Building work at the site in Bremanger in Sogn og Fjordane county cannot continue until it has been established whether or not the area is a breeding ground for the animal, local newspaper Firdaposten reported.
The sighting of a breeding otter was reported to the municipality in Bremanger, meaning work on a new slipway at the Iglandsvik Marina was put on hold, according to the report.
The animal was reportedly seen in the same area as the building work on the slipway.
A protected species in Norway since 1982, the semiaquatic carnivorous mammal is categorised as an endangered species by environmental NGO Friends of the Earth Norway.
Reports of sightings of the animal are taken seriously by municipal authorities in Sogn of Fjordane, senior advisor Heidi Sandvik told Firdaposten, while a representative from Iglandsvik Marina told the newspaper that the area was being checked for the animal.
“We hope this is resolved quickly so that an otter does not stop the development of Iglandsvik Marina,” Jostein Grotle said to Firdaposten.
Otters in Norway live in both coastal and inland areas, according to Friends of the Earth Norway.
Inland, the animal tends to move from place to place and can travel up to 10-20 kilometres a day, looking for new waterways where it can hunt fish. Along the coast, the otters stay within smaller areas, where the access to fish is better.
But the animal is a rare sight in Sogn og Fjordane, researcher and otter expert Jiska Joanneke Van Dijk of the Norwegian Institute for Nature Research told newspaper VG.
“Most of them live in Nordland [county], but this one may have come down the coast from Hordaland or Rogaland, or along the rivers,” Van Dijk said.
The sighting of one animal may mean that others are present in the area. Many otters drown in fish traps in coastal areas, so the decision to suspend the building work makes sense, the researcher added.
“If you spot an otter, it helps a lot if you register it. That gives us a better understanding of population size,” she said.