Fish Barrier Prioritisation (Landscape Scale Coastal)
Description and method logic
The objective of this method is to identify and assess anthropogenic physical barriers (biophysical, such as weed chokes, are not considered) that prevent, delay or obstruct fish migration in coastal catchments. Fish barriers identified through this process are ranked in order of priority, accounting for the cumulative impacts’ barriers have on the environment, fisheries resources and the economy. Social, economic and fisheries productivity benefits of barrier remediation are also considered.
This method systematically identifies all potential physical barriers to fish passage in a study area. The top ranked barriers in the study areas have remediation options costed to facilitate adoption of fish barrier remediation by local governments and natural resource management (NRM) groups. A holistic prioritisation process is used to objectively choose barriers to remediate to obtain the greatest benefits. This holistic process assists decision makers in determining where to best allocate funding opportunities to ensure the greatest environmental and socioeconomic outcomes for the study area. The assessment incorporates the impact on fish movement, location in the catchment (stream order) and surrounding land use in the first stage. The second stage incorporates an assessment of habitat condition and the third stage incorporates an assessment of social, economic and fisheries productivity.
Future assessments involve updating the progress of installing fish passage at barriers, to provide refined guidance for future remediation works, and barriers are scored again. The list of barriers were refined from the priority barriers form the previous biological assessment. Structures remediated were removed from the list, which affected original scores as ‘number of barriers downstream’ were less due to remediated barriers.
Barriers to fish passage such as dams, weirs, causeways, culverts, earthen bunds and floodgates can impact the health of river systems by altering natural flow regimes, and causing impassable barriers to aquatic fauna, especially fish. High value fish species, both ecologically and economically, are in decline due to barriers impeding strict migratory life cycle strategies (i.e. feeding, recruitment) which requires unimpeded access between habitats (i.e. between inland freshwater habitats and estuary/marine habitats).
This method’s objective is to identify and assess physical anthropogenic barriers that prevent, delay or obstruct fish migration in coastal catchments. Fish barriers identified through this process are ranked in order of priority, accounting for the cumulative impacts barriers have on the environment, fisheries resources, economy and local community. The ultimate aim is to remediate barriers preventing connectivity, and this method assists decision makers in choosing which barriers to focus on, as in many coastal catchments there are large numbers of barriers which outweigh the resources available to remediate.
This method identifies and prioritises barriers through 3 major stages.
Stage 1 – Catchment Scale: GIS Analysis – Spatial & Temporal Habitat Characteristics
The first stage systematically identifies all potential barriers to fish passage in the study area. This is done through catchment-scale GIS analysis of biological, geographic and environmental characteristics associated with each potential barrier to produce a prioritised list for ground-truthing.
Stage 2 – Fine Scale: Site Specific Ecological Assessment (includes field validation)
The second stage performs a fine-scale, site specific barrier assessment to validate, score and rank priority barriers based on passability, configuration, in-stream habitat availability and flow conditions.
Stage 3 – Social, Economic and Fisheries Productivity Prioritisation
The third stage further refines and prioritises barriers based on economic, social and fisheries productivity criteria.
The top ranked fish barriers, depending on the area (can vary from 20 to 50) are listed with remediation options and indicative costs. This list is then available for adoption by local governments and NRM groups. Importantly, this stage considers the net benefits of improving connectivity versus the economic cost of remediation. Barriers that can be remediated with low cost fishways while increasing fisheries productivity or restoring vulnerable fish species score high, whereas barriers requiring technical and expensive fishways score lower. Holistic prioritisation process to make this selection effective and applicable straightaway.
Criteria groupings of the method
Stage 1 Catchment Scale: GIS Analysis Spatial & Temporal Habitat Characteristicss
Expert knowledge of riverine fauna ecology including life cycle and habitat requirements. Field assessment skills, and GIS data analysis skills. Knowledge of fisheries in the study area. Research skills to get baseline information about fish species in the study area.
Stage 1 Desktop Analysis: All potential physical barriers in the study area are identified and a dataset is produced with a unique geo-referenced identification number. A prioritised list for ground-truthing is produced.
Stage 2 Field Assessment: A second list of physical barriers is produced, from refining the list in Stage 1. This list scores physical barriers according ecological criteria and contains site specific information about the barrier.
Stage 3 Socio Economic Assessment: A third list of physical barriers is produced from refining the list in Stage 2. This list scores physical barriers based on economic, social and fisheries productivity criteria. A final list of the top ranked fish barriers in the study area is produced, which also show remediation options (fishway options) and indicative costs.
Criteria by category
Physical and chemical
Designed for federal, state or local government agencies, water utilities, and natural resource management groups.
Moore, M. and Marsden, T. (2008). Fitzroy Basin Fish Barrier Prioritisation Project, Queensland Department of Primary Industries and Fisheries, Brisbane, Queensland.
Moore, M. McCann, Jack. and Power, Trent (2018) Greater Brisbane Fish Barrier Prioritisation, Catchment Solutions, Mackay, Queensland
Mackay Whitsunday Fish Barrier Prioritisation, Final Report for Reef Catchments NRM&Mackay Regional Council
Moore, M. (2015). Mackay Whitsunday Fish Barrier Prioritisation, Catchment Solutions, Mackay, Queensland.
O'Brien, Alana. Marsden, Tim. Moore, Matthew. Scanlon, Melinda. (2010) Southern Gulf Catchments Barrier Prioritisation Report, Fisheries Queensland, Queensland
Moore, M & McCann, J (2018) Sunshine Coast Council Fish Barrier Prioritisation. Catchment Solutions, Queensland.
Last updated: 26 November 2020
This page should be cited as:
Department of Environment and Science, Queensland (2020) Fish Barrier Prioritisation (Landscape Scale Coastal), WetlandInfo website, accessed 13 May 2021. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/resources/tools/assessment-search-tool/fish-barrier-prioritisation-landscape-scale-coastal/