| Term | Definition in the context of the 2022 Scientific Consensus Statement |
| Adjuvant | A compound or substance that improves solubility, efficacy or potency of a pesticide. |
| Adoption | The process of discovery, decision and action that an individual or group applies when taking up new practices or innovations. |
| Anthropogenic load | The additional load of sediment or nutrients carried by rivers in current and historical times compared to the load carried prior to European settlement (i.e., pre-development). |
| Basin | There are 35 basins that drain into the Great Barrier Reef. A basin can be made up of one or more rivers (e.g., North and South Johnstone rivers belong to one basin, the Johnstone Basin). These river basins are described in the Bureau of Meteorology (BoM) Geofabric using boundaries defined by the Australian Water Resources Management Committee. |
| Bias | A preference for or against one idea, thing or person. In scientific research, bias is a systematic deviation between observations or interpretations of data and an accurate description of a phenomenon[1]. |
| Body of evidence | All evidence items used to address each of the 30 Questions within the 2022 Scientific Consensus Statement. |
| Climate change | Long-term shifts in temperatures and weather patterns, mostly driven by human activities (i.e., burning fossil fuels like coal, oil and gas) since the 1800s (UN). Climate change-related potential threats in the context of the Scientific Consensus Statement include: increasing temperature, intensity and frequency of heat waves, ocean acidification, altered extreme rainfall events (drought / floods), rising sea-levels, and frequency and strength of tropical cyclones. |
| Co-benefit | An additional benefit from implementing a management action. |
| Combined impact | Negative effects of several stressors on an organism or ecosystem. |
| Condition | The state of Great Barrier Reef ecosystems and their capacity to deliver goods and benefits (i.e., services). |
| Confidence of evidence | For the 2022 Scientific Consensus Statement, the ‘overall confidence’ of a body of evidence was determined by the relevance of studies (both spatial and temporal) and the consistency of findings within the body of evidence’[2].  |
| Connectivity | ‘Ecological connectivity’ refers to the strength of connections between elements of an ecosystem, or between ecosystems, including both structural connections (the physical arrangements of disturbance and/or patches at small to large scales) and functional connections (the movement of individuals and materials within and across habitats, landscapes and seascapes). Barriers to connectivity are physical, chemical and biological obstructions to connections through the land- or seascape and include temporal interruptions as well as poor water quality and extensive weed growth blocking waterways, and structures such as dams, culverts and drop boards. |
| Consensus | In the context of the 2022 Scientific Consensus Statement, it was agreed that consensus is “A public statement on scientific knowledge on Great Barrier Reef water quality and ecosystem condition, drawn from multiple lines of evidence, that is generally agreed by a representative group of experts. The consensus does not necessarily imply unanimity.” |
| Consistency of evidence | Level of convergence or agreement of findings between evidence items. This may be assessed as being consistent both in the direction and magnitude of effect. |
| Convergence | The process of moving towards a uniformity of view on the interpretation of the evidence. |
| Cost-effectiveness | Integration of environmental and economic results for a particular management intervention to calculate the cost-effectiveness. Cost-effectiveness may be calculated as the present value of costs (private, public, program, maintenance) of a particular intervention divided by the per unit reduction in pollutant (e.g., cost per kg of nutrients/sediments abated). |
| Crown-of-thorns starfish (COTS) | Coral-eating species of starfish native to the Great Barrier Reef and reefs throughout the Indo-Pacific region. |
| Current | In the context of the 2022 Scientific Consensus Statement, it refers to the five year period since the 2017 Scientific Consensus Statement (2017-2022). |
| Disadoption | Includes rejection of an innovation after a trial adoption (either partial or complete) through to disadoption after initially deciding to take it beyond the trial stage at a small or a large scale or for a short or lengthier period. |
