Susan Kay

Predicting future thermal habitat suitability of competing native and invasive fish species: From metabolic scope to oceanographic modelling

Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. Here, we determined the effect of temperature on the aerobic metabolic scope of two competing fish species, one native and one invasive, and we predicted their future thermal habitat suitability.

Solutions for ecosystem-level protection of ocean systems under climate change.

The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field and that protected areas cannot address climate change may be oversimplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially explicit manner and then co-mapping human activities such as the placement of renewable energy developments and the distribution of marine protected areas. We test this approach in the NE Atlantic considering also how CCOA impacts the base of the food web which supports protected species, an aspect often neglected in conservation studies. We found that, in this case, current regional conservation plans protect areas with low ecosystem-level vulnerability to CCOA, but disregard how species may redistribute to new, suitable and productive habitats. Under current plans, these areas remain open to commercial extraction and other uses. Here, and worldwide, ocean conservation strategies under CCOA must recognize the long-term importance of these habitat refuges, and studies such as this one are needed to identify them. Protecting these areas creates adaptive, climate-ready and ecosystem-level policy options for conservation, suitable for changing oceans.

Projected changes in area of the Sundarban mangrove forest in Bangladesh due to SLR by 2100

The Sundarbans mangrove ecosystem, located in India and Bangladesh, is recognized as a global priority for biodiversity conservation and is an important provider of ecosystem services such as numerous goods and protection against storm surges. With global mean sea-level rise projected as up to 0.98xa0m or greater by 2100 relative to the baseline period (1985–2005), the Sundarbans – mean elevation presently approximately 2xa0m above mean sea-level – is under threat from inundation and subsequent wetland loss; however the magnitude of loss remains unclear. We used remote and field measurements, geographic information systems and simulation modelling to investigate the potential effects of three sea-level rise scenarios on the Sundarbans within coastal Bangladesh. We illustrate how the Sea Level Affecting Marshes Model (SLAMM) is able to reproduce the observed area losses for the period 2000–2010. Using this calibrated model and assuming that mean sea-level is a better proxy than the SLAMM assumed mean lower low water for Mangrove area delineation, the estimated mangrove area net losses (relative to year 2000) are 81–178xa0km2, 111–376xa0km2 and 583–1393xa0km2 for relative sea-level rise scenarios to 2100 of 0.46xa0m, 0.75xa0m and 1.48xa0m, respectively and net subsidence of ±2.5xa0mm/year. These area losses are very small (<10xa0% of present day area) and significantly smaller than previous research has suggested. Our simulations also suggest that erosion rather than inundation may remain the dominant loss driver to 2100 under certain scenarios of sea-level rise and net subsidence. Only under the highest scenarios does inundation due to sea-level rise become the dominant loss process.

Decadal reanalysis of biogeochemical indicators and fluxes in the North West European shelf‐sea ecosystem

This paper presents the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill, confidence, and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model simulation of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large data set of in situ observations for 10 ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, and oxygen), ∼0.6 for chlorophyll and nutrients (phosphate, nitrate, and silicate), and significant, though lower in value, for partial pressure of dissolved carbon dioxide (∼0.4). The reanalysis captured the magnitude of pH and ammonia observations, but not their variability. The value of the reanalysis for assessing environmental status and variability has been exemplified in two case studies. The first shows that between 325,000 and 365,000 km2 of shelf bottom waters were vulnerable to oxygen deficiency potentially threatening bottom fishes and benthos. The second application confirmed that the shelf is a net sink of atmospheric carbon dioxide, but the total amount of uptake varies between 36 and 46 Tg C yr−1 at a 90% confidence level. These results indicate that the reanalysis output data set can inform the management of the North West European shelf ecosystem, in relation to eutrophication, fishery, and variability of the carbon cycle.

Applying the global RCP–SSP–SPA scenario framework at sub-national scale: A multi-scale and participatory scenario approach

To better anticipate potential impacts of climate change, diverse information about the future is required, including climate, society and economy, and adaptation and mitigation. To address this need, a global RCP (Representative Concentration Pathways), SSP (Shared Socio-economic Pathways), and SPA (Shared climate Policy Assumptions) (RCP-SSP-SPA) scenario framework has been developed by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC-AR5). Application of this full global framework at sub-national scales introduces two key challenges: added complexity in capturing the multiple dimensions of change, and issues of scale. Perhaps for this reason, there are few such applications of this new framework. Here, we present an integrated multi-scale hybrid scenario approach that combines both expert-based and participatory methods. The framework has been developed and applied within the DECCMA1 project with the purpose of exploring migration and adaptation in three deltas across West Africa and South Asia: (i) the Volta delta (Ghana), (ii) the Mahanadi delta (India), and (iii) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India). Using a climate scenario that encompasses a wide range of impacts (RCP8.5) combined with three SSP-based socio-economic scenarios (SSP2, SSP3, SSP5), we generate highly divergent and challenging scenario contexts across multiple scales against which robustness of the human and natural systems within the deltas are tested. In addition, we consider four distinct adaptation policy trajectories: Minimum intervention, Economic capacity expansion, System efficiency enhancement, and System restructuring, which describe alternative future bundles of adaptation actions/measures under different socio-economic trajectories. The paper highlights the importance of multi-scale (combined top-down and bottom-up) and participatory (joint expert-stakeholder) scenario methods for addressing uncertainty in adaptation decision-making. The framework facilitates improved integrated assessments of the potential impacts and plausible adaptation policy choices (including migration) under uncertain future changing conditions. The concept, methods, and processes presented are transferable to other sub-national socio-ecological settings with multi-scale challenges.

