This article aims to shed light on the most pressing dangers endangering marine ecosystems today and explores how these threats interconnect, compounding the challenges faced by marine life worldwide. Furthermore, it offers practical tips from climate advocates on how individuals can contribute to protecting our oceans. By understanding the scale of the problems and adopting responsible habits, we can all play a role in preserving the health of our seas for future generations.

Threat 1: Warming Seas

Since the 1970s, human activities have caused the world’s oceans to warm, with the seas absorbing more than 90% of the excess heat generated by climate change. Additionally, around 20–30% of human-produced carbon dioxide emissions have dissolved into the oceans. When CO₂ dissolves in seawater, it forms carbonic acid, which lowers the pH and causes ocean acidification. The damaging effects of both warming and acidification are already clearly visible in tropical coral reefs. In fact, even if global warming is limited to 1.5 degrees Celsius as outlined in the Paris Agreement, nearly all coral reefs are expected to vanish.

Threat 2: Island Communities and Coastal Areas in Danger

In 2024, sea level rise was greater than expected; according to an analysis by NASA, the rate of increase last year was 5.9 millimeters per year — 1.6 millimeters more than previously estimated. Overall, global sea levels have risen by 10 centimeters since 1993, when satellite measurements of sea level began.

The rising sea level increases the risk of extreme weather events, and many coastal areas are experiencing more frequent tidal flooding. The most at risk are small, low-lying island nations, such as Fiji and the Solomon Islands in the Pacific Ocean. For these island communities, sea level rise is an existential threat.

Threat 3: Oceans as Dumping Grounds for Waste

Marine pollution is primarily caused by plastic waste, oil spills, chemicals, and wastewater. In addition, population growth—along with the increasing demand for raw materials and consumer goods—has led to a continuous rise in maritime traffic. Shipping contributes to environmental harm by emitting pollutants into the air and sea, as well as increasing litter and underwater noise.

Plastic Waste in the Ocean Doesn’t Disappear

The amount of plastic entering the oceans has increased significantly due to rising plastic production and consumption. It is estimated that 14 million tons of plastic end up in the oceans each year, with the majority originating from single-use products. Large plastic debris harms marine animals primarily through entanglement, ingestion, and exposure to toxic chemicals. These impacts are particularly severe for large marine species such as sea turtles, sharks, and rays. Smaller plastic particles, when ingested, can cause internal blockages and physical damage to marine organisms. Even if all plastic emissions were to stop today, the concentration of microplastics in the ocean would continue to increase for decades to come.

The Environmental Impact of Growing Maritime Traffic

Although emissions from ships are largely regulated internationally—especially concerning hazardous waste—some harmful discharges are still permitted. For example, the discharge of greywater is not regulated by international legislation. Greywater includes wastewater from kitchens and showers, which contains pollutants such as detergents, grease, heavy metals, and pesticides.

Furthermore, the increasing volume of oil and chemical transportation by sea raises the risk of accidents in marine areas. Oil and chemical spills can cause long-lasting and severe damage to marine ecosystems. Without stricter regulations, growing maritime traffic will likely lead to an increase in wastewater discharges, oil spills, and chemical leaks into the oceans.

Threat 4: Overfishing Is Emptying the Oceans

As a result of population growth, the demand for food from the ocean has increased significantly. In the 1960s, the average consumption of aquatic food per person was 9.9 kilograms, while by 2020 it had risen to 20.2 kilograms per person. This growth is primarily driven by technological advancements in fishing methods, rising income levels, urbanization, and shifting dietary trends. However, this increased demand has led to unsustainable fishing practices. In 1974, around 90% of fish stocks were considered biologically sustainable, but by 2019, that figure had dropped to just 64.6%.

The fishing capacity of modern fleets far exceeds the natural reproduction rates of most fish species. In addition to overfishing, marine ecosystems are also threatened by destructive and illegal fishing practices. It is estimated that illegal, unreported, and unregulated (IUU) fishing accounts for around 20% of the global fish catch, and in some regions, up to 50%.

Among the most destructive methods are the use of cyanide and explosives, which, fortunately, are banned in most parts of the world. However, some legal fishing methods still cause significant damage. One such example is bottom trawling, in which heavy nets are dragged along the seafloor, destroying habitats and marine biodiversity.

Combined Impacts Make the Problem Worse

Marine organisms may have the ability to adapt to individual threats, such as ocean acidification or rising temperatures. However, the likelihood of species surviving multiple simultaneous environmental pressures is significantly reduced.

Tips from Climate Advocates on How to Help Save the Oceans

1. Eat Responsibly

Since overfishing is one of the major threats to our oceans, adopting a more plant-based diet is a great way to support ocean health. Try to choose plant-based options more often and prioritize locally sourced food. If giving up fish completely feels difficult, you can still make a difference by being mindful about the seafood you consume. Make sure your choices do not unintentionally support overfishing or illegal fishing practices. A helpful tool for making responsible seafood choices is the WWF Seafood Guide, which is available in several countries.

2. Consume Less and Recycle

As with many environmental issues, consuming less also benefits the state of our oceans. Pay attention to your carbon footprint and consumption habits. Buy less, recycle, and repair. Even if repairing a product would be more expensive, it is often the better option for the environment. For example, taking shoes to a shoemaker also supports local businesses, and doing repairs yourself can help you learn new skills.

3. Reduce littering

Did you know that over 80% of ocean waste originates from land? Even recycled trash doesn’t just disappear — it can persist in the environment long after being thrown away. For the health of our oceans, it’s especially important to sort your waste correctly and take hazardous materials to proper collection points. It’s also a good idea to avoid buying unnecessary single-use products whenever possible.

4. Be Aware of Your Plastic Use

Try to reduce your plastic consumption in everyday life — most plastic waste comes from single-use items like bottles, bags, and packaging. You can help by using a reusable water bottle, choosing unpackaged food items, and carrying a reusable shopping bag and produce bags with you.

When it comes to clothing, opt for natural materials instead of synthetic fibers like acrylic or polyester, as these release microplastics when washed. Also, choose cosmetics and toothpastes that are free of microbeads to prevent plastic particles from entering waterways.

5. Avoid Unnecessary Chemicals in Daily Life

By choosing biodegradable and eco-friendly household products, you can significantly reduce the chemical load in your daily life. Also, be mindful with the use of fertilizers in your garden or vegetable patch, as excess nutrients can be washed into waterways and harm marine ecosystems.

6. Support Ocean Conservation Efforts and Spread Awareness about Ocean Issues and Climate Change

Individual actions alone are unfortunately not enough. Protecting our oceans requires addressing the root causes through legislation and international agreements. Share information about the challenges facing the oceans with those around you and encourage your friends and family to take action. Also, hold policymakers accountable by demanding that they prioritize ocean protection and implement effective measures.

Additional tip: Travel and get to know oceans

Get to know the world below the surface now when it is still possible. Snorkel, boat, go diving. For instance, scuba divers are often those who speak the loudest for marine life. However, remember to always make sure that the companies you support do their work in a responsible manner.

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