North American river otter: non-detriment finding

Published 2011-07-22 - Revised 2014-02-17

Summary of Finding:

Export of legally obtained wild-harvested river otter is considered non-detrimental.

• River otter is harvested as a furbearer species under the authorization of trapping permits or licenses. Canadian export is primarily in skins sold at Canadian fur auction houses. Harvest of river otter occurs in all provinces and territories except Prince Edward Island. The distribution of river otter is widespread throughout much of their historic Canadian range although fragmented in some areas.

• Wild Species 2010: The General Status of Species in Canada classifies the river otter as Secure in Canada. Harvest statistics indicate stable or increasing populations and no acute widespread threats to the species have been identified. The river otter has not been identified as a candidate species for status assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as it is considered to be of least concern from a conservation perspective.

• Like all vertebrates in Canada, the river otter is legally protected through provincial and territorial legislation. Under these acts, certain uses of Canadian wildlife are allowed under specific regulations and only with the provision of licenses or permits. Generally, without such a license, the catch, possession, trade, sale, disturbance or destruction of wildlife is prohibited.

• Provincial and territorial governments are responsible for the management of terrestrial wildlife.  River otter harvest activities in Canada occur under programs established for furbearing species and management decisions are guided by planning processes, policy, legislation, trends in historical and recent use, and scientific information. Harvest can be adjusted to ensure sustainable management of the river otter by season, geographical management unit, and/or harvest limit.

Supporting Information:

Biological characteristics

The river otter is a long-lived species with a low reproduction rate. Otters are estimated to live to 10-15 years in the wild. Both genders reach sexual maturity between 2-3 years old although males in captivity have been reported to not breed until they are 5-7 years old. Litters average 2-3 young but may range between 1 and 5 young. Pregnancy rates of wild river otters indicate that they may reproduce annually but are likely to reproduce every two years. Mating occurs in the spring shortly after females give birth and gestation is approximately two months. Female otters undergo a process known as delayed implantation. In this reproductive strategy, the embryos lie dormant in the uterus and do not begin to develop until the following winter. This allows the young to be born in the spring and fully grown before entering the winter season.  River otter are relatively tolerant of human activity, often found near areas of land disturbed by resource development and human activity.

River otter use many types of aquatic habitat and is widely distributed throughout much of Canada, with abundance directly related to prey availability and suitable denning cover. Within the aquatic food chain, river otters are opportunistic omnivores, but prefer fish when available. Otters can range considerable distances overland. In much of Canada, the carrying capacity of river otter habitat is probably determined by the availability of suitable winter habitat. The river otter is a difficult species to target when trapping as it spends a high percentage of time under the ice during the winter season when the pelt is of highest quality.  In some areas, the river otter will utilize habitat modified by beavers and may be harvested by trappers targeting beaver.

Status

River otter populations declined in the late 1800s due to over-harvest, but conservative management throughout the first half of the 20th century have restored Canadian populations to healthy levels. The distribution of river otter is currently widespread throughout much of their historic Canadian range although fragmented in some areas.  River otter no longer occurs on Prince Edward Island, which represents less then 0.1 percent of the original range.

Canadian jurisdictions and furbearer managers infer population trends from harvest data for river otter. Based on information such as trapper reports and harvest levels, range jurisdictions consider the river otter population to be stable or increasing throughout Canada. Although not a direct measure of population size, harvest statistics, collected annually since 1919, provide reliable quantitative information on river otter harvest. These harvest statistics, used in conjunction with information on trapper effort, provide an indication of change in river otter population trends. There is currently no widespread acute threat to the Canadian river otter populations. Some possible local threats include degradation or loss of habitat and the presence of bioaccumulative environmental toxins in the aquatic food chain.

Overall, Wild Species 2010: The General Status of Species in Canada classifies river otter as Secure in Canada, and Secure in all range jurisdictions except Nunavut.  A designation of Sensitive in Nunavut reflects the small portion of the total species range in that jurisdiction, not a conservation concern for the Nunavut population.  The river otter has not been identified as a candidate species for status assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as it is considered to be of least concern from a conservation perspective.

Harvest Management

Management of river otter harvest in Canada is conducted with the goal of long-term population sustainability. Harvest of river otter occurs in all current range jurisdictions and is managed through provincial and territorial wildlife acts that provide regulatory frameworks for sustainable harvest management and monitoring. The river otter is classified as a furbearer species in most jurisdictions.  Aboriginal peoples have the right under the Canadian constitution to harvest wildlife for traditional use.  Jurisdictional management strategies for river otter are reviewed annually, and in most jurisdictions, management is based on designated seasons within geographical areas. Some jurisdictions also set bag limits per trapping line and/or require mandatory reporting and submission of carcasses for collection of biological data.

The purpose of furbearer harvest management regimes in Canada is to maintain sustainable populations while allowing harvest. The trend in river otter harvest has been relatively constant over several decades and current harvest levels are considered below the maximum sustainable limit. Wildlife managers monitor annual harvest statistics for the river otter to ensure that harvest levels remain within the expected range.

Control of Harvest

River otter harvest is managed throughout Canada by a combination of regulatory controls such as trapping licences, allocated trapping areas and geographical management units. The application of these management tools vary with jurisdiction. Wildlife and conservation officers monitor regulatory compliance within each jurisdiction.

As with most furbearer species, river otter seasons are set to correspond with the time of year when its pelt is of marketable quality. Most known illegal off-take of river otter is due to incidental catch when trappers are targeting beaver outside of open river otter seasons. Trappers are not permitted to keep incidental catches and must report these to the natural resources office within their jurisdiction.

The majority of trade in river otter from Canada is for pelts with the occasional export of fur garments and taxidermy mounts. Most river otter skins are sold and exported through auction houses in Ontario. Provincial enforcement staff work very closely with the auction houses to ensure all pelts have been legally obtained, accurately reported and have the appropriate provincial or territorial permits and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) export permits. These systems complement management occurring at the harvest level and contribute to an overall high level of confidence in the compliance of stakeholders with Canadian harvest and permit requirements. The taxidermy industry is also regulated and monitored through mandatory annual reporting of its activities.

Overall, confidence in the Canadian harvest management system of river otter is high as these adaptive management systems allow for strict control of harvest and are reactive to changing conditions, with the aim of ensuring sustainable harvest and maintaining biodiversity.

Harvest Trend

Commercial harvest data for the river otter are available from 1919 in most jurisdictions. Since the 1960s, the Canadian river otter harvest has been stable.

Harvest Monitoring

The provinces and territories require a license or permit for the catch, possession, sale and export of river otter. In some provinces/territories, tagging or the submission of carcasses is also required. All jurisdictions monitor harvest annually, primarily by jurisdictional permits and mandatory reporting by trappers, fur traders and taxidermists.

Incentives and Benefits of Harvest

Management of furbearer species in Canada is a partnership between governments and harvesters. A sustainable long-term harvest is dependent on stable wildlife populations thereby promoting a stewardship attitude towards both the river otter and its habitat.

Protection from Harvest

In general, the adaptive management framework currently applied to wildlife harvest management programs in Canada is very effective at preventing over-harvest of wildlife as restrictive measures can be applied when necessary.  Jurisdictions have the ability to  close specific geographical management areas to river otter harvest, if necessary, to achieve specific conservation goals.