The North West Cape, Western Australia: A Potential Hotspot for Indo-Pacific Humpback Dolphins Sousa chinensis?

2012 ◽  
Vol 18 (4) ◽  
pp. 240 ◽  
Author(s):  
Alex Brown ◽  
Lars Bejder ◽  
Daniele Cagnazzi ◽  
Guido J Parra ◽  
Simon J Allen

Indo-Pacific Humpback Dolphins Sousa chinensis (Humpback Dolphins hereafter) are listed as ‘near threatened’ on an international level and ‘migratory’ in Australian waters. There is limited information on Humpback Dolphins in Western Australian State waters, where the species remains unlisted. This lack of knowledge hinders the management and conservation of the species in a region of rapidly increasing coastal development. We conducted opportunistic boat-based surveys in April 2010 and present data on the location, size and composition of Humpback Dolphin groups encountered in the near-shore waters around the North West Cape, Western Australia. A total of 42 groups were encountered in a variety of habitats during 145 h on the water over ca. 80 km coastline. Group size ranged from 1 to 15, with a mean (± SE) of 5.3 (± 0.48) individuals. A total of 54 Humpback Dolphins were identified from photographs of the unique markings on their dorsal fins. The lack of a plateau in the cumulative discovery curve of identified individuals over the duration of the study suggests that only a subset of dolphins in the area was identified. This region is close to the south-western limit of the species’ Australian distribution and appears to represent an important location for Western Australian Humpback Dolphins. In light of increasing anthropogenic activity around the North West Cape and Exmouth Gulf, these preliminary findings from a limited survey effort indicate that further research into this population is required.

2001 ◽  
Vol 41 (1) ◽  
pp. 497
Author(s):  
W.L. Tinapple

Petroleum exploration activity in Western Australia over the past decade has been on the increase, boosted by the positive results of many new discoveries, mainly on the North West Shelf but also in frontier areas. Significant discoveries in 1999–2000 resulted from new exploration concepts including deep plays in the Barrow/Dampier Sub-basins, heavy oil plays in the Carnarvon Basin, a deep-water gas play west of Gorgon, large gas/condensate plays in the Browse Basin, and a new gas play in the southern Bonaparte Basin. Discovery itself is a great incentive to the industry to further exploration; however, concerns over oil price, the Australian dollar, markets, policies and perceived prospectivity impact on exploration spending. The short-term outlook for WA is good as a result of existing work commitments including an average of 50 exploration wells to be drilled each year for the next three years. Onshore, where exploration has been subdued, there are signs of increased activity. The Western Australian government is playing a key role in promoting the State through gazettals, promotional activities— conferences and publications, acquiring precompetitive data and making petroleum data more accessible. The government funded Petroleum Exploration Initiatives program is continuing and efforts are being made to facilitate exploration. Sustained high oil prices, improvements in technology and efforts to expedite access to land are just some of the factors which will assist companies in their endeavours. In the longer term, continued growth in Western Australia’s petroleum industry is projected.


Zootaxa ◽  
2019 ◽  
Vol 4554 (1) ◽  
pp. 101
Author(s):  
JEAN JUST

The Western Australia fauna of Bubocorophiina (Siphonoecetini) from the Albany area in the south to Port Hedland in the north-west, a coastal stretch of about 2000 km, is reported. One new genus and 11 new species are described: Rhinoecetes sinuduopopulus sp. nov., R. rockinghamia sp. nov., R. makritrichoma sp. nov., R. lowryi sp. nov., R. caetus sp. nov., R. karkharius sp. nov., R. wamus sp. nov., R. setosus sp. nov., Borneoecetes minimus sp. nov. (first record of Borneoecetes Barnard & Thomas, 1984 from Australia); Sinoecetes reni sp. nov. (first record of Sinoecetes Ren, 2012 from Australia), and Pararhinoecetes bicornis gen. et sp. nov. In addition, Cephaloecetes enigmaticus, previously described from the southeast coast of Australia, is recorded in the Albany area. A key to Western Australian Bubocorophiina is presented, and the distribution around Australian of the genera in the subtribe is commented upon. 


Author(s):  
Daryl A. Cornish ◽  
George L. Smit

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.


2019 ◽  
Author(s):  
Darren Cheah ◽  
Kliti Grice ◽  
Cornelia Wuchter ◽  
Alan G. Scarlett ◽  
Marco J. L. Coolen

1994 ◽  
Vol 34 (1) ◽  
pp. 555
Author(s):  
N. M. Lemon ◽  
T. Mahmood

The North West Shelf of Western Australia is an area of known extensional control with a number of inbuilt complexities related to variations in direction of extension and the existence of early fracture sets. Analogue modelling in a sandbox of modest construction and proportions can imitate the style of structures imaged by seismic on the North West Shelf. Models were constructed to simulate deformation in a sedimentary sequence above simple listric, ramp/flat and complex 3D detachment surfaces. A new 3D technique has been devised to simulate progressive deformation above complex detachment morphologies. Analysis of the structures produced has been achieved by marrying sequential plan view photographs of the model surface with serial vertical sections of the bulk of the model once the experiment has been completed and the sand stabilised. This technique also has the ability to simulate geometry and kinematics of extensional structures in a complex polyphase area. This 3D technique has proven particularly useful in the understanding of structures developed in regions where the sedimentary sequence has been subject to more than one period of extension, each with different orientations. The models provide the first understanding of the areal distribution of fault patterns and associated subsidiary troughs in areas of complex detachments. These models show the distribution of pre-rift and syn-rift sediments in extensional terranes and are valuable in the prediction of deformation in areas of poor seismic quality and for confirmation of seismic interpretation.


AAPG Bulletin ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 913-938
Author(s):  
Sam McHarg ◽  
Chris Elders ◽  
Jane Cunneen

1985 ◽  
Vol 36 (2) ◽  
pp. 247 ◽  
Author(s):  
SJM Blaber ◽  
JW Young ◽  
MC Dunning

The species composition and broad trophic structure of the mangrove creek and open shore fish communities of the Dampier region in tropical north-western Australia are described. The habitats are characterized by a lack of freshwater influence, low turbidity and a tidal range in excess of 4 m. Both mangroves and open shores have a diversity of species typical of Indo-west Pacific coastal waters but the physical conditions have modified the community structure both to exclude many families that prefer areas of higher turbidity and reduced salinity, and to include others that usually occur only in clear waters. The fish faunas of the mangroves (113 species) and open shores (106 species) are compared: 54 species were common to both. The deeper waters were dominated by piscivores, which penetrated throughout the mangroves at high tide. Iliophagous species were abundant, particularly in the mangroves where the organic content of the substratum (7.8-8.2%) was not reduced markedly compared with other areas of the Indo-Pacific, despite the lack of freshwater inflow. The clear and deep water in the mangroves at high tide favour predation on juveniles by piscivorous fishes and reduce the effectiveness of such areas as nurseries. There is virtually no overlap of the fauna with that of the deeper waters (>20 m) of the North West Shelf, and the inshore region is not a significant nursery ground for any of the commercially important deeper water species.


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