Population dynamics and status of striped marlin (Kajikia audax) in the western and central northern Pacific Ocean

2013 ◽  
Vol 64 (2) ◽  
pp. 108 ◽  
Author(s):  
Kevin R. Piner ◽  
Hui-Hua Lee ◽  
Ai Kimoto ◽  
Ian G. Taylor ◽  
Minoru Kanaiwa ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Pacific Ocean ◽  
Spatial Data ◽  
Large Scale ◽  
Size Composition ◽  
Maximum Sustainable Yield ◽  
Catch Per Unit Effort ◽  
Fully Integrated ◽  
Northern Pacific ◽  
Spawning Biomass

A new understanding of the structure of striped marlin stocks in the Pacific Ocean was the basis for estimating the population dynamics in the western and central northern Pacific (1975–2010). Dynamics were estimated using large-scale spatial data and a fully integrated length-based and age-structured model. The model used fishery-dependent catch, size composition and catch per unit effort (CPUE) as likelihood components. Time-varying selectivity patterns were used in the modelling to account for changes in fishing practices. Estimates of fishing intensity showed a pattern of exploitation generally exceeding the levels associated with maximum sustainable yield (MSY). Estimates of spawning biomass and recruitment described a population that was relatively stable near biomass levels associated with MSY until the 1990s, when recruitment declined and biomass levels fell below those associated with MSY. The reduction in recruitment could be explained by a loss of spawning biomass and potentially changes in environment. The future prospects of rebuilding the stock will depend on the relative importance of the roles maternal biomass and environment play in determining recruitment strength.

scholarly journals Analysis of 220 Years of Floodplain Population Dynamics in the US at Different Spatial Scales

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 141
Author(s):  
Firoza Akhter ◽  
Maurizio Mazzoleni ◽  
Luigia Brandimarte
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Spatial Scales ◽  
National Level ◽  
State Level ◽  
Economic Activities ◽  
Protection Measures ◽  
Management Planning ◽  
The Us ◽  
Over Time

In this study, we explore the long-term trends of floodplain population dynamics at different spatial scales in the contiguous United States (U.S.). We exploit different types of datasets from 1790–2010—i.e., decadal spatial distribution for the population density in the US, global floodplains dataset, large-scale data of flood occurrence and damage, and structural and nonstructural flood protection measures for the US. At the national level, we found that the population initially settled down within the floodplains and then spread across its territory over time. At the state level, we observed that flood damages and national protection measures might have contributed to a learning effect, which in turn, shaped the floodplain population dynamics over time. Finally, at the county level, other socio-economic factors such as local flood insurances, economic activities, and socio-political context may predominantly influence the dynamics. Our study shows that different influencing factors affect floodplain population dynamics at different spatial scales. These facts are crucial for a reliable development and implementation of flood risk management planning.

scholarly journals Efficient Approximate Range Aggregation over Large-scale Spatial Data Federation

2021 ◽  
pp. 1-1
Author(s):  
Yexuan Shi ◽  
Yongxin Tong ◽  
Yuxiang Zeng ◽  
Zimu Zhou ◽  
Bolin Ding ◽  
...  
Keyword(s):  
Spatial Data ◽  
Large Scale ◽  
Data Federation

scholarly journals Fencing affects African wild dog movement patterns and population dynamics

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Helen M. K. O'Neill ◽  
Sarah M. Durant ◽  
Stefanie Strebel ◽  
Rosie Woodroffe
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Animal Movement ◽  
Landscape Connectivity ◽  
Ecological Impact ◽  
Movement Patterns ◽  
Wrong Side ◽  
African Wild Dog ◽  
Wild Dog ◽  
Wild Dogs

Abstract Wildlife fences are often considered an important tool in conservation. Fences are used in attempts to prevent human–wildlife conflict and reduce poaching, despite known negative impacts on landscape connectivity and animal movement patterns. Such impacts are likely to be particularly important for wide-ranging species, such as the African wild dog Lycaon pictus, which requires large areas of continuous habitat to fulfil its resource requirements. Laikipia County in northern Kenya is an important area for wild dogs but new wildlife fences are increasingly being built in this ecosystem. Using a long-term dataset from the area's free-ranging wild dog population, we evaluated the effect of wildlife fence structure on the ability of wild dogs to cross them. The extent to which fences impeded wild dog movement differed between fence designs, although individuals crossed fences of all types. Purpose-built fence gaps increased passage through relatively impermeable fences. Nevertheless, low fence permeability can lead to packs, or parts of packs, becoming trapped on the wrong side of a fence, with consequences for population dynamics. Careful evaluation should be given to the necessity of erecting fences; ecological impact assessments should incorporate evaluation of impacts on animal movement patterns and should be undertaken for all large-scale fencing interventions. Where fencing is unavoidable, projects should use the most permeable fencing structures possible, both in the design of the fence and including as many purpose-built gaps as possible, to minimize impacts on wide-ranging wildlife.

