Russell Richards

Bayesian belief modeling of climate change impacts for informing regional adaptation options

A sequential approach to combining two established modeling techniques (systems thinking and Bayesian Belief Networks; BBNs) was developed and applied to climate change adaptation research within the South East Queensland Climate Adaptation Research Initiative (SEQ-CARI). Six participatory workshops involving 66 stakeholders based within SEQ produced six system conceptualizations and 22 alpha-level BBNs. The outcomes of the initial systems modeling exercise successfully allowed the selection of critical determinants of key response variables for in depth analysis within more homogeneous, sector-based groups of participants. Using two cases, this article focuses on the processes and methodological issues relating to the use of the BBN modeling technique when the data are based on expert opinion. The study expected to find both generic and specific determinants of adaptive capacity based on the perceptions of the stakeholders involved. While generic determinants were found (e.g. funding and awareness levels), sensitivity analysis identified the importance of pragmatic, context-based determinants, which also had methodological implications. The article raises questions about the most appropriate scale at which the methodology applied can be used to identify useful generic determinants of adaptive capacity when, at the scale used, the most useful determinants were sector-specific. Comparisons between individual BBN conditional probabilities identified diverging and converging beliefs, and that the sensitivity of response variables to direct descendant nodes was not always perceived consistently. It was often the accompanying narrative that provided important contextual information that explained observed differences, highlighting the benefits of using critical narrative with modeling tools.

Temperature-dependent bioaccumulation of copper in an estuarine oyster.

Bioaccumulation models are an important and widely-used tool for assessing ecosystem health with regards to heavy metal contamination. However, these models do not usually account for the potentially significant effect of temperature-dependency in metal uptake. In this study, we explored the role of temperature-dependency in heavy metal bioaccumulation by developing and comparing two kinetic-based copper bioaccumulation models for a common estuarine oyster (Saccostrea glomerata): (i) a standard first-order model that ignores temperature effects; and (ii) a modified first-order model that uses a standard temperature function to account for the temperature-dependency of the uptake rate constant. The models were calibrated within a Bayesian framework so that parameters could be treated as random variables and any uncertainty propagated through to the model output. A 12-month biomonitoring study was carried out within Moreton Bay, Queensland, Australia to provide time-series data for the modelling. Results of the modelling showed that the two bioaccumulation models provided comparable fits of the biomonitoring field data. However, dependent on the time of year and monitoring period selected, the copper uptake rate would vary dramatically due to temperature effects, which could result in an overestimation or underestimation of the copper uptake rate. Finally by calibrating the bioaccumulation models within a Bayesian framework, these models were able to utilize prior knowledge of the model parameters as part of the calibration process and also account for the uncertainty and variability in the bioaccumulation predictions. The ability to account for uncertainty and variability is an important consideration when undertaking environmental risk assessments especially in coastal waterways where there are strong seasonal variations.

Stakeholder Perceptions of Links between Environmental Changes to their Socio-Ecological System and their Adaptive Capacity in the Region of Troms, Norway

Climate change affects the marine environment at all levels of governance. At a global level, researchers expect the projected increase in sea surface temperature to facilitate large changes in the marine food web, which in turn will affect both global fisheries and aquaculture. At the local level, government and stakeholders want to know whether and how this affects their local communities and their adaptive capacity in light of this. Research suggests that risk communication of the effects of changes in the marine food web suffers from stakeholders` short-term mentality and narrow boundaries. This in turn can lead to an underestimation of the potential risks associated with climate change. We explore this theory by mapping the perceptions of marine stakeholders in the region of Troms, Norway. We first developed cognitive maps in a workshop setting, and then used system conceptualization to analyze the feedback mechanisms of the system qualitatively using fuzzy cognitive mapping. We examined the outcomes and compared them for different scenarios using a simple MatLab script. Results demonstrated that stakeholders did not underestimate their risks to climate change. They were aware of environmental changes, and they perceived that a changing climate was the cause of this change, and that it was indeed affecting their livelihoods – and would continue to do so in the future.

