Laguna de Rocha is a 7,200 hectare lagoon of great beauty. It is home to more than 200 species of birds, among them 6% of the global population of the buff-breasted sandpiper (Calidris subruficollis), so it is one of the most important conservation sites for this species in the world. There is also a large concentration of American golden plovers (Pluvialis dominica), and at least 20 more species of shorebirds.
Among the near threatened and vulnerable species recorded in the lagoon area are the black-and-white monjitas (Xolmis dominicana), Olrog’s gull (Larus atlanticus), the Chilean flamingo (Phoenicopterus chilensis). Its population of black-necked swans (Cygnus melanchoryphus) is one of the most important in the world.
Around the coast there are patches of psamophile scrub, formed by spine of the cross (Colletia paradoxa) and Peruvian pepper (Schinus molle), together with cereus, opuntia, hopseed bushes (Dodonaea viscosa), Lithraea molleoides and (Myrsine laetevirens). Various cacti are found, and also Ephedra tweediana, the only native gymnosperm shrub.
As to native mammals, brocket deer (Mazama gouazoubira), foxes, neotropical otters (Longra longicaudis), giant otters (Pteronura brasiliensis), capybara (Hydrochoerus hydrochaeris), the wildcat Leopardus geoffroyi and tucotuco (Ctenomys pearsoni). Their distribution and population figures are unknown.
Other vulnerable species include the toad Melanophryniscus montevidensis.
Laguna de Rocha is another area of importance for conservation. It is listed by Ramsar as laguna de Rocha fue reconocida como área de relevancia nacional e internacional para la conservación. Integra desde 2015 el listado de humedales con relevancia internacional que elabora la Convención Ramsar, and BirdLife International recognises it as an IBA under code UY019. Is is also a designated WHSRN site, and a UNESCO Biosphere Reserve.