Investigation into porpoises washed ashore
Most of the porpoises that washed ashore on Dutch beaches died by drowning in fishing nets. The rest of them appeared to have been unhealthy. These are the main conclusions of the investigation into the cause of the increasing amount of porpoises that lifelessly wash ashore.
Dead porpoises are found during all months of the year. However, during two periods the numbers were especially large. A first wave occurred in March and April. This concerned mainly healthy animals that appear to have died only recently, with stomachs still full. The main cause of death in this group was drowning in fishing nets. A second wave occurred in August. This concerned mainly unhealthy animals with small fat reserves and often empty stomachs. Drowning was almost never the cause of death for these animals.