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Marine otter
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Scientific name: Lontra
felina (Molina, 1782). Description: The marine otter's fur is of a dark brown color. Maximum size is 90 cms with 3-5 kg of weight, being one of the smallest otter species. The marine otter loves rocky coastlines, being exposed to strong wave action, places where many caves are formed either by the wave action or by rocks falling off the cliff. These caves are used as dens. Five dens located in the Department of Lima are located in inaccessible caves carved out of the rock by wave action. In a study completed in Chile, 96.7% of the dens were surrounded by the algae, "Lessonia nigrescens", and 65% of these also showed growth of the algae, "Durvillaea antartica". Both algae species are growing in areas being exposed to strong wave action.
The wide range of distribution causes the marine otters to feed on a wide range of species. There are no detailed studies on the prey of marine otters in Peru. There are however, anecdotal observations of otters feeding on Chalapo clinid (Labrisomus philipii), Peruvian grunt (Anisotremus scapularis), Common clingfish (Sicycaces sanguineus), and Pacific skate (Psammobatis caudispina). In Chile, the feeding habits of marine otters have been investigated by direct observation and analysis of feces, as well as food remains near the dens. In the north of Chile, otters do feed mostly on fish, while in the region of Chiloé (X Region), their diet is mainly based on crustaceans like Taliepus dentatus, Cancer setosus and Homolaspis plana.
Marine otters are most active at sunrise and sunset. Marine otters are usually solitary, but they can also be observed in small groups being composed of a mother with her one or two offspring. Marine otters spend half of their time resting and use only 18-40 % of their time for fishing. Marine otters can dive up to 30 meters deep, but usually they feed in much shallower areas. An average dive lasts 28 seconds. Small fish are eaten while swimming on their back. Bigger fish are taken ashore. Observations in Paracas, Ancon and Cerro Salazar show that otters do have favorite feeding grounds, usually counting with small outcrops or semi-submerged rocks nearby used for feeding on bigger prey. A feeding ground may be shared by several otters.
The reproduction period is between October and November. After two months, up to two offspring are born. They stay with the mother for another ten months, a period in which they learn from their mother how to fish. At first, a parent needs to grab them by the neck in order to submerge them, but soon they learn to dive.
Threats
At the international level, the marine otter is classified as "vulnerable" by the International Union for the Conservation of Nature (IUCN). It is listed as an endangered species on Annex I of the Convention on International Trade in Endangered Species (CITES). In Peru, the marine otter is also declared endangered and therefore protected by law. Nevertheless, there is only one area, the Paracas National Reserve, where marine otters at least officially do count with protection. However, it appears that the otter population within the reserve is in greater danger than in other areas, caused by the constant illegal use of dynamite for fishing. There are reports confirming the presence of marine otters along the entire distribution area of the Peruvian coast. But apart from this, we count with very little information about the species. During a survey of the coast of the
Department of Lima, undertaken by Mundo Azul field researcher Jean Paul
Perret, otters were observed in eight of the nine study areas. Nevertheless,
the marine otter suffers major threats to his survival.
The main threats to the marine otter's survival are losses as "bycatch" and human presence near the dens. In the Department of Lima there exist a high
number of artisan fishermen that climb down the cliffs with ropes in
order to get to the best fishing spots. Therefore, humans have access
to the biggest part of the rocky shoreline and for the otters; there
are very few safe places left that are really inaccessible for humans.
Another common problem is the presence of
fishing boats using fishing nets near the rocky shore. Otters run the
danger of getting caught in these invisible nets and drown. Even though
there is no information available on how many animals die this way,
however, interviews with fishermen indicate that the majority of them
have observed this more than once. In Chile, there exists a similar problem with crab pots. The otters are attracted by the traps, enter to get to the crabs and then drown because they cannot leave the trap..
In Paracas, the constant illegal use of dynamite
for fishing may pose a serious threat for the local otter population.
There exists information from Mexico that river otter populations (Lontra
longicaudis) have disappeared in areas where dynamite fishing was
common. In some areas, otters have managed to live
very close to dense human populations. Like for example, in the harbor
of Pucusana and as well in the beach clubs, Lapa Lapa and San Bartolo
in the south of Lima
Nevertheless, these cases are exceptions to the general rule that otters do disappear from areas where too many humans are present. Therefore the continuous construction of beach clubs without proper planning, mostly in the south of Lima may pose another serious threat to the survival of the marine otter. Additionally, the contaminated effluents from rivers and urban sewage pipes or fishmeal factories are a threat to the otter's survival.
25 percent of the coastline of the
Department of Lima is potential otter habitat, being the rocky cliffs
along the coast. This area is distributed in 35 units with an average
length of 4 km, being separated by sandy beaches with an average length
of 5 km. How to protect marine otters?
One important step could be better protection
of the Peruvian guano islands and cliffs. The guano island system was
created more than 100 years ago in order to give strict protection to
the breeding grounds of several marine bird species, whose dropping
accumulated in these 23 islands and 10 cliffs along the Peruvian coast
and were used as a natural fertilizer for agriculture. Nowadays, the
guano islands are
the breeding grounds for 72 percent of the South
American fur seal (Arctocephalus australis), 84.4% of the
Southern sea lions
(Otaria byronia), 60% of the Humboldt penguins
(Spheniscus humboldti), and, most importantly, the entire population
of the endemic and highly endangered Peruvian diving petrel (Pelecanoides
garnottii). Even though there are no studies on the abundance of
marine otters on the guano islands, there are anecdotal reports confirming
high densities of otters. For several years, the Peruvian government
has held a proposal on ice that plans to declare all guano islands and
cliffs to be protected as a National Reserve. Additional necessary measures are: a prohibition of angling and the use of small scale driftnets close to rocky shorelines in order to reduce mortality as bycatch. Finally, there must be decisive action against illegal dynamite fishing. |
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