scholarly journals Spatio-temporal associations of albacore CPUEs in the Northeastern Pacific with regional SST and climate environmental variables

2014 ◽  
Vol 71 (7) ◽  
pp. 1717-1727 ◽  
Author(s):  
A. Jason Phillips ◽  
Lorenzo Ciannelli ◽  
Richard D. Brodeur ◽  
William G. Pearcy ◽  
John Childers
Keyword(s):  
North Pacific ◽  
Large Scale ◽  
Environmental Variability ◽  
Southern Oscillation ◽  
Spatial Dynamics ◽  
Catch Per Unit Effort ◽  
Variable Effect ◽  
Positive Effects ◽  
The North ◽  
Additive Mixed Models

Abstract This study investigated the spatial distribution of juvenile North Pacific albacore (Thunnus alalunga) in relation to local environmental variability [i.e. sea surface temperature (SST)], and two large-scale indices of climate variability, [the Pacific Decadal Oscillation (PDO) and the Multivariate El Niño/Southern Oscillation Index (MEI)]. Changes in local and climate variables were correlated with 48 years of albacore troll catch per unit effort (CPUE) in 1° latitude/longitude cells, using threshold Generalized Additive Mixed Models (tGAMMs). Model terms were included to account for non-stationary and spatially variable effects of the intervening covariates on albacore CPUE. Results indicate that SST had a positive and spatially variable effect on albacore CPUE, with increasingly positive effects to the North, while PDO had an overall negative effect. Although albacore CPUE increased with SST both before and after a threshold year of 1986, such effect geographically shifted north after 1986. This is the first study to demonstrate the non-stationary spatial dynamics of albacore tuna, linked with a major shift of the North Pacific. Results imply that if ocean temperatures continue to increase, US west coast fisher communities reliant on commercial albacore fisheries are likely to be negatively affected in the southern areas but positively affected in the northern areas, where current albacore landings are highest.

scholarly journals Spatial Agglomeration of China’s Forest Products Manufacturing Industry: Measurement, Characteristics and Determinants

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1006
Author(s):  
Zhenhuan Chen ◽  
Hongge Zhu ◽  
Wencheng Zhao ◽  
Menghan Zhao ◽  
Yutong Zhang
Keyword(s):  
Spatial Distribution ◽  
Spatial Data ◽  
Large Scale ◽  
Manufacturing Industry ◽  
Economies Of Scale ◽  
Forest Products ◽  
Spatial Data Analysis ◽  
Forest Protection ◽  
Spatial Agglomeration ◽  
Continuous Space

China’s forest products manufacturing industry is experiencing the dual pressure of forest protection policies and wood scarcity and, therefore, it is of great significance to reveal the spatial agglomeration characteristics and evolution drivers of this industry to enhance its sustainable development. Based on the perspective of large-scale agglomeration in a continuous space, in this study, we used the spatial Gini coefficient and standard deviation ellipse method to investigate the spatial agglomeration degree and location distribution characteristics of China’s forest products manufacturing industry, and we used exploratory spatial data analysis to investigate its spatial agglomeration pattern. The results show that: (1) From 1988 to 2018, the degree of spatial agglomeration of China’s forest products manufacturing industry was relatively low, and the industry was characterized by a very pronounced imbalance in its spatial distribution. (2) The industry has a very clear core–periphery structure, the spatial distribution exhibits a “northeast-southwest” pattern, and the barycenter of the industrial distribution has tended to move south. (3) The industry mainly has a high–high and low–low spatial agglomeration pattern. The provinces with high–high agglomeration are few and concentrated in the southeast coastal area. (4) The spatial agglomeration and evolution characteristics of China’s forest products manufacturing industry may be simultaneously affected by forest protection policies, sources of raw materials, international trade and the degree of marketization. In the future, China’s forest products manufacturing industry should further increase the level of spatial agglomeration to fully realize the economies of scale.

