It’s hard not to be moved by images of whale’s stomachs showing plastic bags, fishing nets and ropes inside. These things appear as either causes or factors in the death of whales.
An important issue is fishing gear and the impact it has on whales. Often made from plastic and incredibly tough, fishing equipment can be a major risk to wildlife. Whales face the threat of being trapped in both fishing equipment that is actively being used and lost or dumped ‘ghost’ fishing gear – floating death traps drifting in our oceans.
A floating rope can easily wrap around a flipper or tail, and the whale will be forced to drag the ghost gear with it – sometimes for years, resulting in exhaustion, starvation or even death. Reports have shown that 75% of living whales bear the scars of this kind of issue. Researchers from Aarhus University found that lines wrapped around a whale’s fin and body can increase the difficulty of swimming by 160%. Put that way, you start to get a sense of why exhaustion is such a major threat to trapped whales.
Equally sinister, big plastics like ghost nets and other floating rubbish are known to break down into what we call ‘microplastics’ – tiny particles of plastic less than 5mm in size. These microplastics are a threat to filter feeding whales who eat them accidentally.
Getting a true picture of the impact of human activity on whales is difficult, as scientists are not always able to study dead whales to find out why they died. But from the evidence available we know action is needed to protect them.