ECS-ASCOBANS Workshop on recreational activities and their impact on cetaceans

On 9 April 2024, ASCOBANS organised a workshop on recreational activities and their impact on cetaceans, as part of the 35th European Cetacean Society (ECS) Conference in Catania, Italy. Over 30 participants attended.

The workshop provided a platform to review the status of marine recreation across Europe, and gather information about impacts through presentations followed by a facilitated group discussion. Presentations were given on recreational disturbance to coastal species - bottlenose dolphin and harbour porpoise; coastal bottlenose dolphins in the western English channel; challenges, recommendations and solutions in marine mammal disturbance, the welfare implications of recreational boating, and the impact of recreational boats on cetaceans in the Mediterranean Sea - a case study from the northern Adriatic.

Recreational activities pose a significant threat to small cetaceans, with numerous detrimental effects on both individual animals and their populations. The persistent disruption from such vessels can lead to severe consequences, exacerbating the already precarious conservation status of many small cetacean populations.

  • Noise pollution and habitat abandonment: Noise generated by recreational activities can cause small cetaceans to abandon their habitats. This displacement is not necessarily a temporary reaction to immediate disturbances but can result in long-term habitat abandonment, leading to a permanent loss of suitable living environments for these animals.
  • Collisions: Collisions with high-speed vessels often result in immediate death or severe injuries that can lead to delayed mortality.
  • Auditory damage: Exposure to loud noises from recreational craft can cause Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) in cetaceans. These auditory impairments increase the likelihood of cetaceans being unable to detect biologically significant sounds, such as communication signals, predator or prey detection, and anthropogenic threats such as acoustic cues of gillnets. Such sensory damage compromises their ability to survive and reproduce.
  • Separation of female animals and calves: Recreational vessels can also cause the separation of female cetaceans and their calves. This separation is usually fatal for the calves, which rely on their mothers for nutrition, protection, and learning social and other skills.
  • Disruption of vital behaviours: Frequent interruptions of essential behaviours such as feeding, mating, and suckling due to boat disturbances can significantly reduce individual viability. Stress induced by these interruptions further exacerbates their vulnerability. Over time, these behavioural disruptions can lead to reduced reproductive success and increased mortality rates, having repercussions at the population level.

The report of the workshop will be available on the ASCOBANS website in due course.

Last updated on 18 December 2024

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