Many international aviation companies use Estonian airspace for transit passage, and a lot of Russian oil is exported to the world via Estonian terminals.
During migration periods, Estonia is a cross point for arctic waterfowl along the East-Atlantic Flyway of migration. According to estimates, up to 50 million water- and coastal birds pass the Estonian coasts during migration time.
The abundance of coastal wetlands makes Estonia extremely attractive for waterfowl. A lot of them would stop here to build up their resources for the long journey to their breeding grounds in Russian arctic. At the peak time in two first decades of May every small inlet swarms with ducks, geese and swans.
Most well-known coastal wetland in Estonia is Matsalu. This large bay surrounded with various coastal habitats - coastal, alluvial and wooded meadows, reed-beds and islets offers favourable conditions for migrating and breeding waterfowl. During spring migration over 2 millions of waterfowl are supposed to pass Matsalu area. Vast majority of these are long-tailed ducks and other arctic diving ducks. Besides diving ducks there are about 10-20 000 Bewick's Swans (almost whole population of this species passes Estonia, although in last decades these birds have found different feeding locations in Estonia) about 20 000 Barnacle Geese and more than 10 000 Bean and White-Fronted Geese and thousands of waders can be seen here.
Autumn migration in Matsalu is less numerous - over 300 000 waterfowl are estimated to pass Matsalu area by that time. Most spectacular sight in autumn are huge flocks of Common Cranes feeding on fields of the area and gathering to overnight in the sheltered areas of wetland. In 80-ies up to 21 000 cranes were counted in Matsalu, nowadays their numbers have decreased more than twice - in pace with decreasing of the area of fields after the era of high input - low output soviet agriculture became over.
Although Matsalu is the biggest coastal wetland, there are many other smaller but also very important coastal wetlands attracting both migrating and breeding Waterfowl. Some of them - like Vilsandi, Puhtu, Käina bay and Hiiumaa islets are designated as wetlands of international importance (Ramsar areas), still more (Laidevahe, Silma, Väike Väin strait) are in a shadow-list for that.
Main threat for coastal wetlands nowadays is not overexploitation but rather abandoning and undermanagement. Estonian government has recently launched a program for subsidizing the management of seminatural habitats incl. coastal wetlands. Far more serious concern is increasing oil transit, oil spillages and accidents in Baltic. This especially dangerous for the waterfowl wintering in Estonian waters - a.o. to 2000-6000 Stellers' Eiders spending regularly their winters at western coast of Saaremaa.