Eastern King Research Articles

Daily Weather Data From Central and Eastern King George Island (West Antarctica) for 2018–2023

ABSTRACTThe dataset presented in the paper contains meteorological data from four automatic weather stations (AWS) located in the central and western parts of King George Island (near Arctowski Station and Cape Lions Rump). The dataset includes daily mean, maximum and minimum values of air temperature, relative air humidity, air pressure, wind speed and daily sum of solar radiation. The measurement period ran from 2018.01.01 to 2023.12.31, but it is shorter for two of the stations. Mean values were calculated from measurements taken every 10 min. Direct measurements were used to identify extreme values. The described dataset consists offour files, each for one AWS. It is available in the PANGEA online repository under a non‐restrictive CC BY 4.0 licence for anyone after registration. Despite a strong correlation between the daily mean values of the parameters measured at certain stations, some differences between them were also noticeable. These were due to their location at different altitudes, in a place open to the sea or in a shaded place. Generally, values of wind speed, air humidity, solar radiation and pressure are similar to Arctowski during 2013–2017. The only notable distinction is that the mean annual air temperature and the mean air temperature in the winter months were higher than during 1977–1999 and 2013–2017. The data presented can be used as background for other research projects on King George Island, as well as for analysis of the meteorological conditions themselves. They may also be useful for the evaluation of the management plans of the eight Antarctic Specially Protected Areas or Antarctic Specially Managed Area no. 1 that are located on King George Island.

Polychlorinated dibenzodioxins/furans and dioxin-like polychlorinated biphenyls in fish and crustaceans of a recreationally fished estuary, following targeted remediation

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) are a suite of harmful chemicals (hereafter collectively referred to as ‘dioxins’), and their emission into aquatic habitats leads to persistent contamination of sediments, aquatic food-webs, and seafoods. Quantifying contaminant levels in seafood species is important for the ongoing management of exposure risk by fishers, particularly after any remediation actions. We present dioxin concentrations in four seafood species (Yellowfin Bream Acanthopagrus australis, Sea Mullet Mugil cephalus, Eastern School Prawn Metapenaeus macleayi, and Eastern King Prawn Penaeus plebejus) in a recreationally fished estuary, in relation to a contaminated site that has undergone a remediation process, partially removing contaminated sediments (Homebush Bay, Port Jackson, New South Wales, Australia). Dioxin concentrations in these species were measured before (2005/6) and after (2015/16) remediation at a range of locations in and around the remediated site. Dioxin concentrations and congener profiles differed substantially among taxa, and concentrations were frequently higher than Australian screening criteria. The two prawn species showed evidence of a decline in dioxin concentrations after remediation, but the fish species only showed a declining dioxin concentration with distance from the contaminated site (not between periods). There were some minor changes in the congener profile for some species following remediation. While there was evidence for greatly reduced dioxin concentrations in prawn species following remediation, the complex patterns for fish were likely affected by environmental changes, species-specific and temporal changes in lipid content, and animal movement patterns. Future monitoring may aid interpretation of the patterns and modelling of exposure risk associated with seafood consumption into the future.

