Tidal Modifications and Associated Circulation in a Platform Reef Lagoon

1979 ◽  
Vol 30 (4) ◽  
pp. 425 ◽  
Author(s):  
CA Ludington

Comparison of tidal records from One Tree Island and Heron Island, Southern Great Barrier Reef, shows that ponding of water inside the reef crest at One Tree Reef holds the lagoon water level near Mean Water Level for 5-6 h of each tide. The lagoon is therefore isolated from the surrounding ocean for half of each tidal cycle. The level of the tide with respect to the reef crest determines the impact of energy inputs on lagoon circulation. Details of the lagoon tidal curve are described and the implications for lagoon circulation, flushing and sedimentation are discussed.

Zootaxa ◽  
2009 ◽  
Vol 2260 (1) ◽  
pp. 927-930
Author(s):  
J. K. LOWRY ◽  
H. E. STODDART

One species of wandinid amphipod is reported from the Great Barrier Reef, Queensland, Australia. Wandin griffini Lowry & Stoddart is known from Lizard Island, One Tree Island and reefs on the Outer Barrier, living among rubble usually at the base of living coral. The species is rare in this habitat.


1986 ◽  
Vol 37 (5) ◽  
pp. 609 ◽  
Author(s):  
DM Alongi

Population structure and trophic composition of free-living nematodes from carbonate sands within different functional zones (reef crest, reef flat and lagoon) of Davies Reef in the Great Barrier Reef were examined. At the reef crest (station C) and at a shallow lagoon area unprotected by the back wall of the reef flat (station G), sediments were subjected to intense wave action and supported significantly (P < 0.05) lower mean nematode densities (<60 individuals per 10 cm2) than sands within the other reef zones (100-400 individuals per 10 cm2). Mean nematode densities and numerical species richness were highest (P < 0.05) in a shallow lagoon habitat protected from hydrodynamic- induced disturbances by the back wall of the reef flat (station H). Differences in population densities among the reef zones were not related to water depth or sediment granulometry. Species diversity was low within the reef, with only six species present in deep lagoon sands co-inhabited by actively bioturbating ghost shrimps (Callianassa spp.). Normal classification, nodal analysis and detrended correspondence analysis indicated that faunal groups were distinct among the different reefal zones. Very coarse to medium sands at the reef crest and across the reef flat were inhabited primarily by omnivorous and epistrate-feeding nematodes. Most nematodes within the very fine to fine sands of the lagoon were non-selective or selective deposit feeders. Nematode community structure from the reef crest to the shallow lagoon appears to be determined primarily by sediment granulometry as controlled by reef hydrodynamics, whereas in the deep lagoon nematode communities are negatively affected by the presence of thalassinid ghost shrimps.


1990 ◽  
Vol 41 (1) ◽  
pp. 1 ◽  
Author(s):  
IF Somers

The potentially detrimental side-effects of prawn trawling are coming under increasing scrutiny in Australian waters, particularly in such ecologically sensitive areas as Queensland's Great Barrier Reef, and various restrictive measures are being suggested. Before changes are imposed on the prawning industry, the effects of trawling on the target prawn species and the long-term management of these effects need to be fully understood. Using a simulation model of a simplified prawn fishery, this paper describes the basis for the current regulatory mechanisms for Australian's prawn fisheries, in particular the manipulation of both the level and pattern of fishing effort. It is shown that even in moderately fished stocks, the fishery manager has several options, such as seasonal and nursery area closures, that are consistent with the goal of minimizing the impact of prawn trawling, while in no way penalizing the industry economically. With these in mind, possible ways of resolving or reducing the conflict with groups outside the prawning industry are discussed.


2011 ◽  
Vol 33 (3) ◽  
pp. 267 ◽  
Author(s):  
M. Star ◽  
P. Donaghy ◽  
J. Rolfe

The impact of excessive sediment loads entering into the Great Barrier Reef lagoon has led to increased awareness of land condition in grazing lands. Improved ground cover and land condition have been identified as two important factors in reducing sediment loads. This paper reports the economics of land regeneration using case studies for two different land types in the Fitzroy Basin. The results suggest that for sediment reduction to be achieved from land regeneration of more fertile land types (brigalow blackbutt) the most efficient method of allocating funds would be through extension and education. However for less productive country (narrow leaved ironbark woodlands) incentives will be required. The analysis also highlights the need for further scientific data to undertake similar financial assessments of land regeneration for other locations in Queensland.


2019 ◽  
Vol 11 (10) ◽  
pp. 1211 ◽  
Author(s):  
Fardin Seifi ◽  
Xiaoli Deng ◽  
Ole Baltazar Andersen

The latest satellite and in situ data are a fundamental source for tidal model evaluations. In this work, the satellite missions TOPEX/Poseidon, Jason-1, Jason-2 and Sentinel-3A, together with tide gauge data, were used to investigate the performance of recent regional and global tidal models over the Great Barrier Reef, Australia. Ten models, namely, TPXO8, TPXO9, EOT11a, HAMTIDE, FES2012, FES2014, OSUNA, OSU12, GOT 4.10 and DTU10, were considered. The accuracy of eight major tidal constituents (i.e., K1, O1, P1, Q1, M2, S2, N2 and K2) and one shallow water constituent (M4) were assessed based on the analysis of sea-level observations from coastal tide gauges and altimetry data (TOPEX series). The outcome was compared for four different subregions, namely, the coastline, coastal, shelf and deep ocean zones. Sea-level anomaly data from the Sentinel-3A mission were corrected using the tidal heights predicted by each model. The root mean square values of the sea level anomalies were then compared. According to the results, FES2012 compares more favorably to other models with root mean square (RMS) values of 10.9 cm and 7.7 cm over the coastal and shelf zones, respectively. In the deeper sections, the FES2014 model compares favorably at 7.5 cm. In addition, the impact of sudden fluctuations in bottom topography on model performances suggest that a combination of bathymetric variations and proximity to the coast or islands contributes to tidal height prediction accuracies of the models.


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