Microplastics in the sediments of small-scale Japanese rivers: Abundance and distribution, characterization, sources-to-sink, and ecological risks

2021 ◽  
pp. 152590
Author(s):  
A.H.M. Enamul Kabir ◽  
Masahiko Sekine ◽  
Tsuyoshi Imai ◽  
Koichi Yamamoto ◽  
Ariyo Kanno ◽  
...  
Keyword(s):  
Small Scale ◽  
Ecological Risks ◽  
Japanese Rivers ◽  
Abundance And Distribution

scholarly journals Spatial Patterns of Potentially Hazardous Metals in Soils of Lin’an City, Southeastern China

2019 ◽  
Vol 16 (2) ◽  
pp. 246 ◽  
Author(s):  
Shiying Yu ◽  
Zhoulun Chen ◽  
Keli Zhao ◽  
Zhengqian Ye ◽  
Luyao Zhang ◽  
...  
Keyword(s):  
Urban Soils ◽  
Potential Ecological Risk ◽  
Exhaust Emission ◽  
Small Scale ◽  
Ecological Risks ◽  
Southeastern China ◽  
Principle Components Analysis ◽  
Risk Indices ◽  
Components Analysis ◽  
Hazardous Metals

Urban soils are strongly related to human health. In this study, Lin’an city was chosen as a typical small-scale city with which to study the spatial variation of potentially hazardous metals (PHMs) in urban soils and their potential ecological risks using multivariate analysis, geostatistics and GIS techniques. A total of 62 soil samples were collected from the study area. The results showed that the average concentrations of total soil Mn, Cu, Zn, Pb, Cr, Cd were 439.42, 42.23, 196.80, 62.55, 63.65, 0.22 mg·kg−1, respectively. Compared with the background values and the environmental quality standards, these PHMs were accumulated in urban soils to some extent. The single potential ecological risk indices of PHMs indicated that Pb and Cd had relatively high ecological risks. The pH and most of the PHMs had significant correlations (p < 0.05). The principle components analysis (PCA) showed that Pb, Zn and Cu had similar pollution sources related to the vehicles’ exhaust emission; Mn and Cr were mainly from the parent materials; while Cd was from the emission of industrial manufactories. The spatial structures and distributions of PHMs and their corresponding available fractions had strong/moderate spatial autocorrelation, which were influenced by human activities.

scholarly journals Response of frugivorous primates to changes in fruit supply in a northern Amazonian forest

2014 ◽  
Vol 74 (3) ◽  
pp. 720-727 ◽  
Author(s):  
I Mourthé
Keyword(s):  
Small Scale ◽  
Local Distribution ◽  
Primate Ecology ◽  
Cebus Olivaceus ◽  
Spatiotemporal Changes ◽  
Line Transects ◽  
Amazonian Rainforest ◽  
Seasonal Decline ◽  
Abundance And Distribution ◽  
Primate Density

Few attempts have been made to understand how spatiotemporal changes in fruit supply influence frugivores in tropical forests. The marked spatiotemporal variation in fruit supply can affect frugivore abundance and distribution, but studies addressing the effects of this variation on primates are scarce. The present study aimed to investigate how the spatiotemporal distribution of fruits influences the local distribution of three frugivorous primates in the eastern part of the Maracá Ecological Station, a highly seasonal Amazonian rainforest. Specifically, it was hypothesised that primate distribution will track changes in fruit supply, resulting that sites with high fruit availability should be heavily used by primates. During a 1-year study, fruit supply (ground fruit surveys) and primate density (line-transects) were monitored in twelve 2 km-long transects at monthly intervals. Fruit supply varied seasonally, being low during the dry season. The density of Ateles belzebuth was positively related to fruit supply during fruit shortage, but Cebus olivaceus and Alouatta macconnelli did not follow the same pattern. The supply of Sapotaceae fruit was an important component determining local distribution of A. belzebuth during the overall fruit shortage. Highly frugivorous primates such as A. belzebuth respond to seasonal decline in fruit supply by congregating at places with high fruit supply in this forest, particularly, those with many individuals of species of Sapotaceae. This study underscores the importance of small-scale spatiotemporal changes of fruit supply as a key component of frugivorous primate ecology in highly seasonal environments.

