Fisheries Research and Development Corporation

This article presents the results of a global review of organizations that provide sustainable fisheries information—including ecolabels, recommendation lists, and supermarkets—to consumers and supply chain intermediaries. It examined 17 organizations and key supermarkets that communicate on the sustainability of world fisheries and aquaculture products. Certification schemes assess a relatively small number of specific fisheries and indicate sustainability through labels. Recommendation lists cover more species and areas but in less detail. Most schemes showed improving conformance with FAO guidelines for fisheries and aquaculture certification. However, significant variation in fisheries’ assessment exists, calling into question the accuracy and precision of information and advice provided. Inconsistent approaches and contradictory advice among certification schemes and recommendation lists potentially increase consumer confusion and reduce their credibility. The review identifies seven critical attributes that schemes must address—scope, accuracy, independence, precision, transparency, standardization, and cost-effectiveness—and recommends that certification schemes and recommendation lists enhance their consistency and credibility through compliance with these attributes and FAO guidelines. Fish sustainability information schemes play an important role in securing a sustainable future for the oceans. Uptake of this review's recommendations should reduce consumer confusion and increase confidence in the benefits of sustainable purchasing.

Abstract Chemical analysis of calcified structures continues to flourish, as analytical and technological advances enable researchers to tap into trace elements and isotopes taken up in otoliths and other archival tissues at ever greater resolution. Increasingly, these tracers are applied to refine age estimation and interpretation, and to chronicle responses to environmental stressors, linking these to ecological, physiological, and life-history processes. Here, we review emerging approaches and innovative research directions in otolith chemistry, as well as in the chemistry of other archival tissues, outlining their value for fisheries and ecosystem-based management, turning the spotlight on areas where such biomarkers can support decision making. We summarise recent milestones and the challenges that lie ahead to using otoliths and archival tissues as biomarkers, grouped into seven, rapidly expanding and application-oriented research areas that apply chemical analysis in a variety of contexts, namely: (1) supporting fish age estimation; (2) evaluating environmental stress, ecophysiology and individual performance; (3) confirming seafood provenance; (4) resolving connectivity and movement pathways; (5) characterising food webs and trophic interactions; (6) reconstructing reproductive life histories; and (7) tracing stock enhancement efforts. Emerging research directions that apply hard part chemistry to combat seafood fraud, quantify past food webs, as well as to reconcile growth, movement, thermal, metabolic, stress and reproductive life-histories provide opportunities to examine how harvesting and global change impact fish health and fisheries productivity. Ultimately, improved appreciation of the many practical benefits of archival tissue chemistry to fisheries and ecosystem-based management will support their increased implementation into routine monitoring. Graphical abstract

An Australia-wide assessment of ~1000 estuaries and embayments undertaken by the National Land and Water Resources Audit of 1997–2002 indicated that ~30% were modified to some degree. The most highly degraded were in New South Wales, where ~40% were classified as ‘extensively modified’ and <10% were ‘near pristine’. Since that review, urban populations have continued to grow rapidly, and increasing pressures for industrial and agricultural development in the coastal zone have resulted in ongoing degradation of Australia's estuaries and embayments. This degradation has had serious effects on biodiversity, and commercial and recreational fishing. A business case is developed that shows that an Australia-wide investment of AU$350 million into repair will be returned in less than 5 years. This return is merely from improved productivity of commercial fisheries of a limited number of fish, shellfish and crustacean species. Estuary repair represents an outstanding return on investment, possibly far greater than most of Australia's previous environmental repair initiatives and with clearly demonstrated outcomes across the Australian food and services economies.

