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A STEM-based faculty in an Australian university leveraged online educational technology to help address student and academic concerns associated with team-based assessment. When engagement and contribution of all team members cannot be assured, team-based assessment can become an unfair and inaccurate measure of student competency. This case study explores the design and capacity of an online self and intra-team peer-assessment of teamwork strategy to measure student engagement and enable peers to hold each other accountable during team-based assessments. Analysis of student interactions across 39 subjects that implemented the strategy in 2020, revealed that an average of 94.4% of students completed the self and intra-team peer-assessment task when designed as part of a summative team-based assessment. The analysis also revealed that an average of 10.3% of students were held accountable by their peers, receiving feedback indicating their teamwork skills and behaviours were below the required minimum standard. Furthermore, the strategy was successfully implemented in cohorts ranging from seven to over 700 students, demonstrating scalability. Thus, this online self and intra-team peer-assessment strategy provided teaching teams with evidence of student engagement in a team-based assessment while also enabling students to hold each other accountable for contributing to the team task. Lastly, as the online strategy pairs with any discipline-specific team-based assessment, it provided the faculty with a method that could be used consistently across its schools to support management and engagement in team-based assessments.

Marine science picture books have the capacity to shape what young people know and how they think about ocean environments and marine biodiversity. Despite academic scholarship on marine science literacy broadly, relatively little has been done to study the role of picture books in teaching children about this topic. This paper is an attempt to fill that gap, by analysing 100 ocean-themed books against common marine science concepts and the Australian Science Understanding Curriculum streams. A majority of the 100 books analysed were found to link with marine science and the Australian Science Understanding Curriculum (81% and 91%, respectively) where biological concepts were dominant in both cases. Chemical and physical sciences were underrepresented in the 100 books analysed. The study provides examples of books that can be used for teaching marine education in primary schools in Australia and suggest further inquiry into marine science literature for children.

One in four Australian undergraduate students participates in learning abroad during their study. Since 2012, faculty-led mobility programmes have overtaken exchange programs to become the most popular outbound mobility type in Australia. However, little has been known about how faculty-led short-term mobility programmes affect students' employability and what might be the benefits of Australian science students' participation in this type of mobility in the Indo-Pacific. This article analyses how a faculty-led programme in science to Japan affects its participants' employability, from the perspectives of students participating in a New Colombo Plan mobility program funded by the Australian government. The study found that it was changes in the students' guided learning circumstance as they navigated the transient space in off-track locations in Japan that enabled them to learn new disciplinary knowledge, acquire transferable skills, accumulate real-life Indo-Pacific experiences and develop empathy and cultural understandings. Despite the development of these qualities, the study found challenges facing students to link knowledge-skill-attribute development to employability. The article discussed implications for developing a more systemic and coordinated approach across the curriculum, career support unit and global mobility office to integrate learning abroad experiences into pedagogy and career counselling service to enhance student employability.

Embedding learning abroad as part of the curriculum has become popular in Australia, Canada, New Zealand, the US and European countries. In Australia, the government has actively promoted and committed to funding students' learning abroad in the Indo-Pacific region which is considered to be strategic to the nation's prosperity and public diplomacy. The majority of the literature on outbound student mobility has concentrated on its benefits to students' development of global competence and employability. However, little is known about how students are engaged in curriculum-specific learning and development of discipline-specific knowledge through short-term mobility experiences. This article responds to this gap in the existing literature. It aims to examine how a short-term mobility program to Japan affects Australian undergraduate students' curriculum-specific learning. The article draws on 45 interviews with science students across three rounds (pre-departure, in-country, and re-entry). It uses Barnett and Coate's framework of curriculum and Tran's concept of mobility as becoming to analyse whether and how the short-term mobility program engages students in their knowing, acting and becoming whereby they are able to construct, organise and build on what they know and can do to arrive at new knowledge, skills and ways of being/becoming. Based on the findings of the study, we discuss implications for how learning abroad in the Indo-Pacific can potentially enhance Australian students' deep and meaningful learning in not only cultural and social but also academic aspects. Practical principles for optimising students' curriculum-specific learning through short-term mobility programs are generated. [ABSTRACT FROM AUTHOR]

