Patterns of growth, mortality, and size of the tropical damselfish Acanthochromis polyacanthus across the continental shelf of the Great Barrier Reef
Kingsford, Michael J., and Hughes, Julian M. (2005) Patterns of growth, mortality, and size of the tropical damselfish Acanthochromis polyacanthus across the continental shelf of the Great Barrier Reef. Fishery Bulletin, 103 (4). pp. 561-573.
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Age-based analyses were used to demonstrate consistent differences in growth between populations of Acanthochromis polyacanthus (Pomacentridae) collected at three distance strata across the continental shelf (inner, mid-, and outer shelf) of the central Great Barrier Reef (three reefs per distance stratum). Fish had significantly greater maximum lengths with increasing distance from shore, but fish from all distances reached approximately the same maximum age, indicating that growth is more rapid for fish found on outer-shelf reefs. Only one fish collected from inner-shelf reefs reached >100 mm SL, whereas 38-67% of fish collected from the outer shelf were >100 mm SL. The largest age class of adult-size fish collected from inner-and mid-shelf locations comprised 3-4 year-olds, but shifted to 2-year-olds on outer-shelf reefs. Mortality schedules (Z and S) were similar irrespective of shelf position (inner shelf: 0.51 and 60.0%; mid-shelf: 0.48 and 61.8%; outer shelf: 0.43 and 65.1%, respectively). Age validation of captive fish indicated that growth increments are deposited annually, between the end of winter and early spring. The observed cross-shelf patterns in adult sizes and growth were unlikely to be a result of genetic differences between sample populations because all fish collected showed the same color pattern. It is likely that cross-shelf variation in quality and quantity of food, as well as in turbidity, are factors that contribute to the observed patterns of growth. Similar patterns of cross-shelf mortality indicate that predation rates varied little across the shelf. Our study cautions against pooling demographic parameters on broad spatial scales without consideration of the potential for cross-shelf variability.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||continental shelves, barrier reefs, mortality causes, body size, biological age, turbidity, tropical environment, growth curves, variability, reef fish, growth rate, food availability, environmental factors, Acanthochromis polyacanthus, Pomacentridae, ISEW, Australia, Queensland, Great Barrier Reef|
Originally published in the Fishery Bulletin (2005, Vol. 103, Issue 4).
|Date Deposited:||24 May 2007|
|FoR Codes:||06 BIOLOGICAL SCIENCES > 0602 Ecology > 060205 Marine and Estuarine Ecology (incl Marine Ichthyology) @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 100%|
|Citation Count from Web of Science||