Favorites and leftovers on the menu of scavenging seabirds: modelling spatiotemporal variation in discard consumption

Fishery discards subsidise the food supply of a large community of scavenging seabirds, thus substantially influencing seabird ecology. Seabird preference for certain types of discards determines the number and composition of discards available for non-avian marine scavengers. To quantify both portions of discards temporally as well as spatially, we have used a modelling framework that integrates the spatial and temporal variation in seabird distribution, seabird attraction to fishing vessels, and discard distribution. The framework was applied to a case study in the Bay of Biscay, where a wide variation in discard consumption was observed across seabird foraging guilds, discard types, periods, and locations. Seabirds removed about one-quarter of the Bay of Biscay discards. The remaining sinking discards have limited potential to subsidize scavenging benthic communities on a large scale, but they may contribute substantially to scavenger diets on a local scale. Changes in food subsidies caused by discard mitigation measures, such as the “landing obligation” in the European Common Fisheries Policy, are likely to have ecosystem effects on both scavenging seabirds and non-avian marine scavengers.

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Impact of a large-scale area closure on patterns of fishing disturbance and the consequences for benthic communities

ICES Journal of Marine Science ◽

10.1016/s1054-3139(03)00010-9 ◽

2003 ◽

Vol 60 (2) ◽

pp. 371-380 ◽

Cited By ~ 131

Author(s):

T.A Dinmore ◽

D.E Duplisea ◽

B.D Rackham ◽

D.L Maxwell ◽

S Jennings

Keyword(s):

North Sea ◽

Large Scale ◽

Fishery Management ◽

Benthic Communities ◽

Benthic Invertebrate ◽

Homogeneous Distribution ◽

Cumulative Impacts ◽

Management Actions ◽

Fishing Vessels ◽

Fishing Disturbance

Abstract Seasonal area closures of fisheries are primarily used to reduce fishing mortality on target species. In the absence of effort controls, fishing vessels displaced from a closed area will impact fish populations and the environment elsewhere. Based on the observed response of the North Sea beam trawl fleet to the closure of the “cod box” and an existing size-based model of the impacts of beam trawling, we predict the effects of seasonal area closures on benthic communities in the central North Sea. We suggest that repeated seasonal area closures would lead to a slightly more homogeneous distribution of annual trawling activity, although the distribution would remain patchy rather than random. The increased homogeneity, coupled with the displacement of trawling activity to previously unfished areas, is predicted to have slightly greater cumulative impacts on total benthic invertebrate production and lead to localized reductions in benthic biomass for several years. To ensure the effective integration of fisheries and environmental management, the wider consequences of fishery management actions should be considered a priori. Thus, when seasonal closures increase the homogeneity of overall disturbance or lead to the redistribution of trawling activity to environmentally sensitive or previously unfished areas, then effort reductions or permanent area closures should be considered as a management option. The latter would lead to a single but permanent redistribution of fishing disturbance, with lower cumulative impacts on benthic communities in the long run.

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Fishing out collective memory of migratory schools

Journal of The Royal Society Interface ◽

10.1098/rsif.2014.0043 ◽

2014 ◽

Vol 11 (95) ◽

pp. 20140043 ◽

Cited By ~ 21

Author(s):

Giancarlo De Luca ◽

Patrizio Mariani ◽

Brian R. MacKenzie ◽

Matteo Marsili

Keyword(s):

Collective Memory ◽

Large Scale ◽

Group Formation ◽

Individual Preference ◽

Relative Number ◽

Collective Behaviour ◽

Control Group ◽

Adaptive Networks ◽

Modelling Framework ◽

Migration Pathways

Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals’ preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution.

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Global scale hydrological modelling at 100 m, 1 h resolution, in Python

10.5194/egusphere-egu21-7154 ◽

2021 ◽

Author(s):

Kor de Jong ◽

Marc van Kreveld ◽

Debabrata Panja ◽

Oliver Schmitz ◽

Derek Karssenberg

Keyword(s):

