185 research outputs found
Systematic reappraisal of marsh-orchids native to Scotland
© The Author(s), 2023.This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Summary: The intensively studied Eurasian orchid genus Dactylorhiza has become a model system for exploring allopolyploid evolution, yet determining the optimal circumscriptions of, and most appropriate ranks for, its constituent taxa remain highly controversial topics. Here, novel allozyme data and detailed morphometric data for 16 Scottish marsh-orchid populations are interpreted in the context of recent DNA sequencing studies. Despite being derived from the same pair of parental species, the two allopolyploid species that currently occur in Scotland can reliably be distinguished using allozymes, haplotypes, ribotypes or sequences of nuclear genes. A modest range of diverse morphological characters are shown to distinguish the two molecularly-circumscribed species, but they have in the past been obscured by equivalent levels of infraspecific variation in characters rooted in anthocyanin pigments; these characters are better employed for distinguishing infraspecific taxa. Dactylorhiza francis-drucei (formerly D. traunsteinerioides) is confirmed as being distinct from the continental D. traunsteineri/lapponica, probably originating through allopatric isolation once the continental lineage reached Britain. All Scottish populations are attributed to the comparatively small-flowered, anthocyanin-rich subsp. francis-drucei, which includes as a variety the former D. 'ebudensis'; the less anthocyanin-rich subsp. traunsteinerioides is confined to Ireland, North Wales and northern England. In contrast with D. francis-drucei, only a minority of Scottish populations of D. purpurella are attributed to the anthocyanin-rich race, var. cambrensis. This species most likely originated through an allopolyploidy event that occurred comparatively recently within the British Isles, as it contains allozyme alleles distinctive of British rather than continental D. incarnata (its diploid pollen-parent). In contrast, the rare Scottish population of D. incarnata subsp. cruenta shares with its Irish counterparts a continental genotype, and is most likely a recent arrival in Scotland through long-distance dispersal. Among all European allotetraploid dactylorchids, D. purpurella is the species that most closely resembles D. incarnata, both molecularly and morphologically.Peer reviewe
Hitching a ride on Hercules:fatal epibiosis drives ecosystem change from mud banks to oyster reefs
[Excerpt] Best known as a "love them or hate them" luxury food, or for their pearls, oysters are also ecosystem engineers, forming vast oyster reefs. Oyster reefs provide habitat for a myriad of species, and support fisheries, improve water quality and provide coastal protection. These services are estimated to be worth US99,000 per hectare per year (Grabowski et al. 2012). Globally, oyster reefs have declined by 85% through destructive overfishing, coastal development, pollution, and introduced competitors, predators and diseases (Beck et al. 2011). Active restoration is becoming an increasingly popular tool to bring back lost oyster reefs and the ecosystem services they provide (Fitzsimons et al. 2019). However, restoration is not always successful, and knowledge about how reefs naturally form and function is vital to improve restoration success. Oyster larvae only settle on hard substrates. Reefs proliferate because oyster shells provide a settlement surface, and oysters provide chemical and sound cues that facilitate larval settlement (Lillis et al. 2013). However, these reefs often form on intertidal sand and mud banks. This raises the question, how do oyster reefs form on mud banks in the absence of hard surfaces
Sea-weeding: Manual removal of macroalgae facilitates rapid coral recovery
Coral reef ecosystems globally are under threat, leading to declining coral cover and macroalgal proliferation. Manually removing macroalgae (i.e. âsea-weedingâ) may promote local-scale coral recovery by reducing a biological barrier, though the impact of removal on community composition of benthic reef organisms has not been quantified. In this three-year study (2018â2021), fleshy macroalgae (predominantly Sargassum spp.) were periodically removed from 25 m2 experimental plots on two inshore fringing reefs of Yunbenun (Magnetic Island) in the central Great Barrier Reef. By the end of the study, coral cover in removal plots (n = 12 plots) assessed through in-field transects increased by at least 47% (2019 mean: 25.5%, 2021 mean: 37.4%), and macroalgal cover decreased by more than half. In contrast, in control plots (n = 12 plots), there was no change in macroalgal cover while coral cover remained stable (2019 mean: 16.4%, 2021 mean: 13.6%). Changes in benthic cover were supported by photoquadrat data, with Bayesian probability modelling indicating a 100% likelihood that coral cover more than doubled in removal plots over the study period, compared to only a 29% chance of increased coral cover in control plots. Synthesis and applications. Manual macroalgal removal can provide rapid benefits and enhance inshore coral reef recovery. Through involvement of community groups and citizen scientists, larger scale removal of macroalgae is a low-tech, high-impact, and achievable method for local reef management
Interaction of estrogen receptor α with proliferating cell nuclear antigen
The ability of estrogen receptor α (ERα) to modulate gene expression is influenced by the recruitment of a host of co-regulatory proteins to target genes. To further understand how estrogen-responsive genes are regulated, we have isolated and identified proteins associated with ERα when it is bound to DNA containing the consensus estrogen response element (ERE). One of the proteins identified in this complex, proliferating cell nuclear antigen (PCNA), is required for DNA replication and repair. We show that PCNA interacts with ERα in the absence and in the presence of DNA, enhances the interaction of ERα with ERE-containing DNA, and associates with endogenous estrogen-responsive genes. Interestingly, rather than altering hormone responsiveness of endogenous, estrogen-responsive genes, PCNA increases the basal expression of these genes. Our studies suggest that in addition to serving as a platform for the recruitment of DNA replication and repair proteins, PCNA may serve as a platform for transcription factors involved in regulating gene expression
Advances in Aerial Application Technologies and Decision Support for Integrated Pest Management
Treating patients as persons : a capabilities approach to support delivery of person-centered care
Peer reviewedPublisher PD
Coral restoration in a changing world - a global synthesis of methods and techniques
Coral reef ecosystems have suffered an unprecedented loss of habitat-forming hard corals in recent decades, due to increased nutrient outputs from agriculture, elevated levels of suspended sediment caused by deforestation and development, destructive fishing practices, over-harvesting of reef species, outbreaks of corallivorous crown-of-thorns starfish (COTS, Acanthaster planci), coral disease and tropical storms. However, in recent years climate change has emerged as the primary threat to coral reefs. While reefs have a natural capacity for recovery, recurring events like mass coral bleaching and extreme weather events is increasing in frequency, intensity and severity, and are eroding the time for recovery between catastrophic events.