| Dissolved nutrient | Species of nitrogen (N) and phosphorus (P) that are carried in solution by river waters and which contribute to ecosystem impacts of eutrophication when concentrations are well above pre-development levels. This includes dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON), dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP). See also ‘Nutrients’ and ‘Particulate nutrients’. |
| Diversity of study types | The type of studies being used as sources of evidence i.e., observational, experimental, modelling, theoretical or conceptual, and secondary studies such as reviews or summaries. In the context of the 2022 Scientific Consensus Statement, also associated with ‘multiple lines of evidence’[3]. |
| Drivers | “A superior complex phenomena governing the direction of the ecosystem change, which could be both of human and nature origin”[4]. Drivers can be anthropogenic (based on economic, social and political fundamental needs) or natural (majorly independent from anthropogenic causes). In the context of the Scientific Consensus Statement, drivers affect sediments, nutrients and pesticides through physical processes |
| Ecological function | The natural processes, products, or benefits that Great Barrier Reef ecosystems provide or perform. |
| Ecological impact | Ecologically relevant effects of pollutants on biota, including reduced survival, growth, reproductive success. Can be observed in controlled laboratory experiments or in the field following exposure. |
| Ecological processes | Includes reproduction, population dynamics, species interactions, trophic interactions, dissolved and suspended materials processing, organic production, and migration and dispersal. |
| Ecosystem health | An ecological system is healthy and free from distress syndrome if it is stable and sustainable, i.e., if it is active and maintains its organisation and autonomy over time, and is resilient to stress[5]. |
| Ecosystems services | The benefits people obtain from ecosystems. These include provisioning services such as food, water, timber, and fibre; regulating services that affect climate, floods, disease, wastes, and water quality; cultural services that provide recreational, aesthetic, and spiritual benefits; and supporting services such as soil formation, photosynthesis, and nutrient cycling[6]. |
| Effectiveness | The relationship of outputs to program objectives[7]. |
| End-of-catchment | The interface between catchment waterways and the marine environment. It is formally measured as the lowest point in a river or creek where the volume of water passing that point can be accurately measured by a gauging station and typically is not subject to tidal influence close to the upper limit of the tide. |
| Enhanced-Efficiency-Fertilisers | Forms of nitrogen fertiliser that either: 1) delay the release of the nitrogen from the applied product into the soil; and/or 2) reduce the rate at which the nitrogen fertiliser is transformed to nitrate in the soil. |
| Erosion | The movement of sediment particles by the action of water, including overland flow, stream flow and raindrop impact. |
| Estuary | Semi-enclosed bodies of water that open to the sea and are supplied with freshwater draining from the land via rivers and streams. |
| Evidence | Relevant information used in answering a question or hypothesis. |
| Evidence item | An individual piece of evidence which may be a study, data or other documented evidence. |
| Exports (to the Great Barrier Reef) | Mean annual loads (tonnes per year) of sediments and nutrients to the tidal limit excluding estuaries, from river basins draining to the Great Barrier Reef coast. |
| Fungicide | A pesticide used to kill fungi (plant-like organisms that do not make chlorophyll), such as yeasts, rusts and moulds (and their spores). |
| Great Barrier Reef catchment area | The natural drainage area of the catchments adjacent to the Great Barrier Reef. This includes the 35 major drainage basins (described in the Bureau of Meteorology Geofabric using boundaries defined by the Australian Water Resources Management Committee) and the 6 Natural Resource Management regions including Cape York, Wet Tropics, Burdekin, Mackay Whitsunday, Fitzroy and Burnett Mary. |
| Great Barrier Reef ecosystems | In the context of the 2022 Scientific Consensus Statement, it refers to marine (coral, seagrass, pelagic, benthic, and plankton communities), estuarine (estuaries, mangroves, saltmarsh), freshwater (freshwater wetlands, floodplain wetlands) ecosystems within the Great Barrier Reef World Heritage Area. |
| Greenhouse Gas Emissions | Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). |
