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

Reproductive impairment in chondrichthyans: A problem critical to future population success. (#349)

Madeleine Davies-Knight 1 , Jayson Semmens 1 , Cynthia Awruch 2 , David Moreno 1
  1. Institute for Marine and Antarctic Science, Hobart, TASMANIA, Australia
  2. University of Tasmania, Hobart, Tasmania, Australia

Anthropogenic activities are a continuous threat to the health of wildlife populations worldwide. Chondrichthyans (sharks, rays, skates, and chimaeras) are among the most threatened marine groups and are experiencing widespread population declines, with one-third of species estimated to be threatened with extinction. Several concerning reproductive abnormalities have recently been reported in female spiny dogfish (Squalus acanthias) residing in Macquarie Harbour, Tasmania. These could possibly be attributed to combinations of anthropogenic stressors present within this region, although it remains unclear if these are short-term responses or catalysts for population decline. This research investigates mechanisms driving reproductive impairment in chondrichthyans by exploring the reproductive consequences of habitat degradation and pollution using S. acanthias as a model species. This presentation will show preliminary results on reproductive system function using profiles of gonadal hormone concentrations, histological imagery of gonadal tissue structures, and video assessments of sperm quality which will describe baseline indications of reproductive health and condition for the Macquarie Harbour population. The outputs of this research will provide important information on the future reproductive success of S. acanthias, which will be essential to improved monitoring of vulnerable chondrichthyan population health to safeguard future scenarios for population success.