Santa Cruz River Estuary

The Santa Cruz River Estuary is located in the province of Santa Cruz, along the Atlantic coast of Patagonia. The area covers a total of 30,000 hectares and includes municipal, provincial and private lands. Much of the southern edge of the estuary is within the city limits, including the North and South Urban Nature Reserves (UNR). Within the estuary is the Leones Island, a scientific use area under special protection, whose enforcement authority is the Dirección de Áreas Protegidas del Consejo Agrario Provincial (Protected Areas Directorate of the Provincial Agricultural Council). In addition, the estuary has sectors that have been declared Natural Heritage Areas, including the waterfront from the confluence of the Chico and Santa Cruz Rivers to its mouth, the penguin colony at Punta Entrada, and the Leones Islands. The responsible entity for the entire area is the Provincial Secretary of the Environment (SEA).

The Santa Cruz River Estuary has been designated a WHSRN Site of Regional Importance for the presence of more than 1% of the biogeographic population of the Magellanic Oystercatcher (Haematopus leucopodus). The species is present in the area throughout the year, with high numbers in the austral winter when it is concentrated during the non-breeding season. The last highest count was a flock of 929 individuals in April 2021, representing 1,47% of the total population. Based on historical data from 1999-2000, between 700 and 1,200 individuals were estimated for the area during surveys, indicating that high numbers are regularly recorded during the non-breeding season and that the area is an important wintering area for the species.

The WHSRN site provides habitat for a wide variety of resident, Patagonian migrants, and Nearctic migrant birds. It is also recognized as an Important Bird Area (AR268 – Santa Cruz River Estuary) for its importance for the Hooded Grebe (Podiceps gallardoi), Magellanic Penguin (Spheniscus magellanicus), and several species of seabirds.

The site is home to several endangered species with different national conservation status, including the Magellanic Penguin (Vulnerable), which nests in the penguin colony adjacent to Punta Quilla, the Chilean Flamingo (Phoenicopterus chilensis) (Vulnerable), the Darwin’s Rhea (Rhea pennata) (Endangered), and the Upland and Ashy-headed Geese (Chloephaga picta and Ch. Poliocephala) (Endangered). Leones Island also an important nesting site for the Imperial Cormorant (Leucocarbo atriceps) and the Flying Steamer Duck (Tachyeres patachonicus). However, these two species are not considered to be of conservation concern.

Currently, the management of the urban nature reserves within the WHSRN site is the responsibility of the Environmental Department of the City of Puerto Santa Cruz. Recent actions include the installation of a perimeter fence in the northern sector of the WHSRN site, the design of interpretive and informative signage, and monitoring to inventory bird species and the main threats at the site.

In the future, it will be important to continue the community assessment of urban nature reserves, the installation of interpretive and informative infrastructure, and the development of participatory workshops to raise awareness of the importance of the estuary and to learn about current ecosystem uses and needs.

Threats identified for the Santa Cruz River estuary include domestic waste, domestic animals, military activities, aggregate mining, and artisanal and commercial fishing. The highest concentration of garbage is found mainly in the North UNR, which comes from an open, unregulated landfill adjacent to the reserve. Currently, Puerto Santa Cruz has a municipal waste treatment plant, but it is not regularly used. The Province is implementing a program to eradicate open-air dumps, which includes intervention in the city, which contributes to the current conditions of the estuary.

The Navy is located about 200 meters from the southern edge of the South UNR, where military exercises are conducted. The use of ammunition and associated noise disturbs the local fauna.

Boulder mining is carried out sporadically by the municipality and the community itself, mainly in the North UNR. The extraction site is located on a beach used by the Magellanic Oystercatcher for resting and feeding.

In addition to these current threats, there are several potential threats including unregulated tourism, the construction of dams on the Santa Cruz River, and climate change. None of the protected areas in the Puerto Santa Cruz Estuary currently have regulations that govern tourism activities. The Tourism Department of the Municipality of Puerto Santa Cruz is promoting regulation and coordination among the different agencies involved in the Estuary.

The municipality of Puerto Santa Cruz has approximately 4,431 inhabitants, including a community of indigenous people who live in the city. They belong to the Mapuche-Tehuelche community called “Lof Fem Mapu”, which conducts internal activities, some of which have been developed in a sector of the South UNR allotted to their community.

In the city of Puerto Santa Cruz, there are no independent groups whose objectives include the protection or conservation of local biodiversity. However, the Municipality promotes different activities for the enhancement and use of the Estuary resources. Activities include creation of nature reserves, tourist cruises, promotion of the penguin colony, infrastructure for fishing, and other activities.

From 2018 to date, the Asociación Ambiente Sur has collaborated with the Municipality of Puerto Santa Cruz in the development environmental education activities to raise awareness of biodiversity and conservation concerns. Activities include the Hooded Grebe Festival and the Shorebird Festival, which are held annually in the municipality.