Returning goldfish to nature is devastating to the ecosystem. Out of the bowl, the
Carassius auratus
it can live up to 30 years and exceed 45 cm in length, turning into a weed species.
Goldfish are the aquarium fish par excellence: we all had one as children… and often saw it die within a few days. What if we put an end to the suffering of goldfish by releasing them into lakes or rivers and returning them to nature?
Bad idea: perhaps they would splash around happier than in an aquarium, but our good deed would have devastating consequences for the ecosystem.
Parasites
When living in their natural habitat, goldfish (Carassius auratus) reach a length of over 45 cm within 60 days and live up to 30 years. According to what was discovered by a study on Journal of Animal Ecologyoutside their home bowl these little fishes behave like infesting parasites.
From the simulations it emerged that, in addition to making the water much more cloudy by moving the seabed in search of food, the goldfish would almost make the filamentous algae disappear (by eating them), a habitat for small invertebrates who would thus be exposed to predators (and eaten too). Lastly, native fish would also suffer, due to food competition with goldfish.