Kelp forests provide vital ecosystem services such as carbon storage and cycling, and understanding primary production dynamics regarding seasonal and spatial variations is essential. We conducted surveys at three sites in southeast Tasmania, Australia, that had different levels of water motion, across four seasons to determine seasonal primary production and carbon storage as living biomass for kelp beds of Lessonia corrugata (Order Laminariales). We quantified blade growth, erosion rates, and the variation in population density and estimated both the net biomass accumulation (NBA) per square meter and the carbon standing stock. We observed a significant difference in blade growth and erosion rates between seasons and sites. Spring had the highest growth rate (0.02 g C · blade−1 · d−1) and NBA (1.62 g C · m−2 · d−1), while summer had the highest blade erosion (0.01 g C · blade−1 · d−1), with a negative NBA (−1.18 g C · m−2 · d−1). Sites exhibiting lower blade erosion rates demonstrated notably greater NBA than sites with elevated erosion rates. The sites with the highest water motion had the slowest erosion rates. Moreover, the most wave‐exposed site had the densest populations, resulting in the highest NBA and a greater standing stock. Our results reveal a strong seasonal and water motion influence on carbon dynamics in L. corrugata populations. This knowledge is important for understanding the dynamics of the carbon cycle in coastal regions. [ABSTRACT FROM AUTHOR]

Rapid ocean warming is affecting kelp forests globally. While the sporophyte life stage has been well studied for many species, the microscopic life stages of laminarian kelps have been understudied, particularly regarding spatial and temporal variations in thermal tolerance and their interaction. We investigated the thermal tolerance of growth, survival, development, and fertilization of Ecklonia radiata gametophytes, derived from zoospores sampled from two sites in Tasmania, Australia, throughout a year, over a temperature gradient (3–30°C). For growth we found a relatively stable thermal optimum at ~20.5°C and stable thermal maxima (25.3–27.7°C). The magnitude of growth was highly variable and depended on season and site, with no consistent spatial pattern for growth and gametophyte size. Survival also had a relatively stable thermal optimum of ~17°C, 3°C below the optimum for growth. Gametophytes grew to single cells between 5 and 25°C, but sporophytes were only observed between 10 and 20°C, indicating reproductive failure outside this range. The results reveal complex effects of source population and season of collection on gametophyte performance in E. radiata, with implications when comparing results from material collected at different localities and times. In Tasmania, gametophytes grow considerably below the estimated thermal maxima and thermal optima that are currently only reached during summer heatwaves, whereas optima for survival (~17°C) are frequently reached and surpassed during heatwaves, which may affect the persistence and recruitment of E. radiata in a warmer climate. [ABSTRACT FROM AUTHOR]

Kelp aquaculture is an emerging industry outside of Asia. To be successful, this industry requires a reliable production of seedstock, the optimisation of which greatly benefits from a detailed physiological understanding of the microscopic life-cycle stages of the cultured species. This study investigated the impact of six zoospore densities (10–278 mm−2) on the subsequent development of Ecklonia radiata gametophytes and sporophytes. The results showed that germination rates and sex ratio were unaffected by initial zoospore density, but there were significant effects on gametophyte size and sporophyte production. After two weeks, female gametophytes were largest at an initial zoospore density of 40 mm−2 while male gametophytes grew largest at densities below 40 mm−2, but after four weeks gametophyte size showed a negative relationship with initial zoospore density. Significantly more sporophytes developed at initial zoospore densities below 40 individuals mm−2 and no sporophytes were observed at the highest density (271 zoospores mm−2). These results clearly show the importance of initial zoospore density in optimising the nursery stage of kelp aquaculture. [ABSTRACT FROM AUTHOR]

This study examined the effects of a guild of micrograzing harpacticoid copepods (dominated by two species of Paradactylopodia sp. nov. and one species of Scutellidium sp. nov.) and a mesograzing periwinkle, Afrolittorina praetermissa, on the early recruitment of intertidal macroalgae on a wave-exposed, rocky shore. This is the first study, to our knowledge, to examine the effects of micrograzers (, Introduction Widespread loss of canopy-forming macroalgal assemblages is reported to occur across many parts of the world's coastlines and appears to be driven by a combination of urbanisation, pollution and [...]