Modeling and Implementation of Inter-Campuses Equipment Optimized Management Based on WebGIS

2013 ◽  
Vol 680 ◽  
pp. 534-539
Author(s):  
Wei Feng Ma
Keyword(s):  
Information Management ◽  
Spatial Data ◽  
Large Scale ◽  
New Technology ◽  
Rapid Expansion ◽  
Mathematics Model ◽  
Data Mapping ◽  
Geographically Dispersed ◽  
New Research ◽  
Research Challenge

With the rapid expansion of the campus scale and the increasing of the geographically dispersed campus, how to adopt new theory, new method and new technology to realize the equipment optimized assignment and the information management is a new research challenge. It is the key to safeguard the national fund to use reasonably, and to speed up the development of education healthily. Through analyzing the domestic and foreign related research works, the paper proposed that it can take use of the spatial data expression and analysis with Geographic Information System (GIS) to realize the large-scale and inter-campuses equipment optimized assignment and information management. It discussed the mathematics model and the system architecture. Moreover, the paper described the key implementation technology in great detail such as spatial data mapping with MapInfo professional 9 and the development of WebGIS functions with MapXtreme. The results show that the solution is feasible and effective.

A Research of Matching Algorithm and Strategy on Entity with Complex Area

2012 ◽  
Vol 209-211 ◽  
pp. 252-255
Author(s):  
Li Guo ◽  
Hai Ying Zheng ◽  
Yong Hong Wang ◽  
Bin Zhang
Keyword(s):  
Spatial Data ◽  
Large Scale ◽  
Data Matching ◽  
Large Scale Data ◽  
Polygon Area ◽  
Spatial Data Integration ◽  
One And Many ◽  
Complex Polygon ◽  
Scale Data ◽  
Matching Relation

Data matching technology is a key technology for spatial data integration and fusion. This paper represents a solution to the complex polygon area, defines the area overlapped rate in the aspect of geometric measure, presents the data matching idea based on area overlapped rate .Then, this paper discusses and realizes the data matching relation of area elements including one to one , many to one and many to many. At last, region targets are set as the study object, large scale data are taken for example. We draw the conclusion: this algorithm is efficient.

Population genetics, phylogeography, and systematics of the thornyhead rockfishes (Sebastolobus) along the deep continental slopes of the North Pacific Ocean

2000 ◽  
Vol 57 (8) ◽  
pp. 1701-1717 ◽  
Author(s):  
Carol A Stepien ◽  
Alison K Dillon ◽  
Amy K Patterson
Keyword(s):  
Pacific Ocean ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
North Pacific Ocean ◽  
Geographic Distance ◽  
The North ◽  
Continental Slopes ◽  
Genetic Patterns ◽  
Northern Pacific ◽  
Shortspine Thornyhead

Population genetic, phylogeographic, and systematic relationships are elucidated among the three species comprising the thornyhead rockfish genus Sebastolobus (Teleostei: Scorpaenidae). Genetic variation among sampling sites representing their extensive ranges along the deep continental slopes of the northern Pacific Ocean is compared using sequence data from the left domain of the mtDNA control region. Comparisons are made among the shortspine thornyhead (S. alascanus) (from seven locations), the longspine thornyhead (S. altivelis) (from five sites), which are sympatric in the northeast, and the broadbanded thornyhead (S. macrochir) (a single site) from the northwest. Phylogenetic trees rooted to Sebastes show that S. macrochir is the sister taxon of S. alascanus and S. altivelis. Intraspecific genetic variability is appreciable, with most individuals having unique haplotypes. Gene flow is substantial among some locations and others diverged significantly. Genetic divergences among sampling sites for S. alascanus indicate an isolation by geographic distance pattern. Genetic divergences for S. altivelis are unrelated to the hypothesis of isolation by geographic distance and appear to be more consistent with the hypothesis of larval retention in currents and gyres. Differences in geographic genetic patterns between the species are attributed to life history differences in their relative mobilities as juveniles and adults.

scholarly journals Cloud representation in general-circulation models over the northern Pacific Ocean: A EUROCS intercomparison study

2004 ◽  
Vol 130 (604) ◽  
pp. 3245-3267 ◽  
Author(s):  
A.P. Siebesma ◽  
C. Jakob ◽  
G. Lenderink ◽  
R.A.J. Neggers ◽  
J. Teixeira ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
General Circulation ◽  
General Circulation Models ◽  
Northern Pacific ◽  
Intercomparison Study
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