Movements and associated observations of bait-attracted White Sharks, Carcharodon carcharias: A preliminary report

1992 ◽  
Vol 43 (1) ◽  
pp. 13 ◽  
Author(s):  
WR Strong ◽  
RC Murphy ◽  
BD Bruce ◽  
DR Nelson
Keyword(s):  
Preliminary Report ◽  
Average Rate ◽  
South Australia ◽  
Movement Patterns ◽  
Population Parameters ◽  
Time Intervals ◽  
Horizontal Movement ◽  
Carcharodon Carcharias ◽  
Rate Of Movement

Basic population parameters and behaviours of great white sharks, Carcharodon carcharias, were studied during four expeditions to Spencer Gulf, South Australia. In all, 58 white sharks were observed, ranging in length from about 2.2 to 5.5 m TL (X= 3.7 m TL � 0.7 s.d.); of these sharks, 32 were subsequently tagged. Many sharks were observed repeatedly, the most frequently resighted individual being seen on 22 days over a 197-day period spanning two expeditions. Sharks in the study area were segregated by sex but not by size. Females were most abundant at 'inshore' islands, whereas males occurred mainly at 'offshore' islands. Further, there were no marked differences in abundance between summer and winter. Nine ultrasonic trackings, lasting a maximum of 27.5 h, revealed three general horizontal movement patterns: downstream circling, island patrolling, and inter-island cruising. Average rate of movement was 3.2 km h-1 (n = 145 time intervals of 15 min each). Sharks generally remained near the surface or along the bottom (about 20 m), spending relatively little time in midwater. Daytime swimming depths were significantly shallower than those at night.

A PRELIMINARY REPORT OF FIELD WORK IN THE OOLDEA REGION, WESTERN SOUTH AUSTRALIA

Oceania ◽  
1945 ◽  
Vol 15 (3) ◽  
pp. 239-275 ◽  
Author(s):  
Ronald Berndt ◽  
Catherine Berndt
Keyword(s):  
Preliminary Report ◽  
South Australia ◽  
Field Work

Studies on southern Australian abalone (Genus Haliotis). IV. Growth of H. laevigata and H. ruber

1983 ◽  
Vol 34 (3) ◽  
pp. 461 ◽  
Author(s):  
SA Shepherd ◽  
WS Hearn
Keyword(s):  
Growth Rate ◽  
Average Rate ◽  
South Australia ◽  
Annual Growth ◽  
First Year ◽  
Growth Equation ◽  
Annual Growth Rate ◽  
Growth Data ◽  
Differential Growth ◽  
Frequency Distributions

The growth of H. laevigata Donovan and H. ruber Leach was studied at several sites in South Australia by fitting the von Bertalanffy growth equation to growth data, supplemented by analysis of length- frequency distributions. Juvenile individuals of H. laevigata grow at an average rate of 0.9 mm per week, reaching a length of about 40 mm in 1 year at West Island; at Waterloo Bay H. laevigata can reach a length of 50 mm in the first year. After the first year, the annual growth coefficient (K) and the asymptotic length (L∞) for the two species at three sites are, respectively: H. laevigata-0.48 year-1 and 138 mm (West I.); 0.41 year-1 and 131 mm (Tipara Reef); 0.59 year-1 and 148 mm (Waterloo Bay); H, ruber-0 34 year-1 and 139 mm (West I.); 0.32 year-1 and 143 mm (Tipara Reef); 0 41 year-1 and 144 mm (Waterloo Bay). There are also seasonal differences in growth rate between species and between sites. These differences as well as differences in the annual growth rate within a species between sites are associated predominantly with differences in the food supply. There is differential growth between the sexes of H. laevigata at Waterloo Bay, where females grow 25% faster than males and reach a larger size.

A PRELIMINARY REPORT OF FIELD WORK IN THE OOLDEA REGION, WESTERN SOUTH AUSTRALIA

Oceania ◽  
1943 ◽  
Vol 13 (4) ◽  
pp. 362-375 ◽  
Author(s):  
Ronald Berndt ◽  
Catherine Berndt
Keyword(s):  
Preliminary Report ◽  
South Australia ◽  
Field Work

A PRELIMINARY REPORT OF FIELD WORK IN THE OOLDEA REGION, WESTERN SOUTH AUSTRALIA

Oceania ◽  
1944 ◽  
Vol 14 (3) ◽  
pp. 220-249 ◽  
Author(s):  
Ronald Berndt ◽  
Catherine Berndt
Keyword(s):  
Preliminary Report ◽  
South Australia ◽  
Field Work