Nurse plants modify the environment beneath their canopies to create favourable habitats for propagule recruitment. Nurse plants are potentially valuable tools for ecological restoration—yet empirical tests, particularly in polluted environments, remain rare.The few studies that do exist find that nurse plants positively affect propagule recruitment in polluted environments. Yet most tests have focused on pollution‐tolerant species in metal‐contaminated environments. Biotic interactions are highly context dependent, however, such that extrapolations to other suites of species and pollutant types appear premature.We examined changes in intraspecific nurse effects across pollution regimes for a pollution‐sensitive, macroalgal ecosystem engineer that is a target for intertidal restoration. In a manipulative field experiment, we out‐planted propagules in the presence and absence of conspecific canopies at unpolluted control shores and shores that received a partly remediated (low‐toxicity) sewage effluent. We then monitored the performance (survival and growth) of these propagules over time.Algal canopies facilitated the survival and early growth of propagules at control sites, but not at partially remediated sites where propagules performed poorly irrespective of canopy presence.Synthesis and applications. Using a pollution‐sensitive, macroalgal ecosystem engineer, we show for the first time that nurse‐plant effects can be contingent on pollution regime, and that exposure to pollution (even at low levels) can erode nurse effects. We caution that nurse plants are unlikely to be universal tools for ecological restoration, including systems where facilitative nurse effects naturally occur (in our case, macroalgal canopies on unpolluted rocky reefs). Management practitioners should carefully consider the disturbance (e.g. pollution) tolerance of target species, and test whether nurse effects are maintained under current disturbance regimes, before large‐scale translocations are attempted. [ABSTRACT FROM AUTHOR]

One in four Australian undergraduate students participates in learning abroad during their study. Since 2012, faculty-led mobility programmes have overtaken exchange programs to become the most popular outbound mobility type in Australia. However, little has been known about how faculty-led short-term mobility programmes affect students' employability and what might be the benefits of Australian science students' participation in this type of mobility in the Indo-Pacific. This article analyses how a faculty-led programme in science to Japan affects its participants' employability, from the perspectives of students participating in a New Colombo Plan mobility program funded by the Australian government. The study found that it was changes in the students' guided learning circumstance as they navigated the transient space in off-track locations in Japan that enabled them to learn new disciplinary knowledge, acquire transferable skills, accumulate real-life Indo-Pacific experiences and develop empathy and cultural understandings. Despite the development of these qualities, the study found challenges facing students to link knowledge-skill-attribute development to employability. The article discussed implications for developing a more systemic and coordinated approach across the curriculum, career support unit and global mobility office to integrate learning abroad experiences into pedagogy and career counselling service to enhance student employability. [ABSTRACT FROM AUTHOR]

The swimming of male gametes of brown algae is controlled by two heterokont flagella, regardless of reproductive system, but the patterns of flagellar movement can vary. We investigated sperm chemotaxis and phototaxis in four oogamous Australasian fucalean species. Sperm morphology was similar to that of male gametes of isogamous and anisogamous species but their chemotactic behaviours were much closer to those of other oogamous species than those of isogamous and anisogamous species. Moreover, unlike anisogamous species, sperm chemotaxis of the oogamous species, Hormosira banksii, was not inhibited by a phosphodiesterase inhibitor, theophylline, suggesting variability in regulatory mechanisms of sperm chemotaxis amongst brown algae. In our previous work, lower extracellular Ca2+, supernatant of female gametes and theophylline induced the reversal of phototactic signs in anisogamous male gametes. In contrast, lower extracellular Ca2+ and theophylline did not significantly affect phototaxis in sperm of the oogamous H. banksii. Moreover, high extracellular Ca2+ and supernatant of eggs disrupted the negative phototaxis but did not reverse their phototactic sign. These results suggest that the regulation of phototaxis also varies amongst brown algal gametes. Further investigation of brown algal species is warranted to assess the generality of these patterns of chemotaxis and phototaxis among anisogamous and oogamous gametes. [ABSTRACT FROM AUTHOR]

Rising ocean temperatures and extreme temperature events have precipitated declines and local extinctions in many marine species globally, but patterns of loss are often uneven across species ranges for reasons that are poorly understood. Knowledge of the extent of local adaptation and gene flow may explain such patterns and help predict future trajectories under scenarios of climate change. We test the extent to which local differentiation in thermal tolerance is influenced by gene flow and local adaptation using a widely distributed intertidal seaweed (Hormosira banksii) from temperate Australia. Population surveys across ~2,000 km of the species range revealed strong genetic structuring at regional and local scales (global FST = 0.243) reflecting extremely limited gene flow, while common garden experiments (14‐day exposures to 15, 18, 21°C) revealed strong site differences in early development and mortality in response to elevated temperature. Embryos from many sites spanning a longitudinal thermal gradient showed suppressed development and increased mortality to elevated water temperatures, but populations originating from warmer and more variable thermal environments tended to be less susceptible to warming. Notably, there was significant local‐scale variation in the thermal responses of embryos within regions which was corroborated by the finding of small‐scale genetic differences. We expect the observed genetic and phenotypic differentiation to lead to uneven responses to warming sea surface temperatures in this important marine foundation species. The study highlights the challenges of predicting species responses to thermal stress and the importance of management strategies that incorporate evolutionary potential for "climate‐proofing" marine ecosystems. [ABSTRACT FROM AUTHOR]