"Сказание о двенадцати снах царя Шахаиши" в сборниках сибирских старообрядцев

The aim of the study is to identify the text of the Legend of the Twelve Dreams of King Shahaisha " in the Old Believer manuscripts of the XVIII – XX centuries. The narrative of this ancient apocrypha tells of an eastern king telling his dreams to the wisest philosopher, who responds with an interpretation-prophecy to each dream. The material for the study was selected during archaeographic cameral work in the repositories of 13 Siberian archives of the cities of Novosibirsk, Tomsk, Tobolsk, Tyumen and Irkutsk, where it was possible to identify 11 copies of the Legend. It is worth noting that this number indicates the popularity of this apocryphal work: not all early Old Russian texts continued to actively exist in the Old Believers' milieu. Of course, the frequent rewriting of the Legend is connected with the eschatological nature of the literary monument. Earlier, researchers showed interest in earlier texts of the Legend, and the main issues for resolution were the origin and reconstruction of the ancient manuscript monument, the primacy and secondariness of the South Slavic edition and the Russian edition. Based on the material of well - known copies in the beginning of the XX century, a classification of editions was developed, which became the basis for distinguishing the "Siberian" copies of the Legend in this study. An important role for attributing texts to a particular group is the order of the king's dreams and the images in them. Working with the texts de visu and conducting textual analysis allow us to determine that one of the copies belongs to the 1st edition, three lists belong to the 2nd group of the 2nd edition, which indicates the continuation of the coexistence of the two editions in the literary process of the XIX–XX centuries. However, the main result of the study should be called the identification of a new kind of the Legend of the Twelve Dreams of King Shahaisha. It can be called the 3rd redaction. In five copies, new images were found that researchers had not encountered before - four dreams of the king were replaced. Changes in the text may be associated with a different interpretation of dark places that have not been fully understood in all ages: The Old Believers-scribes strive to adapt them for a modern reader. A thoughtful reading of the ancient text and the ability to create a new version of it once again confirms the belief of the archaeographers that the Old Believers can rightfully be called the direct successors of the Old Russian manuscript tradition.

Eastern king prawn Penaeus plebejus stock enhancement-Genetic evidence that hatchery bred prawns have survived in the wild after release.

Eastern king prawn (Penaeus plebejus) is endemic to eastern Australia and is of high commercial and recreational value. As part of a recreational fisheries enhancement initiative, hatchery reared juveniles from Queensland were released into two, more Southern New South Wales (NSW) estuaries between 2014 and 2015. Responsible stock enhancement programs rely on knowledge of the population structure of the released species. Previously, in consideration of fisheries data, it was assumed the king prawn populations in Australia are one single breeding stock. In the present study, our first aim was to test this posit of no genetic differentiation using mtDNA control region (mtCR) sequences from the wild samples collected from four estuaries ranging from Queensland/NSW border (source of the stocked animals) to Southern NSW. The second objective was to test for signals of hatchery-released animals in the two stocked estuaries. All four surveyed populations had an extremely high level of haplotype diversity (average h = 99.8%) and low level of haplotype sharing between populations. Estimates of PhiPT values were <0.01 or close to zero and AMOVA test did not indicate any significant differences among populations. Further, phylogenetic analysis and principal coordinate analysis did not support division of samples by population. Collectively these results suggest that eastern king prawn populations along the NSW coast can be considered as a single stock and stocking from the Queensland samples will not necessarily impact the genetic composition of the overall stock. After stocking of two estuaries, sharing of haplotypes was moderate to very high in the stocked sites (>80% in some collections) but negligible in the two unstocked estuaries (≤2%, which is assumed to be background coancestry unrelated to the hatchery). Moreover, some haplotypes present in the hatchery broodstock were detected in stocked sites, but not in unstocked sites. The highest stocking signal was detected in the estuary which becomes isolated from the sea by sand barrier suggesting such "lakes" maybe more favourable for stocking than estuaries directly open to the sea. Findings in the current study should assist in designing and implementation of future prawn stocking programs.

Effects of spatial management of a penaeid fishery on other target fish species in eastern Australia

AbstractTemporal and spatial closures are often used to manage harvest by trawl fisheries. Trawl closures implemented to benefit a particular species may also benefit other species, but these indirect effects are rarely quantified. Using the New South Wales (Australia) Ocean Trawl Fishery as a case study, the potential unintended effects of trawl closures designed to protect juvenile eastern king prawn were explored for other quota managed Sillaginidae within the fishery (stout whiting Sillago robusta and eastern school whiting Sillago flindersii). Both species of whiting were more abundant within closed areas than adjacent areas, and spawning‐sized stout whiting were proportionally more abundant within closed areas. Thus, closures implemented to protect prawns also provided protection for exploited whiting species, including spawning‐sized individuals, enhancing their overall impact on the fishery. Spatial management of trawl fisheries elsewhere in the world may also similarly benefit other exploited species.

