NOTE Matthews: Movement behavior of Ophiodon elongatus off Vancouver Island 



789 



times crossed flat, open areas that had no hiding places. 

 Locally, harbor seals feed on lingcod, and recently their 

 numbers have dramatically increased (Olesiuk et al. 

 1990). On the other hand, perhaps lingcod are simply 

 more active at night, as my nighttime home-range 

 observations indicated, which would explain their 

 nighttime movement. 



Lingcod homing was fairly directional and confined 

 to the immediate area of Gabriola Island. In contrast, 

 when displaced shorter distances (500 m), copper and 

 quillback rockfishes, which co-occur with lingcod, 

 moved along a bimodal northwest-southeast axis and 

 sometimes retraced that path before finally moving 

 in a westerly direction that led to their home site 

 (Matthews 1990). After displacement, initial movement 

 of lingcod was in the homeward direction only, i.e., no 

 back-and-forth movement between the release site and 

 home site was observed. The more direct and noctur- 

 nal homing in lingcod suggests they are navigating 

 rather than orienting along one compass course or rely- 

 ing on olfactory cues. Orientation can be ruled out 

 (Baker 1978, Able 1980) because lingcod successfully 

 homed from north and south displacements. It is cur- 

 rently unknown whether rocky-reef fish, including 

 lingcod, recognize olfactory cues. 



Lingcod homing was fast in comparison with copper 

 and quillback rockfishes, which took 8-25 d to return 

 from 500 m displacements (Matthews 1990). From an 

 analysis of a large-scale tagging program during 

 1982-87, Smith et al. (1990) estimated that mean 

 dispersal rates for male and female lingcod were 

 500 m/d and 1040 m/d, respectively, similar to those 

 observed in the present study (1 173.7 m/24h). Pre- 

 sumably, lingcod movement rates vary depending upon 

 seasonal requirements (e.g., feeding, spawning, etc.). 



Several hypotheses could explain why the smallest 

 male (no. 8) did not return from displacement. Perhaps 

 lingcod do not develop a resident or homing response 

 until they are older and larger. The length-maturity 

 relationship is determined by their geographic area 

 (Richards et al. 1990), and the 50% maturity level for 

 male lingcod at a similar latitude off the west coast of 

 Vancouver Island is 57.1cm. Thus, if fish no. 8 (57.0 cm) 

 was not sexually mature, it may have lacked the abil- 

 ity to home. Buckley et al. (1984) also noted a lack of 

 homing in small male lingcod. In that study, after 

 4. Syr, the smallest transplanted lingcod (a 57cm male) 

 remained close to the release site after most trans- 

 planted lingcod had apparently homed. Alternatively, 

 the lack of homeward movement could be due to tag 

 shedding, which would also produce a stationary signal. 



This study revealed new information on lingcod hom- 

 ing behavior. After displacement up to 2.8km, lingcod 

 moved at night back to home sites within 60 h and 

 followed a fairly direct route. Because this was a pilot 



study and I displaced only male lingcod, more track- 

 ing studies are needed to increase sample sizes, include 

 females, and attempt longer-distance transplants. 

 Whether they home and reuse spawning areas will be 

 important to document, as this information is crucial 

 if lingcod preserves are established. It does appear that 

 transplant attempts to rebuild lingcod stocks may be 

 ineffective with larger, older males but may be suc- 

 cessful if the lingcod are moved before they reach a 

 certain size or age. 



Acknowledgments 



Claudia Hand, John Candy, and Bronwyn Lewis ably 

 caught the lingcod and assisted in all phases of the field 

 work including the tortuous all-night trips. This 

 research was conducted while I held a Natural Sciences 

 and Engineering Research Council Visiting Scientist 

 Fellowship at the Canadian Department of Fisheries 

 and Oceans Pacific Biological Station under the spon- 

 sorship of Dr. Laura Richards. The Institute of Ocean 

 Sciences in Sidney kindly loaned us the use of the 

 research vessel Orca. Dr. Richards and two anonjmous 

 reviewers provided helpful comments which greatly im- 

 proved the manuscript. 



Citations 



Able, K.P. 



1980 Mechanisms of orientation, navigation, and homing. In 

 Gauthreaux, S.A. Jr. (ed.), Animal migration, orientation, and 

 navigation, p. 283-373. Academic Press, NY. 

 Baker. R.R. 



1978 Evolutionary ecoiogj' of animal migration. Holmes and 

 Meier Publ., Inc., NY. 1012 p. 

 Buckley, R., G. Hueckel, B. Benson, S. Quinnel, and M. Canfield 

 1984 Enhancement research on lingcod {Oph lodon elongatus) 

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 Canadian Hydrographic Service 



1990 Canadian tide and current tables. Pacific Coast, vol. 5. 

 Carlson, H.R., and R.E. Haight 



1972 Evidence for a home site and homing of adult yellowtail 

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 Cass, A.J., R.J. Beamish, and G.A. McFarlane 



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1976 Day versus night activity of reef fishes in a kelp forest 

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 Gerking, S.D. 



1959 The restricted movement of fish populations. Biol. Rev. 

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 Hart, J.L. 



1943 Migration of lingcod. Fish. Res. Board Can., Prog. Rep. 

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