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Anchor scour from shipping is increasingly recognised as a global threat to benthic marine biodiversity, yet no replicated ecological assessment exists for any seabed community. Without quantification of impacts to biota, there is substantial uncertainty for maritime stakeholders and managers of the marine estate on how these impacts can be managed or minimised. Our study focuses on a region in SE Australia with a high proportion of mesophotic reef (30 m), where ships anchor while waiting to enter nearby ports. Temperate mesophotic rocky reefs are unique, providing a platform for a diversity of biota, including sponges, ahermatypic corals and other sessile invertebrates. They are rich in biodiversity, provide essential food resources, habitat refugia and ecosystem services for a range of economically, as well as ecologically important taxa. We examined seven representative taxa from four phyla (porifera, cnidaria, bryozoan, hydrozoa) across anchored and 'anchor-free' sites to determine which biota and which of their morphologies were most at risk. Using stereo-imagery, we assessed the richness of animal forest biota, morphology, size, and relative abundance. Our analysis revealed striking impacts to animal forests exposed to anchoring with between three and four-fold declines in morphotype richness and relative abundance. Marked compositional shifts, relative to those reefs that were anchor-free, were also apparent. Six of the seven taxonomic groups, most notably sponge morphotypes, exhibited strong negative responses to anchoring, while one morphotype, soft bryozoans, showed no difference between treatments. Our findings confirm that anchoring on reefs leads to the substantial removal of biota, with marked reductions of biodiversity and requires urgent management. The exclusion of areas of high biological value from anchorages is an important first step towards ameliorating impacts and promoting the recovery of biodiversity.

For decades, precoated heat- and solvent-set tissues have been the preferred method for mending certain types of library and archival materials due to their translucency and ability to be used with...

Freshwater snails usually possess thin unadorned shells lacking structural components such as spines. Exceptions can be found on the high, well-watered islands of the South Pacific. Streams on these islands support a rich freshwater molluscan fauna with several nerite taxa (Neritimorpha: Neritidae) exhibiting extremely long dorsal spines. We sought to assess the defensive capacity of these structures for several co-occurring nerite genera on the Island of Ovalau, Fiji. Our overarching hypothesis was that spines confer a defensive advantage. We tested four predictions for eight common taxa: (i) predator “rich” habitats (the creek entrance) would be dominated by spine-bearing nerites, (ii) spine-bearing species should be smaller in size, (iii) nerites with spines would exhibit lower levels of shell damage and (iv) nerites with spines should invest less in their shells (i.e., their shells should be thinner). Most of these predictions received support. Spine-bearing species dominated the entrance to the creek and were smaller in size. Levels of shell damage were low overall, with 2 of the 3 spinose taxa exhibiting no shell damage, as did many of the nonspinose taxa. Finally, shells of spinose species were 25% thicker, demonstrating increased rather than decreased investment. Taken together, these findings suggest that the elaborate spines of Clithon spp. play a defensive role.

Marine reserves are an important management tool for conserving local biodiversity and protecting fragile ecosystems such as seagrass that provide significant ecological functions and services to people and the marine environment. With humans placing ever-growing pressure on seagrass habitats, marine reserves also provide an important reference from which changes to seagrass and their ecological assemblages may be assessed. After eight years of protection of seagrass beds (Posidonia australis) in no-take marine reserves (Sanctuary Zones) within the Jervis Bay Marine Park (New South Wales, Australia; zoned in 2002), we aimed to assess what changes may have occurred and assess continuing change through time in fish assemblages within these seagrass meadows. Using baited remote underwater videos (BRUVs), we sampled seagrass fish assemblages at three locations in no-take zones and five locations in fished zones three times from 2010 to 2013. Overall, we observed a total of 2615 individuals from 40 fish species drawn from 24 families. We detected no differences in total fish abundance, diversity, or assemblage composition between management zones, although we observed a significant increase in Haletta semifasciata, a locally targeted fish species, in no-take marine reserves compared with fished areas. Fish assemblages in seagrass varied greatly amongst times and locations. Several species varied in relative abundance greatly over months and years, whilst others had consistently greater relative abundances at specific locations. We discuss the potential utility of marine reserves covering seagrass habitats and the value of baseline data from which future changes to seagrass fish populations may be measured.

Whilst the composition and arrangement of habitats within landscape mosaics are known to be important determinants of biodiversity patterns, the influence of seascape patterning and connectivity on temperate reef fish assemblages remains largely unknown. We examined how habitat patterns at multiple spatial scales (100–1000 m) explained the abundance and diversity of temperate reef fish in a reef-seagrass dominated seascape. Fish assemblages were surveyed using remote underwater videos deployed on 22 reefs in Jervis Bay, NSW, Australia. Using full-subset GAMMs, we investigated if habitat area, edge, structural connectivity and a metric for habitat diversity (Shannon’s diversity index) of reef and seagrass can predict variations in a temperate reef fish assemblage. A key finding of the study was that temperate reefs close ( 6.25 ha) seagrass meadows contained greater abundance and diversity of fish. A consistent negative correlation was also found between reef area (> 0.01 ha) and the fish assemblage. The influence of seascape metrics on the abundance of fishes varied with functional traits (trophic groups, mobility and habitat associations). Fish-seascape relationships occurred at a range of spatial scales with no single scale being solely important for structuring the fish assemblage. We demonstrate that it is important not to view reef habitats in isolation, rather consider a reefs context to adjacent seagrass when predicting the distribution of temperate reef fish. This finding improves current understanding of the multi-scale factors structuring temperate reef fish assemblages and highlights the importance of reef-seagrass connectivty for the management of temperate marine ecosystems.

