Coral community structure and recruitment in seagrass meadows

Coral communities are increasingly found to populate non-reef habitats prone to high environmental variability. Such sites include seagrass meadows, which are generally not considered optimal habitats for corals as a result of limited suitable substrate for settlement and substantial diel and seasonal fluctuations in physicochemical conditions relative to neighboring reefs. Interest in understanding the ability of corals to persist in non-reef habitats has grown, however little baseline data exists on community structure and recruitment of scleractinian corals in seagrass meadows. To determine how corals populate seagrass meadows, we surveyed the established and recruited coral community over 25 months within seagrass meadows at Little Cayman, Cayman Islands. Simultaneous surveys of established and recruited coral communities at neighboring back-reef sites were conducted for comparison. To fully understand the amount of environmental variability to which corals in each habitat were exposed, we conducted complementary surveys of physicochemical conditions in both seagrass meadows and back-reefs. Despite overall higher variability in physicochemical conditions, particularly pH, compared to the back-reef, 14 coral taxa were capable of inhabiting seagrass meadows, and multiple coral families were also found to recruit to these sites. However, coral cover and species diversity, richness, and evenness were lower at sites within seagrass meadows compared to back-reef sites. Although questions remain regarding the processes governing recruitment, these results provide evidence that seagrass beds can serve as functional habitats for corals despite high levels of environmental variability and suboptimal conditions compared to neighboring reefs

Tobacco smoking and nicotine dependence in first episode and established psychosis

Aim People with psychotic disorders have increased premature mortality in comparison with the general population, with high rates of cigarette use a contributing factor. We aimed to describe the prevalence of cigarette use and nicotine dependence (ND) in first episode psychosis (FEP), and established psychosis; and to investigate associations between clinical symptoms and ND. Methodology Smoking and clinical data were collected from two cohorts: 181 people with FEP recruited as part of the Physical Health and Substance Use Measures in First Onset Psychosis (PUMP) study and from 432 people with established psychosis recruited as part of the Improving physical health and reducing substance use in psychosis randomised controlled trial (IMPaCT RCT). Results The prevalence of cigarette smoking was 78% in FEP and 62% in established psychosis. Forty nine percent (n=60) of smokers in the FEP cohort and 69% (n=183) of smokers with established psychosis were highly nicotine dependent. Being a highly nicotine dependent smoker was significantly associated with higher PANSS positive symptom scores (F= 5.480 p= 0.004), and with decreased scores on the Rosenberg self-esteem scale (F=3.261, p=0.039) in established psychosis. There was no diagnostic specificity identified in relation to smoking or ND in both groups. Conclusion High rates of cigarette usage and nicotine dependence are problems from the early stages of psychosis. ND is higher in people with established psychosis. Smoking cessation strategies as part of comprehensive management of psychotic disorders at every stage require further development and evaluation

An assessment of disease prevalence and mitigation strategies among wild and out planted Acropora cervicornis in the Florida Keys.

Decline in live coral tissue due to disease is an ongoing challenge in coral reef conservation and restoration. To better characterize white diseases in South Florida staghorn coral (Acropora cervicornis) populations, field surveys were conducted to characterize disease prevalence in the Florida Keys, particularly with regard to differences between wild colonies and cultured, outplanted colonies. In addition, experimental mitigation treatments were implemented to determine if these treatments were effective in arresting tissue loss associated with the disease state. Results indicated that over the study period, disease prevalence was significantly different between sites. Severe disease outbreak conditions were observed only at outplant sites, although outbreaks did not occur at all outplant sites. Predation by Hermodice carunculata, and Coralliophila abbreviata were also found to vary widely between sites and time intervals and were not correlated to disease prevalence. Among all treated colonies and conditions of high disease prevalence, disease mitigation treatments had no significant effect in arresting tissue loss associated with disease. However, when treatments were performed under conditions of low disease prevalence, tissue loss was arrested at a significantly higher rate than controls for both the epoxy band and excision treatments. No single environmental factor can account for the variation observed in disease prevalence between sites; likely, a synergy of factors is to blame for the disease dynamics observed. These factors should be considered when selecting future outplanting sites, and the effectiveness of epoxy band and excision treatments must be assessed further but may be useful field mitigation techniques under specific conditions.</p