Adaptive Spatial Management to Deal with Postflood Inshore Bycatch in a Penaeid Trawl Fishery

AbstractAdaptive spatial management provides a way to balance the conservation of bycatch species and the potential economic effects of bycatch‐induced closures on a fishery, but implementation can be both data and resource intensive. We present a survey exploring a novel approach to adaptively manage an intermittent bycatch issue in an inshore trawl fishery where Sciaenidae bycatch species (including juvenile Mulloway Argyrosomus japonicus, a species of conservation concern) co‐occur with large aggregations of a valuable target species (eastern school prawn Metapenaeus macleayi), following flood‐induced egression from estuarine habitats. Diurnal sampling surveys followed three flood events and targeted permanent inshore closure zones (designed to protect the normally nocturnally harvested eastern king prawn Melicertus plebejus) and adjacent inshore nonclosure areas. Sciaenidae abundance was mostly &lt;10 fish/ha trawled, but larger catches generally corresponded with larger catches of eastern school prawn, and these relationships appeared to be steeper within nonclosure zones. There were only minor differences in the size structure of eastern school prawn between zones, and patterns were event and location specific. Negligible eastern king prawn were encountered. The results show that temporarily allowing fishers access to permanent trawl closures following floods may support the exploitation of aggregated target species with reduced interaction with bycatch species of concern. The approach presented here is relevant to the consideration of adaptive spatial management in other trawl fisheries.

«Like an unseen god» (Ctesias F1b §21, 7 Lenfant): The Unapproachability of the Near Eastern Kings in Greek Sources as Tool of Power

The aim of this paper is to review the inaccessibility of the Near Eastern kings in Greek sources as a tool of power: inaccessibility, in fact, was considered by the Greeks an essential feature in order to rule over Asia; nonetheless, it is important to note that Greek sources on the one hand emphasize the importance and the political use of this tool and, on the other hand, reflect on the weakness of power built through the king’s inaccessibility.

Modelling the potential consequences of adaptive closure management in a penaeid trawl fishery

Spatial management of fishing effort can be used to avoid catching undesirable size classes for target species, and improve yield-per-recruit for the exploited stock. Adaptive closure management has been proposed as a means to more effectively utilise spatial management, however these management provisions often lack quantitative evaluation which constrains the information available to inform decisions. We demonstrate the use of a spatially and size structured population dynamics model to evaluate the potential impact of spatial management on a multijurisdictional fishery for a highly migratory species (eastern king prawn, Penaeus [Melicertus] plebejus). Under current conditions in the fishery, the overall effect of closures on harvest was estimated to be comparatively minor, regardless of assumptions about how effort or fisher behavior are affected by spatial management. Alternative assumptions about the movement patterns of eastern king prawn had little influence on the impact of closures on overall harvest. However, when effort was increased to historic levels similar to those observed when the closures were implemented, a much greater impact on overall harvest was observed. The approach taken and simulation outcomes are discussed in the context of spatial management for both eastern king prawn, and penaeid fisheries more broadly.

A lithostratigraphical and chronological study of Oligocene-Miocene sequences on eastern King George Island, South Shetland Islands (Antarctica), and correlation of glacial episodes with global isotope events

AbstractKing George Island (South Shetland Islands, Antarctic Peninsula) is renowned for its terrestrial palaeoenvironmental record, which includes evidence for potentially up to four Cenozoic glacial periods. An advantage of the glacigenic outcrops on the island is that they are associated with volcanic formations that can be isotopically dated. As a result of a new mapping and chronological study, it can now be shown that the published stratigraphy and ages of many geological units on eastern King George Island require major revision. The Polonez Glaciation is dated as c. 26.64 ± 1.43 Ma (Late Oligocene (Chattian Stage)) and includes the outcrops previously considered as evidence for an Eocene glacial ('Krakow Glaciation'). It was succeeded by two important volcanic episodes (Boy Point and Cinder Spur formations) formed during a relatively brief interval (&lt; 2 Ma), which also erupted within the Oligocene Chattian Stage. The Melville Glaciation is dated as c. 21–22 Ma (probably 21.8 Ma; Early Miocene (Aquitanian Stage)), and the Legru Glaciation is probably ≤ c. 10 Ma (Late Miocene or younger). As a result of this study, the Polonez and Melville glaciations can now be correlated with increased confidence with the Oi2b and Mi1a isotope zones, respectively, and thus represent major glacial episodes.

