Otter

The otter (Lutra lutra) is a semi-aquatic mammal belonging to the family Mustelidae and the order Carnivora. Within the agricultural sector, specifically in aquaculture and private fish farming, this animal is considered a significant pest due to its predatory impact on cultivated fish stocks.

The biology of the species is strictly linked to aquatic ecosystems. Otters are primarily nocturnal and highly mobile, capable of traveling long distances overland to access different bodies of water. Their reproductive cycle is adapted to ensure the survival of offspring in burrows located near the water's edge, allowing them to remain close to their food source.

The primary economic damage is caused in artificial ponds where fish density is artificially high. Otters are opportunistic hunters and often kill more fish than they can consume. This predatory behavior leads to significant stock loss, physical injury to surviving fish, and increased susceptibility to diseases due to open wounds.

The severity of this pest issue is compounded by the otter's ability to overcome conventional physical barriers. For professional fish farmers, this predator represents a major financial risk, as a single adult otter can destroy a significant portion of a fish harvest in a very short period.

Control and protection measures involve a combination of engineering and management practices:

• Installation of high-quality mesh fencing secured deep into the ground.
• Implementation of electric fencing systems around the perimeter of ponds.
• Use of visual and acoustic deterrents to discourage visitation.
• Strategic placement of underwater structures that provide shelter for fish, making it difficult for the otter to catch them.