scholarly journals Source-Specific Patterns of Marine Debris and Associated Ecological Impacts in the Red River Estuary of Xuan Thuy National Park, Vietnam

2021 ◽  
Vol 9 ◽  
Author(s):  
Rachel K. Giles ◽  
Cindy Anh Thu Nguyen ◽  
Thu Thi Yến Hồ ◽  
Công Văn Nguyến ◽  
Ngoc Thi Ngô ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Standing Stock ◽  
River Estuary ◽  
Canopy Cover ◽  
Population Level ◽  
Mangrove Ecosystem ◽  
Ecological Impacts ◽  
Ecological Effects ◽  
Red River ◽  
Marine Debris

Vietnamese rivers are among the top ten contributors of anthropogenic debris to the ocean. However, there is limited empirical research documenting debris and its effects in Northern Vietnam. The goal of our research was to conduct the first baseline assessment of anthropogenic debris in the Red River. We aimed to understand the sources, accumulation patterns, and ecological effects of anthropogenic debris in the Red River (Song Hong) estuary. To assess debris patterns, we conducted standing stock debris surveys at sites in the mouth, and upstream of the Red River. To assess the ecological effects of anthropogenic debris on mangrove ecosystems, we measured mangrove diameter, canopy cover, and number of crab burrows/m2 in the same debris transects. Anthropogenic debris was found at all sites, and plastic was the most common material. We identified a non-significant trend, whereby ecological indices declined with increasing amounts of debris. Overall, our results demonstrate that anthropogenic debris is ubiquitous in the Red River estuary, composition varies among sites, and this debris may have adverse or neutral ecological effects on mangrove ecosystem health. Future work should conduct debris assessments at larger spatial scales, and assess ecological responses at the community or population level over extended time periods.

scholarly journals Impacts of plastic debris on biota and implications for human health: A South African perspective

2020 ◽  
Vol 116 (5/6) ◽  
Author(s):  
Trishan Naidoo ◽  
Anusha Rajkaran ◽  
Sershen Not available
Keyword(s):  
South Africa ◽  
Human Health ◽  
Research Effort ◽  
Population Level ◽  
Ecological Impacts ◽  
Marine Debris ◽  
Marine Biota ◽  
Lethal Effects ◽  
Plastic Debris ◽  
Marine Plastic Debris

Entanglement and ingestion of plastics are the main ecological impacts of marine plastic debris on marine biota, but indirect effects such as the transport of alien species and benthic smothering are also important to note. Entanglement of invertebrates, sharks, turtles, birds and marine mammals is mainly caused by macroplastics (>5 mm), and leads to reduced mobility, ineffective foraging and subsequent mortality. The main plastic types associated with entanglement are improperly discarded fishing nets, lines, ropes and straps. In South Africa and surrounding waters, plastic ingestion has been reported in a number of marine species: sharks (n=10), fish (n>=7), turtles (n=1) and birds (n=36). Lethal (macroplastic) and sub-lethal effects (microplastic ≤5 mm) of marine debris on biota have been noted, but at the time of this review there were no published reports on impacts at the population level. Consumed shellfish are possible vectors for the introduction of microplastics into humans. The specific impacts of microplastic ingestion on human health are largely unknown, but additives associated with plastics represent a threat. The research infrastructure in South Africa is insufficient to monitor and characterise marine plastic debris and, in many cases, not in line with global standards. More research effort is needed to understand the impacts of marine plastic debris on humans and marine biota in South Africa, particularly at the population level. Significance • Macroplastics affect marine biota mainly via entanglement and microplastics largely through ingestion. • Macro- and microplastic interactions with biota can result in sub-lethal effects and mortality but no population effects have been reported for South Africa. • Consumed shellfish are a potential source of microplastics for humans but their potential effects in humans remain unknown. • Better infrastructure is needed for improved monitoring and research on the effects of marine debris in South Africa.

scholarly journals Distribution of marine debris in Jakarta Bay and its implication to the coastal ecosystem

2021 ◽  
Vol 925 (1) ◽  
pp. 012017
Author(s):  
Nasir Sudirman ◽  
Devi Dwiyanti Suryono ◽  
August Daulat ◽  
Agustin Rustam ◽  
Hadiwijaya L Salim ◽  
...  
Keyword(s):  
River Estuary ◽  
Mangrove Ecosystem ◽  
Coastal Ecosystem ◽  
Marine Debris ◽  
Line Transect ◽  
West Java ◽  
Plastic Debris ◽  
Comprehensive Data ◽  
Polluted Rivers ◽  
Marine Plastic Debris