Non-indigenous invaders may play ecologically similar roles to native species, and this may be reflected in the abundance, richness and composition of associated species assemblages. We investigated whether associations of epifauna with their macroalgal hosts differed between the non-indigenous Codium fragile ssp. fragile and native, congeneric C. fragile on three rocky shores in southeast Australia. Of the 38 taxa we recorded, 13 were unique to the native Codium and four to non-indigenous individuals. Holdfasts of non-indigenous Codium had double the taxon richness of epifauna compared to native holdfasts, and epifaunal abundances showed a similar but non-significant difference. Patterns of abundance and richness of epifaunal taxa on thalli of native and non-indigenous Codium varied depending on whether these measures were expressed per individual alga, thallus area or number of branches. The composition of epifaunal assemblages between native and non-indigenous Codium were significantly different, but differences among rocky shores were as great as those between macroalgal species. On all shores, two taxa, the gastropod Alaba opiniosa and gammarid amphipods, contributed most to compositional differences between native and non-indigenous Codium , and their abundances were influenced by branch number and associated epiphyte load. Host choice experiments manipulating the complexity and subspecies of Codium revealed that amphipods were more strongly influenced by branch number adjusted for epiphyte load than the identity of Codium. Our results highlight the importance of habitat features, such as structural complexity and associated epiphyte load, in determining whether native and non-indigenous species provide functionally equivalent habitats for associated assemblages.

The global marine environment has been impacted significantly by climate change. Ocean temperatures are rising, and the frequency, duration and intensity of marine heatwaves are increasing, particularly affecting coral reefs. Coral bleaching events are becoming more common, with less recovery time between events. Anomalous temperatures at the start of 2020 caused widespread bleaching across the Great Barrier Reef (GBR), extending to southern, previously less affected reefs such as One Tree Island. Here, nine video transects were conducted at One Tree Island, in the Capricorn Bunker Group, and analysed for community composition and diversity, and the extent of bleaching across taxa. Average live hard coral cover across the area was 11.62%, and almost half of this was identified as severely bleached. This bleaching event is concerning as it occurred in an area previously considered a potential refuge for corals and associated fauna from the risks of climate warming. Due to the global impacts of COVID-19 during 2020, this report provides one of potentially few monitoring efforts of coral bleaching. Supplementary information The online version contains supplementary material available at 10.1007/s10661-021-09330-5.

Conflict between humans and large predators is a longstanding challenge that can present negative consequences for humans and wildlife. Sharks have a global distribution and are considered to pose a potential threat to humans; concurrently many shark species are themselves threatened. Developing strategies for coexistence between humans and this keystone group is imperative. We assess blimp surveillance as a technique to simply and effectively reduce shark encounters at ocean beaches and determine the social acceptance of this technique as compared to an established mitigation strategy—shark meshing. We demonstrate the suitability of blimps for risk mitigation, with detection probabilities of shark analogues by professional lifeguards of 0.93 in ideal swimming conditions. Social surveys indicate strong social acceptance of blimps and preference for non-lethal shark mitigation. We show that continuous aerial surveillance can provide a measurable reduction in risk from sharks, improving beach safety and facilitating coexistence between people and wildlife.

We thank Marie-Claire Demers, Rhiannon Kiggins, Mark Fackerell and Simon Rees for assistance with fieldwork. We acknowledge support from JBMP and Booderee National Park staff. We thank Geoff Hurt for assistance and construction of the BRUV units. We thank the 3 anonymous reviewers for their constructive comments. We also thank the Ecological Society of Australia and The Nature Conservancy, Australia, for project support.

Seagrass habitats worldwide are degrading and becoming fragmented, threatening the important ecosystem services they provide. Fauna associated with seagrasses, particularly cryptic species, are expected to respond to these changes, but are difficult to detect at ecologically meaningful scales using non-extractive techniques. We used a small, wide-angle camera (GoPro) and a small quantity of bait positioned within the canopy of Posidonia australis meadows in Jervis Bay, New South Wales to assess the response of fishes to seagrass cover. We saw a clear positive relationship with the condition of P. australis; a high cover of this seagrass had positive effects on the diversity and abundance of cryptic fauna. Our findings highlight ecosystem shifts associated with the loss and fragmentation of biogenic habitat. These changes are of particular relevance for P. australis meadows given their current status as an endangered ecological community in several locations in NSW and their slow rate of recovery from disturbance.

