Predicting changes in distribution of a large coastal shark in the face of the strengthening East Australian Current

2020 ◽  
Vol 642 ◽  
pp. 163-177 ◽  
Author(s):  
Y Niella ◽  
AF Smoothey ◽  
V Peddemors ◽  
R Harcourt

In the face of accelerating climate change, conservation strategies will need to consider how marine animals deal with forecast environmental change as well as ongoing threats. We used 10 yr (2009-2018) of data from commercial fisheries and a bather protection program along the coast of New South Wales (NSW), southeastern Australia, to investigate (1) spatial and temporal patterns of occurrence in bull sharks and (2) environmental factors affecting bull shark occurrence along the coast of NSW. Predicted future distribution for this species was modelled for the forecast strengthening East Australian Current. Bull sharks were mostly harvested in small to larger estuaries, with average depth and rainfall responsible for contrasting patterns for each of the fisheries. There was an increase in the occurrence of bull sharks over the last decade, particularly among coastal setline fisheries, associated with seasonal availability of thermal gradients >22°C and both westward and southward coastal currents stronger than 0.15 and 0.60 m s-1, respectively, during the austral summer. Our model predicts a 3 mo increase in the availability of favourable water temperatures along the entire coast of NSW for bull sharks by 2030. This coastline provides a uniquely favourable topography for range expansion in the face of a southerly shift of warmer waters, and habitat is unlikely to be a limiting factor for bull sharks in the future. Such a southerly shift in distribution has implications for the management of bull sharks both in commercial fisheries and for mitigation of shark-human interactions.

2018 ◽  
Author(s):  
C. A. Ward-Paige ◽  
A. Westell ◽  
B. Sing

AbstractMany marine animals around the world are threatened by a variety of anthropogenic activities, yet there is often a paucity of data to monitor patterns in abundance and distribution or to evaluate human interventions. The new citizen science program eOceans helps to fill this gap by gathering observations of various marine animals from worldwide ocean explorers. In 2012, a dedicated Thailand-wide census of sharks, and other animals, began as collaboration between eOceans scientists and the dive tourism industry. Using the observations from 9,524 dives (9,357 hours underwater) logged by >169 divers on 153 sites, we describe the spatial and temporal patterns of sharks in coastal Thailand. A total of 12 shark species were encountered, most commonly (67%) as individuals, and were observed on 11% of all dives, on 59% of sites, in all months and years. The two most frequently encountered species were blacktip reef (Carcharhinus melanopterus) and leopard sharks (Stegostoma fasciatum). Many species had peak encounter rates in summer, but aggregated in various seasons in different years. Mating events and nursery sites were observed rarely, and only for blacktip reef and whitetip reef (Triaenodon obesus) sharks. These results could be of value to species-or region-specific biologists, ecologists and fisheries scientists, as well as to managers and policy makers that could use the findings to monitor future trends and prioritize conservation strategies. Moreover, this study highlights the value that collaborative eOceans citizen science projects could have in support of marine science, management and conservation efforts worldwide.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yuxiang Fei ◽  
Rong Hou ◽  
James R. Spotila ◽  
Frank V. Paladino ◽  
Dunwu Qi ◽  
...  

Abstract The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.


2020 ◽  
Vol 7 (2) ◽  
pp. 88-97
Author(s):  
Aouadj Sid Ahmed ◽  
Nasrallah Yahia ◽  
Hasnaoui Okkacha ◽  
Khatir Hadj

AbstractThe forest of Doui Thabet is one of the forests of the Mounts of Saida (Western Algeria) which is experiencing a dynamic regressive. Located in the semi-arid bioclimatic stage, it is located at the edge of two phytogeographic sub-sectors: atlas Tellien Oranais (O3) and high plateau subsector (H1). Among the factors that threaten to curb this fragile and weakened ecosystem, in addition to drought and climate aridity and which has become a structural ecological phenomenon; the overgrazing is also a major limiting factor. This current study provides a qualitative and quantitative assessment of anthropogenic pressure exerted in this area zone. The methodology adopted in this study is that of Le Houerou (1969) and Montoya (1983), which it is based on the calculation of the annual needs of the herd in forage units, the estimate of the feed potential of production, the coefficient of overgrazing and in addition to the anthropogenic pressure index. The result of the forage balance in the forest rangelands of the studied area has a forage deficit (overload) of (96.64%) (a sylvopastoral imbalance), in addition to that, the coefficient of overgrazing is (92.3%) and the anthropogenic pressure index is very high (28). The conservation and the restoration of this area is a major concern in the face of global changes, taking into account their mode of reproduction and their dynamics, for the development of restoration strategies and more effective ways of protection.


