44 research outputs found
Review of data on fishes of commerical and recreational fishing interest in the Great Barrier Reef Vol. 2
This document lists 1132 references directly relevant to reef fisheries in general and reef fisheries on the Great Barrier Reef in particular. It was prepared for the Great Barrier Reef Marine Park Authority as part of a review of data on fishes of commercial and recreational fishing interest on the Great Barrier Reef. The companion volume (Volume I, Williams and Russ, 1994) provides a review of the data specifically relating to the Great Barrier Reef and includes its own reference section which is partially, but not completely, a subset of the references provided here.This is Vol 2 of 2. Volume 1 can be found at http://hdl.handle.net/11017/23
Abundance patterns of reef sharks and predatory fishes on differently zoned reefs in the offshore Townsville region final report to the Great Barrier Reef Marine Park Authority
Sharks were counted in six 500 x 20 m transects on the slope of each reef during late
March 2008. Densities of whitetip reef sharks (Triaenodon obesus) were twice as high on
green reefs as on blue reefs but were twice as high on pink reefs as on green reefs.
Similarly, grey reef sharks (Carcharhinus amblyrhynchos) were four times as abundant
on green reefs as on blue reefs, but twice as abundant on pink reefs as on green reefs.
We also recorded the abundance of large teleost reef fishes during all counts. There
were similar patterns in the density of the common coral trout (Plectropomus leopardus),
with 1.5 times as many coral trout on green reefs as on blue reefs but 2.5 times as many
on pink reefs compared with green reefs
A visual survey of demersal biota in the Cairns section of the Great Barrier Reef Marine Park
We surveyed 50 reefs over the entire Cairns Section. including reefs with a history of closure to
extractive uses such as fishing, reefs that had always been open to most uses, and reefs that were
to have their zoning status changed under the as amended zoning plan. In so doing. we were
also in a position to compare the status. in 1990-91, of reefs with different zoning histories.
albeit in the absence of structured baseline data from before the then effective zoning period
(1983-91). We surveyed six locations around the perimeter of each reef by well·established and
tested underwater visual survey methods
Scales and magnitudes of variation in population densities of some coral reef organisms : implications for the design of sampling and monitoring procedures
In this report we have concentrated on the description of variation in abundances of several coral
reef organisms in the Cairns Section of the Great Barrier Reef (GBR) Marine Park. Our focus was
on the implications of spatial variation for the design of sampling and monitoring programmes and
the inference of spatial pattern. Patterns of interest might arise, for example, from effects of areabased
management strategies or human impacts on the reef environment. The data we present
indicate that spatial variation is large at most scales for most organisms. Consequently, it is
unlikely that small or even moderate spatial patterns caused by management strategies, human use,
or natural perturbations will be detectable reliably without considerable expense
Habitat, cross shelf and regional patterns in the distributions and abundances of some coral reef organisms on the northern Great Barrier Reef, with comment on the implications for future monitoring
In this report we describe some relatively large-scale patterns in the distributions and abundances
of several coral reef organisms on the northern Great Barrier Reef. We considered the degree to
which habitat, position across the continental shelf, and region explained variations in abundances.
