scholarly journals Spatial and Temporal Patterns in Macroherbivore Grazing in a Multi-Species Tropical Seagrass Meadow of the Great Barrier Reef

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 12
Author(s):  
Abigail L. Scott ◽  
Paul H. York ◽  
Michael A. Rasheed
Keyword(s):  
Great Barrier Reef ◽  
Large Scale ◽  
Barrier Reef ◽  
Important Process ◽  
Spatial And Temporal Patterns ◽  
Video Cameras ◽  
Seagrass Meadows ◽  
One Year ◽  
The Impact ◽  
Green Island

Macroherbivory is an important process in seagrass meadows worldwide; however, the impact of macroherbivores on seagrasses in the Great Barrier Reef (GBR) has received little attention. We used exclusion cages and seagrass tethering assays to understand how the intensity of macroherbivory varies over space and time in the seagrass meadows around Green Island (Queensland), and what impact this has on overall meadow structure. Rates of macroherbivory were comparatively low, between 0.25–44% of daily seagrass productivity; however, rates were highly variable over a one-year period, and among sites. Loss of seagrass material to macroherbivory was predominantly due to fish; however, urchin herbivory was also taking place. Macroherbivory rates were of insufficient intensity to impact overall meadow structure. No macroherbivory events were identified on video cameras that filmed in the day, indicating that feeding may be occurring infrequently in large shoals, or at night. While relatively low compared to some meadows, seagrass macroherbivory was still an important process at this site. We suggest that in this highly protected area of the GBR, where the ecosystem and food webs remain largely intact, macroherbivory was maintained at a low level and was unlikely to cause the large-scale meadow structuring influence that can be seen in more modified seagrass systems.

Larval dispersal simulations: correlation with the crown-of-thorns starfish outbreaks database

1992 ◽  
Vol 43 (3) ◽  
pp. 569 ◽  
Author(s):  
MK James ◽  
JP Scandol
Keyword(s):  
Great Barrier Reef ◽  
Larval Dispersal ◽  
Large Scale ◽  
Numerical Models ◽  
Temporal Distribution ◽  
Research Programme ◽  
Strong Positive Correlation ◽  
Barrier Reef ◽  
Central Hypothesis ◽  
Scale Population

The work reported in this paper is a further development of results from a research programme whose principal objective is to achieve an understanding of the large-scale population dynamics of Acanthaster planci. The research is based on the development and use of numerical models of hydrodynamics and resulting larval dispersal throughout a large portion of the Great Barrier Reef. It is chiefly concerned with the large-scale statistical patterns of larval dispersal, the central hypothesis being that passive hydrodynamic dispersal plays an important role in the recruitment process. The present aim is to examine more closely than has been done before the consistencies between the modelling results and the database of recorded observations of crown-of-thorns starfish outbreaks. Reefs in the Cairns and Central Sections of the Great Barrier Reef Marine Park that were recorded as carrying active outbreaks during the period 1979-89 were used as sources in a programme of intensive simulations of Acanthaster larval dispersal under forcing by the wind, tidal action and the East Australian Current. The resulting broad-scale patterns of larval dispersal were found to be in strong qualitative agreement with the observed spatial and temporal distribution of adult Acanthaster populations. Statistical analysis of the results revealed a strong positive correlation between potential recruitment on surveyed reefs, as estimated by the dispersal simulations, and the observed presence of outbreak populations on those reefs. The correlation was particularly strong when different cross-shelf zones were considered separately.

Manipulation of fishing effort in Australia's penaeid Prawn Fisheries

1990 ◽  
Vol 41 (1) ◽  
pp. 1 ◽  
Author(s):  
IF Somers
Keyword(s):  
Side Effects ◽  
Great Barrier Reef ◽  
Simulation Model ◽  
Fishing Effort ◽  
Regulatory Mechanisms ◽  
Barrier Reef ◽  
Restrictive Measures ◽  
The Impact ◽  
Term Management

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.

