What is the Mediterranean Sea marine ecoregion?
The Mediterranean Sea is a semi-enclosed marine region with strong seasonal contrasts, unique biodiversity, and intense human pressure. Its geography makes it both ecologically rich and highly sensitive to environmental change.
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In context
What it is
The Mediterranean Sea is a semi-enclosed marine region with strong seasonal contrasts, unique biodiversity, and intense human pressure. Its geography makes it both ecologically rich and highly sensitive to environmental change.
It is a warm, salty and mostly enclosed sea with strong east–west differences in nutrients and productivity. Its varied coastlines, seagrass meadows, reefs, deep habitats and islands support exceptional biodiversity, while limited exchange with the Atlantic makes the system sensitive to warming, pollution and biological invasions.
Why it matters
The Mediterranean supports fisheries, tourism, shipping and the livelihoods of hundreds of coastal communities. Endemic species and habitats such as Posidonia oceanica meadows provide nursery grounds, coastal protection and carbon storage. Its long observation history also makes it an important indicator of rapid ocean change.
FAQ
Why is Mediterranean water so salty?
The region loses more freshwater through evaporation than it receives from rain and rivers. Atlantic water enters at the surface through Gibraltar, becomes saltier and denser as it moves eastward, and some of it eventually returns toward the Atlantic at depth.
Why are invasive species increasing?
Species arrive through shipping, aquaculture and especially the Suez Canal. Warming conditions allow many warm-water species to survive and spread, particularly in the eastern Mediterranean, where they can alter food webs, habitats and fisheries.
Ocean Literacy Connections
This resource can be explored through One ocean, many features and Ocean and humans.
- How do different ocean places belong to one connected system?
- How does the ocean affect our lives, and how do our choices affect the ocean?
Explore and connect
Open the Mediterranean region and compare ecosystem context with species, spill events, and climate-related layers.