2017 ◽  
Vol 9 (2) ◽  
pp. 109
Author(s):  
Paulina Harun ◽  
Atman Poerwokoesoemo

his study aims to: (1) to know and analyze the extent of volatility (vulnerability) of sharia banking industry in Indonesia in the face of competition (2) to know and analyze factors affecting vulnerability of sharia commercial banks; (3) to know and analyze the extent of sustainable development of sharia banking industry to Indonesia's economic development.The research conducted to measure the vulnerability (volatility) of proto folio of syariah bank using observation period 2015, and the data used is cross section data. The research design used in this research is quantitative research, using asset dimension (asset portfolio, liability portfolio, equity portfolio) and stressor (pressure, including: credit risk, market risk, and liquidity risk).The activity plan of this research is: in the initial stage of conducting theoretical study related to the vulnerability related to banking especially BUS; The next step is to determine the asset and stressor dimensions associated with the BUS; Further determine the indicators related to assets and stressors; The next step performs calculations to determine the index of each BUS as well as the dimensions that affect the vulnerabilities faced by each BUS.Target expected outcomes can be generated from this research is: for the object of research (BUS) provide a solution for BUS to deal with and overcome the vulnerabilities encountered and policies that must be done. For policy makers, the results of this study are expected to provide input in decision-making and other policies.Measurement of vulnerability to be performed related to banking operations in the face of competition and the continuity of BUS in Indonesia. The outcomes of this study are expected to be included in Bank Indonesia journals, the selection of this journal is based on studies conducted in the banking sector, especially BUS in Indonesia.


2017 ◽  
Vol 41 (S1) ◽  
pp. S360-S360
Author(s):  
E. Tartakovsky ◽  
N. Rofe

BackgroundThe military is a stressful environment, and many service persons experience army stress. Therefore, it is important to understand the factors affecting army stress and stress resiliency.ObjectiveThe present study examines the connections between personal value preferences and army stress, applying the value congruency paradigm.MethodMale soldiers serving in three combat units in the Israeli Defense Forces participated in the study (n = 257).ResultsThe results obtained demonstrated that personal value preferences explained a significant proportion of the variance in army stress beyond the socio-demographic variables. A lower stress level was associated with a higher preference for the values of societal security, conformity, achievement, and universalism, and with a lower preference for the face and personal security values.ConclusionsThe research promotes our understanding of the relationships between general motivational goals expressed in personal value preferences and stress in the military context. In addition, the results obtained indicate the possible relevance of using values for selecting and preparing recruits who will most likely adjust well to the army framework. Finally, some value-oriented interventions that may be used for promoting the soldiers’ psychological adjustment during their army service are suggested.Disclosure of interestThe authors have not supplied their declaration of competing interest.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Erin Treanore ◽  
Etya Amsalem

Abstract In the face of insect declines, identifying phases of the life cycle when insects are particularly vulnerable to mortality is critical to conservation efforts. For numerous annual insect groups, diapause is both a key adaptation that allows survival of inhospitable conditions and a physiologically demanding life stage that can result in high rates of mortality. As bees continue to garner attention as a group experiencing high rates of decline, improving our understanding of how annual bees prepare for diapause and identifying factors that reduce survival is imperative. Here, we studied factors affecting diapause survival length and their underlying mechanisms using an economically and ecologically important annual bee species, Bombus impatiens. We examined how age and mass upon diapause onset correlate with diapause survival length, and the mechanistic role of nutrient acquisition and oxidative stress post pupal eclosion in mediating these effects. Our findings show that both age and mass were strong predictors of diapause survival length. Heavier queens or queens in the age range of ~6–17 days survived longer in diapause. Mass gain was attributed to increases in lipid, protein and glycerol amounts following pupal eclosion, and the ability to deal with oxidative stress was significantly compromised in older pre-diapause queens. Our results demonstrate that age-related shifts in bee physiology and timing of nutrient acquisition may both be critical factors driving diapause survival.


