The Unfolding Crisis: Key Drivers of Aquatic Biodiversity Loss

The decline in aquatic life is a global emergency. In Europe, for instance, most protected marine habitats and species are in poor or bad shape, with two-thirds of species under the EU Habitats Directive falling into this category.[1] What’s causing this?

• Overfishing and Destructive Fishing: Unsustainable fishing practices, like bottom trawling that decimates habitats, and bycatch (accidental capture of non-target species like dolphins and turtles) are emptying our oceans.[2] While some European fish stocks in the North-East Atlantic show improvement, the Mediterranean and Black Seas remain critical.[1]
• Pollution: Our waters are choking on pollutants. Plastic waste, from nets to microplastics, entangles and is ingested by marine life.[2] Chemical pollutants from farms and industries, along with oil spills, poison aquatic food webs.[2] Nutrient pollution fuels harmful algal blooms and creates oxygen-depleted “dead zones.”[1, 2] Even underwater noise and light pollution cause disruption.[1]
• Climate Change and Ocean Acidification: Oceans absorb excess heat and CO2​, leading to warmer waters and increased acidity.[2] This is devastating for coral reefs, home to about 25% of all marine life, causing widespread bleaching. Acidification also hinders shell-forming creatures like corals and mollusks.[2]
• Habitat Destruction: Coastal development for cities, tourism, and aquaculture is wiping out critical habitats like mangrove forests, seagrass beds, and coral reefs. Seagrass meadows are vanishing at an estimated 7% per year globally.[2]
• Invasive Species: Non-native species, often hitching rides in ship ballast water, can outcompete or prey on native organisms, wrecking local ecosystems.[2]
• Wildlife Trade: The illegal and unsustainable trade in marine wildlife for food, shells, or pets severely threatens species like sea turtles and sharks.[2]

These threats don’t act alone; their combined force erodes ecosystem resilience. This disrupts food webs, threatens the livelihoods and food security of coastal communities, and diminishes the ocean’s ability to provide essential services like climate regulation and coastal protection.[1, 2]