Biological evaluation of an existing spatial management network for an exploited penaeid species

Spatial management may be employed to achieve objectives aimed at maintaining or enhancing productivity and sustainability of exploited populations. Spatial management is used in penaeid fisheries to alter the spatiotemporal distribution of fishing effort to achieve outcomes such as avoidance of undesirable size-classes. Eastern King Prawn (Penaeus [melicertus] plebejus; EKP) is a valuable penaeid species for which harvest is supported by an extensive spatial management network, however these closures have never been evaluated. We examine temporal variation in biomass and size structures within three trawl closure areas spanning four degrees of latitude. There was substantial spatial variation in EKP biomass among locations, fished and non-fished zones and sampling periods, which appeared to be influenced by depth, temperature and distance to the adjacent estuarine nursery. Size structure varied among locations and sampling periods, and differed inside and outside of closure areas, however in many cases the majority of prawns that were protected within closure areas were consistently smaller than the estimated size at first capture for optimal yield per recruit. The data suggest that the closures are likely to be effective at achieving their objective, but there may be some scope for adaptive management.

Lithostratigraphy, age and distribution of Eocene volcanic sequences on eastern King George Island, South Shetland Islands, Antarctica

AbstractNew mapping and dating of volcanic outcrops on the east coast of Admiralty Bay, King George Island, has demonstrated that Eocene volcanic sequences are dominant and also crop out extensively elsewhere, particularly on the eastern part of the island. The sequences can be divided into at least three formations (Hennequin, Cape Vauréal and Carruthers Cliff) together with Eocene strata at Warkocz and near Lions Rump that are currently unassigned stratigraphically. New and recently published40Ar/39Ar ages indicate that all of the formations are Early Eocene in age, mainly Ypresian, extending to Lutetian and possibly even Priabonian time in more easterly outcrops. Compositional contrasts exist between the groups (calc-alkalinevstholeiitic). The formations are mainly composed of lavas, and many show evidence for contemporary inundation by water. They are interbedded with sedimentary rocks deposited mainly during flooding events as debris flows, debris avalanches, hyperconcentrated flows, from traction currents and in lakes. The common presence of juvenile volcanic detritus suggests that the sediments were probably linked to explosive hydrovolcanic eruptions, some of which were possibly rooted in summit ice caps. Other evidence is also permissive, but the presence of Eocene ice on King George Island is not well established at present.

Connectivity between a spatial management network and a multi-jurisdictional ocean trawl fishery

Spatial management is often applied in penaeid trawl fisheries to avoid non-optimal size classes of target species, by providing areas of refuge from trawl fishing effort. Efficient application of spatial management relies on having a detailed knowledge of animal movements, particularly for species with complex life histories. Using Eastern King Prawn (Penaeus (Melicertus) plebejus; EKP) as a case study, we examine how spatial and temporal factors can influence connectivity between a spatial management network designed to protect small prawns from capture by trawlers, and a multi-jurisdictional (Queensland [Qld] and New South Wales [NSW]) fishery. Over 7500 prawns were tagged across multiple years in three northern NSW spatial management areas, and 786 tagged prawns were recaptured across both jurisdictions. The majority of prawns tended to be recaptured from deeper waters adjacent to, or directly north of, the spatial management areas, but tagging location and release timing influenced recapture patterns. Cohorts tagged early in the growth season showed lower recapture rates, but were larger on average at recapture, and had migrated further. Prawns reached the fishery in the adjacent jurisdiction (Qld) within 54 days-post tagging, but for most cohorts the majority of recaptures were in NSW zones. Overall, there was good connectivity between all spatial management areas and the NSW fishery, and tagged prawns also reached the Qld spawning areas. This represents an optimal scenario for NSW fishers (who forgo capture of prawns within these spatial management areas): the prawns protected in the closure areas primarily contribute to harvest of larger sized prawns within NSW waters; and a portion of the protected prawns survive to reach the southern Queensland spawning grounds, which is the primary source of recruits for northern NSW nurseries. These findings are broadly relevant to defining the role and impact of established and proposed spatial management networks within penaeid fisheries.