| Gully | A narrow valley or channel with steep sides, made by a fast-flowing stream. There are two major gully types; alluvial (or river associated) and colluvial (or hillslope gullies). This distinction is based on the material the gullies are eroding into: alluvium – sediments deposited overbank from rivers and streams; and colluvium -sediments derived from in situ weathering on slopes and/or downslope processes on hillslopes. Gullies are typically driven by ephemeral flows (i.e., associated with direct rainfall on the gully and in the gully catchment), although there are some alluvial gullies that can experience overbank flooding or backwatering from river channels to which they are connected. |
| Herbicide | A pesticide that specifically kills or inhibits plant pests. Herbicides usually inhibit a specific biochemical pathway that only occurs in plants and thus are far more toxic to plants than other organisms. |
| Human dimensions | Human behaviours that will impact on water quality outcomes from the aspirations and capacities of landholders, industries and communities, to their stewardship practices and broader governance of the Great Barrier Reef. These aspects reflect social, cultural, institutional and economic factors. |
| Indigenous Australians | Indigenous Australians are people with familial heritage from the Australian continent before British colonisation. |
| Indigenous involvement | The active integration of Indigenous people into the planning, implementation and assessment of activities. |
| Innovation | Includes technologies, improved practices, management practices or techniques (e.g., weed control, fencing riparian areas, irrigation efficiency, record keeping), institutional practices (ways of thinking and working in an organisation, e.g., how the innovation process and the factors that affect adoption are defined), and social (e.g., changes in the services, models and processes that more effectively meet a social need). |
| Insecticide | A pesticide that specifically kills or inhibits insect pests. Insecticides usually inhibit a specific biochemical pathway that only occurs in insects and thus are far more toxic to insects and related arthropods than other organisms. |
| Instruments | Instruments are the means by which governments seek to influence behaviour and generate a land management improvement. Instruments include facilitative, incentive based and coercive instruments. |
| Land-based runoff | Freshwater river discharge from the Great Barrier Reef catchment area (defined above) carrying materials including sediments and dissolved and particulate forms of nitrogen and phosphorus and pesticides and other pollutants to the Great Barrier Reef World Heritage Area. |
| Land management | The process of managing the use and development of land resources. |
| Land use | The purpose for which an area of land is being used. Primary land uses considered in the 2022 Scientific Consensus Statement include: grazing, sugarcane, horticulture, banana, cropping including grains, and urban. |
| Mechanisms | Processes governing how interacting parts of the ecosystem are affected by sediments and nutrients. |
| Mill mud | A byproduct of the sugar milling process that is commonly disposed of by application to sugarcane fields. |
| Monitoring and Evaluation (M&E) | Monitoring is the periodic assessment of programmed activities to determine whether they are proceeding as planned. At the same time, evaluation involves the assessment of the programs towards the achievement of results, milestones, and impact of the outcomes based on the use of performance indicators. |
| Nutrients | Nutrients refer to inorganic nitrogen (N) dissolved in water (DIN), and inorganic phosphorus (P) dissolved in water (DIP). Dissolved nitrogen includes nitrate (NO⁻3), nitrite (NO⁻2) and ammonium (NH4). DIP includes phosphates (PO4). Nutrients can also include organic and particulate forms. See also ‘Dissolved nutrients’ and ‘Particulate nutrients’. |
| Paddock to Reef Integrated Monitoring Modelling and Reporting program | The Paddock to Reef program has been in place since 2009 and integrates monitoring and modelling across a range of attributes and at a range of scales including paddock, sub-catchment, catchment, regional and Great Barrier Reef-wide. In line with the Reef 2050 Water Quality Improvement Plan, the program evaluates management practice adoption, management practice effectiveness (in terms of water quality benefits and economic outcomes), catchment condition (riparian, wetlands and ground cover), pollutant run-off and marine condition. |
| Palustrine wetlands | Vegetated, non-riverine or non-channel wetlands excluding lakes and estuaries. |