1997 ◽  
Vol 77 (3) ◽  
pp. 399-420 ◽  
Author(s):  
Pauliina Palonen ◽  
Deborah Buszard

This article gives an overview of the current state of cold hardiness research in fruit crops by reviewing the recently published studies on cold hardiness of both tree fruit and berry crops. Topics discussed include cold hardiness of fruit species, cultivars and different plant organs, biophysical and biochemical aspects of hardiness, evaluation of hardiness, as well as endogenous, cultural and environmental factors affecting cold hardiness in these species. Lack of cold hardiness is a major limiting factor for production of fruit crops in many regions of the world and improved cold hardiness one of the major objectives in numerous breeding programs and research projects. Screening cultivars or selections for cold hardiness is commonly done, and different methods applied to the evaluation of hardiness are discussed. The physical limit of deep supercooling may be a restricting factor for expanding the production of some fruit crops, such as Prunus species and pear. As for biochemical aspects, a relationship between carbohydrates and cold hardiness is most commonly found. Studies have also been made on different hardiness modifying cultural factors including rootstock, crop load, raised beds and application of growth regulators. The latter seems promising for some species. Cold hardiness is an extremely complex phenomenon and understanding different mechanisms involved is critical. Since hardiness is, however, primarily affected by genotype, developing cold-hardy fruit cultivars and effective screening methods for hardiness are essential. Finally, cultural practices may be improved to further enhance hardiness. Key words: Berries, cold hardiness, fruits, small fruits, stress, winter hardiness


2021 ◽  
Author(s):  
Gregg Henderson

Abstract C. formosanus is often transported by boats and shipping containers to port cities before being carried further inland via landscape materials such as railroad ties (railway sleepers). This may explain the current C. formosanus distribution in the USA with coastal areas more densely infested than inland areas (Hochmair and Scheffrahn, 2010). Temperature and humidity are primary factors affecting the establishment of C. formosanus, and it is potentially invasive to areas of high humidity approximately 35° north and south of the equator (Su and Tamashiro, 1987). Competition from native species is another limiting factor for many exotic pests, but C. formosanus is more aggressive and is known to out-compete the endemic termites such as Reticulitermes species. Another factor that has allowed the successful establishment and spread of C. formosanus in exotic areas has been the pest control industry's heavy reliance on soil termiticide barriers for subterranean termite control since the 1950s. Numerous studies, using mark-recapture methods, have revealed that a single colony of C. formosanus might contain several million termites that forage up to 100 m in the soil (Lai, 1977; Su and Scheffrahn, 1988). These agree with the results of excavation studies for C. formosanus colonies (Ehrhorn, 1934; King and Spink, 1969). Because of the large colony size, the application of soil termiticides beneath a structure does not usually have a major impact on the overall population, and the surviving colony continues to produce alates that can further infest nearby areas. Once established, C. formosanus has never been completely eradicated from an area. The dependency of soil termiticide barriers as the primary tool for subterranean termite control is probably the main reason for the establishment and spread of C. formosanus from four isolated port cities in the 1960s in the USA to all south-eastern states by 2001.


2020 ◽  
Vol 12 (4) ◽  
pp. 707 ◽  
Author(s):  
Megan W. Lang ◽  
Vincent Kim ◽  
Gregory W. McCarty ◽  
Xia Li ◽  
In-Young Yeo ◽  
...  

To best conserve wetlands and manage associated ecosystem services in the face of climate and land-use change, wetlands must be routinely monitored to assess their extent and function. Wetland extent and function are largely driven by spatial and temporal patterns in inundation and soil moisture, which to date have been challenging to map, especially within forested wetlands. The objective of this paper is to investigate the different, but often interacting effects, of evergreen vegetation and inundation on leaf-off bare earth return lidar intensity within mixed deciduous-evergreen forests in the Coastal Plain of Maryland, and to develop an inundation mapping approach that is robust in areas of varying levels of evergreen influence. This was achieved through statistical comparison of field derived metrics, and development of a simple yet robust normalization process, based on first of many, and bare earth lidar intensity returns. Results demonstrate the confounding influence of forest canopy gap fraction and inundation, and the effectiveness of the normalization process. After normalization, inundated deciduous forest could be distinguished from non-inundated evergreen forest. Inundation was mapped with an overall accuracy between 99.4% and 100%. Inundation maps created using this approach provide insights into physical processes in support of environmental decision-making, and a vital link between fine-scale physical conditions and moderate resolution satellite imagery through enhanced calibration and validation.


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