Meet the tiger rockfish. She’s big, she’s old and she produces lots of larvae! The tiger rockfish is one of the many rockfish species living off the coast of British Columbia (BC).
A tiger rockfish. Photo: Ron Caswell
She seems pretty tough, but like most rockfish, she’s particularly sensitive to fishing pressure. Rockfish are long-lived marine fish; many species live for over 100 years! Although females can give birth to millions of larvae, larval survival to reproductive age is sensitive to environmental conditions. Variation in larvae survival makes rockfish populations go through more busts than booms. The older and larger a female is, the better quality and more larvae she can produce. Fishing targets the largest fish, so when an area is fished for rockfish, the best reproducers are removed. Rockfish also have a closed swim bladder used for buoyancy. It expands and causes damage to the fish when they brought to the surface by fishing. They tend to be sedentary as adults and most migration happens as a larvae. As a result, it takes many years for rockfish to recolonize a habitat once they are fished out.
A quillback rockfish. Photo: Ron Caswell
Rockfish have an important role in coastal ecosystems and in fishing economy. They also have a diverse range of habitats so protecting their habitat would benefit many other species.
Next: Rockfish numbers have been declining.