Short-term effects of commercial fishing on the distribution and abundance of walleye pollock (Theragra chalcogramma)

2012 ◽  
Vol 69 (2) ◽  
pp. 354-368 ◽  
Author(s):  
Paul D. Walline ◽  
Christopher D. Wilson ◽  
Anne B. Hollowed ◽  
Sarah C. Stienessen
Keyword(s):  
Walleye Pollock ◽  
Small Scale ◽  
Theragra Chalcogramma ◽  
Commercial Fishing ◽  
Short Term ◽  
Acoustic Data ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Vertical Distributions ◽  
Acoustic Surveys ◽  
Abundance And Distribution

Replicate acoustic surveys conducted near Kodiak Island, Alaska, USA, during summers 2001, 2004, and 2006 showed that the short-term effect of commercial fishing activities on walleye pollock ( Theragra chalcogramma ) during this period was small, in most cases too small to detect. An area with commercial fishing and a nearby comparison area where commercial fishing was prohibited were surveyed before and during the fishery. Acoustic data were used to assess changes in the abundance, geographical and vertical distributions, and small-scale spatial patterns of walleye pollock, which may have occurred after the fishery commenced. A decrease in biomass after fishing began was detected only in 2004. No changes were detected in geographical or vertical distributions that could be attributed to the fishery in any year. Adults did not appear to aggregate or disperse in response to the fishery. Juvenile aggregations did differ between the prefishery and fishery surveys in 1 of the 2 years when juveniles were present. These data suggest that changes in walleye pollock abundance and distribution caused by the fishery are likely quite small compared with natural fluctuations.

scholarly journals Spatiotemporal bioeconomic performance of artificial shelters in a small-scale, rights-based managed Caribbean spiny lobster (Panulirus argus) fishery

2017 ◽  
Vol 81 (1) ◽  
pp. 67 ◽  
Author(s):  
Maren Headley ◽  
Juan Carlos Seijo ◽  
Álvaro Hernández ◽  
Alfonso Cuevas Jiménez ◽  
Raúl Villanueva Poot
Keyword(s):  
Spiny Lobster ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Four Seasons ◽  
Fishing Strategies ◽  
Short Run ◽  
The Caribbean ◽  
Abundance And Distribution ◽  
Pearson Correlations ◽  
Fishing Area

This study presents a bioeconomic analysis of artificial shelter performance in a fishery targeting a spiny lobster meta-population, with spatially allocated, individual exclusive benthic property rights for shelter introduction and harvest of species. Insights into fishers’ short-run decisions and fishing strategies are also provided. Spatiotemporal bioeconomic performance of shelters located in ten fishing areas during four seasons was compared using two-way ANOVAs and Pearson correlations. Results show that there was spatiotemporal heterogeneity in bioeconomic variables among fishing areas, with mean catch per unit effort (CPUE, kg shelter–1) ranging from 0.42 kg to 1.3 kg per trip, mean quasi-profits of variable costs per shelter harvested ranging from USD6.00 to USD19.57 per trip, and mean quasi-profits of variable costs ranging from USD338 to USD1069 per trip. Positive moderate correlations between shelter density and CPUE (kg shelter–1 km–2) were found. Bioeconomic performance of the shelters was influenced by spatiotemporal resource abundance and distribution, fishing area location in relation to the port, shelter density, heterogeneous fishing strategies and the management system. The results provide empirical information on the spatiotemporal performance of shelters and fishing strategies and can contribute to management at the local-scale of a meta-population distributed throughout the Caribbean Sea and Gulf of Mexico.

Patterns of abundance and distribution of species in intertidal rock pools

1993 ◽  
Vol 73 (3) ◽  
pp. 555-569 ◽  
Author(s):  
K. L. Astles
Keyword(s):  
Spatial Scales ◽  
Temporal Variations ◽  
Small Scale ◽  
Rock Pools ◽  
Quantitative Studies ◽  
History Of ◽  
Different Depths ◽  
Random Fluctuations ◽  
Abundance And Distribution ◽  
Sydney Australia

Rock pools are unique and complex habitats in intertidal areas. Quantitative studies of assemblages in pools are few. Abundances and distributions of species in pools on a rock platform near Sydney (Australia) were sampled for two years. Pools of four different depths (5, 15, 30 and 40 cm deep) and up to four strata within each pool (0–5, 5–15, 15–30 and 30–40 cm, from the top of the pool) were sampled, replicated at four sites. The abundances and distributions of most species of plants and animals in pools did not differ between strata nor at different depths in the pools. Abundances of only three species, the encrusting alga, Hildenbrandia prototypus Nardo, the trochid snail, Austrocochlea constricta (Lamarck) and the limpet, Cellana tramoserica (Sowerby) varied significantly between strata and depths. In contrast to other studies on rock pools, most species showed no significant temporal variations in mean abundances in the sites sampled. Significantly large, spatial and temporal, random fluctuations did, however, occur in abundances in individual pools. The consistency of abundances at larger spatial scales indicated that disturbance in these habitats may not be an important structuring process. The large variation between pools does, however, suggest that the history of each pool may have a more significant role in the character of its assemblage. Some implications of small-scale variability are discussed.