The Geochronology of Tasmanian Tin Deposits Using LA-ICP-MS U-Pb Cassiterite Dating

Abstract The island state of Tasmania is the most important tin producer in Australia. The spatial and genetic relationship between Tasmanian tin deposits and Devonian-Carboniferous granites, which intruded throughout the Tabberabberan orogeny, has long been understood. However, little geochronological data is available to link mineralization to nearby intrusions. In this study, we investigate the connection between 19 Tasmanian tin deposits and their potential source granites, using U-Pb cassiterite dating by laser ablation-inductively coupled plasma-mass spectrometry. Archean pegmatitic cassiterite was also characterized and used for the calibration of U-Pb ratios. Tin mineralization in Tasmania occurred between 391 ± 6.3 and 359 ± 7.8 Ma, which is coincident with most postorogenic granites of the Tabberabberan orogeny. In conjunction with the granite ages, cassiterite ages become younger from the east of the state to the west, and tin mineralization occurred over a protracted period spanning 32 m.y. Dating of several placer cassiterite samples produced unexpected results, such as the occurrence of 374 ± 4.7 Ma cassiterite on eastern King Island, an area known only to contain the 350 Ma Grassy granite, suggesting a distant provenance. Tasmanian cassiterite rarely shows evidence of Pb loss; however, some analyses are characterized by elevated Th and U, likely caused by microinclusions such as monazite, which may have a detrimental effect on cassiterite U-Pb dating. This study demonstrates the utility of cassiterite dating for understanding the origin of tin deposits in complex terrains with protracted periods of tin mineralization.

Improving penaeid-trawl efficiencies via ground gear with tickler chains

Penaeid trawls often have poor ecological efficiencies measured as unwanted bycatches (with high discard mortality) and <100% effectiveness for all penaeids interacting with the ground gear (with some escape mortality). This study investigated the utility of varying ground-chain size (8- vs 10-mm diameter (Ø) stainless-steel chain) and the present or absence of a tickler chain (4-mm Ø) for improving efficiencies an Australian fishery diurnally targeting school, Metapenaeus macleayi and eastern king prawns, Penaeus plebejus. There were no treatment effects on wing-end spread and therefore areas trawled. Irrespective of the tickler chain, increasing the ground-chain Ø reduced catches of total penaeids (by 14%) and jellyfish, Catostylus mosaicus (by 39%)—results speculatively attributed to variation in ground contact and/or a slightly higher footrope in trawls with the 10-mm Ø chain. By comparison, installing the tickler chain had no effect on eastern king prawns, but increased catches of school prawns (by 1.13×) and bycatches of blue swimmer crabs, Portunus armatus (1.52×; a species with a low discard mortality) and jellyfish (1.23×), while reducing bycatches of two species with high discard mortalities: southern herring, Herklotsichthys castelnaui (by 38%) and squid, Uroteuthis sp. (37%). The results were attributed to the tickler chain producing (1) mechanical stimuli that augmented the capture of benthic-orientated school prawns (but not eastern king prawns owing to diel variations in emergence from the substrata), blue swimmer crabs and jellyfish; and (2) visual stimuli that possibly enabled some southern herring and squid to detect the trawl and escape. The data show tickler chains can improve trawl efficiency for penaeids with at least some positive effects on bycatch that should be rationalised in terms of species-specific vulnerabilities to unaccounted fishing mortality.