Abstract Citarum River, which ended up in Muaragembong, Bekasi Regency-West Java Province, is known recently as one of the most polluted rivers globally, including pollution caused by plastic litter. This research was conducted in the surrounding river, estuary, and mangrove ecosystem in Muaragembong, which aimed to determine macro debris and analyze its impact on the coastal ecosystem. Marine debris sampling in the mangrove ecosystem was done by line transect, while the net using for marine debris sampling surrounding river and estuary. The result showed that debris composition in Muaragembong consisted of 80% inorganic and 20% organic, where plastic debris dominated with 50-81% and was distributed throughout the estuary and mangrove ecosystem. The highest density was found in the mangrove ecosystem in the Kali Mati Estuary (Pantai Sederhana Village) with 222.67 waste/m2, while the heaviest waste was found in the Bendera Estuary (Pantai Bahagia Village) 4,663.64 grams/m2. This condition explained the lack of marine debris management in the Muaragembong estuary, where most inorganic debris originated from household litter. This research also supports data and information for baseline Indonesia’s marine plastic debris due to comprehensive data needed to reduce 70% of marine plastic debris by 2025.

scholarly journals Future large hydropower dams impact global freshwater megafauna

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christiane Zarfl ◽  
Jürgen Berlekamp ◽  
Fengzhi He ◽  
Sonja C. Jähnig ◽  
William Darwall ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Point Of View ◽  
Ecological Impacts ◽  
Climate Mitigation ◽  
Threat Status ◽  
Hydropower Dams ◽  
Balkan Region ◽  
America South ◽  
Freshwater Management ◽  
Major Attention

AbstractDam construction comes with severe social, economic and ecological impacts. From an ecological point of view, habitat types are altered and biodiversity is lost. Thus, to identify areas that deserve major attention for conservation, existing and planned locations for (hydropower) dams were overlapped, at global extent, with the contemporary distribution of freshwater megafauna species with consideration of their respective threat status. Hydropower development will disproportionately impact areas of high freshwater megafauna richness in South America, South and East Asia, and the Balkan region. Sub-catchments with a high share of threatened species are considered to be most vulnerable; these are located in Central America, Southeast Asia and in the regions of the Black and Caspian Sea. Based on this approach, planned dam locations are classified according to their potential impact on freshwater megafauna species at different spatial scales, attention to potential conflicts between climate mitigation and biodiversity conservation are highlighted, and priorities for freshwater management are recommended.

scholarly journals Responses of Vertebrate Wildlife to Oil and Natural Gas Development: Patterns and Frontiers

2021 ◽  
Author(s):  
A. D. Chalfoun
Keyword(s):  
Natural Gas ◽  
Anthropogenic Activities ◽  
Spatial Scales ◽  
Habitat Type ◽  
Population Level ◽  
Low Frequencies ◽  
Natural Gas Development ◽  
The Usa ◽  
Oil And Natural Gas

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

scholarly journals Evaluation and Hydrologic Validation of Three Satellite-Based Precipitation Products in the Upper Catchment of the Red River Basin, China

2018 ◽  
Vol 10 (12) ◽  
pp. 1881 ◽  
Author(s):  
Yueyuan Zhang ◽  
Yungang Li ◽  
Xuan Ji ◽  
Xian Luo ◽  
Xue Li
Keyword(s):  
River Basin ◽  
Southwest China ◽  
Spatial Scales ◽  
Red River ◽  
Low Flow ◽  
Efficiency Coefficient ◽  
Monthly Streamflow ◽  
Red River Basin ◽  
Hydrological Applications ◽  
Trmm 3B42

Satellite-based precipitation products (SPPs) provide alternative precipitation estimates that are especially useful for sparsely gauged and ungauged basins. However, high climate variability and extreme topography pose a challenge. In such regions, rigorous validation is necessary when using SPPs for hydrological applications. We evaluated the accuracy of three recent SPPs over the upper catchment of the Red River Basin, which is a mountain gorge region of southwest China that experiences a subtropical monsoon climate. The SPPs included the Tropical Rainfall Measuring Mission (TRMM) 3B42 V7 product, the Climate Prediction Center (CPC) Morphing Algorithm (CMORPH), the Bias-corrected product (CMORPH_CRT), and the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) Climate Data Record (PERSIANN_CDR) products. SPPs were compared with gauge rainfall from 1998 to 2010 at multiple temporal (daily, monthly) and spatial scales (grid, basin). The TRMM 3B42 product showed the best consistency with gauge observations, followed by CMORPH_CRT, and then PERSIANN_CDR. All three SPPs performed poorly when detecting the frequency of non-rain and light rain events (<1 mm); furthermore, they tended to overestimate moderate rainfall (1–25 mm) and underestimate heavy and hard rainfall (>25 mm). GR (Génie Rural) hydrological models were used to evaluate the utility of the three SPPs for daily and monthly streamflow simulation. Under Scenario I (gauge-calibrated parameters), CMORPH_CRT presented the best consistency with observed daily (Nash–Sutcliffe efficiency coefficient, or NSE = 0.73) and monthly (NSE = 0.82) streamflow. Under Scenario II (individual-calibrated parameters), SPP-driven simulations yielded satisfactory performances (NSE >0.63 for daily, NSE >0.79 for monthly); among them, TRMM 3B42 and CMORPH_CRT performed better than PERSIANN_CDR. SPP-forced simulations underestimated high flow (18.1–28.0%) and overestimated low flow (18.9–49.4%). TRMM 3B42 and CMORPH_CRT show potential for use in hydrological applications over poorly gauged and inaccessible transboundary river basins of Southwest China, particularly for monthly time intervals suitable for water resource management.

