The hawksbill turtle, Eretmochelys imbricata, in Queensland: population structure within a southern Great Barrier Reef feeding ground.

1992 ◽  
Vol 19 (4) ◽  
pp. 489 ◽  
Author(s):  
CJ Limpus
Keyword(s):  
Great Barrier Reef ◽  
Carapace Length ◽  
Regression Equations ◽  
Barrier Reef ◽  
Growth Data ◽  
Eretmochelys Imbricata ◽  
Nesting Beaches ◽  
Hawksbill Turtles ◽  
Feeding Grounds

Hawksbill turtles, Eretmochelys imbricata, live at low density on coral reefs in the southern Great Barrier Reef. The biomass of the species on Heron Reef was estimated at 0.82 kg ha-1. This is equivalent to 3.34 turtles km-1. The nesting beaches used by these E. imbricata are unknown. However, within the Great Barrier Reef and Coral Sea region, no regular nesting by the species occurs within 1200 km of these reefal feeding grounds. E. imbricata take up long-term residence in these feeding grounds at a minimum curved carapace length of 35.0cm. The E. imbricata feeding over these reefs ranged in size from these small immatures up to adults with curved carapace length of 87.5cm, but the maturity ratio was very strongly biased toward immatures (maturity ratio=0.01 adults). The sex ratio of all size classes was significantly skewed in favour of females (2.57 : 1 females : male overall) while 2% of the turtles were identified as intersex. Growth data from these turtles indicate that they will be decades old at first breeding. A key for sexing and assessing reproductive maturity of E. imbricata is provided. Regression equations for converting between curved carapace length and other standard measures including straight carapace measures, weight, head length and width and plastron length are described.

The Flatback Turtle, Chelonia depressa, in Queensland: Post-Nesting Migration and Feeling Ground Distribution

1983 ◽  
Vol 10 (3) ◽  
pp. 557 ◽  
Author(s):  
CJ Limpus ◽  
CJ Parmenter ◽  
V Baker ◽  
A Fleay
Keyword(s):  
Continental Shelf ◽  
Great Barrier Reef ◽  
Adult Female ◽  
Barrier Reef ◽  
Inshore Water ◽  
Eastern Australia ◽  
North Eastern ◽  
Nesting Beaches ◽  
Feeding Grounds

Between 1968 and 1981, a total of 813 adult female flatback turtles were tagged while nesting on Queensland beaches. Eight have been recovered at a distance, 216-1300 km north of their respective nesting beaches, in waters between the mainland and the Great Barrier Reef. The species' principal feeding grounds seem to be in turbid, shallow inshore water off north-eastern Australia and in the Gulf of Carpentaria; there are no records beyond the continental shelf.

Water quality in the inshore Great Barrier Reef lagoon: Implications for long-term monitoring and management

2012 ◽  
Vol 65 (4-9) ◽  
pp. 249-260 ◽  
Author(s):  
Britta Schaffelke ◽  
John Carleton ◽  
Michele Skuza ◽  
Irena Zagorskis ◽  
Miles J. Furnas
Keyword(s):  
Water Quality ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Reef Lagoon ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Inshore Great Barrier Reef

scholarly journals Does behaviour affect the dispersal of flatback post-hatchlings in the Great Barrier Reef?

2017 ◽  
Vol 4 (5) ◽  
pp. 170164 ◽  
Author(s):  
Natalie Wildermann ◽  
Kay Critchell ◽  
Mariana M. P. B. Fuentes ◽  
Colin J. Limpus ◽  
Eric Wolanski ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Early Life ◽  
Marine Turtle ◽  
Life Stages ◽  
Barrier Reef ◽  
Early Life Stages ◽  
Turtle Species ◽  
Local Water ◽  
Natator Depressus ◽  
Nesting Beaches

The ability of individuals to actively control their movements, especially during the early life stages, can significantly influence the distribution of their population. Most marine turtle species develop oceanic foraging habitats during different life stages. However, flatback turtles ( Natator depressus ) are endemic to Australia and are the only marine turtle species with an exclusive neritic development. To explain the lack of oceanic dispersal of this species, we predicted the dispersal of post-hatchlings in the Great Barrier Reef (GBR), Australia, using oceanographic advection-dispersal models. We included directional swimming in our models and calibrated them against the observed distribution of post-hatchling and adult turtles. We simulated the dispersal of green and loggerhead turtles since they also breed in the same region. Our study suggests that the neritic distribution of flatback post-hatchlings is favoured by the inshore distribution of nesting beaches, the local water circulation and directional swimming during their early dispersal. This combination of factors is important because, under the conditions tested, if flatback post-hatchlings were entirely passively transported, they would be advected into oceanic habitats after 40 days. Our results reinforce the importance of oceanography and directional swimming in the early life stages and their influence on the distribution of a marine turtle species.

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.

scholarly journals Long‐term dynamics and drivers of coral and macroalgal cover on inshore reefs of the Great Barrier Reef Marine Park

2019 ◽  
Vol 30 (1) ◽  
Author(s):  
Daniela M. Ceccarelli ◽  
Richard D. Evans ◽  
Murray Logan ◽  
Philippa Mantel ◽  
Marji Puotinen ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Macroalgal Cover ◽  
Marine Park

The green turtle, Chelonia mydas, in Queensland: breeding males in the southern Great Barrier Reef

1993 ◽  
Vol 20 (4) ◽  
pp. 513 ◽  
Author(s):  
CJ Limpus
Keyword(s):  
Great Barrier Reef ◽  
Green Turtle ◽  
Carapace Length ◽  
Chelonia Mydas ◽  
Barrier Reef ◽  
Adult Males ◽  
Green Turtles ◽  
Adult Females ◽  
Breeding Seasons ◽  
Slow Growing

Breeding male green turtles, Chelonia mydas, at any one courtship area in the southern Great Barrier Reef mate with females that will nest on rookeries spread throughout the region. In comparison with the breeding females from the same breeding unit, the males are smaller in curved carapace length, and a higher proportion of males remigrate for additional breeding seasons at 1-2-year intervals. Like the adult females, adult males are slow-growing, averaging 0.046 cm year-1. Each male appears to display a fidelity to a particular courtship area, to which it returns in successive breeding migrations. At the conclusion of the courtship period, the males disperse to widely scattered feeding areas.

The Use of Measured Scutes of Hawksbill Turtles, Eretmochelys-Imbricata, in the Management of the Tortoiseshell (Bekko) Trade

1990 ◽  
Vol 17 (6) ◽  
pp. 633 ◽  
Author(s):  
CJ Limpus ◽  
JD Miller
Keyword(s):  
Carapace Length ◽  
Size Class ◽  
Strong Positive Correlation ◽  
Eretmochelys Imbricata ◽  
Positive Correlation ◽  
Size Class Distribution ◽  
Class Distribution ◽  
Hawksbill Turtles

A strong positive correlation is demonstrated between the size of selected carapacial scutes (costal 1, vertebral 1 and vertebral 5) and the curved carapace length of hawksbill turtles (Eretmochelys imbricata). A count of any one of these distinctive scute types, and the measurement of these scutes, can be used to determine the number and size class distribution of E. imbricata represented in consignments of raw tortoiseshell.

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