Este artículo contiene 8 páginas, 6 figuras., Sessile organisms are reliant on the use of refugia or chemical and physical defences to avoid or reduce attacks from predators. Many solitary ascidians possess a thick leathery outer tunic, sometimes reinforced with inorganic inclusions, that generally acts to deter predators. The genus Herdmania is remarkable among ascidians in possessing an abundance of barbed needle-like calcareous spicules in both the external tunic and the internal mantle. Our focus was on a habitat-forming subtidal ascidian – Herdmania grandis. We questioned why a large ascidian possessing a leathery test would possess spicules within the mantle – an apparent defence within a defence. We first quantified variation in spicule size and density within animals. Second, we examined the size and density of spicules for individuals of a range of sizes. Third, we incorporated these spicules at natural concentrations into feeding discs and tested their ability to deter gastropod predators that specialise in consuming ascidians and an asteroid that is considered a generalist consumer. Finally, we examined survivorship of lab-reared ascidian recruits when exposed to the starfish predator. Spicules constituted up to 30% dry weight (DW) of the tunic and an astounding 57% DW of the body wall (mantle). Spicules were significantly smaller in the contractile regions of the animal (the siphon and branchial basket) and were also found in lower densities, though not significantly. Mantle spicules were effective feeding deterrents; control feeding discs, lacking spicules, were consumed at three times the rate of discs with spicules (p < 0.05) by specialist ascidian predators, the Ranellid gastropods Cabestana spengleri and Ranella australasia. In contrast, we did not detect a significant difference in the consumption of feeding discs by the seastar Meridiastra calcar. In addition, the seastar reduced survivorship of 90 day old lab-reared recruits by four-fold. We contend that the primary defence mechanism of this ascidian is the leathery test and that this is effective against generalist consumers. The second line of defence – spicules in the mantle –is to thwart gastropod predators that bypass the tunic either by boring through it or by inserting their proboscis directly into soft tissues of their prey via the siphons. The presence of both a leathery tunic and spicules in H. grandis probably contributes to the dominance of this species on shallow subtidal reefs in southeastern Australia, where it is an important habitat-forming species. Our findings confirm the importance of considering a range of consumer strategies and life history stages in assessing potential control of engineering species by predation., We acknowledge financial support from the Centre for Sustainable Ecosystem Solutions, University of Wollongong. This work was completed while XT undertook sabbatical leave in Australia. Funding was provided by project CTM 2017-88080 from the Spanish Government. This represents contribution no. 318 from the Ecology and Genetics Group at UOW.

Seascape variability may confound assessments on the effectiveness of no-take marine reserves (NTMRs) in conserving biodiversity. In most cases baseline data are lacking, resulting in evaluations of NTMR effectiveness being Control Impact (CI) assessments. Even with independent replicate areas among management zones, this approach can make it difficult to detect zone effects if seascape attributes, such as habitat structural complexity varies among experimental areas. To determine the importance of structural complexity in evaluations of NTMR effectiveness we performed assessments on the abundance of a targeted fish, yellowtail kingfish (Seriola lalandi), in the Lord Howe Island Marine Park (LHIMP). We compared assessments which did and did not account for structural complexity, quantified using high resolution multibeam bathymetry. Despite almost 3 times more S. lalandi in NTMRs, the traditional CI assessment explained only 3% of the variation in the abundance of S. lalandi and revealed no clear effect of protection. Incorporating structural complexity into the assessment increased the deviance explained to 65% and uncovered an important interaction between zone and structural complexity. Greater abundances of S. lalandi were detected in NTMRs compared to fished zones but only on highly complex reefs. By accounting for structural complexity, we demonstrate that the precision and accuracy of NTMR assessments can be improved, leading to a better understanding of ecological change in response to this conservation strategy. Consequently, where marine park zones vary greatly in structural complexity, we strongly advocate for quantifying and accounting for such variability in assessments of NTMR performance.

Remote oceanic islands often display high levels of biodiversity and endemism, making them important locations for marine parks aimed at conserving biodiversity. To determine whether marine parks are reaching conservation objectives requires consistent assessments of their effectiveness through time. Lord Howe Island and Balls Pyramid are World Heritage listed remote oceanic islands in the Tasman Sea that support a diverse assemblage of fishes including many endemic and protected species. To conserve the region’s unique marine biodiversity, state and Commonwealth marine parks including no-take zones and partially protected zones open to line fishing were established. After approximately 5, 9 and 13 years of protection of shelf habitat we tested for changes in the marine park’s fish assemblage across management zones through time using baited remote underwater video systems (BRUVs). We detected no difference in total fish abundance, diversity, or assemblage composition between management zone types. The relative abundance of targeted carangids, yellowtail kingfish and silver trevally were 2 and 1.6 times greater in no-take zones than partially protected zones respectively, however, the substantial variation in their abundances among locations and sites meant that these differences were not statistically significant. No clear difference in the relative abundance of endemic, near-endemic and protected species were observed between management zone types. Generally, the abundance and diversity of fishes varied most among locations, sites and sampling years. The overall lack of difference in the fish assemblage between management zone types and its stability through time suggests current anthropogenic threats are relatively minor, and the marine park’s condition is reasonably healthy. Future surveys of the marine park’s fish assemblage will be valuable to test for body-size differences between zone types and to monitor trends in condition, particularly in response to possible changes in the number, frequency and intensity of anthropogenic threats.

