scholarly journals Integrative, regional assessment of bottom trawling impact on benthic habitats in the east Atlantic.

Author(s):  
Gert Van Hoey ◽  
Ole Ritzau Eigaard ◽  
Tobias Van Kooten ◽  
Sebastian Valenko ◽  
Adriaan Rijnsdorp

Based on a European union request, the International Council for the Exploration of the Sea (ICES) has explored and advised on indicators of pressure and impact of bottom trawling on the seabed, and of trade-offs in the catch and value of landings. Such assessment frameworks combine pressure (trawling intensity) with benthic habitats and their sensitivity to estimate the impacts on regional scale. The main differences between the indicators lay in their underlying scientific basis for determining sensitivity. Two approaches, the longevity and the population dynamic approach, are based on a statistical prediction of the longevity distribution of the benthic community, which is a practically very attractive way to capture sensitivity to trawling. The BH3 approach uses a categorical scoring approach for sensitivity. The BH2 relies on empirical observations to estimate changes in Margaleff diversity. In general, the use of continuous environmental variables, rather than the EUNIS habitat classes seemed promising for assessing impacts as they result in larger gradients in the sensitivity layer. Major steps forward in assessing the impact of bottom trawling were made, but improved parameterization and further ground-truthing is required, which will be further taken up in the ICES working group WGFBIT.

2018 ◽  
Author(s):  
Gert Van Hoey ◽  
Ole Ritzau Eigaard ◽  
Tobias Van Kooten ◽  
Sebastian Valenko ◽  
Adriaan Rijnsdorp

Based on a European union request, the International Council for the Exploration of the Sea (ICES) has explored and advised on indicators of pressure and impact of bottom trawling on the seabed, and of trade-offs in the catch and value of landings. Such assessment frameworks combine pressure (trawling intensity) with benthic habitats and their sensitivity to estimate the impacts on regional scale. The main differences between the indicators lay in their underlying scientific basis for determining sensitivity. Two approaches, the longevity and the population dynamic approach, are based on a statistical prediction of the longevity distribution of the benthic community, which is a practically very attractive way to capture sensitivity to trawling. The BH3 approach uses a categorical scoring approach for sensitivity. The BH2 relies on empirical observations to estimate changes in Margaleff diversity. In general, the use of continuous environmental variables, rather than the EUNIS habitat classes seemed promising for assessing impacts as they result in larger gradients in the sensitivity layer. Major steps forward in assessing the impact of bottom trawling were made, but improved parameterization and further ground-truthing is required, which will be further taken up in the ICES working group WGFBIT.


2019 ◽  
Vol 77 (1) ◽  
pp. 278-289 ◽  
Author(s):  
P D van Denderen ◽  
S G Bolam ◽  
R Friedland ◽  
J G Hiddink ◽  
K Norén ◽  
...  

Abstract Bottom trawling disturbance and hypoxia are affecting marine benthic habitats worldwide. We present an approach to predict their effects on benthic communities, and use the approach to estimate the state, the biomass relative to carrying capacity, of the Baltic Sea at the local, habitat, and regional scale. Responses to both pressures are expected to depend on the longevity of fauna, which is predicted from benthic data from 1558 locations. We find that communities in low-salinity regions mostly consist of short-lived species, which are, in our model, more resilient than those of the saline areas. The model predicts that in 14% of the Baltic Sea region benthic biomass is reduced by at least 50%, whereas an additional 8% of the region has reductions of 10–50%. The effects of hypoxia occur over larger spatial scales and lead to a low state of especially deep habitats. The approach is based on a simple characterization of the benthic community, which comes with high uncertainty, but allows for the identification of benthic habitats that are at greatest risk and prioritization of management actions at the regional scale. This information supports the development of sustainable approaches to manage impact of human activities on benthic ecosystems.


2016 ◽  
Vol 74 (3) ◽  
pp. 866-876 ◽  
Author(s):  
Chris Yesson ◽  
Jess Fisher ◽  
Taylor Gorham ◽  
Chris J. Turner ◽  
Nanette Hammeken Arboe ◽  
...  

Benthic habitats are important elements of polar marine environments, but can be vulnerable to anthropogenic influences such as trawling. Bottom trawling can reduce diversity and alter communities, although some habitats show resilience. The shrimp trawl fishery of West Greenland is a significant part of Greenland's economy. It operates along the west coast from the narrow rockier shelf of the south, up to deeper, muddy areas around Disko Bay. Here we use a benthic drop camera to sample 201 sites between latitudes 60–72°N and depths of 61–725m. Linear models examined relationships of taxon abundance and diversity with bottom trawling intensity and environment (depth, temperature, current, iceberg concentration). Trawling intensity is the most important factor determining the overall abundance of benthic organisms, accounting for 12–16% of variance, although environmental conditions also show significant associations. Sessile erect organisms such as corals show a significant negative response to trawling. Soft sediment communities show a higher resilience than rocky areas. On soft sediments significantly lower abundance characterises sites trawled under five years ago. On hard/mixed ground reduced abundance remains characteristic of sites trawled a decade ago. Continued monitoring of benthic habitats is an essential part of evaluating the ongoing impacts of trawl fisheries.


