scholarly journals A human impact metric for coastal ecosystems with application to seagrass beds in Atlantic Canada

FACETS ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 210-237 ◽  
Author(s):  
Grace E.P. Murphy ◽  
Melisa C. Wong ◽  
Heike K. Lotze
Keyword(s):  
Human Impact ◽  
Nutrient Loading ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Nitrogen Loading ◽  
Atlantic Canada ◽  
Seagrass Beds ◽  
Coastal Habitats ◽  
Coastal Bays

Coastal biogenic habitats are vulnerable to human impacts from both terrestrial and marine realms. Yet the broad spatial scale used in current approaches of quantifying anthropogenic stressors is not relevant to the finer scales affecting most coastal habitats. We developed a standardized human impact metric that includes five bay-scale and four local-scale (0–1 km) terrestrial and marine-based impacts to quantify the magnitude of anthropogenic impacts to coastal bays and nearshore biogenic habitats. We applied this metric to 180 seagrass beds ( Zostera marina), an important biogenic habitat prioritized for marine protection, in 52 bays across Atlantic Canada. The results show that seagrass beds and coastal bays exist across a wide human impact gradient and provide insight into which are the most and least affected by human threats. Generally, land alteration, nutrient loading, and shellfish aquaculture were higher in the Gulf of St. Lawrence, whereas invasive species and fishing activities were higher along the Atlantic coast. Sixty-four percent of bays were at risk of seagrass decline from nitrogen loading. We also found high within-bay variation in impact intensity, emphasizing the necessity of quantifying impacts at multiple spatial scales. We discuss implications for management and conservation planning, and application to other coastal habitats in Canada and beyond.

scholarly journals A human impact metric for coastal ecosystems with application to seagrass beds in Atlantic Canada

2018 ◽  
Author(s):  
Grace E.P. Murphy ◽  
Melisa Wong ◽  
Heike K. Lotze
Keyword(s):  
Human Impact ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Coastal Ecosystems ◽  
Atlantic Canada ◽  
Seagrass Beds ◽  
General Application ◽  
Coastal Bays ◽  
Biogenic Habitat ◽  
Seagrass Ecosystems

AbstractCoastal biogenic habitats are particularly vulnerable to cumulative human impacts from both terrestrial and marine realms. Yet the broad spatial scale used in current global or regional approaches of quantifying multiple anthropogenic stressors are not relevant to the local or bay-wide scales affecting most coastal biogenic habitats. To fill this gap, we developed a standardized human impact metric to quantify the magnitude of anthropogenic impacts to coastal ecosystems more broadly, and biogenic habitats in particular. We applied this metric to 180 seagrass beds (Zostera marina), an important biogenic habitat prioritized for marine protection, across Atlantic Canada. Our impact metric includes five bay-scale and four local-scale terrestrial and marine-based impacts. Results show that seagrass beds and coastal bays in Atlantic Canada exist across a wide gradient of human impacts. Considerable differences in the range and intensity of impacts within and between regions provide insight into where coastal bays and seagrass ecosystems are expected to be most and least affected by individual or cumulative human threats. We discuss implications for management and conservation planning, and the general application of our impact metric to other coastal regions and habitats in Canada and beyond.

A qualitative approach to evaluating the impact of human interventions on the middle Charente River (West France)

2020 ◽  
Author(s):  
Amélie Duquesne ◽  
Christine Plumejeaud-Perreau ◽  
Jean-Michel Carozza
Keyword(s):  
Human Impact ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
River Management ◽  
Anthropogenic Pressure ◽  
Human Intervention ◽  
Impact Index ◽  
Human Interventions ◽  
The Impact ◽  
The City