Patterns of recruitment of polychaetes to coral substrates at Lizard Island, Great Barrier Reef - an experimental approach

1982 ◽  
Vol 33 (6) ◽  
pp. 1029 ◽  
Author(s):  
P Hutchings ◽  
A Murray
Keyword(s):  
Great Barrier Reef ◽  
Similar Pattern ◽  
Experimental Approach ◽  
Temporal Patterns ◽  
The Other ◽  
Barrier Reef ◽  
Spatial And Temporal Patterns ◽  
Lizard Island

The spatial and temporal patterns of recruitment of seven species in six families of polychaete to coral substrates at two sites at Lizard Island, Great Barrier Reef, are described. Four species exhibit similar patterns of recruitment to both sites, and another species exhibits a similar pattern to both sites but with different intensities. The other two species recruit in different patterns to the two sites. All species exhibit peaks of recruitment, most during mid-summer. Recruitment during 1977 was significantly greater than during 1976 for five of the seven species. Factors responsible for this variation and the patchiness of successful settlement are discussed.

Economically viable land regeneration in Central Queensland and improved water quality outcomes for the Great Barrier Reef

2011 ◽  
Vol 33 (3) ◽  
pp. 267 ◽  
Author(s):  
M. Star ◽  
P. Donaghy ◽  
J. Rolfe
Keyword(s):  
Great Barrier Reef ◽  
Ground Cover ◽  
Scientific Data ◽  
Barrier Reef ◽  
Sediment Loads ◽  
Land Condition ◽  
Sediment Reduction ◽  
Grazing Lands ◽  
The Impact ◽  
Land Types

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.

scholarly journals Assessment of the Accuracy of Recent Empirical and Assimilated Tidal Models for the Great Barrier Reef, Australia, Using Satellite and Coastal Data

2019 ◽  
Vol 11 (10) ◽  
pp. 1211 ◽  
Author(s):  
Fardin Seifi ◽  
Xiaoli Deng ◽  
Ole Baltazar Andersen
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Root Mean Square ◽  
Tide Gauge ◽  
Bottom Topography ◽  
Deep Ocean ◽  
Mean Square ◽  
Barrier Reef ◽  
In Situ Data ◽  
The Impact

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.

Analysis of the impact of prawn trawling on benthic species in the Great Barrier Reef Marine Park

2004 ◽  
Vol 15 (3) ◽  
pp. 279-289 ◽  
Author(s):  
P. J. Toscas ◽  
M. J. Faddy ◽  
C. Y. Burridge
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Benthic Species ◽  
Marine Park ◽  
The Impact

scholarly journals Effects of trawling on sessile megabenthos in the Great Barrier Reef and evaluation of the efficacy of management strategies

2015 ◽  
Vol 73 (suppl_1) ◽  
pp. i115-i126 ◽  
Author(s):  
C. Roland Pitcher ◽  
Nick Ellis ◽  
William N. Venables ◽  
Ted J. Wassenberg ◽  
Charis Y. Burridge ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Environmental Sustainability ◽  
Large Scale ◽  
Regional Scale ◽  
Regional Distribution ◽  
Dynamic Modelling ◽  
Barrier Reef ◽  
Worst Case ◽  
Management Actions ◽  
Management Interventions

Abstract A series of related research studies over 15 years assessed the effects of prawn trawling on sessile megabenthos in the Great Barrier Reef, to support management for sustainable use in the World Heritage Area. These large-scale studies estimated impacts on benthos (particularly removal rates per trawl pass), monitored subsequent recovery rates, measured natural dynamics of tagged megabenthos, mapped the regional distribution of seabed habitats and benthic species, and integrated these results in a dynamic modelling framework together with spatio-temporal fishery effort data and simulated management. Typical impact rates were between 5 and 25% per trawl, recovery times ranged from several years to several decades, and most sessile megabenthos were naturally distributed in areas where little or no trawling occurred and so had low exposure to trawling. The model simulated trawl impact and recovery on the mapped species distributions, and estimated the regional scale cumulative changes due to trawling as a time series of status for megabenthos species. The regional status of these taxa at time of greatest depletion ranged from ∼77% relative to pre-trawl abundance for the worst case species, having slow recovery with moderate exposure to trawling, to ∼97% for the least affected taxon. The model also evaluated the expected outcomes for sessile megabenthos in response to major management interventions implemented between 1999 and 2006, including closures, effort reductions, and protected areas. As a result of these interventions, all taxa were predicted to recover (by 2–14% at 2025); the most affected species having relatively greater recovery. Effort reductions made the biggest positive contributions to benthos status for all taxa, with closures making smaller contributions for some taxa. The results demonstrated that management actions have arrested and reversed previous unsustainable trends for all taxa assessed, and have led to a prawn trawl fishery with improved environmental sustainability.

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