Marine conservation has primarily focused on passive habitat protection over active restoration, in contrast to terrestrial ecosystems where active restoration is common practice. Further, active restoration is well accepted for wetlands and shellfish reefs however coral reef restoration has remained controversial both in academia and amongst marine managers. This is despite recent research suggesting that optimal conservation outcomes include both habitat protection and restoration. Critics often argue that coral restoration detracts focus from mitigating climate change and other threats to the marine environment, while proponents of coral restoration counter that interventions can serve to protect coral biodiversity and endangered species in the short-term, while mitigation of large-scale threats such as climate change and water quality take effect. Despite this disconnect between coral restoration practitioners, coral reef managers and scientists, active coral restoration is increasingly used as a tool to attempt to restore coral populations.
The field has largely developed through independent work of isolated groups, and has fallen victim to âgrowing painsâ associated with ecological restoration in many other ecosystems. Partly this is due to a reluctance to share outcomes of projects, and in some cases a lack of monitoring or appropriate reporting of project outcomes. To mitigate this, we aimed to synthesise the available knowledge in a comprehensive global review of coral restoration methods, incorporating data from a traditional literature search of the scientific literature, complemented with information gathered from online sources and through a survey of coral restoration practitioners.
We identified 329 case studies on coral restoration, of which 195 were from the scientific literature, 79 were sourced from the grey literature (i.e. reports and online descriptions), and 55 were responses to our survey of restoration practitioners. We identified ten coral restoration intervention types: coral gardening - transplantation phase (23% of records), direct transplantation (21%), artificial reefs (19%), coral gardening - nursery phase (17%), coral gardening (both phases, 7%), substrate enhancement with electricity (4%), substrate stabilisation (4%), algae removal (2%), larval enhancement (1%) and microfragmentation (<1%). The majority of interventions involve coral fragmentation or transplantation of coral fragments (70%). While 52 countries are represented in the dataset, the majority of projects were conducted in the USA, Philippines, Thailand and Indonesia (together representing 40% of projects).
Coral restoration case studies are dominated by short-term projects, with 66% of all projects reporting less than 18 months of monitoring of the restored sites. Overall, the median length of projects was 12 months. Similarly, most projects are relatively small in spatial scale, with a median size of restored area of 500 m2. A diverse range of species are represented in the dataset, with 221 different species from 89 coral genera. Overall, coral restoration projects focused primarily (65% of studies) on fast-growing branching corals. Among all the published documents, the top five species (22% of studies) were Acropora cervicornis, Pocillopora damicornis, Stylophora pistillata, Porites cylindrica and Acropora palmata. Over a quarter of projects (26%) involved the coral genus Acropora, while 9% of studies included a single species - Acropora cervicornis. Much of the focus on Acropora cervicornis and Acropora palmata is likely to have resulted from these important reef-forming species being listed as threatened on the United States Endangered Species List and as Endangered on the International Union for Conservation of Nature Red List of Endangered Species (IUCN 2018).
We have dedicated a section to each intervention type covered in this review, and describe the potential and limitations of each intervention type in detail there. However, collating this information has highlighted the following main points which apply to coral restoration in general.
1. On average, survival in restored corals is relatively high. All coral genera with sufficient replication from which to draw conclusions (>10 studies listing that genus) report an average survival between 60-70%.
2. Differences in survival and growth are largely species and/or location specific, so the selection of specific methods should be tailored to the local conditions, costs, availability of materials, and to the specific objectives of each project.
3. Projects are overall small and short, however substantial scaling up is required for restoration to be a useful tool in supporting the persistence of reefs in the future. While there is ample evidence detailing how to successfully grow corals at smaller scales, few interventions demonstrate a capacity to be scaled up much beyond one hectare. Notable exceptions include methods which propagate sexually derived coral larvae.
