For much of human history, it was assumed that all life depended, directly or indirectly, on the sun. Plants absorbed sunlight through photosynthesis, herbivores ate the plants, and predators ate the herbivores. Each step in the food chain was based on solar energy.
But, in 1977, that notion was turned on its head.
Alive in ways we are only beginning to understand, it is pumping, filtering, sensing, repairing, coordinating.
A sponge survives by moving water. Through thousands or even millions of tiny pores, it draws seawater into its body. Specialised cells beat microscopic hairs that create a continuous current, bringing oxygen and food particles inside. A sponge the size of a football can filter thousands of litres of seawater in a single day.
At the heart of this system lies one of the great mysteries of modern oceanography: the global “thermohaline circulation,” also known as the Atlantic Meridional Overturning Circulation, or AMOC. Scientists are still trying to understand just how stable it is.
In this dim layer, life has taken extraordinary forms. Many creatures are small and transparent, some studded with lights of their own. Lanternfish, hatchetfish, and comb jellies shimmer like stars, using bioluminescence to confuse predators or to signal one another in the gloom. Shrimp flash warning pulses, squid glow along their arms, and gelatinous drifters flow through beams of pale blue light.
Rising ocean temperatures endanger coral reefs, fish and entire ecosystems. Misinformation campaigns stall climate action. However, reducing emissions and protecting habitats can still prevent catastrophic biodiversity loss and ensure a sustainable marine future. Ila France Porcher separates the myths from the facts about the oceanic crisis and global warming.
Beneath the waves, sound travels faster and farther than in air, making it the ocean’s primary language. Whales sing long, complex songs that can carry across entire ocean basins. Dolphins click and whistle in rapid-fire exchanges. Fish croak, drum, squeak and hum. Even tiny crustaceans—snapping shrimp—produce crackling noises so loud that they can mask submarine propellers.
The Kunming-Montreal Global Biodiversity Framework has emphasized the need to urgently address the growing risk of species extinction and ecosystem collapse. The framework calls on global leaders to take steps to reduce human-induced stressors, improve ecosystem integrity, and ensure the sustainability of nature’s contributions to people.
Healthy Seas teamed up with Ghost Diving and SDSS for a third consecutive year, bridging environmental and historical conservation, with the support of Hyundai Motor Europe that is providing funding for the implementation of Healthy Seas cleanup and education activities around the world since 2021.
