Wakefield, C. B., Newman, S. J., Marriott, R. J., Boddington, D. K., and Fairclough, D. V. 2013. Contrasting life history characteristics of the eightbar grouper, Hyporthodus octofasciatus (Pisces: Epinephelidae), over a large latitudinal range reveals spawning omission at higher latitudes. – ICES Journal of Marine Science, 70: 485–497. Demographic data on deep-water groupers are limited despite them being highly exploited throughout the Indo-Pacific. In Western Australia, the continuous distribution of the eightbar grouper, Hyporthodus octofasciatus, spans tropical to temperate waters over ∼3500 km from 12°S–35°S. The maximum age was markedly higher in the northern tropical waters than in southern temperate waters, i.e. 47 vs 20 years. Females attained a significantly larger length-at-age in southern temperate waters. Macroscopic and microscopic examination of gonads and annual trends in mean monthly gonadosomatic indices (GSIs) were used to determine that this monandric protogynous hermaphrodite spawns from late spring to summer (October–February) in northwestern Australia. In the temperate waters of WA, there was no evidence of reproduction and no males were observed south of ∼30°S latitude. The lengths at which 50% of female H. octofasciatus matured and changed sex were estimated from northern tropical populations at 560 mm (6.1 years) and 1022 mm (≥11 years). Although the population connectivity of H. octofasciatus is unknown, the spawning omission in temperate waters suggests recruitment from the northern tropical areas and highlights the importance of preserving spawning stocks in those northern waters.

Over 1,400 km of oil and gas pipeline infrastructure exists within the boundaries of the Pilbara Trap Managed Fishery (PTMF) operating on the North West Shelf of Australia. Some of this infrastructure has reached the end of its operational life and requires decommissioning. Location and speed data collected from 2008-2018 using vessel monitoring systems (VMS) onboard all trap fishing vessels (n = 3) operating in the PTMF were used to understand how fishing activity near pipelines has changed through time, and to identify the best predictive variables to explain hours spent fishing km -2 week -1 . The proportion of fishing activity within 200 m of a pipeline increased over the survey decade and averaged 4.2% across all years. Hours spent fishing km -2 within 200 m of any pipeline was found to be 8.0 hours km -2 , ~11.4 times more than that recorded in the rest of the entire PTMF (0.7 hours km -2 ), and ~4.6 times more than the western portion of the PTMP (1.7 hours km -2 ) where all pipeline infrastructure exists. Fishing activity within 1 km of pipelines increased after their installation, and hence time since installation was the best predictor of fishing. This study demonstrates that trap fishers in the PTMF allocate a small proportion of their time targeting pipeline infrastructure, with the area close to a pipeline experiencing a greater magnitude of fishing than that elsewhere in the PTMF. As such, the results of this study provide decision makers with an understanding of the intrinsic value of this infrastructure to trap fishers.

The bass groper Polyprion americanus is a large demersal teleost (>1.5 m) that inhabits deep continental and oceanic island slopes (50 to 1000 m). Currently, this species is considered Critically Endangered by the IUCN and there is a moratorium on its capture in Brazil. Fishing for this species is no longer commercially viable in Bermuda and they are fully protected in South Africa. In most other locations, this species is rarely encountered and knowledge of its biology and catch history is limited. In the present study, specimens were collected from recreational and commercial catches (n = 151) in the southeastern Indian Ocean from 2005 to 2012. Otolith edge analysis was used to verify that a single opaque zone was deposited annually from May to September. A maximum age of 78 yr for females and 55 yr for males was determined from thin transverse sections of otoliths. The spawning period of this gonochorist was from autumn to early winter (March to June) and partitioned prior to that of the sympatric congener P. oxygeneios (June to September). The lengths and ages at which 50% of females and males matured were 944 and 808 mm total length, and 14.4 and 11.2 yr, respectively. The exceptional longevity, slow growth and late maturation of P. americanus imply a high inherent vulnerability at relatively low levels of exploitation. As such, the overexploitation of P. americanus in both Brazil and Bermuda should warrant close scrutiny in the waters off southwestern Australia, where exploitation of deepwater fisheries resources has increased. KEY WORDS: Life history · Age · Thin otolith sections · Natural mortality · Spawning period · Deepwater · Reproduction · Continental slope · Indian Ocean Resale or republication not permitted without written consent of the publisherAquat Biol 18: [161][162][163][164][165][166][167][168][169][170][171][172][173][174] 2013 known from South America (i.e. Uruguay, Argentina and Brazil), New Zealand and Australia (Pacific and Indian Oceans), including Tristan da Cunha in the South Atlantic Ocean and the St. Paul and Amsterdam Islands in the western Indian Ocean (Sadovy 2003). Ball et al. (2000) reported a wide genetic separation among Polyprion americanus samples from Brazil and the South Pacific (i.e. eastern Australia and New Zealand) similar to the level of genetic separation between P. americanus and P. oxygeneios, suggesting possible cryptic speciation and the likely existence of a third species of Polyprion. Their study concluded that further clarification of Polyprion sys tematics was required. Earlier, Roberts (1986) revised the systematics of Polyprion and attributed P. moeone as a synonym of P. americanus. However, Paxton et al. (1989) reported P. moeone and P. oxygeneios as the only valid species occurring in Australia and New Zealand. More recently, Hoese et al. (2006) and Gomon et al. (2008) have reported P. americanus and P. oxygeneios as the only valid species occurring in Australia and New Zealand, with P. moeone attributed as a synonym of P. americanus. Non...

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