SUMMARY: Complex haploid‐diploid life cycles amongst marine organisms may be maintained by ecological differences in life‐history phases. For red algal species within the Gigartinaceae, such differences may be driven, in part, by different cell wall composition and resultant biomechanical strengths of haploid and diploid phases. A field experiment tested the attachment strengths of gametophytes and tetrasporophytes of the isomorphic red alga, Chondrus verrucosus (with comparisons of fertile and vegetative fronds, with and without natural tissue damage across three wave‐exposed sites). Seventy‐nine percent of all fronds broke at the stipe‐holdfast junction. There were significant differences in attachment strength (break force and break stress), but not gross morphology (frond length, number of branch axes, wet weight and cross‐sectional area of fronds that dislodged at the stipe‐holdfast junction) of life‐history phases, with tetrasporophytes exhibiting weaker tissue strength and attachment, and therefore greater susceptibility to dislodgement by waves. However, fertility and tissue damage did not consistently influence dislodgement in pull‐to‐break tests simulating the effects of single waves. The ecological and evolutionary consequences of greater susceptibility to dislodgement of tetrasporophytes (relative to gametophytes) warrant further investigation. [ABSTRACT FROM AUTHOR]

Recognition of the wide diversity of organisms that maintain complex haploid–diploid life cycles has generated interest in understanding the evolution and persistence of such life cycles. We empirically tested the model where complex haploid–diploid life cycles may be maintained by subtle/cryptic differences in the vital rates of isomorphic haploid–diploids, by examining the ecophysiology of haploid tetraspores and diploid carpospores of the isomorphic red alga Chondrus verrucosus. While tetraspores and carpospores of this species did not differ in size or autofluorescence, concentrations of phycobiliproteins of carpospores were greater than that of tetraspores. However, tetraspores were more photosynthetically competent than carpospores over a broader range of photosynthetic photon flux densities (PPFDs) and at PPFDs found at both the depth that C. verrucosus is found at high tide and in surface waters in which planktonic propagules might disperse. These results suggest potential differences in dispersal potential and reproductive success of haploid and diploid spores. Moreover, these cryptic differences in ecological niche partitioning of haploid and diploid spores contribute to our understanding of some of the differences between these ploidy stages that may ultimately lead to the maintenance of the complex haploid–diploid life cycle in this isomorphic red alga. [ABSTRACT FROM AUTHOR]

Recognition of the wide diversity of organisms that maintain complex haploid–diploid life cycles has generated interest in understanding the evolution and persistence of such life cycles. We empirically tested the model where complex haploid–diploid life cycles may be maintained by subtle/cryptic differences in the vital rates of isomorphic haploid–diploids, by examining the ecophysiology of haploid tetraspores and diploid carpospores of the isomorphic red alga Chondrus verrucosus. While tetraspores and carpospores of this species did not differ in size or autofluorescence, concentrations of phycobiliproteins of carpospores were greater than that of tetraspores. However, tetraspores were more photosynthetically competent than carpospores over a broader range of photosynthetic photon flux densities (PPFDs) and at PPFDs found at both the depth that C. verrucosus is found at high tide and in surface waters in which planktonic propagules might disperse. These results suggest potential differences in dispersal potential and reproductive success of haploid and diploid spores. Moreover, these cryptic differences in ecological niche partitioning of haploid and diploid spores contribute to our understanding of some of the differences between these ploidy stages that may ultimately lead to the maintenance of the complex haploid–diploid life cycle in this isomorphic red alga. [ABSTRACT FROM AUTHOR]

AbstractDespite the opportunity to integrate ocean literacy in schools, there is limited global evidence that learning about the ocean has been prioritised in formal educational systems. An overloaded curriculum, teacher’s lack of ocean knowledge and the limited availability of educational resources are the main barriers for the inclusion of ocean topics in schools. To tackle these challenges, we developed an ocean education training program for primary school teachers and provided them with teaching resources to deliver ocean concepts and increase awareness of a local marine environment. Our results showed a positive response from teachers regarding the program, their experience, and the incorporation of ocean literacy in their lessons across different learning areas. This study emphasises the importance of training teachers in ocean literacy and can be used as a model to design marine education programs that consider the local, cultural, and environmental context of individual schools. [ABSTRACT FROM AUTHOR]

