The River Otter in Missouri
The North American river otter (Lontra canadensis) was a common predatory mammal in Missouri before settlement. But as civilization spread westward, settlers drained the marshes and swamps, destroying the places where otters lived. The otter's fine fur attracted the attention of the fur industry and because of unregulated harvest and habitat destruction, otter numbers declined rapidly. By the 1930's, otters were rarely seen in Missouri. A few otters managed to survive in the Mississippi Lowlands (the Bootheel), west central, and the northeast part of the state. In 1937, a state-wide survey of the otter population indicated that the population had been reduced to about 70 animals.
In 1974, the Missouri Department of Conservation (MDC) placed the river otter on the list of endangered animals in the state. In the late 1970's MDC biologists realized that the otter habitat had been restored to a large part of the otter's original range. They further reasoned that because white-tailed deer and Eastern wild turkey restoration efforts had been such a success, perhaps river otters could flourish in Missouri waters again. Between 1982 and 1992, using wild-trapped river otters from the marshes of Louisiana, a total of 845 otters were released in 35 counties across the state. Coincidentally, most of the otters captured in Louisiana for transfer to Missouri were taken in foot-hold traps.
Media exposure of MDC's otter restoration efforts throughout the release period far exceeded that given to other efforts like the deer and turkey. Especially effective and popular were media events built around the release program. Television and newspaper coverage, and the inclusion of school districts' involvement took the educational aspect to a higher level. It was not uncommon for schools to transport busloads of school children to remote release sites to witness the otter releases firsthand.
By the mid-1990s, statistical estimates, and anecdotal accounts and sightings by people living in the areas where otters had been re-introduced, confirmed that the otters were reproducing well in their new homes.
Otter depredation complaints to MDC from aqua-culture business owners (catfish and crayfish farmers) were heard in growing numbers and severity. Finally, beaver and raccoon trappers were catching otters in larger numbers each year, although the season was closed to otter trapping. Otters so taken had to be surrendered to MDC. During that time, the otter population was estimated to be in excess of 5,000 animals. River otter populations are now widely restored across Missouri's rivers, streams, lakes and even small farm ponds. Estimates of the statewide population in 1999 varied from 11,000 animals (MDC population model) to about 18,000 (University of Missouri population model).
The food habits of river otters in Missouri are being studied. Otters, a supreme aquatic predator, tend to feed primarily on crayfish in the summer. During winter when many species of crayfish are buried in the mud, otters shift to an almost all-fish diet. Otters will supplement their diets with a number of other available foods including snails, small birds (including ducks), small mammals (including muskrats), frogs, salamanders, clams, snakes, insects and their larvae, earthworms, and some vegetation.
The winter feeding habits of otters, because of their
propensity for fish in the diet, puts otters in conflict with people.
Aside from the aqua-culture conflict, otters are capable of damaging
fish populations in farm ponds and in the headwater portions of some
of the clear Ozark streams. Anglers, particularly those that fish for
smallmouth bass in the headwaters of streams, contend that the otters
are responsible for the demise of smallmouth fishing in some parts of
the Ozarks. Granted, otters will catch and eat 17 inch-long smallmouth
bass. Study of the winter feeding habits of otters in the Ozarks, although
preliminary with small sample sizes, indicates that otters prey on sport
fish in higher numbers than other fish groups. The preferred group is
the family Centrarchidae, which includes smallmouth bass, largemouth
bass, longear sunfish and rock bass. Current data suggests that 56 percent
of the fish in this group that were eaten by otters in the Ozark region
were more than four years old and about 17 percent were seven years
of age or older. Smallmouth bass reach 12 inches in length between four
and five years of age.
When MDC embarked on the most aggressive otter restoration program ever undertaken by any state agency in the United States, (845 wild-trapped otters introduced into habitats where only an estimated 70 otters lived), biologists expected that a regulated trapping season might eventually be needed to help control the population 20 to 30 years in the future, assuming the program was successful at all. In 1996, only four short years after the last release was made, MDC biologists suggested the first regulated trapping season be permitted to help control a population that some people thought was already out of control. The damage complaints and new population models indicated that there were numerous otters in some localities. In response, the first two-month statewide trapping season (November 20 to January 20) was permitted that year (1996). Trappers harvested approximately 1,000 otters in each of the trapping seasons from 1996 to 2000. Despite the regulated take of these animals, the MDC population estimate is between 11,000 and 16,000 animals in 2001.