Purpose To evaluate a region of interest (ROI) method of analyzing anterior segment optical coherence tomography (AS-OCT) corneal densitometry (CD) in the setting of Descemet membrane endothelial keratoplasty (DMEK) dehiscence. Methods Retrospective chart review of eyes that underwent (1) DMEK for Fuchs dystrophy (2) between 2018 to 2020 with (3) a partial DMEK dehiscence on AS-OCT, (4) involvement of only one side of the graft, (5) high-quality corneal AS-OCT scan, and (6) location of dehiscence within the central 5.5 mm of the cornea. Image analysis of the ROIs with ImageJ compared the total edematous area, mean stromal CD, and ratio of anterior-to-posterior (A/P) stromal CD for regions of DMEK dehiscence compared to the contralateral side with an attached DMEK graft. Control regions (with no dehiscence) and postdehiscence resolution images were also analyzed. Results Seventy sectors of the 21 images from 21 eyes with DMEK dehiscence were included. Compared to the contralateral side, regions of DMEK dehiscence had larger total areas (P < 0.0001), lower mean stromal CD (P = 0.0003), and higher A/P stromal CD (P < 0.0001). All control regions and postdehiscence resolution images did not show any significant differences compared to the contralateral sides. Conclusions This technique to analyze multiple ROIs on AS-OCT can be useful to evaluate CD of specific regions of corneal pathology. Lower mean stromal CD and higher A/P stromal CD may specify corneal edema. Translational Relevance Analyzing CD via multiple specific ROIs may be more suitable than measuring the CD of the full cornea and has broader applications extending to other corneal pathologies.

The development of environmental guidelines in the Antarctic and subantarctic is essential, because expansion of research, tourism, and fishing is placing these regions at increasing risk of contamination. Data are currently insufficient to create the region-specific guidelines needed for the unique conditions in these areas. To develop the most appropriate environmental guidelines, data from the most sensitive life stages of a species should be included to ensure effective protection throughout its life cycle. It is generally accepted that early life stages are more sensitive to contaminants. We compared the toxicity of copper between juvenile and adult life stages of 4 subantarctic marine invertebrates using sublethal and lethal endpoints. For 2 of the species tested, juveniles were more sensitive than adults. (The 7-d median effect concentration [EC50] values for the gastropod Laevilittorina caliginosa were 79 μg/L at the juvenile stage and 125 μg/L at the adult; for the flatworm Obrimoposthia ohlini, values were 190 μg/L at the juvenile stage and 300 μg/L at the adult.) For the isopod Limnoria stephenseni, juveniles were either more sensitive or of equal sensitivity to adults (7-d EC50 values: juvenile 278 μg/L and adult 320 μg/L). In contrast, for the bivalve Gaimardia trapesina, adults appeared to be more sensitive than young adults (7-d EC50 values: juvenile 23 μg/L and adult

Dredging can have significant impacts on benthic marine organisms through mechanisms such as sedimentation and reduction in light availability as a result of increased suspension of sediments. Phototrophic marine organisms and those with limited mobility are particularly at risk from the effects of dredging. The potential impacts of dredging on benthic species depend on biological processes including feeding mechanism, mobility, life history characteristics (LHCs), stage of development and environmental conditions. Environmental windows (EWs) are a management technique in which dredging activities are permitted during specific periods throughout the year; avoiding periods of increased vulnerability for particular organisms in specific locations. In this review we identify these critical ecological processes for temperate and tropical marine benthic organisms; and examine if EWs could be used to mitigate dredging impacts using Western Australia (WA) as a case study. We examined LHCs for a range of marine taxa and identified, where possible, their vulnerability to dredging. Large gaps in knowledge exist for the timing of LHCs for major species of marine invertebrates, seagrasses and macroalgae, increasing uncertainty around their vulnerability to an increase in suspended sediments or light attenuation. We conclude that there is currently insufficient scientific basis to justify the adoption of generic EWs for dredging operations in WA for any group of organisms other than corals and possibly for temperate seagrasses. This is due to; 1) the temporal and spatial variation in the timing of known critical life history stages of different species; and 2) our current level of knowledge and understanding of the critical life history stages and characteristics for most taxa and for most areas being largely inadequate to justify any meaningful EW selection. As such, we suggest that EWs are only considered on a case-by-case basis to protect ecologically or economically important species for which sufficient location-specific information is available, with consideration of probable exposures associated with a given mode of dredging.

Investigating the impacts of contamination on high latitude ecosystems includes determining the sensitivity of key taxa to contaminants. Unique characteristics, arising from adaption to cold and stable temperatures has likely resulted in marine biota at the poles being particularly sensitive to contamination in comparison to related species at lower latitudes. We aimed to determine the sensitivity of three species of common and ecologically important subantarctic gastropods to copper. This is the first study to investigate the sensitivity of subantarctic marine gastropods to contamination. We determined sensitivity by exposing each species to a range of copper concentrations by establishing mortality and sublethal endpoints. Sensitivity to copper was highly species specific. Laevilittorina caliginosa was relatively tolerant, with no response at Cu concentrations up to 1488 µg/L following 7 d of exposure, while two species (Cantharidus capillaceus coruscans and Macquariella hamiltoni) were highly sensitive with 7 d Cu LC50 estimates of 33 µg/L and 78 µg/L respectively. In a global comparison of gastropod sensitivity data, these two species were highly sensitive to copper, highlighting the vulnerability of polar ecosystems to contamination.