A PRELIMINARY REPORT OF FIELD WORK IN THE OOLDEA REGION, WESTERN SOUTH AUSTRALIA

Oceania ◽  
1944 ◽  
Vol 15 (1) ◽  
pp. 49-80
Author(s):  
Ronald Berndt ◽  
Catherine Berndt
Keyword(s):  
Preliminary Report ◽  
South Australia ◽  
Field Work

scholarly journals Utjecaj rastrošbe na trajnost zasjeka u mekoj stijeni

2015 ◽  
Author(s):  
◽  
Goran Vlastelica
Keyword(s):  
Average Rate ◽  
Laser Scanner ◽  
Soft Rock ◽  
Testing Procedure ◽  
Standard Laboratory ◽  
Time Intervals ◽  
Laboratory Techniques ◽  
Usual Form ◽  
First Results ◽  
Cut Slopes

The Thesis describes basic processes which lead to weathering of soft rock and their typical manifestations on situ. For that, marl from Eocene flysch strata that can be found in Dalmatia, was used as an example of soft rock, while the usual form of open cut slopes was used as an example of a geotechnical construction. A systematic study was carried out using the conventional rock mechanics laboratory techniques and apparatuses, with some additions as well as changes in the procedure and the reinterpretation of some general criteria, all in favour of determining the best way to evaluate material’s susceptibility to weathering. In addition to standard laboratory techniques, new testing procedure based on VIS-NIR spectrometry was also used. First results show that it is possible to detect key mineralogical components for this type of material, and more importantly, the ability to assess susceptibility to weathering. Furthermore, a series of observations in manmade cuts at 14 pilot sites using terrestrial laser scanner were made. For the purpose of forecasting and retrograde analysis, the survey was conducted in different time intervals and number of observations, all for purpose of defining the average rate of erosion in cuts of this type of material. Consequently, two known mathematical models for development of erosion in cuts are calibrated and the guidelines on their usage are proposed.

scholarly journals Glaciological observations in the south-western Scoresby Sund region. A preliminary report

1973 ◽  
Vol 58 ◽  
pp. 49-54
Author(s):  
O.B Olesen ◽  
N Reeh
Keyword(s):  
Preliminary Report ◽  
The South ◽  
East Greenland ◽  
Fjord System ◽  
Ice Production ◽  
Rate Of Movement

The glaciological work on the 1972 geological expedition to Scoresby Sund, East Greenland, was an expansion of the observations made on the expedition in 1968 (see Olesen & Reeh, 1969). In 1968 observations on rate of movement and estimations of the calve-ice production in the northern parts of the Seoresby Sund fjord complex were carried out. A natural continuation of this study was to observe the remainder of the major glaciers, draining the lnland lce into the southern parts of the same fjord system.

scholarly journals AUTOMATIC EXTRACTION OF DUNES FROM GOOGLE EARTH IMAGES NEW APPROACH TO STUDY THE DUNES MIGRATION IN THE LAÂYOUNE CITY OF MOROCCO

2016 ◽  
Vol XLII-2/W1 ◽  
pp. 53-59 ◽  
Author(s):  
D. Dakir ◽  
H. Rhinane ◽  
O. Saddiqi ◽  
E. El Arabi ◽  
L. Baidder
Keyword(s):  
Large Scale ◽  
Average Rate ◽  
Google Earth ◽  
Automatic Extraction ◽  
New Approach ◽  
Analysis Techniques ◽  
North East ◽  
South West ◽  
Barchan Dunes ◽  
Rate Of Movement

In desert environments, the sandy dune movements are considered as the main threat to the livelihoods and productivity of people living in Laâyoune city, South of Morocco. Studying dunes at a large scale requires intensive fieldwork and a huge dataset. But this task is not always easy because of the high cost and the limited availability of data. In this paper we present a new approach to study and evaluate the dune dynamic using Google earth archive image acquired from 2005, 2011, 2012, and 2013. To achieve this goal, an area with 3577 meter square including 40 barchan dunes, were selected, and the barchan dunes were automatically extracted from these images using Geographic Information System (GIS) and spatial analysis techniques provided by image processing software. The result shows not only the dune shape but also direction of dunes movements, and distance separating dunes. The obtained direction is ranging from North east to South west. The average rate of movement of the extracted dunes between 2005 and 2013 was calculated and is estimated at 32m per year. Validation of these dunes movement of the Laâyoune city was confirmed by the field data and previous studies.

scholarly journals Movement of the Ross Ice Shelf Near Scott Base

1961 ◽  
Vol 3 (29) ◽  
pp. 859-866 ◽  
Author(s):  
W. J. P. Macdonald ◽  
T. Hatherton
Keyword(s):  
Ross Sea ◽  
Average Rate ◽  
The South ◽  
Ice Shelf ◽  
Mcmurdo Sound ◽  
Ross Ice Shelf ◽  
Rate Of Movement

Abstract The rate of movement of the Ross Ice Shelf has been determined at its terminal face to the south-east of Scott Base. An average rate of movement of 23 cm./day in a direction 270° True was determined for the period March 1957 to October 1958. The terminating face of the ice shelf in McMurdo Sound is only about 3 metres thick compared with a thickness of several hundred metres in the Ross Sea. Altimeter heights are used to demonstrate a thinning of the shelf which is attributed to melting from below.

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