Larval fish are sensitive to environmental changes, with many oceanographic processes influencing their distribution, abundance and survival. Most species have eggs and larvae that can be sampled with simple plankton nets in the upper mixed layer of the water column resulting in the capture of a broad suite of larval fishes (Koslow & Wright, 2016).
The sensitivity to ocean oceanographic processes, and the ease of capture, make larval fish useful indicators of change. IMOS provides a national oceanographic monitoring framework, although there are many gaps in different parts of the ecological system, particularly fish reproduction.
Ichthyoplankton monitoring began at three east coast National References Stations (NRS) – North Stradbroke Island (NSI), Port Hacking (PH) and Maria Island (MAI) – and subsequently including Kangaroo Island (KAI) and Rottnest Island (ROT), and north Queensland Yongala site. The initial two years of data and over three decades of historical larval fish data were integrated and recently published (Smith et al. 2018). Our key advance was to recognise 218 standard, distinctive and abundant larval fish taxa, and to determine indicator taxa for the eastern seaboard. However, the power to detect temporal trends in these taxa was compromised by the lack of seasonal sampling and the Tasmanian waters were not well represented in the post 1997/98 ENSO event years. Our vision is for larval fish monitoring to continue and investigate alternative technologies such as DNA barcoding.