Large Scale ◽

Model Building ◽

Flow Direction ◽

Building Blocks ◽

Global Scale ◽

Data Availability ◽

Hydrological Models ◽

Continental Scale ◽

Modelling Framework ◽

Scale Models

Data availability at global scale is increasing exponentially. Although considerable challenges remain regarding the identification of model structure and parameters of continental scale hydrological models, we will soon reach the situation that global scale models could be defined at very high resolutions close to 100 m or less. One of the key challenges is how to make simulations of these ultra-high resolution models tractable ([1]).Our research contributes by the development of a model building framework that is specifically designed to distribute calculations over multiple cluster nodes. This framework enables domain experts like hydrologists to develop their own large scale models, using a scripting language like Python, without the need to acquire the skills to develop low-level computer code for parallel and distributed computing.We present the design and implementation of this software framework and illustrate its use with a prototype 100 m, 1 h continental scale hydrological model. Our modelling framework ensures that any model built with it is parallelized. This is made possible by providing the model builder with a set of building blocks of models, which are coded in such a manner that parallelization of calculations occurs within and across these building blocks, for any combination of building blocks. There is thus full flexibility on the side of the modeller, without losing performance.This breakthrough is made possible by applying a novel approach to the implementation of the model building framework, called asynchronous many-tasks, provided by the HPX C++ software library ([3]). The code in the model building framework expresses spatial operations as large collections of interdependent tasks that can be executed efficiently on individual laptops as well as computer clusters ([2]). Our framework currently includes the most essential operations for building large scale hydrological models, including those for simulating transport of material through a flow direction network. By combining these operations, we rebuilt an existing 100 m, 1 h resolution model, thus far used for simulations of small catchments, requiring limited coding as we only had to replace the computational back end of the existing model. Runs at continental scale on a computer cluster show acceptable strong and weak scaling providing a strong indication that global simulations at this resolution will soon be possible, technically speaking.Future work will focus on extending the set of modelling operations and adding scalable I/O, after which existing models that are currently limited in their ability to use the computational resources available to them can be ported to this new environment.More information about our modelling framework is at https://lue.computationalgeography.org.References[1] M. Bierkens. Global hydrology 2015: State, trends, and directions. Water Resources Research, 51(7):4923&#8211;4947, 2015. [2] K. de Jong, et al. An environmental modelling framework based on asynchronous many-tasks: scalability and usability. Submitted. [3] H. Kaiser, et al. HPX - The C++ standard library for parallelism and concurrency. Journal of Open Source Software, 5(53):2352, 2020.

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A shift from science to politics : a content analysis of COVID-19 Videos on YouTube (Preprint)

10.2196/preprints.33948 ◽

2021 ◽

Author(s):

Chyun-Fung Shi ◽

Matthew C So ◽

Sophie Stelmach ◽

Arielle Earn ◽

David J D Earn ◽

...

Keyword(s):

Public Health ◽

Social Media ◽

Content Analysis ◽

Large Scale ◽

Control Measures ◽

Mitigation Measures ◽

Health Campaigns ◽

Public Attention ◽

Conflicting Information ◽

Social Media Platforms

BACKGROUND The COVID-19 pandemic is the first pandemic where social media platforms relayed information on a large scale, enabling an “infodemic” of conflicting information which undermined the global response to the pandemic. Understanding how the information circulated and evolved on social media platforms is essential for planning future public health campaigns. OBJECTIVE This study investigated what types of themes about COVID-19 were most viewed on YouTube during the first 8 months of the pandemic, and how COVID-19 themes progressed over this period. METHODS We analyzed top-viewed YouTube COVID-19 related videos in English from from December 1, 2019 to August 16, 2020 with an open inductive content analysis. We coded 536 videos associated with 1.1 billion views across the study period. East Asian countries were the first to report the virus, while most of the top-viewed videos in English were from the US. Videos from straight news outlets dominated the top-viewed videos throughout the outbreak, and public health authorities contributed the fewest. Although straight news was the dominant COVID-19 video source with various types of themes, its viewership per video was similar to that for entertainment news and YouTubers after March. RESULTS We found, first, that collective public attention to the COVID-19 pandemic on YouTube peaked around March 2020, before the outbreak peaked, and flattened afterwards despite a spike in worldwide cases. Second, more videos focused on prevention early on, but videos with political themes increased through time. Third, regarding prevention and control measures, masking received much less attention than lockdown and social distancing in the study period. CONCLUSIONS Our study suggests that a transition of focus from science to politics on social media intensified the COVID-19 infodemic and may have weakened mitigation measures during the first waves of the COVID-19 pandemic. It is recommended that authorities should consider co-operating with reputable social media influencers to promote health campaigns and improve health literacy. In addition, given high levels of globalization of social platforms and polarization of users, tailoring communication towards different digital communities is likely to be essential.