These factors have been invoked as major determinants of pattern in abundances in past studies
and we sought to examine the consistency and generality of such models. Our main focus was on
the implications of systematic patterns in abundance for the spatial design of sampling and
monitoring programmes. Ignorance or inappropriate treatment of strong systematic patterns when
designing monitoring and assessment programmes has the potential to cause mistaken conclusions
about the merits of future management strategies or the performance of existing strategies
High densities of the large bodied parrotfishes (Scaridae) at two Venezuelan offshore reefs: comparison among four localities in the Caribbean
Declining grouper spawning aggregations in Western Province, Solomon Islands, signal the need for a modified management approach
Globally, groupers (Epinephelidae) that form fish spawning aggregations (FSAs) are highly vulnerable to overfishing and often require site-specific approaches to management. Over 5-years (2009-2013), we conducted underwater visual censuses (UVC) at a well-known spawning site at Njari Island, Gizo, Western Province, Solomon Islands, that supports aggregations of squaretail coralgrouper (Plectropomus areolatus), camouflage grouper (Epinephelus polyphekadion) and brown-marbled grouper (E. fuscoguttatus). Findings show that while there were species-specific variations in the duration and timing of the spawning season, aggregation densities peaked from March to June, representing the main spawning season for all three species. For P. areolatus, gonad analysis from samples taken from 2008 to 2011 confirmed reproductive activity in support of density trends observed through UVC. Over the 5-year UVC monitoring period, FSA densities declined for P. areolatus and E. polyphekadion. Conversely, following the first year of monitoring, E. fuscoguttatus densities increased. These inter-specific differences may reflect variable responses to fishing as shown elsewhere, or for example, differences in recruitment success. In response to known declines in FSAs of these species, in 2018 the Solomon Islands government placed a nationwide ban on these species' harvest and sale between October and January. As this study shows, this ban does not encompass the peak aggregation period at Njari and will offer limited protection to other FSAs of these species that are known to vary in reproductive seasonality across the Solomon Islands. A more biologically meaningful and practical management strategy would be to implement a nationwide ban on the harvest and sale of these groupers each month between full and new moons when these FSAs form consistently throughout the country. Since effective management of FSAs typically requires a combined approach, spatial management that protects both spawning sites and reproductive migratory corridors is warranted
Patterns of biogeographic and regional life-history trait variation in four large-bodied tropical wrasses
Ectotherms display substantial demographic variation across latitudinal gradients of temperature. Higher temperatures are often associated with smaller size, rapid initial growth rates, and early maturation, generally described as the Temperature-Size Rule (TSR). The longevity of most ectotherms also declines at warmer, lower latitudes. However, these patterns may be modified by increases in food resources that can flow on to continuous growth and large adult size. The present study estimates age-based demographic parameters of large-bodied tropical wrasses (Hemigymnus melapterus, H. fasciatus, Cheilinus fasciatus, and Oxycheilinus digramma) collected from Philippine fish markets (9-11 degrees N) and sampled from Palm (18.53-18.70 degrees S) and Whitsunday (20.05-20.21 degrees S) reefs on the Great Barrier Reef, Australia (GBR). Differences in longevity, initial growth rates, and the age at sexual maturation at a biogeographic scale, between the Philippines and GBR, conformed to predictions of the TSR. However, Philippine specimens exhibited greater relative body condition and sustained periods of growth beyond sexual maturity resulting in larger adult size than GBR samples. Size-structure data from Philippine marine reserves and fished sites indicated that these differences were not confounded by fishery-dependent sampling. Moreover, latitudinal length-weight relationships could not be explained by lower densities of the focal wrasses in the Philippines or by relative gonad size. Less pronounced patterns of demographic variation that differed across species were evident at a regional scale, among Palm and Whitsunday reefs. Patterns of demographic variation between the Philippines and GBR strongly suggest that differences in food resource levels will be important in explaining the observed geographic variation
High temporal resolution sampling reveals reef fish settlement is highly clustered
Coral reef fish larvae settle on reefs predominantly at night around the new-moon phase, after an early developmental period spent in the pelagic environment. Most sampling is conducted across whole nights, and any studies that have examined the frequency of arrival within nights have typically been limited to coarse sampling time scales of 1–5 h. Here, we present results for arrival numbers of fish caught between dusk and midnight from light traps sampled every 15 min at an Indonesian coral reef, providing the finest temporal resolution for this type of study to date. A spatial analysis by distance indices analysis, adapted to temporal data, revealed clustering of reef arrival times for many species, with an increase in catches immediately after dusk dropping off towards midnight. Importantly, the timing of clusters differed among species, indicating that different factors determine the timing of arrival among taxa. Our results support the hypothesis that larval behaviour influences the timing of arrival at a coral reef for different fish species