Evaluation of adaptive spatial management in a multi-jurisdictional trawl fishery

Management of exploited resources that span multiple jurisdictions can be complex, with activities in one area potentially affecting productivity in another. Consequently, management decisions need to consider implications across the entire area in which the resource occurs. The study presents a unique study design that examines the impact of spatial management across two jurisdictions in an Australian penaeid multi-jurisdictional trawl fishery. Specifically, two areas relevant to Eastern King Prawn (Penaeus [Melicertus] plebejus; EKP, an important penaeid species harvested across eastern Australia) that are closed to trawling (on a permanent, and temporary basis) were evaluated using a combination of trawl and tag-recapture surveys. Over 1,250 EKP were tagged and released across the permanent and temporary trawl closure, and ∼15.4% of all tagged prawns were recaptured and reported by fishers in both New South Wales (33% of recaptures) and the adjacent jurisdiction of Queensland (67% of recaptures, up to 730 km from the point of tagging) during 7 months post-tagging. There were significant differences in prawn size and abundance across the permanent and temporary trawl closure areas with both depth and distance to the adjacent estuarine nursery explaining these patterns, but prawns generally exceeded the minimum size-at-first-capture estimated by relevant yield per recruit models before they left areas closed to trawling. While more prawns were captured in Queensland, recapture rates were far greater in New South Wales when standardised by relative effort. Patterns in these data highlight the broader considerations of spatial management in multi-jurisdictional fisheries.

Evidence for inter- and intraspecific trophic niche separation among deepwater elasmobranchs on the southern Great Barrier Reef, Australia

Quantifying the trophic structure and interactions of deepwater (&gt;200 m depth) elasmobranch assemblages is required to improve our understanding of deepwater ecosystems and the impacts of increased deepwater exploitation. To this end, we investigated the trophic ecology of deepwater elasmobranchs on the Great Barrier Reef (GBR) using a stable isotope (δ13C and δ15N) approach. Our study included 4 species captured in the southern GBR deepwater eastern king prawn trawl fishery: the eastern spotted gummy shark Mustelus walkeri, the piked spurdog Squalus megalops, the pale spotted catshark Asymbolus pallidus, and the Argus skate Dentiraja polyommata. The δ13C and δ15N values of all 4 species ranged from -18.6 to -16.2‰ and 8.3 to 13.8‰, respectively. The small δ13C range was likely due to the limited number of unique carbon baseline sources typically found in deepwater environments. Despite this, 3 of the 4 species exhibited relatively low core (40% SEAb) isotopic niche overlap (&lt;1 to 44%). Isotopic niche separation may be driven by multiple interacting factors including morphology, feeding strategies, or resource partitioning to reduce competition. Isotope analysis also provided evidence for intraspecific variation; S. megalops, D. polyommata and M. walkeri exhibited significant increases in δ15N (~3‰) and δ13C (~2‰) with size. Latitude, longitude, and depth had statistically significant but comparatively minor effects on isotope values (≤1‰) of the 4 species. Cumulatively, our results indicate that isotopic variation among deepwater elasmobranchs on the GBR is principally driven by size and species-level differences in resource use.

Stable isotopes reveal the importance of saltmarsh-derived nutrition for two exploited penaeid prawn species in a seagrass dominated system

Estuaries represent highly important nursery habitats for a range of species, with refuge and nutrition being two key benefits derived from estuaries. Quantifying these benefits provides us with a means for enhancing fisheries productivity. Metapenaeus macleayi (School Prawn) and Penaeus plebejus (Eastern King Prawn) are two commercially and recreationally important species in New South Wales that utilise estuarine nurseries throughout their life history. In this study, stable isotopes of carbon, nitrogen and sulfur were used to determine the proportional contribution of primary producers to prawn nutrition in Brisbane Water (NSW). Both the saltmarsh grass Sporobolus virginicus and seagrass Zostera muelleri were found to support a high trophic contribution to prawns (up to 53% and 40%, respectively). The contributions of other primary producers such as mangroves, fine benthic organic matter (FBOM) and C3 saltmarsh plants were generally found to be much lower (0.7–15%). Such findings are generally consistent with patterns observed in other south-east Australian estuaries, however such a dominant role of saltmarsh in the presence of seagrass is a novel finding. These results highlight linkages between habitats of conservation concern and highly valuable fisheries species, and the benefit of using sulfur as an additional marker in Bayesian mixing models examining estuarine food webs.