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Winter migration and diving behaviour of porbeagle shark, Lamna nasus, in the Northeast Atlantic

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq145 ◽

2010 ◽

Vol 68 (1) ◽

pp. 166-174 ◽

Cited By ~ 28

Author(s):

Ryan A. Saunders ◽

François Royer ◽

Maurice W. Clarke

Keyword(s):

Spatial Ecology ◽

Large Scale ◽

Depth Distribution ◽

Diving Behaviour ◽

Depth Range ◽

Bay Of Biscay ◽

Night Time ◽

Fishing Activity ◽

Northeast Atlantic ◽

Winter Migration

Abstract Saunders, R. A., Royer, F., and Clarke, M. W. 2011. Winter migration and diving behaviour of porbeagle shark, Lamna nasus, in the Northeast Atlantic. – ICES Journal of Marine Science, 68: 166–174. The porbeagle is one of the top marine predators in the North Atlantic. However, little is known about its biology, abundance, or spatial ecology there. Results are presented on the migration and behaviour of three porbeagles tagged with archival pop-up tags off Ireland between September 2008 and January 2009. One shark migrated >2400 km to the northwest of Morocco, residing around the Bay of Biscay for approximately 30 days. The other two remained more localized in off-shelf regions around the Celtic Sea/Bay of Biscay and off western Ireland. The sharks occupied a broad vertical depth range (0–700 m) and a relatively limited temperature range (∼9–17°C), with notable variations in diving behaviour between individual sharks. There were distinct day–night differences in depth distribution, each shark being positioned higher in the water column by night than by day. Night-time depth distribution also appeared to be driven by the lunar cycle during broad-scale migration through oceanic waters. Our results show that porbeagles occupy and traverse regions of high fishing activity where they are potentially vulnerable to population depletion. Such large-scale movement outside the ICES Area underlines the need for international coordination in their assessment and management.

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Development of An Exposure Model for Bridge Structures in Northern Algeria

IABSE Conference, Copenhagen 2018: Engineering the Past, to Meet the Needs of the Future ◽

10.2749/copenhagen.2018.146 ◽

2018 ◽

Author(s):

Andrés Abarca ◽

Ricardo Monteiro

Keyword(s):

Risk Assessment ◽

Large Scale ◽

Risk Mitigation ◽

Regional Scale ◽

Mitigation Measures ◽

Exposure Model ◽

Building Stock ◽

Earthquake Scenarios ◽

Northern Algeria ◽

Bridge Structures

In recent years, the use of large scale seismic risk assessment has become increasingly popular to evaluate the fragility of a specific region to an earthquake event, through the convolution of hazard, exposure and vulnerability. These studies tend to focus on the building stock of the region and sometimes neglect the evaluation of the infrastructure, which has great importance when determining the ability of a social group to attend to a disaster and to eventually resume normal activities. This study, developed within the scope of the EU-funded project ITERATE (Improved Tools for Disaster Risk Mitigation in Algeria), focuses on the proposal of an exposure model for bridge structures in Northern Algeria. The proposed model was developed using existing national data surveys, as well as satellite information and field observations. As a result, the location and detailed characterization of a significant share of the Algeria roadway bridge inventory was developed, as well as the definition of a taxonomy that is able to classify the most common structural systems used in Algerian bridge construction. The outcome of this study serves as input to estimate the fragility of the bridge infrastructure inventory and, furthermore, to the overall risk assessment of the Northern Algerian region. Such fragility model will, in turn, enable the evaluation of earthquake scenarios at a regional scale and provide valuable information to decision makers for the implementation of risk mitigation measures.

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Estimates of future flood risk in Western Europe and its potential impact on insured losses.

10.5194/egusphere-egu21-12689 ◽

2021 ◽

Author(s):

Remi Meynadier ◽

Hugo Rakotoarimanga ◽

Madeleine-Sophie Deroche ◽

Sylvain Buisine

Keyword(s):

Climate Change ◽

Flood Risk ◽

Large Scale ◽

Western Europe ◽

Complex Nature ◽

Flood Risks ◽

Hazard Exposure ◽

Modelling Framework ◽

Loss Modelling ◽

The Impact

The large-scale and complex nature of climate change makes it difficult to assess and quantify the impact on insurance activities. Climate change is likely affecting the probability of natural hazard occurrence in terms of severity and/or frequency.Natural catastrophe risk is a function of hazard, exposure and vulnerability. As a (re)-insurer it is seen that changes in year-on-year losses are a function of all these components and not just the hazard.The present study focuses, in a first step, on assessing impacts of climate change on fluvial flood risks in Europe solely due to changes in hazard itself. A stochastic catalogue of future flood risk events is derived from Pan-European data sets of river flood probability of occurrence produced within EU FP7 RAIN project. The loss modelling framework internally developed at AXA is then used to provide a geographical view of changes in future flood risks.&#160;

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Mitigating Impacts of Natural Hazards on Fishery Ecosystems

