scholarly journals Monitoring by telemetry reveals differences in movement and survival following hatchery or wild rearing of an endangered fish

2009 ◽  
Vol 60 (1) ◽  
pp. 45 ◽  
Author(s):  
B. C. Ebner ◽  
J. D. Thiem

Species reintroduction is a management strategy used to conserve endemic fish biodiversity. The present study investigated stocking on-grown endangered trout cod (Maccullochella macquariensis) in the Murrumbidgee River, Australia. The hypothesis that post-juvenile dispersal underpins the long-term scarcity of adults recorded at fingerling stocking locations was also tested. Radio-tracking was used to quantify dispersal of stocked sub-adults (2-year old hatchery fish, n = 27) compared with fish originally stocked as fingerlings (unknown-age wild fish, n = 31), but we encountered poor survivorship of the former group (survivorship = 9% and 95%, respectively, at 13 months post release). The hatchery group exhibited both limited dispersal and large-scale dispersal (up to 55 km) downstream from the release site. Wild fish exhibited limited net dispersal, occupying home-ranges within a 13-km reach and occasionally undertook large-scale excursions (10–70 km). It is concluded that (1) re-establishment of cod populations based on release of on-grown fish is not straightforward, and (2) adults of this species have an ability to disperse away from stocking sites. The study demonstrates the benefit of using radio-tracking to monitor the movement and survivorship of stocked threatened fish and indicates a need to consider the effects of hatchery rearing when conducting fish reintroductions.


2009 ◽  
Vol 60 (4) ◽  
pp. 346 ◽  
Author(s):  
B. C. Ebner ◽  
L. Johnston ◽  
M. Lintermans

Radio-tracking provides an effective means of studying the spatial ecology of threatened fishes where almost inaccessible habitats and species rarity render conventional mark–recapture methods impractical. Initially, validation of an effective radio-tagging method is required; in the present study, an aquaria trial based on nine hatchery-reared, adult male Maccullochella maquariensis (Percichthyidae) was conducted. Fish resumed feeding within days of being internally implanted with a radio-tag, and tag rejection was not observed (0%, n = 9) based on a 2-month observational period. Following release into an upland stream, individual-specific movements resulted in upstream (n = 1) and downstream (n = 6) dispersal as well as fidelity to the release site (n = 2) at the completion of the study. Individuals established small home-ranges (mean length of river used by an individual per diel period ranged from 47 to 292 m) and were most active in the early morning and evening (n = 6). Complete survivorship of individuals bearing active radio-transmitters (n = 8) was recorded up until 4 months after release. However, an estimated zero or one individual was alive when the last active radio-tag expired 11 months after release (n = 8). The present study highlights the use of radio-tracking in monitoring the dispersal and survivorship of small numbers of hatchery-reared threatened fish released into natural habitats as part of species re-introduction programs.



2003 ◽  
Vol 30 (1) ◽  
pp. 15 ◽  
Author(s):  
K. E. Moseby ◽  
E. O'Donnell

Nine bilbies were reintroduced to a 14-km2 reserve free of rabbits, cats and foxes in South Australia in April 2000. The survival, growth and ecology of the population were studied for 17 months after release by means of radio-tracking and trapping. Reproduction was continuous over the study period, with juveniles successfully recruited into the population. Home-range size of female bilbies averaged 0.18 km2 and was significantly smaller than home ranges of males, which averaged 3.16 km2. Wild-born subadults had smaller home ranges than adults. While male home ranges, and male and female home ranges overlapped considerably, females appeared to maintain areas discrete from other adult females. Bilbies showed a significant preference for dune habitat. As swale habitat appears too hard for burrow construction and males moved greater distances from diurnal burrows than females, males are likely to access food reserves that are under-used by females. Both males and females reused at least 30% of their burrows, and females displayed long-term site fidelity. The release was considered successful and suggests that despite historical damage from rabbits and stock, bilbies are able to successfully recolonise parts of their former range in arid South Australia once rabbits, cats and foxes are removed.



1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.



Author(s):  
Linda S. Gottfredson ◽  
Joan M. Finucci ◽  
Barton Childs


1967 ◽  
Vol 06 (01) ◽  
pp. 8-14 ◽  
Author(s):  
M. F. Collen

The utilization of an automated multitest laboratory as a data acquisition center and of a computer for trie data processing and analysis permits large scale preventive medical research previously not feasible. Normal test values are easily generated for the particular population studied. Long-term epidemiological research on large numbers of persons becomes practical. It is our belief that the advent of automation and computers has introduced a new era of preventive medicine.



2014 ◽  
pp. 124-129
Author(s):  
Z. V. Karamysheva

The review contains detailed description of the «Atlas of especially protected natural areas of Saint Petersburg» published in 2013. This publication presents the results of long-term studies of 12 natural protected areas made by a large research team in the years from 2002 to 2013 (see References). The Atlas contains a large number of the historical maps, new satellite images, the original illustrations, detailed texts on the nature of protected areas, summary tables of rare species of vascular plants, fungi and vertebrates recorded in these areas. Special attention is paid to the principles of thematic large-scale mapping. The landscape maps, the vegetation maps as well as the maps of natural processes in landscapes are included. Reviewed Atlas deserves the highest praise.



2000 ◽  
Vol 151 (3) ◽  
pp. 80-83
Author(s):  
Pascal Schneider ◽  
Jean-Pierre Sorg

In and around the state-owned forest of Farako in the region of Sikasso, Mali, a large-scale study focused on finding a compromise allowing the existential and legitimate needs of the population to be met and at the same time conserving the forest resources in the long term. The first step in research was to sketch out the rural socio-economic context and determine the needs for natural resources for autoconsumption and commercial use as well as the demand for non-material forest services. Simultaneously, the environmental context of the forest and the resources available were evaluated by means of inventories with regard to quality and quantity. According to an in-depth comparison between demand and potential, there is a differentiated view of the suitability of the forest to meet the needs of the people living nearby. Propositions for a multipurpose management of the forest were drawn up. This contribution deals with some basic elements of research methodology as well as with results of the study.



2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.



Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Yam Nath Paudel ◽  
Efthalia Angelopoulou ◽  
Bhupendra Raj Giri ◽  
Christina Piperi ◽  
Iekhsan Othman ◽  
...  

: COVID-19 has emerged as a devastating pandemic of the century that the current generations have ever experienced. The COVID-19 pandemic has infected more than 12 million people around the globe and 0.5 million people have succumbed to death. Due to the lack of effective vaccines against the COVID-19, several nations throughout the globe has imposed a lock-down as a preventive measure to lower the spread of COVID-19 infection. As a result of lock-down most of the universities and research institutes has witnessed a long pause in basic science research ever. Much has been talked about the long-term impact of COVID-19 in economy, tourism, public health, small and large-scale business of several kind. However, the long-term implication of these research lab shutdown and its impact in the basic science research has not been much focused. Herein, we provide a perspective that portrays a common problem of all the basic science researchers throughout the globe and its long-term consequences.



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