Speed Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Assessing Changes in Threatened Black Rockcod Epinephelus daemelii Abundance and Length Over the Past 15 Years. (#528)

Hamish Malcolm 1 , David Harasti 2
  1. Fisheries Research, NSW Department of Primary Industries, Coffs Harbour, NSW, Australia
  2. Fisheries Research, NSW Department of Primary Industries, Port Stephens, NSW, Australia

Black rockcod has been protected as a threatened species in NSW for more than 40 years and is listed as Vulnerable under Commonwealth legislation. Before protection in 1983, their abundance had strongly declined due to targeted line and spearfishing, combined with their life history as a long-lived, slow-growing, large protogynous grouper. Their life-history also constrains recovery. Although baseline data from 1983 does not exist, we have been monitoring their relative abundance and length at 22 key sites over the past 15 years to assess recent recovery trends, using roving diver timed counts with stereo-video measurements. We also undertook two broader-scale surveys using these methods in 2009-11 and 2023. Relative abundance at key sites has remained relatively constant or declined since 2010, rather than increasing. Comparisons between 84 broadscale sites in 2009-11 versus 2023 (117 vs 69 individuals) indicate a recent decline in abundance. Increasing abundance as a positive metric of recovery is not supported for recent times. This decline in abundance was spread across their main distribution in NSW, including Lord Howe Island. There has been some increase in length frequency. After 40 years, this species is still threatened and additional management appears essential to aid their recovery.