Scales of spatial and temporal variation of small bodied nekton within intermittently closed/open lakes and lagoons (ICOLLs) in south-eastern Australia

Intermittently open/closed lakes and lagoons (ICOLLs) are common in temperate regions of the southern hemisphere and are also found in parts Europe and North America. They are important nursery grounds for a variety of fish and crustacean species, and while they are regularly studied for a variety of purposes, dedicated analysis aimed at identifying levels of spatial and temporal variance, particularly for abundant smaller nekton are lacking. A hierarchical study was undertaken using cast nets, spanning four estuaries at multiple nested spatial and temporal scales to determine at which levels greater variation occurs. The four most common species including Glassfish (Ambassis jacksoniensis), Small-mouth Hardyhead (Atherinosoma microstoma), Eastern King Prawn (Penaeus plebejus) and Glass Shrimp (Macrobrachium intermedium) were considered separately. A consistent pattern emerged where high levels of spatial variance occurred among individual samples, while the least was generally observed among sites nested within estuaries. A similar pattern occurred when the nekton community was considered as a whole. However levels of residual variation were reduced by pooling individual casts into fewer replicates from each site, resulting most notably in an increase in the variation attributed to the Estuary scale. This produced a good balance in capturing both the small scale variation and broader patterns among estuaries. Temporal levels of variation were lower than the spatial observations for all four common species, as well as the community as a whole. However, greater variation was observed among seasons compared to months nested within seasons. These findings should provide guidance for future studies in ICOLLs where an efficient sampling program would focus on increased replicate samples within a site rather than sampling a large number of sites within a system and focus on seasonal variation.

Stable isotopes infer the value of Australia’s coastal vegetated ecosystems from fisheries

AbstractWild capture fisheries provide substantial input to the global economy through employment and revenue. The coastal zone is especially productive, accounting for just 7% of the total area of the ocean, but supporting an estimated 50% of the world's fisheries. Vegetated coastal ecosystems—seagrass meadows, tidal marshes and mangrove forests—are widely cited as providing nutritional input that underpin coastal fisheries production; however, quantitative evidence of this relationship is scarce. Using Australia as a case study, we synthesized fisheries stable isotope data to estimate nutritional input derived from coastal vegetated ecosystems and combined these “proportional contribution” estimates with total annual catch data from commercial fisheries to determine species‐specific dollar values for coastal vegetated ecosystems. Based on the data from 96 commercially important fish species across Australian states (total landings 14 × 106 tonnes pa), we provide a conservative estimate that Australia's coastal vegetated ecosystems contribute at least 78 million AUD per year to the fisheries economy. Two thirds of this contribution came from tidal marshes and seagrasses that were both equally valued at 31.5 million AUD per year (39.4%) followed by mangroves at 14.9 million AUD per year (18.6%). The highest dollar values of coastal ecosystems originated from eastern king prawn (Melicertus plebejus) and giant mud crab (Scylla serrata). This study demonstrates the substantial economic value supported by Australia's coastal vegetated ecosystems through commercial fisheries harvest. These estimates create further impetus to conserve and restore coastal wetlands and maintain their support of coastal fisheries into the future.

Impacts of habitat repair on a spatially complex fishery

Restoring juvenile habitat remains a key fisheries management action, but a persistent challenge is identifying the areas likely to most efficiently improve fishery outcomes. A spatial simulation model is presented that estimates the anticipated improvement in harvest of the Eastern King Prawn fishery in New South Wales, Australia, following potential restoration. By integrating environmental, biological and fisheries information gleaned from previous studies, this model suggests zones with ample larval settlement but greatly diminished habitat for juvenile life stages (recruitment), and that are in close proximity to the main fishery grounds, are likely to provide the greatest anticipated improvements in harvest. Uncertainty analyses demonstrated the particular sensitivity of these outcomes to assumptions of larval dispersal, and zone-specific recruitment at unfished conditions. The work emphasizes the utility of spatial models for restoration planning, but also the dependence of these models on information provided from empirical studies. This work also highlights the implications of input-controlled fisheries in which total effort is regulated, as this will determine the form of, and to whom, benefits of potential restoration actions will accrue.