Canopy-forming fucoid algae have an important role as ecosystem engineers on rocky intertidal shores, where they increase the abundance of species otherwise limited by exposure during low tide. The facilitative relationship between Ascophyllum nodosum and associated organisms was explored using a frond breakage experiment (100%, 50%, 25%, 0% intact-frond treatments) in southern England, to assess the consequences of disturbance. Understorey substratum temperature was on average 3°C higher in 0% and 25% intact-frond treatments than in plots with 50% and 100% intact fronds. Light (as PAR during low tide) doubled in 0% intact-frond treatments in comparison to other treatments (which had similar light levels). Mobile invertebrate species richness declined by on average 1 species per m2 in the treatments with only 25% and 0% intact fronds, and the abundance of Littorina obtusata declined by 2.4–4.2 individuals per m2 in the treatments with 25 and 0% intact fronds. Sessile taxa, including Osmundea pinnatifida and encrusting coralline algae, declined by half on average in the 0% intact-frond treatment. These results suggest that the ability of Ascophyllum to mediate environmental conditions to the understorey is the mechanism responsible for species distributed in the understorey (autogenic ecosystem engineering). The results of this study imply that a pulse disturbance resulting in a 50% breakage of Ascophyllum fronds significantly increases temperature and decreases the abundance of mobile invertebrates usually associated with Ascophyllum. Sessile taxa associated with Ascophyllum can, however, withstand disturbances down to 25% intact Ascophyllum fronds. [ABSTRACT FROM AUTHOR]

Seaweed aquaculture beds (SABs) that support the production of seaweed and their diverse products, cover extensive coastal areas, especially in the Asian-Pacific region, and provide many ecosystem services such as nutrient removal and CO assimilation. The use of SABs in potential carbon dioxide (CO) mitigation efforts has been proposed with commercial seaweed production in China, India, Indonesia, Japan, Malaysia, Philippines, Republic of Korea, Thailand, and Vietnam, and is at a nascent stage in Australia and New Zealand. We attempted to consider the total annual potential of SABs to drawdown and fix anthropogenic CO. In the last decade, seaweed production has increased tremendously in the Asian-Pacific region. In 2014, the total annual production of Asian-Pacific SABs surpassed 2.61 × 10 t dw. Total carbon accumulated annually was more than 0.78 × 10 t y, equivalent to over 2.87 × 10 t CO y. By increasing the area available for SABs, biomass production, carbon accumulation, and CO drawdown can be enhanced. The conversion of biomass to biofuel can reduce the use of fossil fuels and provide additional mitigation of CO emissions. Contributions of seaweeds as carbon donors to other ecosystems could be significant in global carbon sequestration. The ongoing development of SABs would not only ensure that Asian-Pacific countries will remain leaders in the global seaweed industry but may also provide an added dimension of helping to mitigate the problem of excessive CO emissions. [ABSTRACT FROM AUTHOR]

As coastal population growth increases globally, effective waste management practices are required to protect biodiversity. Water authorities are under increasing pressure to reduce the impact of sewage effluent discharged into the coastal environment and restore disturbed ecosystems. We review the role of benthic macroalgae as ecosystem engineers and focus particularly on the temperate Australasian fucoid Hormosira banksii as a case study for rocky intertidal restoration efforts. Research focussing on the roles of ecosystem engineers is lagging behind restoration research of ecosystem engineers. As such, management decisions are being made without a sound understanding of the ecology of ecosystem engineers. For successful restoration of rocky intertidal shores it is important that we assess the thresholds of engineering traits (discussed herein) and the environmental conditions under which they are important. [ABSTRACT FROM AUTHOR]

Hormosira banksii is a dominant intertidal alga characterised by limited dispersal of propagules, yet it has a broad distribution throughout temperate Australasia. However, the high abundance of beach wrack of H. banksii on sandy beaches along southwest Victoria, the frequency of frond dislodgment and the force required to break it from the substratum remain unknown. Dislodgment of macroalgae has been shown to influence dispersal processes; therefore, we tested the model that long-distance dispersal of H. banksii is facilitated by weak attachment to the substratum and frequent dislodgment of fertile fronds. We monitored the dislodgment of H. banksii individuals and conducted in situ pull tests to determine the attachment strength of fronds of H. banksii. We further tested whether thallus size or pull direction influenced attachment strength of H. banksii. We found that breakage of vesicles and fronds was a regular event during the survey period and that the mean attachment strength of fronds of H. banksii was weak compared to other intertidal algae. Furthermore, we found that thallus size did not influence the force required to break fronds of H. banksii from the substratum but that the direction that fronds were pulled from the substratum did. We suggest that fronds of H. banksii do drift frequently and that long-distance dispersal is likely to be an important mechanism for the distributional success of this species. [ABSTRACT FROM AUTHOR]

