Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
Shopping Cart: ( empty )
You are here: Home > Journals > MF > MF09278
RESEARCH ARTICLE
Contents Vol 61(10)

Spatial and fishing effects on sampling gear biases in a tropical reef line fishery

David J. Welch A B E , Bruce D. Mapstone C , Campbell R. Davies C and Garry R. Russ D
+ Author Affiliations
- Author Affiliations

A Queensland Primary Industries and Fisheries, Department of Employment, Economic Development and Innovation, PO Box 1085, Oonoonba, 4811 Qld, Australia.

B Fishing and Fisheries Research Centre, James Cook University, Townsville, Qld 4811, Australia.

C CSIRO Marine and Atmospheric Research, Castray Esplanade, Hobart, Tas. 7005, Australia.

D School of Marine and Tropical Biology and ARC Centre for Coral reef Studies, James Cook University, Townsville, Qld 4811, Australia.

E Corresponding author. Email: david.welch@jcu.edu.au

Marine and Freshwater Research 61(10) 1134-1146 https://doi.org/10.1071/MF09278
Submitted: 2 November 2009  Accepted: 27 April 2010   Published: 14 October 2010

Abstract

Biased estimates of population parameters for harvested stocks can have severe implications for fishery management strategy choices. Hook-and-line fishing gear is size-selective and therefore collects biased samples from wild populations. Such biases may also vary in space and time. To assess this assertion, we compared line- and spear-caught samples of the main target species of an Australian hook-and-line fishery to quantify relative bias in size and age structure estimates. We also assessed the consistency of biases among four fishery regions and between two management zones – areas open and closed to fishing. Fish less than 310 mm and younger than 4 years comprised a larger proportion of the speared than the line samples regardless of region or management zone. Conversely, hook-and-line sampled more fish in larger size classes (>370 mm) and older age classes (≥6 years) relative to spear fishing. These biases were qualitatively, but not quantitatively, consistent in all regions and management zones. This variation in sampling resulted in different inferences about regional and zone-related patterns in population size and age structure. We recommend careful consideration of sampling bias when drawing conclusions about regional and management zone effects on fish populations.

Additional keywords: bias, coral trout, Great Barrier Reef, hook-and-line, no-take zones, selectivity, spearfishing.


Acknowledgements

We thank Lizard Island Research Station, the crews of ‘Whyllaway’, ‘Hamdon Star’ and ‘RV James Kirby’, Judy Horsfall, Matt Kenway, and members of the Townsville Skindiving Club, particularly Bill Roberts and John Robinson, for assisting in the field collections. Ashley Williams (AW in Methods) assisted with otolith counts. The CRC Reef Research Centre is acknowledged for the financial support. We are grateful for the constructive comments received from the Editor, Professor Andrew Boulton, and two anonymous referees. Sampling work was conducted under the following permits: GBRMPA permits G96/454, QFMA Permit No. 42294, and JCU Ethics approval No. A771_02. This manuscript is a contribution from the Co-operative Research Centre’s Reef Effects of Line Fishing Project.


References

Alós, J. , Palmer, M. , Grau, A. M. , and Deudero, S. (2008). Effects of hook size and barbless hooks on hooking injury, catch per unit effort, and fish size in a mixed-species recreational fishery in the western Mediterranean Sea. ICES Journal of Marine Science 65, 899–905.
| Crossref | GoogleScholarGoogle Scholar | Ayling A. M., and Ayling A. L. (1997). Bramble Reef replenishment area: Pre- and post-opening surveys. Report to the Great Barrier Reef Marine Park Authority, Townsville, Australia.

Ayling A. M., Ayling A. L., and Mapstone B. D. (1992). Possible effects of protection from fishing pressure on recruitment rates of the coral trout (Plectropomus leopardus: Serranidae). Bureau of Rural Resources Proceedings 16, 210–215.

Bakeman R., and Robinson B. F. (1994). ‘Understanding Log-Linear Analysis with ILOG: An Interactive Approach.’ (Lawrence Erlbaum Associates: Hillsdale, NJ.)

Begg, G. A. , Hare, J. A. , and Sheehan, D. D. (1999). The role of life history parameters as indicators of stock structure. Fisheries Research 43, 141–163.
| Crossref | GoogleScholarGoogle Scholar | Brown I. W., Squire L., Baltus C., and Sellin M. (1996). Effect of zoning changes on the fish populations of unexploited reefs. Stage 2: Post-opening assessment. Report to the Great Barrier Reef Marine Park Authority, Queensland Department of Primary Industries, Deception Bay, Australia.

Bullock, L. H. , Murphy, M. D. , Godcharles, F. , and Mitchell, M. E. (1992). Age, growth and reproduction of jewfish Epinephelus itajara in the eastern Gulf of Mexico. Fishery Bulletin 90, 243–249.
Davies C. R., Williams A. J., Mapstone B. D., Benzie J., van Herwerden L., et al. (2006). Stock structure and regional variation in population dynamics of the red throat emperor and other target species of the Queensland tropical reef line fishery. CRC Reef Research Centre Technical Report No. 61, CRC Reef Research Centre, Townsville, Australia.

DeVries, D. A. (2007). No evidence of bias from fish behaviour in the selectivity of size and sex of the protogynous red porgy (Pagrus pagrus, Sparidae) by hook-and-line gear. Fishery Bulletin 105, 582–587.
Doherty P. J. (1996). The early life history of the common coral trout. Australian Institute of Marine Science Report to the Co-operative Research Centre: Reef Research Centre, Townsville, Australia.

Doherty, P. J. , Fowler, A. J. , Samoilys, M. A. , and Harris, D. A. (1994). Monitoring the replenishment of coral trout (Pisces: Serranidae) populations. Bulletin of Marine Science 54, 343–355.
Haddon M. (2001). ‘Modelling and Quantitative Methods in Fisheries.’ (Chapman and Hall/CRC: Boca Raton, FL, USA.)

