The Muri Lagoon is a

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

in the district of

Ngatangiia Ngatangiia is one of the five districts of the Cook Islands, districts that make up the island of Rarotonga in the Cook Islands. It is located in the east of the island, to the south of the districts of Matavera and Avarua, and northeast of the d ...

on the eastern coast of

Rarotonga Rarotonga is the largest and most populous of the Cook Islands. The island is volcanic, with an area of , and is home to almost 75% of the country's population, with 10,898 of a total population of 15,040. The Parliament of the Cook Islands, Coo ...

in the

Cook Islands The Cook Islands is an island country in Polynesia, part of Oceania in the South Pacific Ocean. It consists of 15 islands whose total land area is approximately . The Cook Islands' Exclusive Economic Zone (EEZ) covers of ocean. Avarua is its ...

. The lagoon is a significant tourist attraction and the largest tourism revenue earner in the Cook Islands, accounting for 25% of tourism bed usage on Rarotonga. In 2015 the Cook Islands government declared the environmental condition of the lagoon a national disaster.

Geography

The lagoon is approximately wide has a maximum depth of . It is bounded on the north by Ngatangiia harbour, and the south by the ''motu'' of Taakoka. It contains three small islets or ''motu''. From north to south, the islets are: #Motutapu, #Oneroa, #Koromiri, The islet of Taakoka () forms the southern boundary of lagoon. The Avana and Turangi streams both flow into the lagoon. Water circulation is driven by waves breaking across the reef, with outflow through the Ngatangiia Harbour.

Pollution

The lagoon is heavily polluted, with nitrogen from agricultural runoff and leaking septic tanks leading to the growth of noxious seaweed and decreased water visibility. In 2015 the Cook Islands government declared the environmental condition of the lagoon a national disaster. In 2016 the Cook Islands Chamber of Commerce began a program to scrape algae from the bottom of the lagoon. In 2019 the government proposed a centrally-operated wastewater system to reduce the supply of nutrients. In December 2020 the lagoon suffered an

anoxic event An anoxic event describes a period wherein large expanses of Earth's oceans were depleted of dissolved oxygen (O2), creating toxic, euxinic ( anoxic and sulfidic) waters. Although anoxic events have not happened for millions of years, the geol ...

, and local residents were warned to avoid swimming or harvesting seafood from the area.

References

{{reflist Landforms of the Cook Islands Rarotonga