While aerial shark spotting has been a standard practice for beach safety for decades, new technologies offer enhanced opportunities, ranging from drones/unmanned aerial vehicles (UAVs) that provide new viewing capabilities, to new apps that provide beachgoers with up-to-date risk analysis before entering the water. This report describes the Sharkeye platform, a first-of-its-kind project to demonstrate personal shark alerting for beachgoers in the water and on land, leveraging innovative UAV image collection, cloud-hosted machine learning detection algorithms, and reporting via smart wearables. To execute, our team developed a novel detection algorithm trained via machine learning based on aerial footage of real sharks and rays collected at local beaches, hosted and deployed the algorithm in the cloud, and integrated push alerts to beachgoers in the water via a shark app to run on smartwatches. The project was successfully trialed in the field in Kiama, Australia, with over 350 detection events recorded, followed by the alerting of multiple smartwatches simultaneously both on land and in the water, and with analysis capable of detecting shark analogues, rays, and surfers in average beach conditions, and all based on ~1 h of training data in total. Additional demonstrations showed potential of the system to enable lifeguard-swimmer communication, and the ability to create a network on demand to enable the platform. Our system was developed to provide swimmers and surfers with immediate information via smart apps, empowering lifeguards/lifesavers and beachgoers to prevent unwanted encounters with wildlife before it happens.

The direct impacts of fishing on chondrichthyans (sharks, rays and chimeras) are well established. Here we review a largely unreported, often misinterpreted and poorly understood indirect impact of fishing on these animals — capture-induced parturition (either premature birth or abortion). Although direct mortality of discarded sharks and rays has been estimated, the prevalence of abortion/premature birth and subsequent generational mortality remains largely unstudied. We synthesize a diffuse body of literature to reveal that a conservative estimate of > 12% of live bearing elasmobranchs (n = 88 species) show capture-induced parturition. For those species with adequate data, we estimate capture-induced parturition events ranging from 2 to 85% of pregnant females (average 24%). To date, capture-induced parturition has only been observed in live-bearing species. We compile data on threat-levels, method of capture, reproductive mode and gestation extent of premature/aborted embryos. We also utilise social media to identify 41 social-media links depicting a capture-induced parturition event which provide supplementary visual evidence for the phenomenon. The mortality of embryos will have implications for elasmobranch populations, and there are limited options to deal with this problem. This review is the first to synthesize available data on capture-induced parturition in sharks and rays, and highlights an important ethical and management issue for fishers and managers deserving of much greater attention.

Stressors associated with climate change and contaminants, resulting from the activities of humans, are affecting organisms and ecosystems globally. Previous studies suggest that the unique characteristics of polar biota, such as slower metabolisms and growth, and the generally stable conditions in their natural environment, cause higher susceptibility to contamination and climate change than those in temperate and tropical areas. We investigated the effects of increased temperature and decreased salinity on copper toxicity in four subantarctic marine invertebrates using realistic projected conditions under a future climatic change scenario for this region. We hypothesised that these relatively subtle shifts in environmental stressors would impact the sensitivity of cold-adapted species to copper. The four test species were: a copepod Harpacticus sp.; isopod Limnoria stephenseni; flatworm Obrimoposthia ohlini; and bivalve Gaimardia trapesina. These species occupy a range of ecological niches, spanning intertidal and subtidal nearshore zones. We predicted that species would differ in their tolerance to stressors, depending on where they occurred within this ecological gradient. Organisms were exposed to the multiple stressors in a factorial design in laboratory based toxicity tests. Sensitivity estimates for copper (LC50) were calculated using a novel statistical approach which directly assessed the impacts of the multiple stressors. In three of the four species tested, sensitivity to copper was amplified by small increases in temperature (2-4 °C). The effects of salinity were more variable but a decrease of as little as 2 ppt caused a significant effect in one species. This study provides some of the first evidence that high latitude species may be at increased risk from contaminants under projected future climate conditions. This interaction, between contaminants and the abiotic environment, highlights a potential pathway to biodiversity loss under a changing climate.

Mid-water baited remote underwater video systems (BRUVS) are becoming an increasingly popular tool for examining pelagic fish assemblages in a non-destructive, fisheries independent manner. As the technique is relatively novel, critical methodological questions such as the most appropriate attractant for pelagic fish to mid-water RUVS remain unresolved. In this study, we compared the relative effectiveness of 4 attractant treatments (sight: metallic reflectors, sound: bait fish recordings, scent: pilchards and their combination) on the time of first arrival, total abundance of pelagic fish and the relative abundance of 3 pelagic fish species: Trachurus novaezelandiae, Sarda australis and Seriola lalandi. Recordings were made using mid-water RUVS in the Jervis Bay Marine Park, Australia. RUVS using a combination of all attractants recorded the highest abundances and shortest time of first arrival of pelagic fish. This result was primarily driven by Trachurus novaezelandiae. Although not significant, the abundance of Sarda australis was also greatest on the RUVS with all attractants. In contrast, the type of attractant had no effect on the abundance of Seriola lalandi. Bait, the standard attractant used in BRUVS surveys, was a poor performer for pelagic fish in all instances. We suggest that future studies using this sampling method employ multiple attractants. Disciplines Medicine and Health Sciences | Social and Behavioral Sciences Publication Details Rees, M. J., Knott, N. A., Fenech, G. V. & Davis, A. R. (2015). Rules of attraction: enticing pelagic fish to midwater remote underwater video systems (RUVS). Marine Ecology: Progress Series, 529 213-218. This journal article is available at Research Online: http://ro.uow.edu.au/smhpapers/3002

Este artículo contiene 8 páginas, 2 tablas, 7 figuras., The distribution of intertidal organisms can depend on processes operating early in their life history. The ascidian Pyura praeputialis, a mid- to low-intertidal habitat-forming ecosystem engineer, was strongly associated with specific types of habitat (biogenic vs. bare rock). We examined field patterns and performed laboratory and field experiments to assess the nature of this association. Recruits were frequently found on the tunics of conspecifics and clumps of turfing coralline algae. Larvae preferred these same habitats in a series of laboratory settlement assays. Laboratory-reared juveniles (20- & 50-days-old) survived poorly on bare rock in the laboratory, while those on rugose surfaces - the tunic of adults and turfing corallines - showed high survivorship. Fieldcollected juveniles (< 2 cm) affixed to these rugose habitats also exhibited high survivorship in the field. We conclude that both pre and post-settlement processes determine spatial pattern in this important habitat-forming taxon. The acute sensitivity of juveniles to desiccating conditions was unexpected in an intertidal organism., We acknowledge financial support from the Centre for Sustainable Ecosystem Solutions, University of Wollongong and from project CTM2017-88080 (AEI, FEDER-UE) from the Spanish Government.