scholarly journals A synthesis of scale-dependent ecology of the endangered mountain caribou in British Columbia, Canada

Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 33
Author(s):  
Robert Serrouya ◽  
Bruce N. McLellan ◽  
Clayton D. Apps ◽  
Heiko U. Wittmer
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Spatial Scales ◽  
Management Strategies ◽  
Population Level ◽  
Limiting Factors ◽  
Conservation Strategies ◽  
Integrative Approach ◽  
Rangifer Tarandus Caribou ◽  
Multi Scale

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou) that live in highprecipitation, mountainous ecosystems of southeastern British Columbia and northern Idaho. The distribution and abundance of these caribou have declined dramatically from historical figures. Results from many studies have indicated that mountain caribou rely on old conifer forests for several life-history requirements including an abundance of their primary winter food, arboreal lichen, and a scarcity of other ungulates and their predators. These old forests often have high timber value, and understanding mountain caribou ecology at a variety of spatial scales is thus required to develop effective conservation strategies. Here we summarize results of studies conducted at three different spatial scales ranging from broad limiting factors at the population level to studies describing the selection of feeding sites within seasonal home ranges of individuals. The goal of this multi-scale review is to provide a more complete picture of caribou ecology and to determine possible shifts in limiting factors across scales. Our review produced two important results. First, mountain caribou select old forests and old trees at all spatial scales, signifying their importance for foraging opportunities as well as conditions required to avoid alternate ungulates and their predators. Second, relationships differ across scales. For example, landscapes dominated by roads and edges negatively affect caribou survival, but appear to attract caribou during certain times of the year. This juxtaposition of fine-scale behaviour with broad-scale vulnerability to predation could only be identified through integrated multi-scale analyses of resource selection. Consequently we suggest that effective management strategies for endangered species require an integrative approach across multiple spatial scales to avoid a focus that may be too narrow to maintain viable populations. Abstract in Norwegian / Sammendrag:Skala-avhengig økologi og truet fjellvillrein i Britisk ColumbiaFjellvillreinen i de nedbørsrike fjellområdene i sørøstre Britisk Columbia og nordlige Idaho som er en truet økotype av skogsreinen (Rangifer tarandus caribou), har blitt kraftig redusert både i utbredelse og antall. Mange studier har vist at denne økotypen er avhengig av vinterføden hengelav i gammel barskog hvor det også er få andre klovdyr og dermed få predatorer. Slik skog er også viktige hogstområder, og å forstå økologien til fjellvillreinen i forskjellige skaleringer er derfor nødvendig for å utvikle forvaltningsstrategier som kan berge og ta vare på denne reinen. Artikkelen gir en oversikt over slike arbeider: fra studier av begrensende faktorer på populasjonsnivå til studier av sesongmessige beiteplasser på individnivå. Hensikten er å få frem et mer helhetlig perspektiv på fjellvillreinen og finne hvordan de begrensende faktorene varierer etter skaleringen som er benyttet i studiet. Oversikten vår frembragte to viktige resultater; 1) Uansett skalering så velger dyrene gammel skog og gamle trær. 2) Dyrenes bruk av et område kan variere med benyttet skalering, for eksempel vil landskap utbygd med veier og hogstflater være ufordelaktig for overlevelsen, men synes likevel å kunne tiltrekke fjellvillreinen til visse tider av året. Forholdet mellom atferd ut fra fin-skalering og stor-skalering sårbarhet hva gjelder predasjon, ville kun blitt avdekket ved flere-skaleringsanalyse av hvordan ressursene benyttes. Ut fra dette foreslår vi at forvaltningsstrategier for truete bestander som eksempelvis fjellvillreinen, må baseres på tilnærminger ut fra ulike skaleringer for å hindre at et for snevert perspektiv kan begrense muligheten for vedvarende levedyktighet.