2017 ◽  
Vol 131 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Lena Clayton ◽  
Glen Dennison

Where marine waters are shallow and bathymetric features are steep, the typically employed multi-beam side scan sonar is not always reliable for identifying complex biological structures. Here, we present a cost-efficient method used in Howe Sound, British Columbia, for bathymetric mapping, exploration, and ground-truthing of glass sponge bioherms. A simple depth sounder and software package was used to produce bathymetric maps. From these maps, prospective sites were selected and surveyed to investigate bioherm presence with a simple drop-camera towed off the bow of a small drifting vessel during calm seas. This method was used during a 4-year citizen science initiative that led to the discovery of 12 glass sponge bioherms in Howe Sound, the first step in protecting these globally unique reefs from the impact of bottom-contact fishing, anchoring, and potential industrial contamination. Before our work using this method, only two glass sponge bioherms had been identified in Howe Sound. The method also proved effective as a means to quantify damage to bioherms from fishing gear.


2020 ◽  
Vol 12 (3) ◽  
pp. 528 ◽  
Author(s):  
Jingye Li ◽  
Jian Gong ◽  
Jean-Michel Guldmann ◽  
Shicheng Li ◽  
Jie Zhu

Land use/cover change (LUCC) has an important impact on the terrestrial carbon cycle. The spatial distribution of regional carbon reserves can provide the scientific basis for the management of ecosystem carbon storage and the formulation of ecological and environmental policies. This paper proposes a method combining the CA-based FLUS model and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model to assess the temporal and spatial changes in ecosystem carbon storage due to land-use changes over 1990–2015 in the Qinghai Lake Basin (QLB). Furthermore, future ecosystem carbon storage is simulated and evaluated over 2020–2030 under three scenarios of natural growth (NG), cropland protection (CP), and ecological protection (EP). The long-term spatial variations in carbon storage in the QLB are discussed. The results show that: (1) Carbon storage in the QLB decreased at first (1990–2000) and increased later (2000–2010), with total carbon storage increasing by 1.60 Tg C (Teragram: a unit of mass equal to 1012 g). From 2010 to 2015, carbon storage displayed a downward trend, with a sharp decrease in wetlands and croplands as the main cause; (2) Under the NG scenario, carbon reserves decrease by 0.69 Tg C over 2020–2030. These reserves increase significantly by 6.77 Tg C and 7.54 Tg C under the CP and EP scenarios, respectively, thus promoting the benign development of the regional ecological environment. This study improves our understanding on the impact of land-use change on carbon storage for the QLB in the northeastern Qinghai–Tibetan Plateau (QTP).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Katy Tobin ◽  
Sinead Maguire ◽  
Bernie Corr ◽  
Charles Normand ◽  
Orla Hardiman ◽  
...  

Abstract Background Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative condition with a mean life expectancy of 3 years from first symptom. Understanding the factors that are important to both patients and their caregivers has the potential to enhance service delivery and engagement, and improve efficiency. The Discrete Choice Experiment (DCE) is a stated preferences method which asks service users to make trade-offs for various attributes of health services. This method is used to quantify preferences and shows the relative importance of the attributes in the experiment, to the service user. Methods A DCE with nine choice sets was developed to measure the preferences for health services of ALS patients and their caregivers and the relative importance of various aspects of care, such as timing of care, availability of services, and decision making. The DCE was presented to patients with ALS, and their caregivers, recruited from a national multidisciplinary clinic. A random effects probit model was applied to estimate the impact of each attribute on a participant’s choice. Results Patients demonstrated the strongest preferences about timing of receiving information about ALS. A strong preference was also placed on seeing the hospice care team later rather than early on in the illness. Patients also indicated their willingness to consider the use of communication devices. Grouping by stage of disease, patients who were in earlier stages of disease showed a strong preference for receipt of extensive information about ALS at the time of diagnosis. Caregivers showed a strong preference for engagement with healthcare professionals, an attribute that was not prioritised by patients. Conclusions The DCE method can be useful in uncovering priorities of patients and caregivers with ALS. Patients and caregivers have different priorities relating to health services and the provision of care in ALS, and patient preferences differ based on the stage and duration of their illness. Multidisciplinary teams must calibrate the delivery of care in the context of the differing expectations, needs and priorities of the patient/caregiver dyad.


2021 ◽  
Vol 106 (1) ◽  
pp. 881-912
Author(s):  
Jingbo Sun ◽  
Shengwu Qin ◽  
Shuangshuang Qiao ◽  
Yang Chen ◽  
Gang Su ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 323
Author(s):  
Guilherme Pontes Luz ◽  
Rodrigo Amaro e Silva

The recently approved regulation on Energy Communities in Europe is paving the way for new collective forms of energy consumption and production, mainly based on photovoltaics. However, energy modeling approaches that can adequately evaluate the impact of these new regulations on energy community configurations are still lacking, particularly with regards to the grid tariffs imposed on collective systems. Thus, the present work models three different energy community configurations sustained on collective photovoltaics self-consumption for a small city in southern Portugal. This energy community, which integrates the city consumers and a local winery, was modeled using the Python-based Calliope framework. Using real electricity demand data from power transformers and an actual winery, the techno-economic feasibility of each configuration was assessed. Results show that all collective arrangements can promote a higher penetration of photovoltaic capacity (up to 23%) and a modest reduction in the overall cost of electricity (up to 8%). However, there are clear trade-offs between the different pathways: more centralized configurations have 53% lower installation costs but are more sensitive to grid use costs (which can represent up to 74% of the total system costs). Moreover, key actor’s individual self-consumption rate may decrease by 10% in order to benefit the energy community as a whole.


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