Spain imported US crayfish in 1974; 50 years later, they cannot be removed

Fifty years ago, American red crayfish were introduced to Spain’s Guadalquivir River basin, and they have since established a permanent presence. These aggressive invaders have wreaked havoc on local wildlife and disrupted aquatic ecosystems. Yet, local communities have successfully built an economy around their harvesting and processing. This dependence has sparked legal disputes, resulting in a compromise that permits regulated harvesting, balancing ecological health with economic viability.