Dive Dry with Dr. Bill

#202: Rosie the Rockfish

Here on Catalina, when one thinks of Rosie, they are usually referring to Rosie Cadman, long-time owner of Earl & Rosie's Fish & Chips on the green Pleasure Pier. Think back to the days of abalone burgers for $0.50. Yummy. Old timers might think instead of Rosie the Riveter, a popular symbol during World War II. Of course I'm much too young for that. Both these ladies deserve columns of their own, but today I'm focusing on another Rosie, or more accurately Rosy... rosy the rockfish.

Rosy is another pretty lady that I've encountered on my deep dives at Ship Rock. No, she's not a figment of nitrogen narcosis... she's a real lady, or gentleman since I really couldn't tell its gender. I first encountered Rosy on a dive to 180 feet on the deep ridge on the outer side of Ship Rock. Of course she didn't look very rosy until I turned on my video light and illuminated this deep habitat. Almost no red light penetrates to these depths so anything red looks very dark unless it is artificially lit.

These members of the rockfish group have orange or reddish flanks with 4-5 white blotches on their backs. There may be purple mottling on the back and head region. Fish greater than 10" in length are not seen with any regularity although they may reach 14" long. They are said to range from Puget Sound to central Baja California. Like some of their rockfish relatives, the young are generally found in shallower (100-200 feet) waters and the adults at greater average depths (180-350 feet). At my maximum depth of 180 feet, I observed both small (2-4") and larger (7-8") fish, since I was in the overlap of these two zones.

Their habitat is mainly deep, offshore, high relief rocky areas. They often frequent crevices, holes in the rocks or ledges, and overhangs. Certainly the deep waters off Ship Rock qualify in this category. It is one of several places on the island that my deep diving is possible due to the steep slope of the terrain. A few other sites include Farnsworth Bank offshore, or Goat Harbor and Blue Car Wreck due to the step submarine slopes.

In southern California rosies reach sexual maturity between 6-8" in length and a minimum of seven years old, although further north they may not be reproductive until they are 2" longer. These fish may spawn at anytime from New Years to after Labor Day (how appropriate), although in our waters the peak appears to be in May. Dr. Milton Love at UCSB reports up to 95,000 eggs per female.

Munching consists of sampling bottom dwelling crustaceans like crabs and shrimps (but no abalone burgers). I could get used to a diet like that since I love them in my Thai green curry! They are commonly taken by party boats and occasionally by commercial fishers. Having never tasted one, I can't say if the effort is worth it... but rockfish do tend to be good eating. Of course, that's one of the reasons several of these species are in trouble in California waters.

I long held that 100 ft was generally deep enough for my diving. That is well within the recreational limit of 130 feet imposed by some agencies. As a kelp forest ecologist, my research subjects rarely were found deeper than those depths. I would NEVER advocate deep diving to others, especially if it were simply for the sake of going deep. However, for a biologist like myself with substantial diving experience, I weigh the risks of such deep diving against the wealth of new species I can see and film down there. In view of these potential depths, I also adjust my gear configuration accordingly. This is not a world for new divers, or those with the "rapture of the deep," to explore, so I'm bringing them to you... no wetsuit or cold water required. That's my job!

© 2006 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays. Please help me climb out of self-imposed poverty... buy my "Munching and Mating in the Macrocystis," "Great White Sharks of Guadalupe," "Calimari Concupiscence: Mating Squid, " "Playful Pinnipeds: California Sea Lions," "Belize It or Not: Western Caribbean Invertebrates, Fish and Turtles" or "Gentle Giants: Giant Sea Bass" DVD's. Yes, take Dr. Bill home with you... we'll both be glad you did!

Rosy rockfish in the depths of Ship Rock... no relation to Avalon's favorite Rosie of course!

This document maintained by Dr. Bill Bushing.
Material and images © 2006 Star Thrower Educational Multimedia