4. To date, coral restoration has been plagued by the same common problems as ecological restoration in other ecosystems. Mitigating these will be crucial to successfully scale up projects, and to retain public trust in restoration as a tool for resilience based management.
a. Lack of clear objectives - There is a clear mismatch between the stated objectives of projects, and the design of projects and monitoring of outcomes. Poorly articulated or overinflated objectives risk alienating the general public and scientists, by over-promising and under-delivering. Social and economic objectives have inherent value and do not need to be disguised with ecological objectives.
b. Lack of appropriate monitoring - A large proportion of projects do not monitor metrics relevant to their stated objectives, or do not continue monitoring for long enough to provide meaningful estimates of success. Further, there is a clear need for standardisation in the metrics that are used, to allow comparisons between projects.
c. Lack of appropriate reporting - The outcomes of a large proportion of projects are not documented, which restricts knowledge-sharing and adaptive learning.
While we attempted to access some of the unreported projects through our survey, it is clear we have only scratched the surface of existing knowledge.
d. Poorly designed projects - An effect of inadequate monitoring and reporting is that projects are poorly suited to their specific area and conditions. Improved knowledge-sharing and development of best practice coral restoration
guidelines aims to mitigate this problem
Best practice coral restoration for the Great Barrier Reef
As the Great Barrier Reef (GBR) continues to degrade through repeated mass bleaching events, crown-of-thorns starfish and major disease outbreaks, and the impacts of intense cyclones, pressure is growing for direct intervention to assist the recovery of reef-building corals. Decreasing coral cover on the GBR and other Australian reefs has been recognised as a serious problem relatively recently in Australia but follows a global trend, with many overseas reefs now highly degraded. Various types of coral restoration, rehabilitation and assisted recovery projects have been trialled overseas for decades and it makes sense to look at what has and hasnât worked overseas to determine a range of options that may suit GBR conditions. Some direct interventions to assist coral recovery have been trialled in Australia such as transplanting corals, algae removal to promote coral recovery and larval enhancement promoting direct coral recruitment. In addition, after physical damage from cyclones, ship strikes or dragged anchors, local dive operators and dive clubs (permitted or unpermitted) often attempt to assist the recovery of corals by tipping over flipped tabular corals and reattaching broken branching corals or sea fans. These latter assisted recovery techniques are rarely underpinned by scientific data on coral recovery. A lack of best practice guidelines for these actions limits the chance of success and increases the health and safety risks of these activities
Suspended sediment prolongs larval development in a coral reef fish
Increasing sediment input into coastal environments is having a profound influence on shallow marine habitats and associated species. Coral reef ecosystems appear to be particularly sensitive, with increased sediment deposition and re-suspension being associated with declines in the abundance and diversity of coral reef fishes. While recent research has demonstrated that suspended sediment can have negative impacts on post-settlement coral reef fishes, its effect on larval development has not been investigated. In this study, we tested the effects of different levels of suspended sediment on larval growth and development time in Amphiprion percula, a coral reef damselfish. Larvae were subjected to four experimental concentrations of suspended sediment spanning the range found around coastal coral reefs (0-45 mg l(-1)). Larval duration was significantly longer in all sediment treatments (12 days) compared with the average larval duration in the control treatment (11 days). Approximately 75% of the fish in the control had settled by day 11, compared with only 40-46% among the sediment treatments. In the highest sediment treatment, some individuals had a larval duration twice that of the median duration in the control treatment. Unexpectedly, in the low sediment treatment, fish at settlement were significantly longer and heavier compared with fish in the other treatments, suggesting delayed development was independent of individual condition. A sediment-induced extension of the pelagic larval stage could significantly reduce numbers of larvae competent to settle and, in turn, have major effects on adult population dynamics
Turning a lost reef ecosystem into a national restoration program
Achieving a sustainable socioecological future now requires large-scale environmental repair across legislative borders. Yet, enabling large-scale conservation is complicated by policy-making processes that are disconnected from socioeconomic interests, multiple sources of knowledge, and differing applications of policy. We considered how a multidisciplinary approach to marine habitat restoration generated the scientific evidence base, community support, and funding needed to begin the restoration of a forgotten, functionally extinct shellfish reef ecosystem. The key actors came together as a multidisciplinary community of researchers, conservation practitioners, recreational fisher communities, and government bodies that collaborated across sectors to rediscover Australia's lost shellfish reefs and communicate the value of its restoration. Actions undertaken to build a case for large-scale marine restoration included synthesizing current knowledge on Australian shellfish reefs and their historical decline, using this history to tell a compelling story to spark public and political interest, integrating restoration into government policy, and rallying local support through community engagement. Clearly articulating the social, economic, and environmental business case for restoration led to state and national funding for reef restoration to meet diverse sustainability goals (e.g., enhanced biodiversity and fisheries productivity) and socioeconomic goals (e.g., job creation and recreational opportunities). A key lesson learned was the importance of aligning project goals with public and industry interests so that projects could address multiple political obligations. This process culminated in Australia's largest marine restoration initiative and shows that solutions for large-scale ecosystem repair can rapidly occur when socially valued science acts on political opportunities
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