Oceanerna

Oceanerna (the oceans) are the interconnected system of saltwater bodies that covers about 71% of Earth’s surface. The term is used to refer collectively to five principal basins: the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. These waters form one global ocean with distinct basins but widespread hydrological and ecological connectivity.

Physical characteristics: The ocean is on average 3,700 meters deep; average salinity around 35 practical salinity units. It contains currents, waves, tides, and thermohaline circulation, a global conveyor belt that transports heat and nutrients between surface waters and the deep ocean.

Habitats and life: The oceans host a vast range of ecosystems from shallow coastal zones to the dark abyss. Coral reefs, mangroves, kelp forests near coasts, and open-ocean and deep-sea habitats support biodiversity. The ocean acts as a major carbon sink and supports diverse life forms.

Human reliance and pressures: The oceans provide food, oxygen, climate regulation, transportation routes, and energy resources. They face threats including overfishing, habitat destruction, pollution, climate change, warming, sea-level rise, acidification, and plastic pollution.

Conservation and knowledge: Ocean research informs navigation, weather forecasting, and policy. International cooperation governs maritime zones and resource management. Ongoing efforts aim to protect biodiversity, reduce pollution, and sustain fisheries, as well as to understand and adapt to climate-related changes.