TY - JOUR
T1 - From an irrigation system to an ecological asset
T2 - Adding environmental flows establishes recovery of a threatened fish species
AU - Stuart, Ivor
AU - Sharpe, Clayton
AU - Stanislawski, Kathryn
AU - Parker, Anna
AU - Mallen-Cooper, Martin
PY - 2019
Y1 - 2019
N2 - Worldwide, riverine fish are the target of environmental water because populations have declined in lotic river habitats following river regulation. Murray cod is an endangered Australian riverine fish with remaining populations associated with lotic river reaches with instream habitat, including some creeks operated as part of irrigation systems. Our objectives were to develop a life history model, apply the building block method of environmental flows to enhance the abundance of juvenile Murray cod and promote population recovery. From 2008 to 2018 we evaluated changes to Murray cod juvenile abundance before and after implementation of a perennial environmental flow regime that began in 2013. During the first year of the environmental flow, larvae were collected as evidence of spawning. Murray cod abundance can be enhanced with environmental flows that target: (1) an annual spring spawning or recruitment flow with no rapid water level drops; (2) maximising hydrodynamic complexity (i.e. flowing habitats that are longitudinally continuous and hydrodynamically complex); and (3) an annual base winter connection flow. Recognition that incorporating hydraulics (water level and velocity) at fine and coarse time scales, over spatial scales that reflect life histories, provides broader opportunities to expand the scope of environmental flows to help restore imperilled fish species in regulated ecosystems.
AB - Worldwide, riverine fish are the target of environmental water because populations have declined in lotic river habitats following river regulation. Murray cod is an endangered Australian riverine fish with remaining populations associated with lotic river reaches with instream habitat, including some creeks operated as part of irrigation systems. Our objectives were to develop a life history model, apply the building block method of environmental flows to enhance the abundance of juvenile Murray cod and promote population recovery. From 2008 to 2018 we evaluated changes to Murray cod juvenile abundance before and after implementation of a perennial environmental flow regime that began in 2013. During the first year of the environmental flow, larvae were collected as evidence of spawning. Murray cod abundance can be enhanced with environmental flows that target: (1) an annual spring spawning or recruitment flow with no rapid water level drops; (2) maximising hydrodynamic complexity (i.e. flowing habitats that are longitudinally continuous and hydrodynamically complex); and (3) an annual base winter connection flow. Recognition that incorporating hydraulics (water level and velocity) at fine and coarse time scales, over spatial scales that reflect life histories, provides broader opportunities to expand the scope of environmental flows to help restore imperilled fish species in regulated ecosystems.
KW - Australia
KW - building block method
KW - Gunbower Creek
KW - Murray cod
KW - recruitment
KW - water management
UR - http://www.scopus.com/inward/record.url?scp=85069918510&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85069918510&partnerID=8YFLogxK
U2 - 10.1071/MF19197
DO - 10.1071/MF19197
M3 - Article
AN - SCOPUS:85069918510
SN - 1323-1650
VL - 70
SP - 1
EP - 12
JO - Marine and Freshwater Research
JF - Marine and Freshwater Research
IS - 9
ER -