Abstract Biogeochemical tracers found in the hard parts of organisms are frequently used to answer key ecological questions by linking the organism with the environment. However, the biogeochemical relationship between the environment and the biogenic structure becomes less predictable in higher organisms as physiological processes become more complex. Here, we use the simultaneous combination of biogeochemical tracers and fish growth analyzed with a novel modeling framework to describe physiological and environmental controls on otolith chemistry in an upwelling zone. First, we develop increasingly complex univariate mixed models to describe and partition intrinsic (age effects) and extrinsic (environmental parameters) factors influencing fish growth and otolith element concentrations through time. Second, we use a multivariate mixed model to investigate the directionality and strength between element‐to‐element and growth relationships and test hypotheses regarding physiological and environmental controls on element assimilation in otoliths. We apply these models to continuous element (Na, Sr, Mg, Ba, Li) and growth increment profiles (monthly resolution over 17 yr) derived from otoliths of reef ocean perch ( Helicolenus percoides ), a wild‐caught, site‐attached, fully marine fish. With a conceptual model, we hypothesize that otolith traits (elements and growth) driven by environmental conditions will correlate both within an otolith, reflecting the time dependency of growth and element assimilation, and among individuals that experience a similar set of external conditions. We found some elements (Sr:Ca and Na:Ca) are mainly controlled by physiological processes, while other elements (Ba:Ca and Li:Ca) are more environmentally influenced. Within an individual fish, the strength and direction of correlation varies among otolith traits, particularly those under environmental control. Correlations among physiologically regulated elements tend to be stronger than those primarily controlled by environmental drivers. Surprisingly, only Ba:Ca and growth are significantly correlated among individuals. Failure to appropriately account for intrinsic effects (e.g., age) led to inflated estimates of among individual correlations and a depression of within individual correlations. Together, the lack of among‐individual correlations of otolith traits in properly formulated models and the biases that can be introduced by not including appropriate intrinsic covariates suggest that caution is needed when assuming multi‐elemental signatures are reflective solely of shared environments.

To optimize dietary protein level in relation to growth, semipurified diets with an essential amino acid profile similar to that of the soft body profile were fed for 59 days to young greenlip abalone, Haliotis laevigata (initial shell length, 15–25 mm). Animals were housed in 10-L acrylic tanks, with flow-through seawater supplied at 1 L min–1 (20 °C, salinity= 36 g L–1). Protein level of feeds ranged from 122 g kg–1 to 461 g kg–1 crude protein (CP) on an ‘as is’ basis. Second-order polynomial regression analysis of specific growth rate indicated that maximal growth occurs at 270 g kg–1 CP. The protein and energy components of the feed were estimated to have a digestibility of 71.7% and 55.6%, respectively.

Abstract The growth, condition, and feed utilization patterns of juvenile southern bluefin tuna (SBT) fed moist‐pellets were examined over a 19‐wk period from March to July 1999. The SBT had significant weight gain over the course of the study, increasing on average from about 27 to 34 kg (dependent on size class). No significant weight gain by the SBT occurred in the first 5 wk of the study. Following this initial period of slow growth, the rate of weight gain increased, ranging between 40 to 90 g/d. Weight gain peaked after 11 wk, with no further gain occurring after this time point. Weight gain was strongly related to average daily feed intake (AFI) which was predominantly influenced by water temperature. Weight gain was minimal following the decrease of water temperatures below 15 C, consistent with a decrease in feed intake from peak values at the beginning of the study to basal levels by week 13. Basal feeding levels were maintained for the remainder of the study through to week 19. Although water temperature and AFI were strongly related, other time related effects also appeared to be signillcant. A relationship between condition index and feed intake was also identified. Condition index of the SBT increased from about 19 kg/m 3 to 22 kg/m 3 over the 19‐wk period. Similar to the patterns observed in growth, there was also an initial delay in increases of condition index. The results from this study support that the majority of weight gain by juvenile SBT occurs during the early part of the production season and that this is most likely influenced indirectly through responses to water temperature. The results of this study also suggest that there is little value in conducting growth trials beyond the point where water temperatures decrease below 15 C. Although there was minimal weight gain or improvement in condition beyond the 11‐wk time point, these parameters would need to be considered in conjunction with flesh quality characteristics to identify optimum harvesting regimes.

Combined fishway-culvert facilities are common in many tropical river systems in South East Asia, but little is known regarding their mutual passage effectiveness. We investigated the lateral passage of Lower Mekong Basin fish in Lao PDR, through a combined cone fishway-sluice gate culvert facility between the Mekong River and an adjacent wetland. Fish abundance and species richness were assessed during the beginning of the 2014 wet season at three locations within the fishway-culvert facility: (i) the bottom of the fishway (i.e. downstream end of the facility); (ii) the top of the fishway; and (iii) the top of the culvert (i.e. upstream end of the facility). Neither total fish abundance nor species richness varied significantly among the three locations while the wetland remained at levels where the culvert was only partially inundated and the culvert gate was fully open. However, part-way through the study the culvert became completely inundated and the culvert gate had to be partially closed to protect the downstream fishway. During this period of partial gate closure, fish abundance and species richness became significantly lower at the top of the culvert than at the two fishway locations. This suggests that sluice gate culverts are most effective at facilitating the lateral movement of fish in tropical river systems when they are designed and operated appropriately for the local hydrological conditions, and their gates remain fully open.

