In addition, environmental factors, such as El Niño events that may change the availability of prey, may make animals more vulnerable to disruption than they would be otherwise.
Aux termes de la Loi sur les pêches au Canada et de la Marine Mammals Protection Act (MMPA) aux États-Unis, il est interdit au public de perturber (harceler) les mammifères marins, y compris les épaulards.