Mortality rate of a cohort of the coral trout, Plectropomus leopardus, in zones of the Great Barrier Reef Marine Park closed to fishing

1998 ◽  
Vol 49 (6) ◽  
pp. 507 ◽  
Author(s):  
Garry R. Russ ◽  
Dong C. Lou ◽  
James B. Higgs ◽  
Beatrice P. Ferreira
Keyword(s):  
Mortality Rate ◽  
Great Barrier Reef ◽  
Small Sample ◽  
Barrier Reef ◽  
Coral Trout ◽  
Marine Park ◽  
Plectropomus Leopardus ◽  
Catch Rates ◽  
Small Sample Sizes ◽  
Annual Mortality

From 1990 to 1993, samples of coral trout, Plectropomus leopardus, were collected at two coral reefs closed to fishing since 1987 in the central Great Barrier Reef (GBR). The age structure was dominated by a strong cohort which settled in early 1984 and which accounted for 54%, 45%, 42% and 36% of the experimental hook-and-line catches at Glow and Yankee reefs. Catch rates (fish person-1 hour-1) per age class per reef per year provide the first reliable estimates of the exponential rate of mortality of coral trout in zones of the GBR Marine Park closed to fishing. The annual mortality rate between the ages of 6 and 9 years was 0.115 (s.e. 0.040) at Glow reef and 0.189 (s.e. 0.100) at Yankee reef. The annual mortality rate between ages 6 and 9 years was 0.147 (s.e. 0.028) at the two reefs combined. Age-specific estimates of annual mortality ranged from 0.024 (age 7–8 at Glow) to 0.442 (age 6–7 at Yankee) but were unreliable because of small sample sizes. This is one of the first estimates of mortality rate of an exploited species in an area closed to fishing in the tropics.

A new species of Stephanostomum Looss, 1899 (Digenea, Acanthocolpidae) with a bizarre oral sucker: S. adlardi sp. nov. from the common coral trout Plectropomus leopardus (Lacepède, 1802) (Perciformes, Serranidae) from Lizard Island, Great Barrier Reef

2007 ◽  
Vol 52 (3) ◽  
Author(s):  
Rodney Bray ◽  
Thomas Cribb ◽  
Andrea Waeschenbach ◽  
D. Littlewood
Keyword(s):  
New Species ◽  
Great Barrier Reef ◽  
Oral Sucker ◽  
Ribosomal Rna ◽  
Barrier Reef ◽  
Coral Trout ◽  
Lizard Island ◽  
The Common ◽  
Plectropomus Leopardus ◽  
A New Species

AbstractA new species of Acanthocolpidae, Stephanostomum adlardi is described from the serranid Plectropomus leopardus from Lizard Island in the northern Great Barrier Reef. It differs from all previously described acanthocolpids in the structure of the oral sucker which is extended into dorsal and ventral lobes each bearing a row of spines. A phylogenetic tree estimated from combined nuclear small and partial large ribosomal RNA gene sequences shows that, despite the unusual oral sucker structure, the species is a true member of the genus Stephanostomum. The molecular results also suggest that Monostephanostomum nolani is derived from within Stephanostomum.

Population estimates and size structure of Plectropomus leopardus (Pisces : Serranidae) in relation to no-fishing zones: mark-release-resighting and underwater visual census

2000 ◽  
Vol 51 (3) ◽  
pp. 221 ◽  
Author(s):  
D. C. Zeller ◽  
G. R. Russ
Keyword(s):  
Great Barrier Reef ◽  
Population Size ◽  
Size Structure ◽  
Barrier Reef ◽  
Visual Census ◽  
Underwater Visual Census ◽  
Coral Trout ◽  
Population Size Estimates ◽  
Lizard Island ◽  
Plectropomus Leopardus

A mark–release–resighting (MRR) technique was used to estimate population size of the coral trout, Plectropomus leopardus, on coral reefs fringing Lizard Island, Great Barrier Reef, Australia. Fish were captured by hook-and-line fishing, and marked with individual freeze-brand numbers in August 1995. An underwater visual census (UVC) technique was used during September and October 1995 both for resighting of marked fish and to make an independent estimate of fish density and thus population size. The study area was 750 966 m2 . The UVC sampled 154 000 m2 (20.5%) of this area. Six different methods of analysis of MRR gave similar population size estimates (e.g. Petersen 12 873; 95% CI 9989–15 754) extrapolated to the 4.5 million-m2 reef area from datum to 20-m depth around Lizard Island. UVC gave a population size estimate (24 182; 95% CI 21 860–26 504) twice that of MRR. The lower estimate derived from MRR may be the result of tag-induced mortality, or of the relative difficulty in discriminating between marked and unmarked trout by UVC. This is only the second estimate of population size of coral trout on an area of the Great Barrier Reef.