scholarly journals Spatial Management Measures Alter Vessel Behavior in the Aleutian Archipelago

2021 ◽  
Vol 7 ◽  
Author(s):  
Benjamin K. Sullender ◽  
Kelly Kapsar ◽  
Aaron Poe ◽  
Martin Robards
Keyword(s):  
North Pacific ◽  
Risk Mitigation ◽  
Spatial Scales ◽  
Great Circle ◽  
Ecological Impacts ◽  
Study Region ◽  
The North ◽  
Management Measures ◽  
Before And After ◽  
The North Pacific

The Aleutian Archipelago and surrounding waters have enormous ecological, cultural, and commercial significance. As one of the shortest routes between North American and Asian ports, the North Pacific Great Circle Route, which crosses through the Aleutian Archipelago, is traveled by thousands of large cargo ships and tanker vessels every year. To reduce maritime risks and enhance navigational safety, the International Maritime Organization built upon earlier offshore routing efforts by designating five Areas To Be Avoided (ATBAs) in the Aleutian Islands in 2016. The ATBAs are designed to keep large vessels at least 50 nautical miles (93 km) from shore unless calling at a local port or transiting an authorized pass between islands. However, very few studies have examined the effectiveness of ATBAs as a mechanism for changing vessel behavior and thereby reducing the ecological impacts of maritime commerce. In this study, we use 4 years of satellite-based vessel tracking data to assess the effectiveness of the Aleutian ATBAs since their implementation in 2016. We determined whether vessels transiting the North Pacific Great Circle Route changed behavior after ATBA implementation, both in terms of overall route selection and in terms of compliance with each ATBA boundary. We found a total of 2,252 unique tankers and cargo vessels &gt;400 gross tons transited the study region, completing a total of 8,794 voyages. To quantify routing changes of individual vessels, we analyzed the 767 vessels that transited the study region both before and after implementation. The percentage of voyages transiting through the boundaries of what would become ATBAs decreased from 76.3% in 2014–2015 (prior to ATBA designation) to 11.8% in 2016–2017 (after implementation). All five Aleutian ATBAs had significant increases in compliance, with the West ATBA showing the most dramatic increase, from 32.1% to 95.0%. We discuss the framework for ATBA enforcement and highlight the value of local institutional capacity for real-time monitoring. Overall, our results indicate that ATBAs represent a viable strategy for risk mitigation in sensitive ecological areas and that through monitoring, spatial protections influence vessel route decisions on multiple spatial scales.

Assessment of Water Quality in Coastal Zone of the Red River Estuary (Nam Dinh Province, Vietnam)

APAC 2019 ◽  
2019 ◽  
pp. 837-843
Author(s):  
Dang Thi Huyen ◽  
Le Nhu Da ◽  
Vu Duc Toan ◽  
Le Thi Phuong Quynh ◽  
Duong Thi Thuy
Keyword(s):  
Water Quality ◽  
Coastal Zone ◽  
River Estuary ◽  
Red River

scholarly journals Human-induced reductions in fish predator boldness decrease their predation rates in kelp forests

2019 ◽  
Vol 286 (1900) ◽  
pp. 20182745 ◽  
Author(s):  
O. Kennedy Rhoades ◽  
Steve I. Lonhart ◽  
John J. Stachowicz
Keyword(s):  
Protected Areas ◽  
Size Structure ◽  
Spatial Scales ◽  
Ecological Impacts ◽  
Predatory Fish ◽  
Kelp Forests ◽  
Fish Predator ◽  
Spatial And Temporal Scales ◽  
Predatory Fishes ◽  
Predation Rates

Humans have restructured food webs and ecosystems by depleting biomass, reducing size structure and altering traits of consumers. However, few studies have examined the ecological impacts of human-induced trait changes across large spatial and temporal scales and species assemblages. We compared behavioural traits and predation rates by predatory fishes on standard squid prey in protected areas of different protection levels and ages, and found that predation rates were 6.5 times greater at old, no-take (greater than 40 years) relative to new, predominantly partial-take areas (approx. 8 years), even accounting for differences in predatory fish abundance, body size and composition across sites. Individual fishes in old protected areas consumed prey at nearly twice the rate of fishes of the same species and size at new protected areas. Predatory fish exhibited on average 50% longer flight initiation distance and lower willingness to forage at new protected areas, which partially explains lower foraging rates at new relative to old protected areas. Our experiments demonstrate that humans can effect changes in functionally important behavioural traits of predator guilds at large (30 km) spatial scales within managed areas, which require protection for multiple generations of predators to recover bold phenotypes and predation rates, even as abundance rebounds.

Sign in / Sign up

Export Citation Format

Share Document