| Particulate nutrients | Nutrients (nitrogen or phosphorus) that are in a particulate form as particulate organic matter sourced from land-based or marine (e.g., plankton) sources. Particulate nitrogen may also be adsorbed to the surface of sediments and can be readily bioavailable. Particulate inorganic phosphorus may also be present in mineral forms but is not particularly bioavailable. See also ‘Nutrients’ and ‘Dissolved nutrients’. |
| Peer reviewed literature | Any evidence item that has undergone a review by external independent experts in the same field and the feedback is addressed by the authors to generate a revised document. In the context of the Scientific Consensus Statement, this includes traditional academic literature, but also grey literature (e.g., reports, theses) as long as it has been independently peer reviewed and is publicly accessible. |
| Pesticides | Land-sourced chemicals used to kill, repel, or control forms of animal and plant life considered to damage or be a nuisance in agriculture and domestic life. They include herbicides, insecticides, and fungicides[8]. |
| Pesticide Mixtures | A pesticide mixture is considered a substance containing more than one active ingredient in its makeup (excluding water which is generally used as the primary solvent). |
| Photosystem II (PSII) herbicide | Herbicides that inhibit the photosynthetic process in plants by binding to specific sites within the photosystem II complex in plant chloroplasts, blocking electron transport and stopping CO2 fixation, and production of energy needed for plant growth. |
| Pollutant | Any contaminant above natural background which may or may not cause an adverse effect. |
| Pre-development | Before the arrival of Europeans to the Great Barrier Reef catchment area c. 1850. |
| Quantity of evidence | A relative assessment of the size of the body of evidence used to address each Scientific Consensus Statement question based on the total number of evidence items. While it is not possible to quantify the number of studies that is adequate for answering specific questions, authors used their topic expertise to suggest whether the number of studies used was ‘high’, ‘moderate’ or ‘low’. |
| Rapid review | A form of knowledge synthesis that follows the formal Systematic Review process (defined below), but parts of the process are simplified or omitted to produce information within specified resources, in a timely manner and to meet specific user needs[9]. |
| Rehabilitation | Action, or actions to repair, enhance and/or replace ecosystem processes and/or components, to improve intrinsic values and/or ecosystem services. |
| Relevance of evidence | The extent to which the evidence is relevant to the question being asked. Relevance is often referred to as the ‘external validity’ of the study (i.e., whether it can be generalised from the original study to address the review question). For the 2022 Scientific Consensus Statement two aspects of relevance were assessed: 1) the relevance of the study approach and results to the question and 2) the spatial and temporal relevance to the question. |
| Resilience | The capacity of ecosystems (or species or individuals) to resist from and recover after a disturbance. |
| Restoration | An action, or actions to bring back a former, original, normal, or unimpaired ecosystem condition. |
| Riparian areas | Riparian areas are defined as any area within 50 metres of a (mapped) stream or riverine wetland[10]. Removal or degradation of riparian vegetation can accelerate streambank erosion, which contributes to 24% of the total load of sediments exported to the Great Barrier Reef. |
| Sediment | The loose sand, clay, and other soil particles that are broken down from processes of weathering and erosion or from the decomposition of plants and animals. While all sediment types are considered in the Scientific Consensus Statement, fine sediments or total suspended solids (TSS) less than 20 mm (mostly clay and silt) are the biggest concern as this fraction contains almost all particulate nutrients, stays longer in suspension, and increases turbidity in coastal waters. |
| Single Draft Text Procedure | Effective way to facilitate creative, joint problem-solving whenever there are multiple stakeholders whose input to a decision or plan needs to be considered or whose support may be needed for implementation. This method places all drafting responsibility in the hands of a single drafter or drafting team. All other parties are involved in the process as critics who provide input. In this way, the inefficiencies of working with multiple drafts are minimised. Parties work together to iterate and improve a single, shared working draft. Parties are asked to note how and why the current draft version of the agreement is not acceptable or could be improved (in terms of technical content only, avoiding wordsmithing). The drafting team iterates between soliciting criticism and revising the draft until the predetermined maximum number of agreed iterations for making a decision is reached. At this point, the drafting team presents all parties with a final draft for acceptance[11],[12]. |