Integrative Analysis Applying the Delta Dynamic Integrated Emulator Model in South-West Coastal Bangladesh

A flexible meta-model, the Delta Dynamic Integrated Emulator Model (ΔDIEM), is developed to capture the socio-biophysical system of coastal Bangladesh as simply and efficiently as possible. Operating at the local scale, calculations occur efficiently using a variety of methods, including linear statistical emulators, which capture the behaviour of more complex models, internal process-based models and statistical associations. All components are tightly coupled, tested and validated, and their behaviour is explored with sensitivity tests. Using input data, the integrated model approximates the spatial and temporal change in ecosystem services and a number of livelihood, well-being, poverty and health indicators of archetypal households. Through the use of climate, socio-economic and governance scenarios plausible trajectories and futures of coastal Bangladesh can be explored.

Corrigendum to importance of fisheries for food security across three climate change vulnerable deltas Science of the total Environment 640–641 (2018) 1566–1577

a Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL13 DH, United Kingdom b Institute for Coastal Marine Environment (IAMC), National Research Council (CNR), Via L. Vaccara n 61, Mazara del Vallo, TP 91026, Italy c School of Oceanographic Studies, Jadavpur University, 188, Raja S. C. Mullik Road, Kolkata 700 032, India d ARAID (Aragonese Agency for Research and Development) Researcher, Agrifood Institute of Aragon (IA2), Department of Economic Analysis, Faculty of Economics and Business Studies, University of Zaragoza, Gran Vía, 2-50005 Zaragoza, Spain e BC3-Basque Centre for Climate Change – Klima Aldaketa Ikergai Edificio Sede 1, Planta 1a|Parque Científico de UPV/EHU, 48940 Leioa, Bizkaia, Spain f BC3 Basque Centre for Climate Change, Scientific Campus of the University of the Basque Country, 48940 Leioa, Spain g Department of Marine and Fisheries Sciences, University of Ghana, P.O. Box LG99, Legon, Ghana h TARA, 1 Purbachal Road, Nartheast Badda, Dhaka 1212, Bangladesh i Department of Fish, Biology and Genetics, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh j Fisheries and Aquaculture Policy and Resources Division, Food and Agriculture Organisation of the United Nations (FAO), Rome 00153, Italy k AZTI, Herrera Kaia Portualdea z/g, E-20110 Pasaia, Gipuzkoa, Spain

Importance of fisheries for food security across three climate change vulnerable deltas

Deltas are home to a large and growing proportion of the worlds population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries, however these coastal environments are extremely vulnerable to climate change. The Ganges-Brahmaputra-Meghna (Bangladesh/India), the Mahanadi (India), and the Volta (Ghana) are among the most important and populous delta regions in the world and they are all considered at risk of food insecurity and climate change. The fisheries sector is vital for populations that live in the three deltas, as a source of animal protein (in Bangladesh and Ghana around 50-60% of animal protein is supplied by fish while in India this is about 12%) through subsistence fishing, as a source of employment and for the wider economy. The aquaculture sector shows a rapid growth in Bangladesh and India while in Ghana this is just starting to expand. The main exported species differ across countries with Ghana and India dominated by marine fish species, whereas Bangladesh exports shrimps and prawns. Fisheries play a more important part in the economy of Bangladesh and Ghana than for India, both men and women work in fisheries, with a higher proportion of women in the Volta then in the Asian deltas. Economic and integrated modelling using future scenarios suggest that changes in temperature and primary production could reduce fish productivity and fisheries income especially in the Volta and Bangladesh deltas, however these losses could be mitigated by reducing overfishing and improving management. The analysis provided in this paper highlights the importance of applying plans for fisheries management at regional level. Minimizing the impacts of climate change while increasing marine ecosystems resilience must be a priority for scientists and governments before these have dramatic impacts on millions of peoples lives.

Marine Ecosystems and Fisheries: Trends and Prospects

Within the Bangladesh delta there is a significant dependence on aquatic ecosystem services both economically and for local well-being. The fisheries industry has seen steady growth with production tripling in the last two decades, largely driven by the expansion in inland aquaculture fisheries. Analysis shows that the impacts of climate change are likely to decrease the potential total fish production in the marine waters of Bangladesh by less than ten per cent. However, these potential impacts are much larger for the two major commercial species, Hilsa shad and Bombay duck. Under sustainable management practices, climate effects are likely to reduce Hilsa and Bombay duck catches by 2050 by up to 40 per cent of the current catches, with larger declines possible under unsustainable management. This underlines the importance of management adaptations to minimize the effects of climate change, particularly in situations where current exploitation rates exceed sustainable limits.

Present and Future Fluvial, Tidal and Storm Surge Flooding in Coastal Bangladesh

The magnitude and extent of fluvial, tidal and storm surge flooding in coastal Bangladesh are quantified using hydrodynamic numerical models under a series of climate and sea-level rise scenarios to 2100. Fluvial floods occur from July to October and are confined to the northern part of the coastal region. Tidal floods occur in the southern part of the coastal region along the banks of the estuaries and only last a few hours. The flood extents for both types of flood are influenced by sea-level rise and increased upstream river flows. Flooding associated with cyclone landfall and resulting storm surge also increases in extent, with a nearly four times increase by the end of the century in extreme cases, reinforcing the need for a long-term adaptation strategy.