<p><span>Although many studies have analyzed the impact of human interventions on European rivers over decades or centuries, researchers have rarely evaluated the geomorphological effects of these anthropogenic pressures on fluvial systems. However, quantifying anthropogenic impacts is fundamental to understanding how rivers are affected by human interventions and to improving the river management and restoration. The aim of this study is to propose a new and original qualitative method to estimate the importance of human impacts on rivers over the last three centuries using the middle Charente River as a test case. The study area is an anastomosing, low-energy and little mobile river of the lowlands of Western France. It extends from the city of Angoulême (Charente) to the city of Saintes (Charente-Maritime), with a length of approximately 100 km. The study segment has been subjected to high anthropogenic pressure since the High Middle Ages, and it was enhanced during the 19th century to facilitate navigation and terrestrial transportation, to ensure the exploitation of the water's driving force (water mills and paper mills), to maintain the local people (fishing dams and agro-pastoral uses) and to allow for flood protection. To understand and estimate the anthropogenic heritage of the Charente River, this study employed a two-stage method: 1) an inventory of the human interventions on the fluvial system through the consultation of geo-historical data (textual archives, historical maps and iconography) dating from the end of the 17th century to the 2010s and 2) an evaluation of the human impact of each human intervention, sub-category and category of intervention based on the calculation of the Cumulative Human Impact Index. The Cumulative Human Impact Index is composed of several qualitative attributes graded by an evaluator. The results allow one 1) to generate a database and typology of the human interventions affecting the middle Charente River over the long term; 2) to map the cumulative impacts of human interventions on the study area; and 3) to analyze the unitary and overall impact of each human intervention, sub-category and category of intervention on the river landscape's heritage. Finally, this study concludes with 1) a discussion of the advantages of using a qualitative methodology for the estimation of anthropogenic impacts and 2) a reflection on the use of the maps of cumulative human impacts for Charente River management and restoration.</span></p>

scholarly journals Limnological Characteristics and Diatom Dominants in Lakes of Northeastern Poland

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 374
Author(s):  
Monika Eliasz-Kowalska ◽  
Agata Z. Wojtal
Keyword(s):  
Human Impact ◽  
Linear Models ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Hierarchical Cluster ◽  
P Value ◽  
Diatom Assemblages ◽  
Large Area ◽  
Mean Values ◽  
Dominance Structure

Determination of the relationships between environmental factors and diatom assemblages is usually made for several hundred lakes spread over a large area. However, the analysis of several lakes located near Lake Wigry also gives interesting results. Lakes in Wigry National Park (Poland) with broad similarity of geological origin show clear limnological, physical, and chemical differences. Here, we report on an investigation into how these dissimilarities influence diatom assemblages. Hierarchical Cluster Analysis showed that the studied lakes can be divided into three groups: (1) disharmonic, (2) harmonious with greater human impact on the environment, and (3) harmonious with a more limited human impact. The harmonious lakes could be divided into two groups that are mainly in line with the contents of the chloride and sulfates ions taken as indicative of human impacts on the environment. Overall, the three groups had different dominance structures, as reference to the Dominance Index (DI) made clear (mean values being: (1) −70.54%, (2) −72%, and (3) −54.58%, Generalized Linear Models with the categorical independent variable (group) showed significant differences between groups (for 1–3, 2–3) p value < 0.05). Lakes impacted by anthropopressure and disharmonic ones had the strongest dominance structure. More broadly, DI differences between the groups are consistent with the Species Pool Hypothesis (SPH), while studied differences can be said to result from natural geological dissimilarities, as well as disparate anthropogenic impacts.

scholarly journals Two millennia of anthropogenic landscape modification and nutrient loading at Dian Lake, Yunnan Province, China

The Holocene ◽  
2018 ◽  
Vol 29 (3) ◽  
pp. 505-517 ◽  
Author(s):  
Aubrey L Hillman ◽  
Alice Yao ◽  
Mark B Abbott ◽  
Daniel J Bain
Keyword(s):  
Nutrient Loading ◽  
Environmental Changes ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Sediment Cores ◽  
Sediment Quality ◽  
Small Scale ◽  
Landscape Modification ◽  
Fine Grained ◽  
Definitive Evidence