| Streambank | The term “streambank” is used in a broader sense to include the whole channel and riparian zone, rather than just a specific bank, as projects are increasingly focusing on the revegetation/treatment of whole stream reaches as a management intervention. |
| Strength of evidence | The use of a combination of information from several independent sources to give sufficient evidence to fulfil an information requirement. It depends on factors such as the quantity and quality of the data, consistency of results (including replicability and multiple lines of evidence), robustness, reliability, and relevance of the information[13]. |
| Synthesis | Synthesis occurs when disparate data, concepts, or theories are integrated in ways that yield new knowledge, insights, or explanations[14]. Synthesis creates emergent knowledge in which the whole is greater than the sum of the parts. By engaging experts with multiple perspectives, synthesis is capable of vetting a vast body of information for use by other disciplines or by society in general[15]. |
| Uncertainty | Refers to situations involving limited knowledge or unknown information where it is not possible to clearly describe the existing state, the processes occurring, a future outcome, or more than one possible outcome. |
| Water quality | The physical, chemical, and biological characteristics of water and the measure of its condition relative to the requirements for one or more biotic species and/or to any human need or purpose[16]. |
| Waterbodies | Marine waterbodies: Five distinct water bodies are defined for the Great Barrier Reef under the Great Barrier Reef Water Quality Guidelines 2010 – inshore [enclosed coastal + open coastal], midshelf, offshore and the Coral Sea. These are important context for the Scientific Consensus Statement when describing the extent of influence of water quality on the Great Barrier Reef. |
| Wetlands | Wetlands are areas of marsh, fen, peatland, or water, whether natural or artificial, permanent, or temporary, with water that is static or flowing, fresh, brackish, or salt, including areas of marine water the depth of which at low tide does not exceed six metres[17]. In the context of the 2022 Scientific Consensus Statement, it includes riverine, estuarine, palustrine (or vegetated swamps) and lacustrine wetlands. Subtidal and subterranean wetlands, i.e., coral reefs, seagrass meadows and aquifers are excluded |
[1] How bias affects scientific research
[2] UK Department for International Development (2014) Assessing the Strength of Evidence: How to Note.
[3] Deriving guideline values using multiple lines of evidence
[4] Oesterwind D, Rau A, & Zaiko A (2016). Drivers and pressures – Untangling the terms commonly used in marine science and policy. Journal of Environmental Management, 181, 8–15
[5] Costanza R (1992) Toward an operational definition of ecosystem health. In R Costanza, B Norton & B Haskell (Eds.), Ecosystem health: new goals for environmental management (pp. 239– 256). Island Press, Washington DC
[6] Millennium Ecosystem Assessment. (2005). Ecosystems and human well-being: Wetlands and water synthesis. World Resources Institute
[7] Eberhard, R., Jarvis, D., Coggan, A., Deane, F., Loechel, B., Hamman, E., Helmstedt, K. J., Baresi, U., Deane, A., Taylor, B. M., Mayfield, H. J., Vella, K. J., & Stevens, L. (2021). RP 225 Building a policy instrument impact model for the reef.
[8] National Institute of Environmental Health Sciences 2023
[9] Khangura S, Konnyu K, Cushman R, Grimshaw J, Moher D (2012) Evidence summaries: the evolution of a rapid review approach. Systematic Reviews, 1(1), 1–9
[10] https://www.reefplan.qld.gov.au/tracking-progress/reef-report-card/2021-22/faqs#toc-20
[11] Overview of the one-text procedure
[14] Pickett STA, Kolasa J, Jones CG (2007) Ecological Understanding: The Nature of Theory and the Theory of Nature. 2nd ed. Academic Press.
[15] Carpenter SR, Armbrust EV, Arzberger PW, Chapin FS, Elser JJ, Hackett EJ, Ives AR, Kareiva PM, Leibold MA, Lundberg P, Mangel M, Merchant N, Murdoch WW, Palmer MA, Peters DPC, Pickett STA, Smith KK, Wall DH, Zimmerman AS (2009) Accelerate Synthesis in Ecology and Environmental Sciences, BioScience, 59 (8), 699–701.
[16] Australian and New Zealand Guidelines for fresh & marine water quality glossary of terms
[17] https://wetlandinfo.des.qld.gov.au/wetlands/what-are-wetlands/definitions-classification/wetland-definition.html