Unmanned aerial systems (UAS) have the potential to collect high-resolution photographs of marine mammals for life-history studies without disturbing the species being studied. We conducted a pilot study near Igloolik, Nunavut, in early July 2013 to col- lect identification-quality photographs of bowhead whales and record the responses of the whales to overflights by an UAS. Operating under a restrictive line-of-sight permit from Transport Canada, we successfully collected high quality photographs of bowhead whales and none of the whales overflown responded to the overflights in an observable manner. If the UAS were operated under a beyond-line-of-sight permit, the UAS could be used to search for whales ahead of and to the side of the survey vessels making it more efficient to find whales to photograph. Even when operating under the restrictive line-of-sight permit, large numbers of whales could be photographed, which would provide important life-history information on the poorly studied Eastern Canada - West Greenland population. Resume : Les systemes aeriens sans pilote (UAS) peuvent recueillir des photographies de haute resolution de mammiferes marins, aux fins d'etudes sur les cycles biologiques, sans pour autant deranger les especes a l'etude. On a mene une etude pilote pres d'Igloolik, au Nunavut, au debut de juillet 2013 pour recueillir des photographies d'une qualite permet- tant l'identification des baleines boreales et pour consigner les reactions des baleines a des survols d'un UAS. Utilisant un UAS en vertu d'un permis de visibilite directe restrictive de Transport Canada, on a recueilli des photographies de haute qualite de baleines boreales, et aucune des baleines que l'UAS a survolees n'y a reagi de maniere observable. Si l'UAS etait utilise en vertu d'un permis au-dela de la visibilite directe, celui-ci pourrait servir a chercher les baleines en avant et a cote des navires hydrographiques, ce qui rendrait la tâche de reperer des baleines a photographier plus efficace. Meme en utilisant un UAS en vertu d'un permis de visibilite directe restrictive, il serait possible de photographier un grand nombre de baleines, ce qui apporterait des informations importantes sur le cycle biologique de la population de l'Est du Canada et de l'Ouest du Groenland, population peu etudiee. Mots-cles : baleines boreales, derangement, identification photographique, systeme aerien sans pilote, visibilite directe.

The importance of 'top-down' regulation of assemblages by predators is well doc- umented at a variety of spatial and temporal scales on rocky-shores. Predators have consump- tive and non-consumptive impacts on their prey; however, much remains to be discovered about how climate change may affect predator-prey interactions and processes related to these interactions. We investigated the effect of predicted near-future ocean acidification on a molluscan defence mechanism: shell repair. We simulated non-consumptive damage by a durophagous (shell crushing) predator to 2 common intertidal gastropod species: Austrocochlea porcata and Subninella undulata. Our data show a stark contrast in the response of these 2 gastropods to simulated ocean acidification; A. porcata exhibited a depressed shell repair rate, compromised shell integrity and reduced condition. These 3 critical attributes for survival and protection against predators were all severely affected by ocean acidification. In contrast S. undulata was unaffected by ocean acidification. These results suggest that if atmospheric CO2 levels continue to rise, and ocean pH subsequently drops, then less resistant species such as A. porcata may face increased predation pressure and competition from more successful taxa within the same community. This could affect predator-prey relationships, with the potential to cascade through intertidal communities.

Aim To examine the potential of remotely sensed abiotic measures as surrogates for the abundance, diversity and community composition of temperate rocky reef fishes and sessile invertebrates.

Aim Estuaries are common focal points for industry and development, but often little is known of their biology or ecology, particularly for sessile taxa. We sought to examine how size and opening regime of shallow saline coastal lakes altered patterns of diversity and abundance for a suite of epifaunal invertebrates. We also sought to determine how these patterns were affected by the degree of lake modification by humans. Location We sampled 10 coastal barrier lakes of a range of sizes, opening regimes and degrees of modification in south-eastern Australia. Methods We quantified the diversity and abundance of sponges and ascidians in transects and undertook timed searches for these fauna at multiple locations within each coastal lake; placing the data in a hypothesis testing framework. Results Eighteen species of sponge, most of which appear to be new to science, and six species of ascidian were found among the 10 lakes we examined. All sponges and most ascidians were extremely patchily distributed among the lakes. Few species were widespread, with most restricted to one or two lakes. Diversity was largest in lakes mostly open to the sea and large in size. Diversity and abundance were smaller in highly modified lakes. Main Conclusions We suggest that sponge assemblages in these lakes consist of a combination of species largely restricted in distribution to lakes, and marine species that are at their limits of distribution. In contrast, ascidian assemblages were dominated by species that were more widespread. Conservation of biodiversity in these systems will rely heavily on effective management, which will in turn rely on a sound scientific understanding of natural processes; this will require the management of water quality through protection of catchments. The control of opening regimes should consider the ecological consequences rather than being purely based on ad hoc and reactive management.