Landscapes have been shaped by human activities for millennia and there is a pressing need to characterize pre-industrial impacts in order to mitigate present-day effects. We present the analysis of two sediment cores from Dian Lake in Yunnan, China, which span 4000 years. We compare cores from the northern and southern ends of the lake to investigate spatial variability in natural and anthropogenic environmental changes in this large (300 km2) lake. To document the initiation of human impacts on the landscape and characterize the attendant changes in the lake water and sediment quality, we rely on organic and inorganic geochemical measurements as well as sedimentology and stratigraphy. The character and magnitude of proxy changes are coherent between the two core sites with slight differences in the timing of events. At both core sites, we find definitive evidence for substantial anthropogenic change beginning AD 100 (1850 yr BP), coincident with the introduction of terraced agriculture. Sedimentological shifts are distinctive and characterized by an increase in magnetic susceptibility values and a visible change to red, fine-grained clay. The geochemistry of this sediment suggests that it was sourced from the eastern catchment of the lake and delivered into the basin following intensive agriculture and soil erosion. Anthropogenic impacts intensify after AD 900 through hydrologic modification and cultural eutrophication resulting from increased nutrient loading. This study presents evidence that human-affected landscapes have been present in this region of China for longer than previously believed and that ‘small-scale’ land use change can have measureable impacts on lakes.

Anthropogenic impacts on the ecosystems of coastal lagoons: modelling fundamental biogeochemical processes and management implications

2004 ◽  
Vol 55 (1) ◽  
pp. 67 ◽  
Author(s):  
Ian T. Webster ◽  
Graham P. Harris
Keyword(s):  
Coastal Lagoon ◽  
Nutrient Loading ◽  
Anthropogenic Impacts ◽  
Coastal Lagoons ◽  
Alternative Stable States ◽  
Nitrogen Loading ◽  
Biogeochemical Model ◽  
Nutrient Loads ◽  
Stable States ◽  
Flushing Rate

This paper presents a biogeochemical model of a coastal lagoon intended to be representative of lagoons occurring along the south-east and south-west coasts of Australia. Many of these lagoons are threatened by increased nutrient loads because of land use change, by alterations to their freshwater inflows and by modification to their tidal flushing regimens. The model simulates the biogeochemical response of the lagoon to nutrient (nitrogen) loading and includes nutrient transformation processes in the sediments, as well as in the water column. The paper focuses on the response of primary producers to increasing and decreasing nutrient loads and how the response is altered by changes in the flushing rate of the lagoon with the sea. In common with lakes, the modelled lagoon exhibits alternative stable states representing macrophyte or phytoplankton dominance depending on nutrient loading and history. A third state representing severe degradation occurs when denitrification shuts down. A characteristic of Australian coastal lagoon systems is that, due to highly sporadic rainfall patterns, nutrient inflows are dominated by intermittent extreme events. The modelling demonstrates that such a loading regimen may be expected to generally increase the vulnerability of the lagoon to increasing nutrient loads. The results of the analysis presented are pertinent to several questions raised by coastal managers, such as what are the expected benefits of improving flushing by dredging and what are the consequences of altering the timing and magnitudes of the loads reaching the lagoons?

Natural and anthropogenic impacts on the composition of lake sediments

2008 ◽  
Vol 72 (1) ◽  
pp. 411-413 ◽  
Author(s):  
T. Eskola ◽  
V. Peuraniemi
Keyword(s):  
World War Ii ◽  
Lake Sediments ◽  
Human Impact ◽  
Catchment Area ◽  
Anthropogenic Impacts ◽  
Heavy Traffic ◽  
World War ◽  
Small Lakes ◽  
Anthropogenic Effect ◽  
The City

AbstractLake sediments were studied from four lakes in environmentally different areas in northern Finland. Lakes Pyykösjärvi and Kuivasjärvi are situated near roads with heavy traffic and the city of Oulu. Lakes Martinlampi and Umpilampi are small lakes in a forest area with no immediate human impact nearby. The concentration of Pb increases in the upper parts of the sedimentary columns of Lake Kuivasjärvi and Lake Pyykösjärvi. This is interpreted as being an anthropogenic effect related to heavy traffic in the area and use of Lake Pyykösjärvi as an airport during World War II. High Ni and Zn concentrations in the Lake Umpilampi sediments are caused by weathered black schists. Sediments in Lake Martinlampi show high Pb and Zn contents with increasing Pb concentrations up through the sedimentary column. The sources of these elements are probably Pb-Zn mineralization in the bedrock, Pb-Zn-rich boulders and anomalous Pb and Zn contents in till in the catchment area of the lake.

