North Atlantic right whales number fewer than 360 individuals and face entanglement mortality that exceeds reproductive replacement, making each individual welfare incident critically important.
Right whales entangled in fishing rope carry heavy gear across their migrations for months, causing progressive exhaustion, injury, and eventually death. Entangled whales lose body condition as the energetic cost of dragging gear exceeds their feeding capacity. Rope cuts cause infections that progress to septicaemia. Pregnant entangled females cannot provide adequate nutrition to developing calves, causing calf death. The population is so small that each entanglement-related death or injury reproductive failure affects the genetic viability of the entire species.