Further habitat encroachment takes place through scallop farming. The dolphins were observed changing their course to avoid the farms. The dolphins also suffer from a reduced food supply caused by overfishing of anchovies. Apparently to improve their hunting strategies, they tend to aggregate in groups of more than 30 animals in this area, which is rather unusual for dolphins living in coastal areas. The largest school of dolphins sighted near Pisco in 2000 included about 60 individuals.
Marine pollution poses another threat.
Not only the region's fishmeal plants, but also waste in the form of plastic bottles and bags, pieces of nets, batteries and other objects, pollute water and coasts alike. They constitute potential threats to dolphins, including entanglement and accidental ingestion. Dolphin Studies During the regular boat excursions and land-based observations only bottlenose dolphins were sighted. The studies included extended behavioral studies. They have revealed that, during hunting, dolphins fenced the fish against the shore.