No-take marine reserves increase abundance and biomass of reef fish on inshore fringing reefs of the Great Barrier Reef

2004 ◽  
Vol 31 (2) ◽  
pp. 149-159 ◽  
Author(s):  
D.H. WILLIAMSON ◽  
G.R. RUSS ◽  
A.M. AYLING

The application of no-take marine reserve status to an area is expected to increase abundance and average size of individuals of species targeted by fisheries. The majority of the evidence supporting such expectations still involves comparisons of abundance at the one time of sites with and without marine reserve protection. Very few studies have data on the abundance and size structure of species targeted by fisheries in an area before reserve status is applied. Quantitative estimates of density and biomass of coral trout, Plectropomus spp., the major target of the hook and line fisheries on the Great Barrier Reef (GBR), Australia, on inshore fringing reefs of the Palm and Whitsunday Island groups, central GBR, are provided for 3–4 years before (1983–1984), and 12–13 years after (1999–2000) the establishment of no-take reserves in 1987. Quantitative estimates of density and biomass of coral trout in areas open to fishing were also collected in 1999–2000 at these two island groups. Density and biomass of coral trout increased significantly (by factors of 5.9 and 6.3 in the Palm Islands, and 4.0 and 6.2 in the Whitsunday Islands) in the reserve sites, but not the fished sites, between 1983–1984 and 1999–2000. In 1999–2000, density and biomass of coral trout and a secondary target of the fisheries, Lutjanus carponotatus, were significantly higher in the protected zones than in the fished zones at both island groups. The density and biomass of non-target fish species (Labridae, Siganidae and Chaetodontidae) did not differ significantly between reserve and fished zones at either island group. This is the most convincing data to date that the management zoning of the world's largest marine park has been effective, at least for coral trout on inshore reefs.

2000 ◽  
Vol 51 (3) ◽  
pp. 221 ◽  
Author(s):  
D. C. Zeller ◽  
G. R. Russ

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.


1989 ◽  
Vol 40 (2) ◽  
pp. 205 ◽  
Author(s):  
J Alder ◽  
R Braley

A survey of giant clams (family Tridacnidae) at Lizard Island fringing reefs on the Great Barrier Reef in July 1985 indicated that over the previous 6 weeks the combined total mortality for Tridacna gigas and T. derasa was 28% at Watson's Bay (WB) and 20% at the channel between Palfrey Island and South Island (P-S). Sporadic mortalities continued at intervals through to December 1985 when combined total mortalities at WB and P-S had reached 38% and 32%, respectively. By January 1987, mortality for these two species was 54% at WB and 51% at P-S. Deaths were not restricted to a particular size class and the average size of clams that died did not change with time during the study. Mortality rates for clams which had been previously biopsied for gonad condition and/or those induced to spawn with serotonin injection were not significantly different from controls. Distribution of dead clams was random to slightly clumped with respect to alive and dead clams within WB, and random within P-S. Results of heavy-metal analyses of tissues from moribund clams were similar to previous results for normal clams. The histopathology of tissues from six of eight moribund clams revealed an unidentified unicellular organism which was not found in Tridacna spp. from previous or subsequent samples from Lizard Island reefs or from other reef areas.


2007 ◽  
Vol 52 (3) ◽  
Author(s):  
Rodney Bray ◽  
Thomas Cribb ◽  
Andrea Waeschenbach ◽  
D. Littlewood

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.


2020 ◽  
Vol 287 (1936) ◽  
pp. 20201432
Author(s):  
Andreas Dietzel ◽  
Michael Bode ◽  
Sean R. Connolly ◽  
Terry P. Hughes

The age or size structure of a population has a marked influence on its demography and reproductive capacity. While declines in coral cover are well documented, concomitant shifts in the size-frequency distribution of coral colonies are rarely measured at large spatial scales. Here, we document major shifts in the colony size structure of coral populations along the 2300 km length of the Great Barrier Reef relative to historical baselines (1995/1996). Coral colony abundances on reef crests and slopes have declined sharply across all colony size classes and in all coral taxa compared to historical baselines. Declines were particularly pronounced in the northern and central regions of the Great Barrier Reef, following mass coral bleaching in 2016 and 2017. The relative abundances of large colonies remained relatively stable, but this apparent stability masks steep declines in absolute abundance. The potential for recovery of older fecund corals is uncertain given the increasing frequency and intensity of disturbance events. The systematic decline in smaller colonies across regions, habitats and taxa, suggests that a decline in recruitment has further eroded the recovery potential and resilience of coral populations.


2018 ◽  
Vol 69 (8) ◽  
pp. 1201
Author(s):  
B. K. Diggles ◽  
I. Ernst ◽  
S. Wesche

Coral reefs worldwide are under increasing stress from anthropogenic impacts, but there are relatively few reports of increased rates of disease in coral reef fish. Herein we report the emergence of abnormal skin lesions in wild-caught wire netting cod (Epinephelus quoyanus) near Heron Island in the southern Great Barrier Reef. The lesion involves conspicuous darkening and disorganisation of the brown ‘wire netting’ colouration pattern typical of this species, most commonly on the lower jaw, premaxilla and head, with occasional involvement of the flanks and dorsal fin in some fish. The lesion was not present during research conducted in the mid-1990s; however, since it was first recorded in 2012, the prevalence of grossly visible lesions has increased to 16.9% in 2017, with fish >340mm long most affected (prevalence 64.7%). These data suggest emergence of the lesion is a recent phenomenon and that causative factors may be age related. Abnormal pigmentation lesions have only been observed to affect E. quoyanus and coral trout (Plectropomus leopardus; since 2010). Given the species affected and the currently unknown aetiology of these lesions, we name the condition serranid pigment abnormality syndrome (SPAS). Further research is required to determine its geographic distribution, establish causation and describe the course of disease in E. quoyanus.


1991 ◽  
Vol 42 (3) ◽  
pp. 241 ◽  
Author(s):  
RG Pearson ◽  
JL Munro

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.


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