When MDC announced the trapping season in 1996, it triggered what immediately became the "otter debate." The most immediate response was from local and national animal rights groups expressing their outrage that an animal only recently restored would be subjected to the very threat that, by their descriptions, carried the otter population to the brink of oblivion in the first place. An annual survey conducted for MDC by the Gallup organization in 1997, revealed that about 70 percent of Missourians think "trapping is O.K. as long as it is regulated."
Animal rights groups filed two lawsuits questioning MDC's data on population estimates. Their intent was to stop otter trapping in Missouri. The first lawsuit was filed by the Animal Legal Defense Fund and two Missouri citizens. In dismissing that challenge, the court ruled that MDC's otter trapping season was not "arbitrary and capricious" as the suit alleged, and that the MDC had followed all proper procedures in establishing the wildlife rules.
The second lawsuit was again filed by the Animal Legal Defense Fund, joined by the Humane Society of the United States. This suit was filed in the United States District Court against the United States Fish and Wildlife Service. In 1996 MDC requested export authority from the United States Fish and Wildlife Service (as required for CITES listed species), and temporary permits were granted each year until final authority was obtained in 1999. This authority was sought because, although not "endangered" in Missouri, river otters from Missouri resemble species of endangered otters that live in other countries. This case was dismissed by a Federal Judge who ruled that since the MDC was going to have a trapping season anyway, granting an export permit had no impact.
With so much controversy surrounding the river otter re-introduction program, and to clarify otter management issues further, MDC's Director Jerry Conley requested the establishment of an Otter Advisory Committee in 1998. This is a citizens group consisting of people who have varied and divergent interests in the otter in Missouri. The committee is made up of anglers, an aqua-culture business owner, University of Missouri and MDC biologists, a county commissioner, a trapper, businessmen and landowners in the Ozarks where damage complaints run high, a member of an otter protection group, and an otter behaviorist. This group meets at different times throughout the year. They address, discuss, and dispute issues related to otter population estimates, the impact of river otter depredation on fish in private lakes and ponds, headwater Ozark streams and commercial aqua-culture businesses, and issues surrounding the trapping of otters.
This committee faces "head on," management options dealing with the delicate problem of managing this population of predatory mammals in the state. On one hand there is the "kill no otters" attitude. On the other hand, some folks contend that MDC was reckless in restoring otters to a landscape where game fish were vulnerable to otter predation. They point to degraded aquatic habitat in Ozark streams that leave game fish especially vulnerable to the otter's predatory efficiency. Discussions address the problems of gravel accumulation, siltation and nutrification from fertilizer and municipal sources that have weakened the ecosystem. Some folks think that most fish could still survive until MDC added otters to the list of problems that fish had to deal with.
In addressing the problem of how to deal with such a sensitive subject, the Otter Advisory Committee, though not without dispute, eventually recommended that MDC consider an adaptive strategy for managing otters based on the relative abundance of otters in Missouri. MDC staff responded by proposing five otter management zones with limits and season length extensions where appropriate, based on factors such as otter population indices, impact on public fisheries, and damage to private impoundments. Basically the proposal suggested a five-otter trapping limit in three zones adjacent to Missouri's three major metro areas-Kansas City, Saint Louis, and Springfield: a 20-otter limit in most of the balance of the state; and finally a zone in which otters could be taken in any numbers with an extended 31 day season in that zone only. This focused on Missouri's south-central region where the consequences of otters have been particularly significant.
In the final stages, and after much heated discussion,
MDC's Regulations Committee adopted the Five Zone Approach. It was approved
based on the following points: (1) the most current biological data
relative to otter densities was compatible with current harvest rates,
(2) it was responsive to the polar views-"kill no otters"
and "kill 'all' otters"-and was consistent with the Otter
Advisory Committee recommendations, and (3) it contained elements that
could help alleviate otter damage in areas that were most affected.
During the 1999-2000 season, 1,058 otters were taken statewide.
In 2000-2001, 1,378 otters were taken by trappers. This was a 30 percent