Mitigating Impacts of Natural Hazards on Fishery Ecosystems ◽

10.47886/9781934874011.ch8 ◽

2008 ◽

Keyword(s):

Natural Hazards ◽

Large Scale ◽

Gulf Coast ◽

Commercial Fishing ◽

Single Beam ◽

Coastal Bays ◽

Fishing Vessels ◽

Northern Gulf Coast ◽

Hurricanes Katrina And Rita ◽

Survey Planning

Abstract.—Hurricanes Katrina and Rita critically impacted the northern Gulf Coast. Shrimping and other commercial fishing industries saw large scale destruction of vessels and shore based facilities in addition to a deposition of large amounts of debris on fishing grounds from Alabama to Louisiana. In 2006, the National Oceanic and Atmospheric Administration’s (NOAA’s) Office of Coast Survey and Office of Response and Restoration started the implementation of a large scale hazards survey program to map the coastal waters of Louisiana, Mississippi, and Alabama. The first phase of the effort involved surveying more than 600 square nautical miles of coastal bays and nearshore waters with sidescan and single beam acoustic sonar. Survey findings are posted each week on a NOAA public Web site displaying the location of each hazard and debris found. The survey work is also updating the NOAA navigation charts for coastal areas that are used heavily by fishing vessels, the navigation industry, and recreational boaters. Survey planning and implementation is conducted cooperatively with the marine fisheries agencies of Alabama, Mississippi, and Louisiana.

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Taking the Pulse of Environmental and Fisheries Law: The Common Fisheries Policy, the Habitats Directive, and Brexit

Journal of Environmental Law ◽

10.1093/jel/eqy027 ◽

2019 ◽

Vol 31 (3) ◽

pp. 443-464 ◽

Cited By ~ 1

Author(s):

Thomas Appleby ◽

James Harrison

Keyword(s):

Nature Conservation ◽

Conservation Law ◽

Habitats Directive ◽

Member States ◽

Progressive Reform ◽

Fishing Vessels ◽

Fisheries Policy ◽

The Common ◽

Fisheries Law ◽

The Eu

Abstract There has long been a tension between environmental regulation and the European Common Fisheries Policy (CFP), which has been addressed over time through progressive reform of the CFP. It is now recognised that Member States may comply with their obligations under EU nature conservation law by taking unilateral non-discriminatory measures within their territorial seas to protect the marine environment from threats posed by fishing. Nevertheless, fundamental uncertainties remain when it comes to the application of these obligations to offshore waters. This article explores the options available to coastal states in this context and the weaknesses of the procedures introduced to the reformed CFP in 2013. It is argued that compliance with nature conservation law in the context of fisheries is not discretionary and that in the absence of measures agreed at the EU level, Member States must comply with their obligations under the Habitats Directive in their capacity as a flag state. Finally, the article addresses the implications of Brexit for the protection of European Marine Sites in UK waters, suggesting that Brexit offers opportunities to strengthen the protection of marine ecosystems by making future access arrangements for foreign fishing vessels conditional upon compliance with nature conservation laws.

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Backbone—An Adaptable Energy Systems Modelling Framework

Energies ◽

10.3390/en12173388 ◽

2019 ◽

Vol 12 (17) ◽

pp. 3388 ◽

Cited By ~ 5

Author(s):

Niina Helistö ◽

Juha Kiviluoma ◽

Jussi Ikäheimo ◽

Topi Rasku ◽

Erkka Rinne ◽

...

Keyword(s):

Power Plants ◽

Large Scale ◽

Unit Commitment ◽

Energy Systems ◽

Mixed Integer ◽

Investment Planning ◽

Planning And Scheduling ◽

Modelling Framework ◽

Wide Range ◽

Systems Modelling

Backbone represents a highly adaptable energy systems modelling framework, which can be utilised to create models for studying the design and operation of energy systems, both from investment planning and scheduling perspectives. It includes a wide range of features and constraints, such as stochastic parameters, multiple reserve products, energy storage units, controlled and uncontrolled energy transfers, and, most significantly, multiple energy sectors. The formulation is based on mixed-integer programming and takes into account unit commitment decisions for power plants and other energy conversion facilities. Both high-level large-scale systems and fully detailed smaller-scale systems can be appropriately modelled. The framework has been implemented as the open-source Backbone modelling tool using General Algebraic Modeling System (GAMS). An application of the framework is demonstrated using a power system example, and Backbone is shown to produce results comparable to a commercial tool. However, the adaptability of Backbone further enables the creation and solution of energy systems models relatively easily for many different purposes and thus it improves on the available methodologies.

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