Hamley, J. M. (1975). Review of gillnet selectivity. Journal of the Fisheries Research Board of Canada 32, 1943–1969.
Hilborn R., and Walters C. J. (Eds) (1992). ‘Quantitative Fisheries Stock Assessment: Choice, Dynamics and Uncertainty.’ (Chapman and Hall: London.)

Horn, P. L. (1997). An ageing methodology, growth parameters and estimates of mortality for hake (Merluccius australis) from around the South Island, New Zealand. Marine and Freshwater Research 48, 201–209.
| Crossref | GoogleScholarGoogle Scholar | Jones G. P. (1991). Post-recruitment processes in the ecology of coral reef fish populations: a multifactorial perspective. In ‘The Ecology of Fishes on Coral Reefs’. (Ed. P. F. Sale.) pp. 294–328. (Academic Press: San Diego, CA.)

Karpouzi, V. S. , and Stergiou, K. I. (2003). The relationships between mouth size and shape and body length for 18 species of marine fishes and their trophic implications. Journal of Fish Biology 62, 1353–1365.
| Crossref | GoogleScholarGoogle Scholar | Mapstone B. D., Campbell R. A., and Smith A. D. M. (1996a). Design of experimental investigations of the effects of line and spear fishing on the Great Barrier Reef. CRC Reef Research Technical Report No. 7. Reef Research Centre. Townsville. Australia. Available at www.reef.crc.org.au/publications/techreport/TechRep7 [Verified 28 July 2010].

Mapstone B. D., McKinlay J. P., and Davies C. R. (1996b). A description of the commercial reef line fishery logbook data held by the Queensland Fisheries Management Authority. Report to the Queensland Fisheries Management Authority, Brisbane, Australia.

Mapstone B. D., Davies C. R., Slade S. J., Jones A., Kane K. J., et al. (2001). Effects of live fish trading and targeting spawning aggregations on fleet dynamics, catch characteristics, and resource exploitation by the Queensland commercial demersal reef line fishery. Research Report No 96/138, Fisheries Research and Development Corporation, Canberra, Australia.

Mapstone B. D., Davies C. R., Little L. R., Punt A. E., Smith A. D. M., et al. (2004). The effects of line fishing on the Great Barrier Reef and evaluation of alternative potential management strategies. Co-operative Research Centre’s Reef Research Centre Technical Report No. 52. Reef Research Centre. Townsville. Australia. Available at www.reef.crc.org.au/publications/techreport/techrept52 [Verified 11 May 2010].

Mapstone, B. D. , Little, L. R. , Punt, A. E. , Davies, C. R. , and Smith, A. D. M. , et al. (2008). Management strategy evaluation for line fishing in the Great Barrier Reef: balancing conservation and multi-sector fishery objectives. Fisheries Research 94, 315–329.
| Crossref | GoogleScholarGoogle Scholar | Pauly D. (1984). Fish population dynamics in tropical waters: A manual for use with programmable calculators. International Centre for Living Aquatic Resources Studies and Reviews 8, 325.

Quinn T. J., and Deriso R. B. (1999). ‘Quantitative Fish Dynamics.’ (Oxford University Press: New York.)

Ralston, S. (1990). Size selection of snappers (Lutjanidae) by hook and line gear. Canadian Journal of Fisheries and Aquatic Sciences 47, 696–700.
| Crossref | GoogleScholarGoogle Scholar | Sokal R. R., and Rohlf F. J. (1981). ‘Biometry: The Principles and Practice of Statistics in Biological Research.’ (W. H. Freeman: San Francisco, CA.)

St John, J. , Russ, G. R. , Brown, I. , and Squire, L. (2001). The diet of the large coral reef serranid, Plectropomus leopardus, in two fishing zones on the Great Barrier Reef, Australia. Fishery Bulletin 99, 180–192.
Strachan Fulton E. (1996). An investigation of the determinants of the commercial catch rate of Plectropomus leopardus (Serranidae), with regard to the targeting of spawning aggregations, using computer simulation. Honours thesis, Departments of Marine Biology and Mathematics and Statistics, James Cook University, Townsville, Australia.

Tabachnick B. G., and Fidell L. S. (2006). ‘Using Multivariate Statistics.’ 5th edn. (Allyn and Bacon: Needham Heights, MA.)

Welch, D. J. , Mapstone, B. D. , and Begg, G. A. (2008). Spatial and temporal variation and effects of changes in management in discard rates from the commercial reef line fishery of the Great Barrier Reef, Australia. Fisheries Research 90, 247–260.
| Crossref | GoogleScholarGoogle Scholar | Williams D. McB. (1991). Patterns and processes in the distribution of coral reef fishes. In ‘The Ecology of Fishes on Coral Reefs’. (Ed. P. F. Sale.) pp. 437–474. (Academic Press: San Diego, CA.)

Williams, A. J. , Davies, C. R. , Mapstone, B. D. , and Russ, G. R. (2003). Scales of spatial variation in demography of large coral reef fish: An exception to the typical model? Fishery Bulletin 101, 673–683.


Willis, T. J. , Millar, R. B. , Babcock, R. C. , and Tolimieri, N. (2003). Burdens of evidence and the benefits of marine reserves: putting Descartes before des horse? Environmental Conservation 30, 97–103.
| Crossref | GoogleScholarGoogle Scholar |

Zeller, D. C. (1997). Home range and activity patterns of the coral trout Plectropomus leopardus (Serranidae). Marine Ecology Progress Series 154, 65–77.
| Crossref | GoogleScholarGoogle Scholar |