Though they hold stable territories, "P. colias" moves from time to time. In a study, "P. colias" can move with on average of 2.09±2.12 km, this could potentially be home range shifts. It is reported that "P. colias" emigrate from coastal to offshore waters in May of each year, this is thought to be a preparation for mating and spawning in early winter. "P. colias" seem to be migratory at certain times in a year, but little is known about their migration. Other studies indicated that they are relatively sedentary, however, long-term dispersal has been suggested due to a record that one individual travelled 156 km over 20 months. Many fish species are generalists; thus, they are not limited by the predator-prey cycle. "P. colias" is one of them. They have been recorded to have 52 taxa in their diet, where adults are found to be more selective than juveniles. It makes sense that when "P. colias" grows bigger, the variety of species in their diet also increases, this includes polychaetes, crustaceans, molluscs, Pisces, algae and even its own spawn! This means that "P. colias" are omnivores which "feeds on more one trophic level". In short, you can say that they consume anything that is abundant and available locally. Other than the development of the fish itself, what they consume differs from region to region and whether the area is fished or not plays an important role as well. One study showed that oyster dredged habitat can reduce their prey diversity and have a negative effect on fish size. They usually stalk, seize and swallow their prey. After being caught, they tend to regurgitate the stomach contents. ‘Our Big Blue Backyard’ is a documentary of New Zealand marine and shoreline species. In the Chatham Islands episode, blue cod ("P. colias") waits to feed on pāua, an endemic sea-snail that attaches itself on hard surfaces such as rocks, at its most vulnerable phases – when they move or are grasped up by a starfish using hundreds of tube feet. They are also said to be voracious. "Homo sapiens" (humans) fish 2000 to 2500 tons of "P. colias" annually. Natural predators include:   As many marine predators are generalists there are many other potential predators not listed.