Current status and environmental impact of transgenic forest trees

2004 ◽  
Vol 34 (6) ◽  
pp. 1163-1180 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Tannis Beardmore
Keyword(s):  
Large Scale ◽  
Lignin Content ◽  
Fiber Quality ◽  
Herbicide Tolerance ◽  
Current Status ◽  
Small Scale ◽  
Gene Pools ◽  
Ecological Risks ◽  
Forest Trees ◽  
The Impact

Advances in technology for in vitro propagation and genetic transformation have accelerated the development of genetically engineered trees during the past 15 years. At least 33 species of transformed forest trees have been successfully regenerated to date. Targeted traits include herbicide tolerance, pest resistance, abiotic stress tolerance, modified fiber quality and quantity, and altered growth and reproductive development. Commercial potential has been demonstrated in the field for a few traits, in particular herbicide tolerance, insect resistance, and altered lignin content. Now that commercial implementation is feasible, at least for the few genotypes that can be efficiently transformed and propagated, environmental concerns have become the main obstacle to public acceptance and regulatory approval. Ecological risks associated with commercial release range from transgene escape and introgression into wild gene pools to the impact of transgene products on other organisms and ecosystem processes. Evaluation of those risks is confounded by the long life span of trees, and by limitations of extrapolating results from small-scale studies to larger-scale plantations. Issues that are central to safe deployment can only be addressed by permitting medium- to large-scale release of transgenic trees over a full rotation. Current regulations restricting field releases of all transgenes in both time and space need to be replaced with regulations that recognize different levels of risk (as determined by the origin of the transgene, its impact on reproductive fitness, and nontarget impacts) and assign a commensurate level of confinement. The next step in determining acceptability of transgene technology for forest tree improvement is the unconfined release of constructs that pose little risk in terms of gene escape and nontarget impacts, such as lignin-altered poplar or pine, to permit evaluation of ecological risks and environmental or agronomic benefits at relevant scales.

Abundance and distribution of Antarctic krill (Euphausia superba) nearshore of Cape Shirreff, Livingston Island, Antarctica, during six austral summers between 2000 and 2007

2010 ◽  
Vol 67 (7) ◽  
pp. 1159-1170 ◽  
Author(s):  
Joseph D. Warren ◽  
David A. Demer
Keyword(s):  
Antarctic Krill ◽  
Austral Summer ◽  
Euphausia Superba ◽  
Acoustic Backscatter ◽  
Small Scale ◽  
Biomass Density ◽  
Single Beam ◽  
Livingston Island ◽  
Abundance And Distribution ◽  
Antarctic Krill Euphausia Superba

Abundance and distribution of Antarctic krill ( Euphausia superba ) in the nearshore waters north of Livingston Island, Antarctica, were characterized from six small-boat surveys conducted in late January or early February from 2000 to 2007. The first three surveys (2000, 2002, 2004) were conducted using a 120 kHz split-beam echosounder to measure water column acoustic backscatter. The last three surveys (2005–2007) were conducted using 38 kHz and 200 kHz single-beam echosounders. A portion of the acoustic backscatter was attributed to Antarctic krill based on the results of net tows, underwater video observations, and a multiple-frequency acoustic classification algorithm. The annual mean krill biomass density in the survey area ranged from 11 to 84 g·m–2. Results are compared with the western Scotia Sea area of the US Antarctic Marine Living Resources (AMLR) program’s acoustic surveys of krill biomass density for the same years. Nearshore krill biomass densities were significantly larger (t test, p < 0.05), more stable, and the coefficients of variation were smaller than the much larger AMLR surveys. Increased competition between seals, penguins, and humans for the nearshore krill resource, especially during the austral summer months, could impact the recruitment success of these land-based krill predators. Implications of nearshore krill biomass on small-scale management units are discussed.

scholarly journals Assessment of Cu and CuO nanoparticle ecological responses using laboratory small-scale microcosms

2020 ◽  
Vol 7 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Fan Wu ◽  
Bryan J. Harper ◽  
Lauren E. Crandon ◽  
Stacey L. Harper
Keyword(s):  
Small Scale ◽  
Ecological Risks ◽  
Rapid Testing ◽  
Ecological Responses ◽  
Biological Uptake ◽  
Cuo Nanoparticle ◽  
Testing Paradigm

An efficient and rapid testing paradigm to evaluate the biological uptake, distribution, and ecological risks of Cu based NPs.

Reasons to strike first

2019 ◽  
Vol 42 ◽  
Author(s):  
William Buckner ◽  
Luke Glowacki
Keyword(s):  
Intergroup Conflict ◽  
Small Scale

Abstract De Dreu and Gross predict that attackers will have more difficulty winning conflicts than defenders. As their analysis is presumed to capture the dynamics of decentralized conflict, we consider how their framework compares with ethnographic evidence from small-scale societies, as well as chimpanzee patterns of intergroup conflict. In these contexts, attackers have significantly more success in conflict than predicted by De Dreu and Gross's model. We discuss the possible reasons for this disparity.

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