No abstract

No abstract

Small numbers of blue grenadier, Macruronus novaezelandiae, larvae were found in coastal waters off eastern Victoria and southern New South Wales in August 1993. This is the first record of larval blue grenadier from mainland Australian waters. It is considerably further north than previous records of larvae and remote from the single known spawning ground off western Tasmania. Larvae were aged between 17 and 36 days and were largely confined to an inshore northward flowing water mass. Back calculated spawning dates indicated that larvae from eastern Victoria/southern NSW were spawned earlier than larvae collected during the same period off western and southern Tasmania. Otolith increment widths were significantly wider in larvae caught in eastern Victoria/southern NSW suggesting that they experienced faster growth and development conditions than the Tasmanian larvae. Three-dimensional modelling of circulation and particle advection suggested that the source of eastern Victoria/southern NSW larvae was most likely eastern Bass Strait. These data suggest that there is a second, albeit limited, spawning area for blue grenadier in south-eastern Australia.

No abstract

The global importance of mesopelagic fish is increasingly recognised, but they remain poorly studied. This is particularly true in the Southern Ocean, where mesopelagic fishes are both key predators and prey, but where the remote environment makes sampling challenging. Despite this, multiple national Antarctic research programs have undertaken regional sampling of mesopelagic fish over several decades. However, data are dispersed, and sampling methodologies often differ precluding comparisons and limiting synthetic analyses. We identified potential data holders by compiling a metadata catalogue of existing survey data for Southern Ocean mesopelagic fishes. Data holders contributed 17,491 occurrence and 11,190 abundance records from 4780 net hauls from 72 different research cruises. Data span across 37 years from 1991 to 2019 and include trait-based information (length, weight, maturity). The final dataset underwent quality control processes and detailed metadata was provided for each sampling event. This dataset can be accessed through Zenodo. Myctobase will enhance research capacity by providing the broadscale baseline data necessary for observing and modelling mesopelagic fishes.