Large predatory fish that alter the behaviour of smaller species may affect visual estimates of abundance by making organisms more or less difficult to observe and quantify. To evaluate the non-consumptive influence of large predators on rocky reef fishes observed with Baited Remote Underwater Video (BRUV), we tested the hypothesis that fish assemblages monitored when large (ca 1.5 m) piscivorous sharks, Mustelus antarcticus, were present differ from those observed when sharks were absent. We did this in two ways using recordings from rocky reefs in Batemans Marine Park, NSW, Australia. First, we examined 6 min of each 30 min tape; 3 min when sharks were present and 3 min when they were absent, in a paired sample design from 17 sites. Second, we compared fish assemblages for complete tapes (30 min) at sites with sharks present compared to sites where they were absent. The diversity and total abundance of fishes was consistently lower in the presence of sharks; we detected significant assemblage-wide change (PERMANOVA, P

Baited remote underwater video stations (BRUVS) are increasingly being used to examine assemblages of fishes, yet critical methodological questions related to sampling limitations and bias, such as the influence of bait type, remain poorly understood. At multiple locations, we examined the hypothesis that diversity and abundance in temperate reef fish assemblages were independent of bait type. We used 3 bait types (abalone viscera, pilchards and crushed urchin) and quantified commonly used metrics for the fish assemblage, including species richness, time of first arrival and relative abundance on 3 shallow rocky reefs in southeastern Australia over 2 yr. We distinguished the following 6 feeding guilds: herbivore, zooplanktivore, alga/ invertebrate consumers, invertebrate carnivore, macroinvertebrate carnivore and generalist carnivore. The response of fishes was dependent on bait type, with urchin bait performing particularly poorly. Although we did not detect statistical differences between the performance of pilchards and abalone viscera as bait, pilchards produced more consistent outcomes. Importantly, we also observed strong spatial effects. In general, bait type had a marked effect on species richness, but little influence on relative abundance. Overall we conclude that oily bait such as pilchards, which have been widely used in most studies, yield the most consistent outcomes. Consequently, bait type and spatial variation in fish assemblages needs to be considered in sampling designs to assess the limitations of BRUVS.

In the book of Ruth there are numerous instances of disagreement in gender between a pronoun and its antecedent. Without discounting the various philo logical explanations that have been given for this disagreement, this article argues that the gender discord is also a literary device that makes an important contribution to the book's narrative design and its development of characters. The laconic style of Hebrew narrative usually offers no glimpse of characters' inner lives, but by recognizing the concentration of discordant forms in Naomi's speech, we can appreciate how they characterize her grief and her ambivalence toward Ruth. The discord also highlights the theme of gender reversal in the book of Ruth. However the examples of gender discord might be explained grammatically, they also play an integral role in the characterization of Naomi and her relationship with Ruth. Disagreement in gender between a pronoun and its antecedent is common enough in Biblical Hebrew that it has been treated in the fields major reference grammars. Most often, the gender discord consists of a masculine pronoun stand ing for a feminine noun, and the grammars agree that this replacement is related to "a weakening in the distinction of gender" by which the feminine plural suffix was subsumed under its masculine counterpart.1 Furthermore, such disagreement has been regarded as a late phenomenon that is especially prevalent in the later books of the Hebrew Bible and also in the Dead Sea Scrolls.2

It is generally considered that on relatively homogenous marine soft sediment habitats, such as sand, fish are unlikely to show site attachment. This poses challenges for management and the evaluation of the efficacy of marine protected areas, in which soft sediments often make up more than 70 % of habitats. The blue-spotted flathead is a commercially and recreationally targeted species found on soft sediments in coastal marine waters of south-eastern Australia. There are no published data on its movement patterns. Here, using active acoustic telemetry, we aim to (a) quantify movement and habitat use of blue-spotted flathead, (b) compare area usage to no-take sanctuary zone size and (c) obtain data to aid in the design of a large passive receiver array to be used in long-term comprehensive tracking of soft sediment fish. Three of five blue-spotted flathead that were tagged exhibited strong site attachment and were detected close to their release points for the entire 60-day study period. The two other fish were not detected after 4 and 25 days and were likely to have moved out of the study area (search radius ≈ 3 km). For the three fish tracked over 60 days, the area used was compact (mean ± SE = 0.021 km2 ± 0.037) and two patterns of movement were apparent: (1) a small activity space used in its entirety each day (two fish) and (2) a larger activity space in which a separate area is utilised each day (one fish). Our study is the first to document the movement of blue-spotted flathead, and these preliminary results demonstrate two broad movement patterns shown by this species on soft sediments in Jervis Bay. Over the course of 60 days, a majority of fish in this study showed strong site attachment; however, a number of fish also made larger-scale movements. Finally, our study suggests that a tightly spaced, passive acoustic array would provide meaningful results for this species, although strategically placed receivers outside this array would be required to detect any longer range movements.

