Decline/loss of critical fish spawning cues, habitat and larval survival black bream – black bream is apex predator recreationally important species salinity structure linked to Newton (1994, Black bream – of ecological community relatively long-lived (29y) recruitment variability 1996); Morison et al. Acanthopagrus butcheri (also applies to other fish completes entire in spawning mainly occurs in salinities identified link between flow (1998); Nicholson et species, e.g. estuary perch stratified estuary > 10 ppt and triggered by temperature above and year class strength al. (2008); Jenkins et & marine southern 15 °C high levels of dissolved al. (2010); Williams anchovy) in Hopkins most bream eggs found at oxygen (DO) associated et al. (2013) 14.9 17.5 °C and larvae at with typical spawning – 12.6 17.5 °C season – spawning cued with salt-wedge emplacement eggs fail to hatch or larvae phase and mass hatching of dormant copepod die in DO of 40% saturation eggs, which provides abundant prey for or less. newly hatched larvae Decline/loss of biodiversity from pathogen epidemic of estuarine copepods viral pathogen first detected in 2007 in Hopkins (and first virus targets reproductive Williams et al. Pathogen - iridovirus infection found in at least record of virus in zooplankton) system leading to (2005); Roennfeldt ZoopIIV [HR] three estuarine-endemic temperature a driver of viral infection reproductive failure and/or (2013) calanoid copepods development (especially above 23 °C) morbidity of dominant – primary location of discovery the Hopkins, estuarine-endemic copepods Gladioferens pectinatus, and but also observed in estuaries within the infection of male and female Gippslandia estuarina EC including the Glenelg and Painkalac Sulcanus conflictus. Gladioferens pectinatus leading to limited recruitment behavioural effects limited – escape response on disturbance, reduced swimming efficiency
Decline/loss of critical fish spawning cues, habitat and larval survival – black bream Black bream – Acanthopagrus butcheri (also applies to other fish species, e.g. estuary perch & marine southern anchovy) black bream is apex predator of ecological community completes entire in stratified estuary recreationally important species relatively long-lived (29y) spawning mainly occurs in salinities > 10 ppt and triggered by temperature above 15 °C in Hopkins most bream eggs found at 14.9 – 17.5 °C and larvae at 12.6 – 17.5 °C spawning cued with salt-wedge emplacement phase and mass hatching of dormant copepod eggs, which provides abundant prey for newly hatched larvae salinity structure linked to recruitment variability identified link between flow and year class strength high levels of dissolved oxygen (DO) associated with typical spawning season eggs fail to hatch or larvae die in DO of 40% saturation or less. Newton (1994, 1996); Morison et al. (1998); Nicholson et al. (2008); Jenkins et al. (2010); Williams et al. (2013) Decline/loss of biodiversity from pathogen epidemic of estuarine copepods Pathogen - iridovirus ZoopIIV [HR] viral pathogen infection found in at least three estuarine-endemic calanoid copepods – Gladioferens pectinatus, Gippslandia estuarina and Sulcanus conflictus. first detected in 2007 in Hopkins (and first record of virus in zooplankton) temperature a driver of viral infection development (especially above 23 °C) primary location of discovery the Hopkins, but also observed in estuaries within the EC including the Glenelg and Painkalac virus targets reproductive system leading to reproductive failure and/or morbidity of dominant estuarine-endemic copepods infection of male and female Gladioferens pectinatus leading to limited recruitment behavioural effects – limited escape response on disturbance, reduced swimming efficiency Williams et al. (2005); Roennfeldt (2013)
consultation-document-salt-wedge-estuaries.docx