There was an oversight in the authorship at the time of publication and the article is corrected to include Patrick Charapata and Stephen Trumble from the Biology Department, Baylor University, Waco, TX 76706, USA. The correct full authorship is given below: Patrick Reis-Santos; Bronwyn M. Gillanders; Anna M. Sturrock; Christopher Izzo; Dion S. Oxman; Jessica A. Lueders-Dumont Karin Hüssy; Susanne E. Tanner; Troy Rogers; Zoë A. Doubleday; Allen H. Andrews; Clive Trueman; Deirdre Brophy; Jason D. Thiem; Lee J. Baumgartner; Malte Willmes; Ming-Tsung Chung; Patrick Charapata, Rachel C. Johnson; Stephen Trumble, Yvette Heimbrand; Karin E. Limburg; Benjamin D. Walther. Author contributions are corrected accordingly to read: “…DSO and AMS drafted the section on maturity and reproduction, with contributions from PC and ST…”. The end of the caption of Figure 3 should read: “(Charapata, Oxman, and Trumble, unpublished)”. In the manuscript and reference list, Charapata et al 2020 should read, respectively, “Charapata et al (2022)”, and “Charapata P, Oxman D, McNeel K, Keith A, Mansouri F, Trumble S (2022) Lifetime hormone profiles for a long-lived teleost: Opercula reveal novel estimates of age-specific reproductive parameters and stress trends in yelloweye rockfish (Sebastes ruberrimus). Canadian Journal of Fisheries and Aquatic Sciences. ”.

The Bird Island in Algoa Bay supports a breeding colony of South African (Cape) fur seals, Arctocephalus pusillus pusillus (n = 1000–3000) on Black Rocks which is the easternmost extreme of their breeding range and so it is likely to be the most environmentally marginal of the existing fur seal colonies. Conditions on Bird Island for seal pups are not as benign as they might first appear, particularly with regard to air temperatures. Climatic conditions on Bird Island were recorded in 1993–1995 and are compared to the conditions at Port Elizabeth Airport 63 km W-SW from the Bird Islands. Daily maximum and minimum temperatures, sea surface temperatures (SSTs) and rainfall were compared to concurrent Port Elizabeth data. Wind speeds and directions and sea swell heights at Bird Island were also recorded. Air temperatures ranged from 9°C to 33°C, SSTs ranged from 12°C to 23°C, total annual rainfall was ≈ 600 mm and there were typically relatively strong winds (13–15 knots/7–8 m s− 1) predominantly W-SW and E-NE. Intermittent periods of calm hot weather during summer pupping season would lead to potentially lethal hyperthermia (heat stroke). In 1993–1995, about 50% of summer days were potentially lethal to seal pups in the open by hyperthermia if the wind speed is near zero. Eddying of the Agulhas Current and strong winds leads to irregular favourable small-scale upwelling events, but incursions of warm water in hot still weather occurred in January–March 1993 and November–December 1993 and likely lead to starvation of some pups as well as endangering seal pups by hyperthermia. Detailed climate data are usually not available for seal colony sites, but we found good correlations between the offshore Bird Islands and climate data collected from the nearest permanent weather station (Port Elizabeth Airport) making it possible to infer long-term changes in conditions on Bird Island based upon Port Elizabeth data. We show that modest (2°C) increases in average summer temperatures would greatly increase the number of potentially lethal hot days.

Widespread marine heatwaves (MHWs) affected Australia over the 2024/25 summer and autumn. They impacted marine species, ecosystems, and coastal communities, with emerging economic consequences. Across northern Australia, severe coral bleaching occurred for the first time along both the western and eastern coasts, and a mass fish kill occurred in Western Australia. In South Australia, prolonged MHW conditions and impacts from an extensive harmful algal bloom of the dinoflagellate Karenia included extensive fish kills, human health effects, losses for ocean-dependent industries, and currently unquantified effects on the broader marine ecosystem. In Tasmania, a range of impacts were linked to warm water, including blooms of salps, Noctiluca, and jellyfish. In New South Wales, a fish mortality event linked to thermal shock generated considerable community concern and media coverage. Trial seasonal forecasts available several months ahead of MHW emergence, combined with national marine climate briefings, helped prepare industry, researchers, and governments for possible impacts. This resulted in increased awareness and development of regional and industry MHW response plans with proactive strategies at both short and long timescales.