A participatory approach for system conceptualization and analysis applied to coastal management in Egypt

This paper presents a participatory approach to conceptualizing systems models and to identifying critical issues in complex socio-environmental systems, combining information collected from individual experts and stakeholders. A method was developed to: (i) capture individuals mental models in the form of causal loop diagrams, using interaction matrices; (ii) build a conceptual model of the system combining the contribution of all stakeholders; (iii) identify critical issues for the system and (iv) prepare a combined causal loop diagram for further discussion and system dynamics simulations. This method was used to engage a group of stakeholders involved in the preparation of a plan for integrated coastal zone management in Egypt. The experience helped highlight the critical issues of the system in terms of importance given by the actors involved in the exercise and their impact on the coastal system. This approach also demonstrated the utility of conceptualizing complex socio-environmental systems for identifying critical issues in data-poor environments.

Towards an Integrated Ecosystem-Based Bioaccumulation and Metal Speciation Model

Heavy metal bioaccumulation models are important for interpreting water quality data, predicting bioaccumulation in organisms, and investigating the provenance of contaminants. To date they have been predominantly used as single-issue models, under steady-state conditions and in isolation of the biogeochemical processes that control metal bioaccumulation. Models that incorporate these processes would allow a more holistic approach to bioaccumulation modeling and contaminant assessment; however, this has been rarely undertaken, probably because it requires the integration of inter-disciplinary areas. In this study, we have developed such a model that integrates three key multi-disciplinary areas (biological, metal speciation, and bioaccumulation processes) and responds to variations in temporal external and internal forcing. Furthermore, spatial context is provided by developing the model within a simple hydrodynamic box-modeling framework. The calibrated model was able to predict with reasonable accuracy the temporal and spatial trends of soft-tissue copper bioaccumulation in a coastal oyster. This exploratory model was also used to highlight the importance of phytoplankton as an important vector of copper uptake dynamics by an oyster, therefore reinforcing the importance of the integrated approach. Finally, our model provides a framework for greater application beyond this specific example such as in the areas of waterway restoration, which has been shown to be an important area of ecological and environmental research.

To adapt or not adapt: assessing the adaptive capacity of artisanal fishers in the Trondheimsfjord (Norway) to jellyfish (Periphylla periphylla) bloom and purse seiners

Abstract Worldwide increases of jellyfish has occurred during the last several decades. A dense population of a large scyphozoan jellyfish, Periphylla periphylla, has established itself as top predator in the Trondheimsfjord in Norway, impacting traditional fisheries. On this background we discuss the adaptive capacity of artisanal fishers and stakeholder involvement in environmental management. A serendipitous discovery was that fishers report that their capacity to adapt to the presence of jellyfish in fact was sufficient. What they could not adapt to, within the context of jellyfish proliferation, was top-down decisions from the national government allowing purse seiners into the fjord to harvest Sprat Sprattus sprattus and Atlantic Herring Clupea harengus rest quotas and thereby also large bycatches of the local codfishes. This harvest was perceived more detrimental to their fishery than was the jellyfish invasion. Relative to fisheries managements choice of regulatory mechanisms during times of climatic change, we argue that by involving stakeholders intimately, the resulting policy advice will be experienced bottom-up and, thus, more legitimate and serendipitous results of a critical nature are more likely to surface.

Using generalized additive modelling to understand the drivers of long-term nutrient dynamics in the Broadwater Estuary (a subtropical estuary), Gold Coast, Australia

ABSTRACT Richards, R.; Chaloupka, M.; Strauss, D., and Tomlinson, R., 2014. Using generalized additive modelling to understand the drivers of long-term nutrient dynamics in the Broadwater Estuary (a subtropical estuary), Gold Coast, Australia. Conclusions drawn from comparing short-term monitoring data with a baseline data set and water-quality guidelines need to be viewed in the context of numerous physical and biogeochemical mechanisms controlling nutrient concentrations within a system over long timescales. This paper highlights the use of generalized additive models (GAMs) to explore the functional relationships between four commonly used water-quality indicators (total nitrogen, total phosphorous, ammonia, nitrate) and a range of drivers including catchment inflow, wind speed, and tidal current. The results of this GAM assessment highlighted that nutrient concentrations within a subtropical estuary (Broadwater, Australia) is most dependent on catchment inflow. In particular, this assessment indicated the apparent importance of the Nerang River as a determinant of the nutrient concentrations observed in the Broadwater compared with the role of other tributaries, even though these other rivers provide the bulk of the freshwater flow into the system. This assessment also highlighted that the potential effects of monitoring location, tides, wind, and monitoring year need to be accounted for when framing the results of short-term data.