Growth, mortality and recruitment rates of giant clams, Tridacna gigas and T. derasa, at Michaelmas Reef, central Great Barrier Reef, Australia

1991 ◽  
Vol 42 (3) ◽  
pp. 241 ◽  
Author(s):  
RG Pearson ◽  
JL Munro
Keyword(s):  
Great Barrier Reef ◽  
Growth Curve ◽  
Size Structure ◽  
Mortality Rates ◽  
Small Sample ◽  
Parameter Estimates ◽  
Barrier Reef ◽  
Giant Clams ◽  
Tridacna Gigas ◽  
Annual Mortality

Growth, recruitment and mortality rates of a population of giant clams (Tridacna gigas and T. derasa) were monitored between 1978 and 1985 in a 2.7 ha study area on Michaelmas Reef, Great Barrier Reef. The initial 1978 census revealed the presence of 1166 T. gigas and 44 T. derasa. For T. gigas, the Fabens method provided growth-parameter estimates of L∞ = 85.7 cm, K = 0.07 and to = 0.732 year. The generated von Bertalanffy growth curve was a relatively poor fit to an empirical growth curve. A better description of growth was obtained for younger clams by using a forced value of L∞, = 80 cm, yielding K = 0.105 and to = 0.145 year. There was marked variability in the growth rate of individual clams, which has implications for the aquaculture industry. Average annual mortality rates in two census intervals (1978 to 1980-81 and 1980-81 to 1985) were 3.4 and 10.7% respectively. A comparison of the calculated size structure (assuming constant recruitment) with the observed size structure clearly suggested that recruitment was not constant and had declined drastically from a peak in the 1950s. For the much smaller population of T. derasa, the Fabens routine yielded estimates of L∞ = 46.91 cm, K= 0.108 and to = -0.188 year. The average annual mortality rate was 4.4%. Trends in recruitment could not be determined because of the small sample size. This study has highlighted the need for follow-up studies of this and other populations of giant clams if we are to understand more fully the processes of growth, recruitment and mortality in wild stocks and the implications for stock management and aquaculture.

Effects of fishing on a protogynous hermaphrodite

2001 ◽  
Vol 58 (3) ◽  
pp. 568-578 ◽  
Author(s):  
Paul R Armsworth
Keyword(s):  
Great Barrier Reef ◽  
Population Dynamic ◽  
Dynamic Models ◽  
Barrier Reef ◽  
Coral Trout ◽  
Precise Understanding ◽  
Protogynous Hermaphrodite ◽  
Reef Fish Species ◽  
Plectropomus Leopardus ◽  
Behavioural Mechanism

Population dynamic models and simulations are analysed for a harvested reef fish species that is a monandric, protogynous hermaphrodite. The models are applied to data for the coral trout Plectropomus leopardus (Pisces: Serranidae) on the Great Barrier Reef. One model examines the situation where sexual transition is induced by some exogenous behavioural mechanism, and another considers the case where transition is determined by some endogenous developmental schedule. The conclusions regarding the effects of fishing are common to both models, and the implementation of more efficient harvesting practices may not require a precise understanding of the mechanisms governing sexual transition.

Management of Water Quality in the Great Barrier Reef Marine Park

1989 ◽  
Vol 21 (2) ◽  
pp. 31-38 ◽  
Author(s):  
Simon Woodley
Keyword(s):  
Water Quality ◽  
Coral Reef ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Management Issue ◽  
Reef System ◽  
Marine Park ◽  
World Heritage List ◽  
The World ◽  
Coral Reef System

The Great Barrier Reef is the largest coral reef system in the world. It is recognised and appreciated worldwide as a unique environment and for this reason has been inscribed on the World Heritage List. The Reef is economically-important to Queensland and Australia, supporting substantial tourism and fishing industries. Management of the Great Barrier Reef to ensure conservation of its natural qualities in perpetuity is achieved through the establishment of the Great Barrier Reef Marine Park. The maintenance of water quality to protect the reef and the industries which depend on it is becoming an increasingly important management issue requiring better knowledge and possibly new standards of treatment and discharge.

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