A telemetric study of the home 

 ranges and homing routes of lingcod 

 Ophiodon elongatus on shallow rocky 

 reefs off Vancouver Island, 

 British Columbia 



Kathleen R. Matthews 



Pacific Southwest Research Station. U.S Forest Service 

 Box 245, Berkeley. California 94701 



Lingcod Ophiodon elongatus are an 

 important commercial and recrea- 

 tional fish in the northeast Pacific 

 (Miller and Geibel 1973, Cass et al. 

 1990). In some areas lingcod show 

 serious population declines. In 

 Washington, after signs of deple- 

 tion, the fishery was closed in cen- 

 tral Puget Sound for 5 years (1978- 

 83) to allow rebuilding (Buckley et 

 al. 1984). Currently in central Puget 

 Sound, the now tightly-restricted 

 fishery allows only recreational use, 

 a 6-week opening, and a daily limit 

 of 1 fish. Similarly in British Colum- 

 bia, landings and average size of the 

 catch have declined and tighter reg- 

 ulations imposed (Richards and 

 Hand 1991). Because of lingcod de- 

 clines, it is crucial to understand 

 their life-history characteristics in 

 order to determine possible causes 

 of decline and to help recovery ef- 

 forts. One area of uncertainty re- 

 garding lingcod life history is their 

 movement behavior. 



Despite a number of studies of 

 lingcod movements (Miller and Gei- 

 bel 1973, Mathews and La Riviere 

 1987, Jagielo 1990, Smith et al. 

 1990), many questions remain about 

 their movement patterns. Most 

 studies describe lingcod as seden- 

 tary (Miller and Geibel 1973, 

 Mathews and La Riviere 1987, 

 Smith et al. 1990); yet lingcod do 

 make migrations, and movement up 

 to 385 km has been documented 

 (Mathews and La Riviere 1987, 



784 



Jagielo 1990). Although not verified 

 through tagging, it is thought that 

 most lingcod movements, including 

 possible homing behavior, are re- 

 lated to spawning. Female lingcod 

 may seasonally leave deeper reefs 

 and move inshore to lay demersal 

 eggs that the shallower living males 

 guard. There is indirect evidence 

 for the inshore movement of fe- 

 males; an increase of larger gravid 

 females in the inshore catch occurs 

 during fall months just prior to 

 spawning (Miller and Geibel 1973). 

 Furthermore, some studies have 

 indicated the homing behavior of 

 lingcod, similar to many rocky reef 

 fishes (Hart 1943, Williams 1957, 

 Carlson and Haight 1972, Matthews 

 1990); i.e., when fish move away 

 for any reason (including spawning, 

 experimental displacement, etc.) 

 they will return to areas previous- 

 ly occupied (Gerking 1959). In an 

 early study in Canada, 4 of 14 dis- 

 placed lingcod returned 9.7km to 

 original capture sites (Hart 1943). 

 Additional evidence of lingcod 

 homing behavior came from an 

 attempt to enhance overfished 

 areas by transplanting lingcod 

 (Buckley et al. 1984). None of the 

 transplanted lingcod were resighted 

 at the release area (i.e., the en- 

 hancement was unsuccessful), 

 whereas nine of the transplanted 

 lingcod were caught close to the 

 original capture site (190 km from 

 release site). 



Lingcod movement behavior has 

 implications for enhancement ef- 

 forts and habitat management. At- 

 tempts to rebuild populations in 

 overfished areas by transplanting 

 lingcod from areas of higher abun- 

 dance would be unsuccessful if ling- 

 cod simply returned to their original 

 home sites. Furthermore, move- 

 ment information is valuable be- 

 cause if lingcod preferentially home 

 to certain reefs, then those reefs 

 could be designated as management 

 reserves. Thus, any new knowledge 

 of lingcod homing will lead to a 

 better understanding of their move- 

 ment behavior and the effect of 

 rehabilitation efforts. The objec- 

 tives of this pilot study were to use 

 ultrasonic tagging to (1) describe 

 home ranges and movements of 

 lingcod on rocky reefs, and (2) 

 determine the homing routes of 

 displaced lingcod. 



Methods 

 Study sites 



The study was conducted during 

 April 1990 off eastern Gabriola 

 Island on the eastern side of Van- 

 couver Island, British Columbia 

 (Fig. 1). The area is characterized 

 by extensive shallow rocky reefs 

 and pinnacles. Depths encountered 

 during ultrasonic tracking were in 

 the range 3-35 m. Two reef areas 

 were chosen for the tracking work: 

 Gabriola reefs and Valdes reefs 

 (each is actually a series of small, 

 separate reefs) (Fig. 1). Both reefs 

 are approximately 15-30 m deep, 

 although shallower areas were 

 sometimes encountered. Although 

 bullkelp Nereocystis leutkeana is 

 present on these reefs during the 

 summer and fall, no surface kelp 

 was present during this April study. 



Ultrasonic tagging 



The transmitters (48 x 15 mm, 18 g 

 in air, 8.3g in seawater) were ex- 

 Manuscript accepted 29 July 1992. 

 Fishery Bulletin, U.S. 90:784-790 (1992). 