Comparison of Methods of Evaluating Cotton Abrasion

Authors differ in their definitions of abrasion, but agree that it is one of the most important of several factors contributing to wear.Much research has been done on the evaluation of cotton abrasion tests, but little has been done on the comparison of these evaluations to find the most suitable methods for particular fabrics, fibers and testing machines. The purpose of this study was to abrade cotton fabric in the Accelerotor, to evaluate the abrasion damage of the fabric after abrasion, and to compare the evaluation methods investigated to find those most suitable to use for cotton abraded in the Accelerotor. A sampling plan was developed to cut twelve specimens of cotton fabric from each of six areas of the cloth.The specimens within the areas were randomly chosen.Five specimens from each area were abraded with the grit liner in the Accelerotor at time intervals of one, two, three, seven, and fifteen minutes. Four specimens from each area were abraded with the friction liner at one, three, ten, and thirty minutes. Two specimens from each area were held for replacement and one was left unabraded. The Accelerotor was run at constant speed. Physical, visual, and dyeing tests were used to evaluate the degree of abrasion received by the fabric.The methods used were weight of the whole specimen;weight per square yard of the fabric; breaking strength; yarn count; visual ratings of the fabric, yarn, and fiber; and congo red and differential dyeing tests.The results of these tests were compared to find those most suitable to evaluate cotton fabric abraded in the Accelerotor. Because some tests are subjective and more irreproducible than others and all tests do not measure the same abrasion phenomena, no single test can be used for the evaluation of abrasion.A combination of tests seems to be the best way to evaluate cotton abraded in the Accelerotor.The tests which were judged best for this purpose were weight per square yard, yarn count, and the congo red tests. Advisor: June Ericso

Relationships of invasive lionfish with topographic complexity, groupers, and native prey fishes in Little Cayman

The invasion of Indo-Pacific lionfish on Caribbean reefs has prompted resource-demanding removals. Ecological tools to optimise the outcome of these costly efforts are scarce. Topographic complexity usually correlates strongly with fish abundance and can be mapped over large spatial scales. Determining the nature and strength of its relationship with lionfish abundance is therefore an important step in generating spatial prioritisation tools for removal programmes. Here, we quantify the relationships of lionfish density and hunting behaviour with topographic complexity, grouper biomass, and prey availability on the north-east reefs of Little Cayman. Lionfish density varied across sites irrespective of topographic complexity or density of prey fish, but was highest on the most rugose section of the reef terraces. Increased topographic complexity along the edge of the drop-offs caused modest increases in lionfish density. Grouper biomass caused no clear reduction in mean lionfish density, but narrowed the variance. Lionfish invested more time hunting on rugose sites with a paucity of prey refugia, implying that these may be places where prey fish are most vulnerable to predation. Under the reasonable assumption that lionfish display strong site fidelity, targeted removals are likely to yield the highest conservation benefits if focused on most rugose sites and at the edges of drop-offs. Determining whether longer hunting times yield increased predation rates, and quantifying the effectiveness of physical refugia in protecting prey from lionfish predation strikes, are important future research directions. If topographic complexity determines lionfish hunting success, there is a scope for mapping the vulnerability of prey, thus optimising practises aimed at managing the invasion

Optimizing the productivity of a coral nursery focused on staghorn coral Acropora cervicornis

The rapid decline of the staghorn coral Acropora cervicornis throughout the Caribbean prompted the development of coral gardening as a management strategy to restore wild stocks. Given that coral gardening relies on propagating corals collected from wild donor colonies, it is imperative to optimize growth within a nursery to reduce dependence on wild collections. This study determined the maximum amount of coral that may be clipped from a colony during propagation without causing mortality or decreased growth. We applied 3 experimental treatments to 12 nursery-reared staghorn corals, in which 25, 50, or 75% of the colony\u27s total biomass was removed and fragmented to create additional, smaller fragments. Four additional colonies served as unfragmented controls. Treatment had no effect on colony productivity, defined as the ratio of new tissue growth to initial colony size, over 87 d. Similarly, treatment had no effect on the rate at which colonies developed new branches. Results indicate that 75% of the biomass of staghorn colonies may be removed without affecting their growth. We anticipate that our observations will have practical applications for maximizing propagation of staghorn coral within nurseries throughout the wider Caribbean while minimizing the impact of this management measure on remnant wild populations

Disease dynamics and potential mitigation among restored and wild staghorn coral, Acropora cervicornis