Understanding of macroalgal dispersal has been hindered by the difficulty in identifying propagules. Different carrageenans typically occur in gametophytes and tetrasporophytes of the red algal family Gigartinaceae, and we may expect that carpospores and tetraspores also differ in composition of carrageenans. Using Fourier transform infrared (FT-IR) microspectroscopy, we tested the model that differences in carrageenans and other cellular constituents between nuclear phases should allow us to discriminate carpospores and tetraspores of Chondrus verrucosus Mikami. Spectral data suggest that carposporophytes isolated from the pericarp and female gametophytes contained κ-carrageenan, whereas tetrasporophytes contained λ-carrageenan. However, both carpospores and tetraspores exhibited absorbances in wave bands characteristic of κ-, ι-, and λ-carrageenans. Carpospores contained more proteins and may be more photosynthetically active than tetraspores, which contained more lipid reserves. We draw analogies to planktotrophic and lecithotrophic larvae. These differences in cellular chemistry allowed reliable discrimination of spores, but pretreatment of spectral data affected the accuracy of classification. The best classification of spores was achieved with extended multiplicative signal correction (EMSC) pretreatment using partial least squares discrimination analysis, with correct classification of 86% of carpospores and 83% of tetraspores. Classification may be further improved by using synchrotron FT-IR microspectroscopy because of its inherently higher signal-to-noise ratio compared with microspectroscopy using conventional sources of IR. This study demonstrates that FT-IR microspectroscopy and bioinformatics are useful tools to advance our understanding of algal dispersal ecology through discrimination of morphologically similar propagules both within and potentially between species. [ABSTRACT FROM AUTHOR]

We describe the abundance, including spatial and temporal variability, of phases of the isomorphic Chondrus verrucosus Mikami from Japan. Chondrus verrucosus occurred in a dense (∼90% cover) and temporally stable bed on a small, isolated rocky outcrop (Oyakoiwa) in Shizuoka Prefecture. Small vegetative fronds were always much more abundant than large vegetative and fertile fronds over the spring to late summer periods in 1999 and 2000. Over the same period, fertile carposporophytic fronds were generally more abundant than fertile tetrasporophytic fronds, and fertile male fronds appeared infrequently at low densities. Using the resorcinol-acetal test, we determined the proportion of gametophytes and tetrasporophytes in three populations of C. verrucosus: Oyakoiwa and Noroshi (Shizuoka) in the summers of 1999 and 2000 and Kamehana Point (Miyagi) in autumn 2000. All populations had a significantly higher proportion of gametophytes than tetrasporophytes in both years, although gametophytic proportions were lower at Noroshi (∼70%) than at Oyakoiwa (∼80%) and Kamehana Point (∼97%). However, examination of all isolated individuals sampled on Noroshi showed equal proportions of each phase in 1999, but gametophyte dominance (74%) in 2000. Differences in dispersal and spore production between phases are discussed as mechanisms potentially contributing to variation in gametophyte dominance. [ABSTRACT FROM AUTHOR]

Drifting, fertile thalli are well documented to be the primary long-distance dispersal vector for many marine macroalgae, but little information about reproductive viability of drift is known. This study examined the reproductive viability and longevity of floating fragments of the intertidal Australasian fucoid Hormosira banksii (Turner) Decne. Beach wrack surveys and field experiments were conducted to test the model that long-distance dispersal is achieved in H. banksii via floating, fertile fronds. High densities of beach wrack fragments were evident during summer compared to autumn. The majority of beach wrack occurred on sandy beaches rather than rocky shores. Both male and female fragments were present in the beach wrack. Detached fronds were capable of releasing gametes up to 8 weeks after detachment. Beach wrack produced high fertilization rates and recruited successfully onto artificial panels. Results suggest that detached fragments are reproductively viable and that floating, fertile fronds may be an important mechanism for facilitating long-distance dispersal in this species. Nevertheless, the frequency of fronds reaching a suitable habitat and contributing to gene flow between populations, or colonizing new populations, may not be proportional to the total density of beach wrack. [ABSTRACT FROM AUTHOR]