The New Zealand vessel San Aspiring carried out an exploratory research program for toothfish in the South Pacific Regional Fisheries Management Organisation (SPRFMO) Convention Area during August 2016 (Fenaughty et al. 2016) and September 2017. Analysis of the information collected showed high catch rates of post-spawning Antarctic toothfish, similar in magnitude to catch rates in the north region of CCAMLR subareas 88.1 and 88.2. The toothfish catch was almost entirely Antarctic toothfish except for two juvenile Patagonian toothfish. Sex ratios showed a high proportion of males to females. Fish were in poor body condition as assessed using Fulton’s condition factor indicative of full or partial starvation which would be consistent with a spawning event prior to the sampling in 2016 and 2017. Body condition was slightly better in 2017 when sampling occurred about 5 weeks later than in 2016. Fish length and mass, body condition, sex ratio, and gonad condition were consistent with previous observations from the northern Ross Sea region in CCAMLR Subareas 88.1 and 88.2 (Fenaughty 2006, Fenaughty et al. 2008, Parker & Marriott 2012, Stevens et al. 2016).
These results give a strong indication that Antarctic toothfish also spawn north of 60° south latitude in the Southern Ocean. Biological measurements collected from fish sampled in this SPRFMO area of study are consistent with previous information and analyses from the northern regions of CCAMLR Subarea 88.1, indicative of spawning in that region suggesting that Antarctic toothfish spawning may extend over a wider geographic area than initially hypothesised.