The lake is the largest in South America, stretching from Peru to Bolivia across a 12000sq km shoreline, and yet, it only holds four native species which constitute a substantially small fish population. The most commonly known species is the endemic Titicaca Orestias, but there are also Bartram’s Sprinkled Darter, a species of small South American catfish and the Piranha. All four species populate the lake but in limited numbers, only 40 metric tons of the Titicaca Orestias are produced each year.
In the early 1900s, scientists collected countless samples from Lake Titicaca in hopes of finding more species. The species of Orestias found in the lake indicated an evolution process, but researchers were unable to discover any more. Initially, experts suggested that the shallow depths of Lake Titicaca may have had something to do with the lack of diversity, as usually species have a more complex diversity in deep-water bodies with lower light levels, however, this assumption is yet to be confirmed.
It is probable that, historically, Lake Titicaca was home to many fish species before the influx of predators and fisherman to the region. Nowadays, fishing only occurs by permit and the main stronghold of conservation is mainly the Bolivian side of the lake, as the Peruvian authorities ignore regulations, favouring fisheries industrialised catch. Additionally, non-native species are entering the ecosystem and deteriorating the environment and the native species, this could also be responsible for the decline of fish diversity.
Effects of increased Fishing
Since the introduction of intensive fishing and pollution from the 20th century, the fish population in Lake Titicaca has been greatly reduced in both quantity and size. The shallow depth of the lake and its associated habitats favour the growth of several exotic fish species, and unfortunately due to the lack of resources and legal enforcement, much of the lake is being overfished. This impacts both native and exotic species, with the native species feeling more of the brunt due to the lack of understanding, awareness and resources by the local people. Introducing fishing and artificial fertilizers is seriously damaging the ecosystem, which in turn is depleting the food supply and destroying the already fragile population of native fish.
In an effort to conserve the lake’s native fish, the Bolivian government has implemented several protective measures. These include an increase in surveillance and enforcement of fishing restrictions, the closure of overfishing areas, and a collaborative research project studying the lake for several years now. However, this hasn’t been enough and the declining numbers of fish remain a major threat to the lake and its human inhabitants.
High Altitude Challenges
Apart from the devastating human actions, the lake also faces ongoing challenges due to its high altitude and extreme environmental conditions. Being almost 4,000 meters above sea level and with temperatures as low as -19 degrees celsius, the lake creates a harsh habitat for species to survive. Also, the water is highly oxygen-depleted and with decreased levels of oxygen, fish struggle to stay alive and thrive there.
Furthermore, human activity has exacerbated the natural process. Pollution, in the form of fertilizers and chemical run-off, has contaminated the water and destroyed the already fragile population of native fish and invasive species. This has had an even greater effect as Lake Titicaca is a closed, landlocked lake, meaning that water is not able to be replaced naturally
Conservation Efforts
Thankfully, there have been conservation initiatives put in place by both local and international governments in efforts to stimulate the ecosystem. These include controlled fishing, introduction of hatcheries and artificial fish stocking, initiatives to increase awareness and implementation of eco-tourism activities. Nevertheless, the introduction of fish has raised questions of creating hybrid species, as well as introducing a certain level of pollution into the lake.
Governments have also implemented legislation settings to limit the amount of rentable fishing boats, set limits on the number of fish collected, and prevent the introduction of competing and non-native species. The Bolivian government has also taken an active role in the monitoring and enforcement of these regulations by providing financial support and community involvement.
Invasive Species
While researchers are focusing on conservation, the effects of non-native species on the ecosystem cannot be overlooked. Several exotic species from around the world are present in Lake Titicaca, such as catfish, trout, and carp. These species compete for resources and threaten the fragile population of native fish. These factors combined have created an environment where it is very difficult for the native species to reproduce, as they have to compete with more voracious invasives for food and habitat. To stop the spread of invasive species, monitoring programmes are essential to ensure they are not brought in and to remove any that have been introduced.
Impact of Human Activity
Perhaps the most worrying issue is the extent to which humans are damaging the lake. Increasing coastal use, dam construction and urbanisation are all having a significant impact on the lake’s fragile environment, by releasing pollutants such as fertilisers and pesticides into the water. This further affects the fish, leading to a decrease in both survival and reproductive rates.
In addition, the growing demand for land and water for farming, industry and tourism is placing significant pressures on the lake’s already fragile ecosystem. The lake’s fragile ecological balance will only be endangered further if human activities are not regulated or monitored more closely.
The Future of the Fish Population
Lake Titicaca has the potential to become a haven for many fish species, with adequate protection, legislation, research and resources. However, it is future needs to be safeguarded and managed carefully in order to maintain its biodiversity.
In order to preserve this high-altitude lake, there needs to be a clear and definitive set of regulations in place and resources allocated to enforce them. Further research needs to be conducted and more accurate data needs to be collected, in order to gain a better understanding of the lake and its inhabitants.
Lastly and perhaps most importantly, government in both Peru and Bolivia must commit and collaborate to ensure long-term sustainability for the lake, its fish population and its human inhabitants. Only with a cohesive effort can the future of the lake be secured and the native fish population be protected.
