Hutt Lagoon is a marine salt lake located near the Indian Ocean coast 2 kilometres (1.2 mi) north of the mouth of the Hutt River, in the Mid West region of Western Australia. Hutt Lagoon is an elongate lake that sits in a dune swale adjacent to the coast.

The town of Gregory is located between the ocean and the lake's southern shores. The road between Northampton and Kalbarri, George Grey Drive, runs along its eastern edge.

The lake is about 14 km (9 mi) in length along its northwest-southeast axis, parallel with the coast, and around 2.3 km (1.4 mi) wide.

Hutt Lagoon comprises most of the Hutt Lagoon System, a DIWA-listed wetland system that also takes in a number of adjacent small lakes, such as Utcha Swamp. Hutt Lagoon is a pink lake, a salt lake with a red or pink hue due to the presence of the carotenoid-producing algae Dunaliella salina, a source of ß-carotene, a food-colouring agent and source of vitamin A. 

The lagoon contains the world's largest microalgae production plant, a 250-hectare (620-acre) series of artificial ponds used to farm Dunaliella salina. The Dunaliella salina plant producing the valuable carotenoid β-carotene from this alga. The plant is located in Hutt Lagoon, north of Geraldton.

According to en.wikipedia