FISHING World has reported over the last few years on a couple of Australian studies that have suggested that the average size of the fish we catch has declined over time.
That certainly seems true for some common species targeted by both commercial fisherman and anglers, such as yellowfin bream, tarwhine and luderick.
The theory has been based on natural selection combined with minimum size limits: keeping larger fish takes out more bigger, fitter breeders and releasing smaller fish protects smaller, weaker but still fertile individuals.
A New Scientist report now suggests that this can occur in a very short time, particularly for species where large specimens are heavily targeted commercially. A decade-long study of Atlantic silversides has shown that intense targeting of large individuals can halve average size in just four generations.
Go to www.newscientist.com and search for “fish growing up fast” for a full explanation and links to related stories.
