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Seas

Seas and enclosed basins where water chemistry and human use intersect.

3 records
Dead Sea

The most saline large water body in the world and the lowest land elevation on Earth. It is shrinking rapidly because the Jordan River, its only significant inflow, is now almost entirely …

Mediterranean Sea

A nearly enclosed sea where evaporation greatly exceeds river inflow and precipitation, making it saltier than the Atlantic and driving a permanent inflow of Atlantic water through the Str…

Baltic Sea

The largest brackish water body in the world, and one of the most severely eutrophied. Its restricted exchange with the North Sea means nutrients and oxygen depletion persist for decades.

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Hydrionis is an evidence-led water intelligence resource. Every figure carries its source, its method and its licence. Where Hydrionis does not hold a value, it says so rather than estimating one.

Hydrionis presents scientific and regulatory information for general reference. It is not medical, legal or engineering advice. Drinking water standards are jurisdictional: a limit applies only where it was made. For a concern about the water at your own property, contact your water supplier or the relevant regulator.

Data is drawn from public and open sources under their respective licences. Contains public sector information licensed under the Open Government Licence v3.0. Contains modified Copernicus service information. Country outlines derived from Natural Earth (public domain).

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