The threatened status (both ecologically and legally) of Caribbean staghorn coral, Acropora cervicornis, has prompted rapidly expanding efforts in culture and restocking, although tissue loss diseases continue to affect populations. In this study, disease surveillance and histopathological characterization were used to compare disease dynamics and conditions in both restored and extant wild populations. Disease had devastating effects on both wild and restored populations, but dynamics were highly variable and appeared to be site-specific with no significant differences in disease prevalence between wild versus restored sites. A subset of 20 haphazardly selected colonies at each site observed over a four-month period revealed widely varying disease incidence, although not between restored and wild sites, and a case fatality rate of 8%. A tropical storm was the only discernable environmental trigger associated with a consistent spike in incidence across all sites. Lastly, two field mitigation techniques, (1) excision of apparently healthy branch tips from a diseased colony, and (2) placement of a band of epoxy fully enclosing the diseased margin, gave equivocal results with no significant benefit detected for either treatment compared to controls. Tissue condition of associated samples was fair to very poor; unsuccessful mitigation treatment samples had severe degeneration of mesenterial filament cnidoglandular bands. Polyp mucocytes in all samples were infected with suspect rickettsia-like organisms; however, no bacterial aggregates were found. No histological differences were found between disease lesions with gross signs fitting literature descriptions of white-band disease (WBD) and rapid tissue loss (RTL). Overall, our results do not support differing disease quality, quantity, dynamics, nor health management strategies between restored and wild colonies of A. cervicornis in the Florida Keys

Optimizing return‐on‐effort for coral nursery and outplanting practices to aid restoration of the Great Barrier Reef:Optimizing coral restoration return-on-effort

Coral nursery and outplanting practices have grown in popularity worldwide for targeted restoration of degraded “high value” reef sites, and recovery of threatened taxa. Success of these practices is commonly gauged from coral propagule growth and survival, which fundamentally determines the return‐on‐effort (RRE) critical to the cost‐effectiveness and viability of restoration programs. In many cases, RRE has been optimized from past successes and failures, which therefore presents a major challenge for locations such as the Great Barrier Reef (GBR) where no local history of restoration exists to guide best practice. In establishing the first multi‐taxa coral nursery on the GBR (Opal Reef, February 2018), we constructed a novel scoring criterion from concurrent measurements of growth and survivorship to guide our relative RRE, including nursery propagule numbers (stock density). We initially retrieved RRE scores from a database of global restoration efforts to date (n = 246; 52 studies) to evaluate whether and how success commonly varied among coral taxa. We then retrieved RRE scores for Opal Reef using initial growth and survivorship data for six key coral taxa, to demonstrate that RRE scores were high for all taxa predominantly via high survivorship over winter. Repeated RRE scoring in summer is therefore needed to capture the full dynamic range of success where seasonal factors regulating growth versus survivorship differ. We discuss how RRE scoring can be easily adopted across restoration practices globally to standardize and benchmark success, but also as a tool to aid decision‐making in optimizing future propagation (and outplanting) efforts

Data from: Resolving coral photoacclimation dynamics through coupled photophysiological and metabolomic profiling

Corals continuously adjust to short term variation in light availability on shallow reefs. Long-term light alterations can also occur due to natural and anthropogenic stressors, as well as management interventions such as coral transplantation. Although short term photophysiological responses are relatively well-understood in corals, little information is available regarding photoacclimation dynamics over weeks of altered light availability. We coupled photophysiology and metabolomic profiling to explore changes that accompany longer-term photoacclimation in a key Great Barrier Reef coral species (Acropora muricata). High (HL) and low light (LL) acclimated corals were collected from the reef and reciprocally exposed to high and low light ex situ. Rapid light curves using Pulse Amplitude Modulation (PAM) fluorometry revealed photophysiological acclimation of LL to HL and HL to LL shifted corals within 21 days. A subset of colonies sampled at 7 and 21 days for untargeted LC-MS and GC-MS metabolomic profiling revealed metabolic reorganization before acclimation was detected using PAM fluorometry. Metabolomic shifts were more pronounced for LL to HL treated corals than their HL to LL counterparts. Compounds driving metabolomic separation between HL-exposed and LL control colonies included amino acids, organic acids, fatty acids and sterols. Reduced glycerol and campesterol suggest decreased translocation of photosynthetic products from symbiont to host in LL to HL shifted corals, with concurrent increases in fatty acid abundance indicating reliance on stored lipids for energy. We discuss how these data provide novel insight into environmental regulation of metabolism and implications for management strategies that drive rapid changes in light availability