Loutre de mer

The major threats derive from an intensive urbanization of western South America, where the immense anthropogenic pressure on the coastal ecosystem is leading to accelerated habitat degradation and increased fragmentation (Brownell 1978, Eisenberg and Redford 1989, Sielfield and Castilla 1999, Medina-Vogel et al. 2008, Vianna et al. 2010). Urban development conflicts with the Marine Otter’s use of the coastline. It is not yet clear at what point these fragmentation forces will cause isolation to result in local extinction events due to lack of gene flow (Valqui 2012). In any case, these global changes will trigger more specific local threats in different regions.

Human-otter coexistence must acknowledge competition for resources that humans exploit for food, commerce and housing (Moreno et al. 1984; Ostfeld et al. 1989; Moreno 2001; Medina-Vogel et al. 2004, 2007, 2008). Industrial and artisan fishing ports have been established along the Pacific coast, affecting structure and productivity of marine life communities. Although Lontra felina shows certain capacity to coexist with humans, for example in fishing ports (Valqui 2004, Ruiz 2009, Medina-Vogel et al. 2007, Mangel et al. 2010), fishing has intensified global natural declines in the abundance of many forage fishes, leading to reduced reproductive success and reduced abundance of many birds and marine mammals (Majluf et al. 2002). Additionally, Marine Otters may be persecuted and killed directly for alleged damage to local fish, bivalves, and shrimp populations (Miller et al. 1983, Redford and Eisenberg 1992, Apaza et al. 2004). The species' preference for coastal waters that offer an abundance and diversity of prey conflicts with growing small-scale fisheries. Small-scale fishermen increased 34% from 1995 to 2005, and fishing boats 54% within the same decade (Alfaro-Shigueto et al. 2010). Although there is no qualitative documentation of bycatch, there are an increasing number of reports of Marine Otters entangled and drowned in fishing nets (Mangel et al. 2011, Pizarro 2008). Illegal fishing techniques (e.g. dynamite fishing) are a frequent problem in several localities of the Peruvian coast, such as Huarmey (Valqui 2012) and Paracas (Apaza et al. 2004, Valqui 2012). Industrial ships have frequently been observed fishing closer to the coast than allowed by law (Apaza et al. 2004), perturbing the coastal habitat on a broader scale. Another threat for Marine Otter is accidental death by entanglement (bycatch) in fishing nets (Brownell 1978, Mangel and Alfaro-Shigueto 2004, Pizarro 2008) and in crab pots (Medina-Vogel et al. 2004), although the dimension of these mortality cases is unknown.

Urban development within the region results in an increase in domestic and feral dogs, cats, and rats, which can introduce infectious diseases (Mangel et al. 2011). Around human settlements, large dens with terrestrial entrances may be occupied by dogs, cats and rats, displacing the Marine Otter from its reproduction, feeding and resting areas (Apaza et al. 2003, Valqui 2012). Dog attacks are increasingly reported in several locations of the distribution (Medina-Vogel et al. 2008, Mangel et al. 2010, Vianna et al. 2010).

Releases from mining tailings and sewage into the ocean expose Marine Otters to heavy metals, pesticides and other toxic elements. Heavy metals and other toxic substances can be diffused through currents and progressively transmitted through the food chain, at least at a regional level (Valqui 2004, Apaza et al. 2004). Oil spillage and extreme noise affect the species in areas near beach resorts in the vicinity of big cities (Valqui 2004) and in several centres of industrial fishing activity like Chimbote (probably the most important fishing port on the Peruvian coast) and mining cities Ite, Ilo and Marcona in Peru (Apaza et al. 2004). Oil spills in ports are a constant impact in central Chile, generating broad damage to the ecosystems that Marine Otters inhabit. Spills of domestic effluents reach the ocean directly or through rivers (Hinrichsen 1998, Thorne-Miller 1999) and affect the Marine Otter environments.

From central to northern Chile, the need for water for industrial use and human consumption has generated the search for solutions such as desalination plants. The impact generated by this is not well studied in the case of otters and is an added concern for populations in these areas.

Chile is one of the top ten countries in aquaculture production, and the deep and long-term impacts of the industry on rivers and marine ecosystem will expose the species to bacteria, viruses and antibiotics.

Recent development plans for infrastructure, such as dams in Arequipa, may impact Marine Otter presence in the known freshwater population far from the coast (Valqui et al. 2018a, Ugarte-Nuñez 2021).

Laws protect this endangered species in Peru and Chile, but enforcement is very weak. If an otter is killed or poached, the perpetrators may be identified, photographed or filmed, and still no legal action is taken. Rules in natural protected areas such as no hunting, fishing, poaching, or trespassing are not always respected.

Global natural factors like the El Niño Southern Oscillation (ENSO) also may considerably affect the Marine Otter population (Vianna et al. 2010), due to the more or less drastic climatic and oceanographic changes that cause mortality of several marine communities from fish to mammals (Apaza and Figari 1999, Wang and Fiedler 2006).

The Marine Otter is protected in Argentina, Chile, and Peru. It is listed in Appendix I of CITES and in Appendix I of the Bonn Convention (Convention on the Conservation of Migratory Species of Wild Animals (CMS)).

The Global Otter Conservation Strategy for the species (Valqui et al. 2018b) recommends priority actions that include:

An initiative to establish a regional conservation area in southern Peru -- Area de Conservación Regional Marino Costero Morro Sama, Tacna -- was started around 2003, but effective implementation stopped in 2006 because of a change in government, and the situation has not progressed since then. The area is the only otter hotspot on the Peruvian coast (with about 88 individuals in 55 km of coast) (Alfaro and Mangel 2008). Thus, the initiative of establishing a protected area containing an otter hot spot should be supported and completed. A strategy to protect otter habitats along the entire coast, coupled with initiatives to create specific regional conservation areas, is a challenging, but ideal goal for Marine Otter protection. Thirty-four existing natural protected areas in Peru and another ten in Chile could host artificial habitats, such as wave breakers, and specially designed artificial otter habitats. These should be visibly advertised to raise awareness of the Marine Otter’s presence to local communities. A reassessment is needed concerning the construction of two hydroelectric power stations, on the Colca-Majes River and the Cotahuasi-Ocoña River, both in Peru, and inhabited by the Marine Otter. Specific mitigation measures for impacts on wildlife should be considered. Dam construction should be approved only if careful and explicit mitigation measures are put in place. An effective programme to control invasive feral dogs, cats, and rats should be developed, and should be paired with studies on prevalence of transmittable diseases, especially in populations near human settlements. In Chile, studies on disease transmission to otters are already being conducted. Environmental education programmes should be carried out, such as the one by the NGO Chinchimén and Pro Delphinus, aimed at the general public and the young people who are the stakeholders of the future and will help to develop sustainable activities in their region. In order to stem further declines, studies should be undertaken to explain why the distribution of the Marine Otter is discontinuous along its coastal range. Moreover, both the northern limit and southern limits of its distribution need to be clarified through surveys (Alfaro et al. 2011). Although not all fishermen consider otters to be pests, some do, and may kill them “just in case.” Fishermen can be informed through awareness programmes that the amount of damage otters do has a minor economic impact. Reintroduction programmes are not recommended until more is known about the reasons for the decline of Marine Otter populations. High logistical and economic efforts are needed for such programmes, and efforts should concentrate on habitat protection and research for the time being.