[2] Matsalu Bay is one of the most important wetland bird areas in Europe, due to its prime position on the East Atlantic Flyway.

[6] Matsalu National Park covers a total area of 486.1 km2 (187.7 sq mi), encompassing Matsalu Bay along with the delta of the Kasari River and its surrounding areas — floodplains, coastal meadows, reedbeds, woodlands, wooded meadows, and the section of Väinameri around the mouth of the bay, which includes more than 50 islands.

[6] Reeds and rushes surrounding the main channel expand westwards up to 100 m (328 ft) every year.

[6] The rivers carry large quantities of nutrient-rich sediments into the bay from an over 3,500 km2 (1,350 sq mi) drainage basin.

[4][5][7] Every spring over two million waterfowl pass Matsalu, including 10,000—20,000 Bewick's swans, 10,000 greater scaups, common goldeneyes, tufted ducks, goosanders and many others.

[13] Matsalu Nature Reserve was founded in 1957, mainly to protect nesting, moulting and migratory birds.

[16] The European Diploma of Protected Areas was awarded to Matsalu Nature Reserve in 2003 by the Council of Europe, in recognition of the park's success in preserving the diversity of habitats and the numerous species of birds and other biota groups in the nature reserve.

[4][5][15] Matsalu has seven bird-watching towers (Penijõe, Kloostri, Haeska, Suitsu, Jugasaare, Küdeva and Keemu) and three hiking trails.

[23] In 2007, organizers of the Matsalu International Nature Film Festival received the Environmental Award of the Year from the Estonian Ministry of Environment.

The ministry pointed out persistent and successful organization of the film festival over the years, which has popularized nature protection and contributed significantly to environmental awareness.