Whale watch or no watch: the Australian whale watching tourism industry and climate change

Abstract Whale watching is a billion dollar industry worldwide. One of the most popular species for whale watching is the humpback whale (Megaptera novaeangliae). The migratory corridors, feeding, resting and calving sites which are used for whale watching may be influenced by changing ocean currents and water temperatures. Here, we used an innovative approach addressing the emerging issue of climate change on the whale watch industry. This involved participatory modelling using key stakeholders for the whale watching industry to develop a systems conceptualisation model for evaluating the potential effects of climate change based on a case study from the east coast of Australia. This participatory approach allowed us to identify the causal linkages (including feedback pathways) between different “Elements” of the system within which the whale watching industry operates. It also allowed us to integrate multiple drivers covering socio-economic and environmental aspects including climate change (e.g. temperature), policy (e.g. number of boats), ecology (e.g. number of whales) and socio-economics (e.g. number of tourists) to evaluate the changes in the overall system. We then developed a Bayesian belief network model from the systems conceptualisation on which stakeholders identified a priority issue (Profitability). Stakeholders provided the structure and the quantification of this model, and a sensitivity analysis was carried out to help identify important intervention points for the industry. Overall, our research illustrates how such a modelling process can assist local tourism operators and authorities in making rational management decisions within a holistic or systems-based framework and its approach is applicable to other regions.

A novel coupled biokinetic-equilibrium model to capture oyster metal bioaccumulation in a contaminated estuary (Sydney estuary, Australia)

Enriched concentrations of metal contaminants have been reported in surficial sediments and tissues of aquatic organisms in Sydney estuary, New South Wales, Australia. Dietary ingestion of contaminated, suspended sediments is potentially a major route of metal exposure to the filter-feeder Saccostrea glomerata. A dynamically coupled biokinetic-equilibrium bioaccumulation model was developed to explore sediment-oyster-metal uptake interactions. The biokinetic component simulated the sediment dynamics and oyster uptake and loss kinetics while the ion equilibrium model accounted for the metal speciation reactions. Results of a laboratory-based mesocosm experiment as well as data from the literature were used to parameterise the model. The model demonstrated a good fit of the experimental data and indicated that dissolved and particulate organic matter were important determinants of metal bioavailability to this species. The model served also as a unique tool to formulate testable hypotheses and help to better explain the bioaccumulation patterns observed from the experiment. Novel model was able to replicate oyster bioaccumulation and depuration patterns.Organic matter complexation dominated speciation for 6 studied metals.Organic matter controlled oyster metal uptake from dissolvedź+źparticulate sources.The model explored deeper into experimental results and helped form new hypotheses.

Implementing the United Nations’ sustainable development goals for water and beyond in Australia: A proposed systems approach

ABSTRACT The 17 United Nations’ Sustainable Development Goals (SDGs) form an internationally-agreed agenda for development, and include a dedicated goal for water and sanitation (SDG 6). Yet, the presentation of the SDGs potentially invites appraisal and response ‘goal-by-goal’- to the possible neglect of the mutual influences between them.We applied a systems approach to understand the interrelationships in an Australian context. While there are multiple potential ‘readings’ of these interrelationships, our approach is intended to initiate debate around the SDG commitments. We found the SDGs for global partnerships (SDG 17) and climate action (SDG 13) are enabling influences for the other goals, and the SDG for health (SDG 3) is influenced by all the other goals. Within SDG 6, we found that integrated water resources management target (SDG 6.5) is key to achieving the other targets. Inter-sectoral collaboration by government agencies will be essential to progress achievement of the SDGs.