns.

In January, the US National Oceanic and Atmospheric Administration (NOAA) finalised revisions to its regulations that govern the deep seabed mining of critical minerals in areas beyond the country’s jurisdiction. The revisions follow an executive order issued by US President Donald Trump in spring 2025, directing the Secretary of Commerce to ‘expedite the process for reviewing and issuing seabed mineral exploration licenses and commercial recovery permits’. The executive order highlighted the US’ national security and economic interest in this area, and the challenges the country faces in securing reliable supplies of critical minerals.

The NOAA’s new rules establish a consolidated process for companies to simultaneously apply for both an exploration licence as well as a mining permit. Meanwhile, only a single environmental impact statement is now necessary for evaluating the effects of both exploration and commercial recovery activities.

Under the UNCLOS, the seabed and subsoil are beyond the limits of national jurisdiction and its mineral resources are designated as the ‘common heritage of mankind’. Part XI of the treaty created the International Seabed Authority to manage activities related to such resources. The Authority has sought to establish rules to cover deep seabed mining but hasn’t yet issued final regulations. The US, meanwhile, isn’t a party to the UNCLOS, partly because of its issues with Part XI of the treaty. Concerns have been raised that the US approach would seem to bypass the Authority and UNCLOS more generally. Campaign groups, such as the Deep Sea Conservation Coalition, have called on governments to establish a moratorium on deep-sea mining.

Meanwhile, there are environmentally damaging activities that should be banned but remain legal. For example, analysis by environmental campaign and research group DeSmog shows companies have been dumping toxic and radioactive oilfield waste in the North Sea for decades. In 2022, the last year for which reporting is complete, oil and gas companies operating in the territorial waters of Denmark, the Netherlands, Norway and the UK dumped over 244 million cubic metres of ‘produced water’ – that can contain dangerous chemicals from drilling and production operations – into the North Sea.

According to DeSmog, records from the Protection of the Marine Environment of the North-East Atlantic Commission show that, in 2022, around 181,000 tonnes of chemicals used by the offshore oil and gas industry were discharged into the Northeast Atlantic, with the majority going the North Sea. These toxic chemicals kill most sea life they come into contact with.

Plastic peril

Experts say that one of the key structural weaknesses of international environmental law relates to plastic pollution. Oceans are by far the world’s largest dumping ground for plastic, which accounts for at least 85 per cent of total marine waste. Some estimates suggest that by 2050, there could be more plastic in the sea than fish.

Julio Reyes is a Legal and Environmental Manager at Chilean water company Aguas Nuevas. ‘Controlling marine plastic pollution is becoming increasingly necessary, especially the need for these measures to be adopted multilaterally. Traditional international regulations, especially related to transport, fishing, mining and maritime exploitation, have proven insufficient,’ he says.

For example, says Reyes, Vice-Chair of the IBA Water Law Committee, the London Dumping Convention originally represented a major step forward in establishing rules to control a series of activities that were once common but are extremely harmful to marine ecosystems. However, this instrument has become less effective since much of the waste found in the sea now originates from land-based sources – a result of the increasing use of synthetic materials and highly durable plastics.

The UNCLOS did establish a broad principle for the protection of ecosystems, obliging signatories to prevent, reduce and control pollution of the marine environment, regardless of its source. The Convention also covers pollution caused by incidents or activities under the jurisdiction or control of signatories from extending beyond the areas over which they exercise sovereignty – which includes land-based sources such as rivers, estuaries and drainage structures.

In August, meanwhile, representatives from 184 countries met in Geneva for the latest round of talks on the creation of a UN treaty to address plastic pollution. The negotiations were intended to agree a pathway to reduce the exponential growth of plastic production and place global, legally binding controls on toxic chemicals used in its manufacture. Every year, the world makes more than 400 million tonnes of new plastic – and an estimated 11 million tonnes end up in lakes, rivers and seas annually, according to UN statistics.

He believes that in order to best manage and control plastics, special standards should be established, which are adapted to the specifics of this type of material. ‘On the one hand, we cannot deny [the] growing and essential importance [of plastics] in the modern economy,’ says Reyes. ‘On the other hand, their long shelf life, inability to biodegrade, and health risks – especially when they degrade as microplastics – require the adoption of specific measures to avoid greater impacts on ecosystems, especially maritime ones.’ He adds that while establishing international regulations is complex, ‘especially because it involves changing the status quo […] setting ambitious goals can be a good way to break the inertia of the international community.’

Alexandra Harrington was involved in the negotiations in Geneva as Chair of the International Union for Conservation of Nature’s World Commission on Environmental Law Agreement on Plastic Pollution Task Force. She believes the lack of a deal is not the failure it has been presented as, highlighting that the one existing international agreement solely dedicated to removing plastic waste from the oceans – a series of amendments to the Basel Convention – was only adopted in 2019. Trying to build on that so soon, then, ‘reflects a quicker turnaround – as well as a willingness to address the problem – than many people have assumed,’ says Harrington.

According to a statement published by the campaign group the Environmental Justice Foundation, released after the adjournment of the negotiations, ‘the overwhelming majority of nations in Geneva pushed for real solutions to the plastics crisis.’ The Foundation outlined how 57 countries called for toxic-free reuse, refill and repair systems, while 89 wanted a reduction in plastic production. Meanwhile, 120 countries demanded substantial controls on chemicals.

In February, the UN body tasked with negotiating the treaty to end plastic pollution met to elect a new chair to lead the process – an essential move in order to restart the talks.

Harrington adds that following the negotiations in Geneva, ‘countries have a much better understanding of what is needed, what the concerns are of the key oil producing countries, and that an agreement of some sort is much more likely next time around.’ Talks are expected to resume later in 2026, she says. ‘It is not unusual for some international treaties to take decades to agree, ratify and put into effect,’ says Harrington. And, she says, it is encouraging that that there is likely to be an agreement in place to cut plastics pollution so soon after the last one.

Neil Hodge is a freelance journalist and can be contacted at neil@neilhodge.co.uk

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