scholarly journals Novel approach to enhance coastal habitat and biotope mapping with drone aerial imagery analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
João Gama Monteiro ◽  
Jesús L. Jiménez ◽  
Francesca Gizzi ◽  
Petr Přikryl ◽  
Jonathan S. Lefcheck ◽  
...  
Keyword(s):  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Low Cost ◽  
Human Populations ◽  
Coastal Habitat ◽  
Coastal Monitoring ◽  
Monitoring Programs ◽  
Novel Approach ◽  
Aerial Platforms ◽  
Rocky Habitats

AbstractUnderstanding the complex factors and mechanisms driving the functioning of coastal ecosystems is vital towards assessing how organisms, ecosystems, and ultimately human populations will cope with the ecological consequences of natural and anthropogenic impacts. Towards this goal, coastal monitoring programs and studies must deliver information on a range of variables and factors, from taxonomic/functional diversity and spatial distribution of habitats, to anthropogenic stress indicators such as land use, fisheries use, and pollution. Effective monitoring programs must therefore integrate observations from different sources and spatial scales to provide a comprehensive view to managers. Here we explore integrating aerial surveys from a low-cost Remotely Piloted Aircraft System (RPAS) with concurrent underwater surveys to deliver a novel approach to coastal monitoring. We: (i) map depth and substrate of shallow rocky habitats, and; (ii) classify the major biotopes associated with these environmental axes; and (iii) combine data from i and ii to assess the likely distribution of common sessile organismal assemblages over the survey area. Finally, we propose a general workflow that can be adapted to different needs and aerial platforms, which can be used as blueprints for further integration of remote-sensing with in situ surveys to produce spatially-explicit biotope maps.

scholarly journals Identifying Human-Induced Spatial Differences of Soil Erosion Change in a Hilly Red Soil Region of Southern China

2019 ◽  
Vol 11 (11) ◽  
pp. 3103
Author(s):  
Dong Huang ◽  
Xiaohuan Yang ◽  
Hongyan Cai ◽  
Zuolin Xiao ◽  
Dongrui Han
Keyword(s):  
Soil Erosion ◽  
Human Impact ◽  
Human Impacts ◽  
Southern China ◽  
Red Soil ◽  
Jiangxi Province ◽  
Negative Effects ◽  
Gravity Center ◽  
Local Conditions ◽  
Spatial Differences

Soil erosion (SE) processes are closely related to natural conditions and human activities, posing a threat to environment and society. Identifying the human impact on regional SE changes is increasingly essential for pertinent SE management. Jiangxi province is studied here as a representative area of hilly-red-soil regions within southern China. The main objectives of this study were to investigate the changing trend of SE within Jiangxi and identify human impacts on regional SE change from the perspective of spatial differences, through a new approach based on a gravity-center model. Our results showed that SE status presented an overall amelioration from 1990 to 2015, while the average soil erosion modulus (SEM) declined from 864 to 281 Mg/(km2·a). Compared to the situation under human and natural impacts, human-induced spatial differences of SE change demonstrated that the western and northwest regions showed stronger negative effects; the southern region shifted towards negative effects; the northeast region presented a much weaker negative effect. Our results indicated that 4 cities with strong negative effects need more attention in further SE management suited to their local conditions and development, and also suggested that the approach based on a gravity-center has potential for identifying the human impact on regional SE change from the perspective of spatial patterns.

scholarly journals The Past, Present, and Future of Tuna at Lake Moāwhitu: Drawing on the two knowledge baskets of Mātauranga Māori and Western Science

2021 ◽  
Author(s):  
Russleigh Parai
Keyword(s):  
Algal Blooms ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Land Use Changes ◽  
Environmental Dna ◽  
Western Science ◽  
Lake Water Quality ◽  
Dna Metabarcoding ◽  
Remedial Intervention ◽  
Life Force

