BISMARCK, N.D. — North Dakota’s Game and Fish Department has closed the state’s inaugural otter trapping season, after the limit of 15 otters was reached.

The agency said earlier this year that enough otters had moved into eastern North Dakota from Minnesota to warrant a trapping season. Gov. Doug Burgum signed off on the idea last summer.

The season opened Nov. 27 and was closed Monday, a week later.

Experts say the U.S. otter population is thriving thanks to improvements in water quality, reintroduction programs in many states and regulated harvests. Animal welfare groups worry the expansion of otter trapping in the U.S. and Canada in recent decades isn’t sustainable. But there was no organized effort to oppose North Dakota’s season, as there has been in other states.