The pervasive effects of invasive ecosystem engineers, that is those species that modify their environment, are well documented, but rarely have the broader impacts of one foundation invertebrate species being replaced by another been examined. In New Zealand, green‐lipped mussels, Perna canaliculus, commonly dominate wave‐exposed rocky shores. The recent appearance of an invasive ecosystem engineer, the ascidian Pyura doppelgangera, at the very northern tip of New Zealand now threatens to exclude these bivalves from this habitat. Here, we report major shifts in assemblages associated with the invader and chronicle its continued spread. We examined epibiota associated with clumps of mussels and clumps of Pyura from two rocky shore habitats—pools and emergent substrata at two locations. We detected some differences in species richness in biota associated with the two foundation species, but faunal abundance only differed between the locations. These minor changes were dwarfed by the shift in species composition within clumps of each foundation species. Molluscs, particularly gastropods, and crustaceans dominated the assemblage within mussels. In contrast, tubicolous polychaetes dominated the fauna associated with the ascidian. Sessile epifauna, notably barnacles and calcareous tube‐dwelling polychaetes, were common on mussels, but never encountered on the ascidian. Multivariate analysis revealed marked dissimilarity (>80%) between the characteristic mussel and ascidian faunas with virtually no overlap. This biotic shift overshadowed any differences between habitats and locations. The broader implications of these faunal shifts for local and regional patterns of biodiversity, as well as ecosystem function, remain unclear, but deserve further attention.

Shark repulsion devices (SRDs; e.g. Shark Shield™) use an electric field to deter large and potentially dangerous sharks. The use of these devices is becoming increasingly widespread for a range of recreational activities as well as scientific and commercial diving. We sought to determine if SRDs might modify the behaviour of chondrichthyan and osteichthyan fishes and thereby impact on fish assemblages, as well as potentially bias diver census techniques. To assess the potential impacts of this technology, we attached SRDs to baited remote underwater video (BRUV) units and deployed them on shallow rocky reefs in Jervis Bay Marine Park (New South Wales, Australia). We did not detect any impacts of the SRD on the diversity or relative abundance of shallow-reef fishes. In addi- tion, approach of fishes to the bait did not differ whether the SRDs were on or off. At the smallest spa- tial scale we investigated, contact with the bait was half as frequent when the SRD was switched on compared to when it was off. Surprisingly, even the cartilaginous species were apparently unaffected by the SRD, with the eastern fiddler ray Trygonorrhina fasciata making contact with the bait several times when SRDs were activated. We contend that the ecological impacts of SRDs at all but the small- est scales are minimal and they are unlikely to introduce bias in assessments of fish assemblages, at least for non-cartilaginous and small cartilaginous species.

Some sessile invertebrates are capable of maintaining space in barren habitats pro- duced by sea urchins, thereby creating species-rich patches in a species-poor landscape. We sought to determine the role of a large and common barnacle, Austrobalanus imperator, in the establishment and persistence of these species-rich patches. Barnacle density was modified in 2 experiments at sites in southeastern Australia. The first experiment concerned community establishment and involved the addition of barnacles in 4 densities (zero (control), low, medium and high) to plots on vertical rock surfaces. The addition of barnacles at ecologically realistic densities and spatial arrangements rapidly resulted in statistically significant increases in invertebrate cover and diversity. After 56 mo, the diversity of invertebrates was significantly higher on plots that received high densities of barna- cles relative to controls. However, invertebrate cover no longer differed between treatment plots, despite evidence that barnacles modify the grazing intensity of sea urchins. The second experi- ment assessed the persistence of sessile invertebrates following the removal of barnacles from well- established assemblages dominated by sponges. The removal of barnacles did not hinder the rapid recovery of sponges to pre-manipulation levels, indicating that barnacles played an inconsequential role in well-established assemblages. We conclude that barnacles play an important functional role in this system, as they promote the recruitment of sessile invertebrates. It was also clear that the de- velopment of invertebrate assemblages on natural vertical surfaces was very slow, which raises the question of whether we are examining these important occupiers of space at appropriate temporal and spatial scales.

Caulerpa taxifolia is a habitat-forming green alga that has invaded several temperate regions worldwide. Although C. taxifolia covers large areas of soft-sediment habitat, little is known about its effects on soft-sediment invertebrate assemblages. We compared soft-sediment macroinvertebrate assemblages in 2 estuaries in southeastern Australia invaded by C. taxifolia to examine 2 main predictions: (1) areas covered with C. taxifolia will have different assemblages compared to unvegetated sediment because infauna are inhibited but epifauna are facilitated, and (2) areas with C. taxifolia will have different assemblages compared to those with native seagrasses (Halophila ovalis and Zostera capricorni) because infauna are inhibited but epifauna are not. Multidimensional scaling and ANOSIM showed differences in invertebrate assemblages between all habitats. In C. taxifolia, infauna were less abundant and epifauna were more abundant compared to unvegetated sediment. However, when compared to native seagrasses, epifauna in C. taxifolia were more abundant than in H. ovalis in one estuary but less abundant than in Z. capricorni in another estuary, while infauna in C. taxifolia were less abundant than in both seagrass species. The consistently low infaunal abundance in C. taxifolia, irrespective of infaunal feeding mode, suggests C. taxifolia impacts infauna generally. Examination of environmental factors potentially responsible for the low abundance of infauna indicated that differences in redox potential (and associated chemical changes) may explain patterns in abundance of infauna among habitats. Our findings indicate that invasion by C. taxifolia causes important changes to soft-sediment macroinvertebrate assemblages and suggest that infauna may be particularly vulnerable to invasion because of changes to sediment chemistry. © Inter-Research 2009.