<p><b>Knowledge generated through experience and understanding relies on the senses, one of which is listening. This thesis provides an opportunity to hear the diminishing voice of tuna utilizing paleolimnological techniques and our natural senses through traditional Indigenous methodologies in order to track the presence of tuna back in time. </b></p> <p>This study provides historical environmental context of Lake Moāwhitu catchment (Rangitoto ki te Tonga) as a once significant mahinga kai site for manawhenua, Ngāti Koata. The strong connection to place is not lost on Ngāti Koata despite for many their geographic detachment to their turangawaewae. They hear the voice of tuna calling them back to sustain them as they have sustained Māori from the beginning of time. Now considered wāhi tapu due to significant degradation, Moāwhitu is currently undergoing remedial intervention by Ngāti Koata, DoC, Lakes380 and stakeholders to restore the mauri (life force) of the Lake and adjacent wetland ecosystem.</p> <p>Drawing from two distinct knowledge streams of western science and mātauranga Māori, this study draws new (on-site) understandings about the anthropogenic impacts on tuna as well as their status and relationship as tuākana (older sibling) to Māori. Through this journey a ‘te ao Māori’ (Māori worldview) is explored, revealing a historically healthy and abundant tuna population and thriving tuākana-teina relationship up until recent decades. This information complements the environmental reconstruction derived from western science methods applied to a lake Moawhitu sediment core spanning the last 1000 years or so. Through a combination of palynology, hyperspectral scanning and bacterial environmental DNA metabarcoding, it is clear that lake water quality remained high despite various historical land cover and land use changes, until recent decades when deteriorating quality has accompanied a rise in cyanobacteria and toxic algal blooms. These changes appear to coincide with intensified pastoralism accompanying draining of the lake and fringing wetlands since the mid-twentieth century. How tuna have endured these recent human impacts and why their survival and sustainability is important to Aotearoa today is at the heart of this thesis which seeks to explore how two vastly different knowledge streams converge and navigate unchartered waters. The two knowledge baskets (with their respective world views) are held up for the reader to view and consider what an effective collaborative partnership looks like by recognising basic intrinsic values of respect, reciprocity and kindness. The challenge remains to draw out the very best of people (he tangata) as a way to bring about urgent regenerative solutions for our tuākana, tuna, and in turn humanity itself.</p>

Testing the effects of durability (shell thickness) on species over-representation in death assemblages, a taphonomic baseline for conservation paleobiology

2021 ◽  
Author(s):  
Adam Tomašových ◽  
Susan M. Kidwell
Keyword(s):  
Southern California ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Organic Content ◽  
Time Averaging ◽  
Shell Size ◽  
Interspecific Differences ◽  
Conservation Paleobiology ◽  
Death Assemblages ◽  
Species Abundances

&lt;p&gt;Differences in the taxonomic or functional composition of living and death assemblages is a key means of identifying the magnitude and drivers of past ecological changes in conservation paleobiology, especially when assessing the effects of anthropogenic impacts. However, such live-dead differences in species abundances can arise not only from ecological (stochastic or deterministic) changes in abundance over the duration of time averaging but also from interspecific differences in the postmortem durability of skeletal remains or from the lifespan of the individuals. Here, we attempt to directly incorporate the effects of durability on species abundances in death assemblages by modeling dead abundance as a function of species&amp;#8217; durability traits and using abundances in living assemblages as a prior. Species inferred to be negatively affected by anthropogenic impacts should be over-represented in death assemblages relative to their abundance in death assemblages predicted by the durability model (rather than just relative to their abundance in living assemblages). Using species-level durability trait data for bivalves (shell size, thickness, mineralogy, shell organic content, and life habit) from the southern California shelf, we find that, among these traits, valve thickness correlates consistently positively and at multiple spatial scales with the log of the dead:live ratio of species abundances, and accounts for ~20-30% of live-dead mismatch. Using this benchmark for the discordance that might be taphonomic in origin, we confirm that the over-representation of epifaunal suspension-feeders and siphonate deposit-feeders in death assemblages of the southern California shelf owes in fact to their ecological decline in recent centuries, even when accounting for their greater durability.&lt;/p&gt;

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