Two Popular Sport Fishes Have Surprisingly Small Home Range

A female sheephead. Photo: Chris Lowe

Researcher:

Christopher Lowe, Ph.D.
Department of Biological Sciences
California State University Long Beach
Long Beach, CA 90840
E.: clowe@csulb.edu
T.: (562) 985-4918

Relevant Link:

CSULB Sharklab

Tools:

Revised:

March 5, 2008

March 4, 2008

Contact: Christina S. Johnson, csjohnson@ucsd.edu, 858-822-5334

A recently completed tagging and tracking study funded by the California Department of Fish and Game and California Sea Grant shows that Catalina Island kelp bass and barred sand bass have relatively tiny home ranges, a discovery that suggests these fish might get more protection from small marine reserves than previously thought.

Sea Grant Trainee Darin Topping changes an automated underwater acoustic receiver. An array of these receivers was used to monitor tagged reef fish in Catalina Island Marine Science Center Marine Life Refuge for more than a year. Photo: Chris Lowe

CSU Long Beach professor Chris Lowe reports that the average home range of an island kelp bass is

less than half the size of a NFL football field, a paltry 3,200 square meters.

Barred sand bass, the main catch of summer party boats in Southern California, occupy a larger but still relatively cozy 10,000-square-meter area – about 1.5 football fields.

“Before this study, nothing was known about the movements of barred sand bass,” Lowe said. “There are still gaps because we have yet to document their spawning behavior.” The fish’s spawning behaviors are important for management because party boat anglers in summer fish on top of spawning aggregations.

Besides tracking fish, Lowe and UC Santa Barbara researcher Jennifer Caselle, a co-investigator on the project, have been looking at how benthic topography influences fish movements and home range size. That is, they are interested in understanding how seafloor terrain constrains and defines fish movements.

One noteworthy finding from this study is the importance of edge habitats (transition zones between rock reef and sandy bottomed areas) to not only kelp bass and barred sand bass but also two other popular sport fish, sheephead and ocean white fish.

All four species tend to congregate around these transition zones, Lowe reported.

Sea Grant Trainee Tom Mason follows a tagged barred sand bass in the Catalina Island Marine Science Center Marine Life Refuge. Photo: Chris Lowe

In terms of designing marine reserves to maximize protection

for fish, the results suggest reserve boundaries should be placed in the sand at least 100 meters from edge habitats, Lowe said. Alternatively, if “spill over” is desired, to increase sport fishing opportunities, boundaries should be placed closer to these areas.

“The information Chris is collecting on fish movements is critical to understanding both how effective marine protected areas will be in protecting various species and in determining their potential to provide new fishing opportunities outside their boundaries,” said John Ugoretz, manager of the marine habitat conservation program manager at the California Department of Fish and Game.