Satellite tracking improves conservation outcomes for nesting hawksbill turtles in Solomon Islands

The remote tracking of endangered animals is often justified by the application of movement data to conservation problems, but examples of where scientific findings have rapidly informed conservation actions are relatively rare. In this study we satellite tracked 30 adult female hawksbill turtles (Eretmochelys imbricata) that were captured after nesting in the Arnavon Community Marine Park (ACMP), Solomon Islands. Ten hawksbill turtles were tagged in April 2016, ten in May 2017 and ten in November 2018. Our primary aim was to determine if the ACMP boundaries that were demarcated in 1995 were large enough to protect female hawksbill turtles throughout their entire nesting season. Our home range analysis revealed that collectively, tracked hawksbill turtles spent 98.5% of their inter-nesting season within the ACMP, confirming that the original park boundaries were adequate. Our first year's results were shared with community and government stakeholders and assisted in getting the ACMP declared as the Solomon Islands first national park in May 2017. Our fine scale analysis of inter-nesting habitats also highlighted that most hawksbill turtle nests were being laid on an island in the ACMP that did not have a permanent ranger presence and was experiencing persistent poaching. Based on this finding an additional ranger station was established on this uninhabited island and staffed with community rangers in 2017. Our study demonstrates how involving community, government and NGO stakeholders in applied research can lead to results being rapidly utilised to inform policy and conservation practice as soon as they become available

Spironolactone for People Age 70 Years and Older With Osteoarthritic Knee Pain:A Proof‐of‐Concept Trial

Objective: To determine whether spironolactone could benefit older people with osteoarthritis (OA), based on a previous study showing that spironolactone improved quality of life. Methods: This parallel-group, randomized, placebo-controlled, double-blind trial randomized community-dwelling people ages ≥70 years with symptomatic knee OA to 12 weeks of 25 mg daily oral spironolactone or matching placebo. The primary outcome was between-group difference in change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores. Secondary outcomes included WOMAC stiffness and physical function subscores, EuroQol 5-domain (EQ-5D) 3L score, and mechanistic markers. Analysis was by intent to treat, using mixed-model regression, adjusting for baseline values of test variables. Results: A total of 421 people had eligibility assessed, and 86 were randomized. Mean ± SD age was 77 ± 5 years and 53 of 86 (62%) were women. Adherence to study medication was 99%, and all participants completed the 12-week assessment. No significant improvement was seen in the WOMAC pain score (adjusted treatment effect 0.5 points [95% confidence interval (95% CI) - 0.3, 1.3]; P = 0.19). No improvement was seen in WOMAC stiffness score (0.2 points [95% CI -0.6, 1.1]; P = 0.58), WOMAC physical function score (0.0 points [95% CI -0.7, 0.8]; P = 0.98), or EQ-5D 3L score (0.04 points [95% CI -0.04, 0.12]; P = 0.34). Cortisol, matrix metalloproteinase 3, and urinary C-telopeptide of type II collagen were not significantly different between groups. More minor adverse events were noted in the spironolactone group (47 versus 32), but no increase in death or hospitalization was evident. Conclusion: Spironolactone did not improve symptoms, physical function, or health-related quality of life in older people with knee OA

An Antenna-Coupled Dual-Gated Electron Channel as Direct Detector of 2 THz Radiation

An antenna-coupled dual-gated two-dimensional electron gas (2DEG) based on a GaAs-AlGaAs heterostructure shows a pronounced response to 2 THz radiation. The device is shown to be a direct detector, and its photoresponse arises without any source-drain bias. The detection is based on a novel mechanism that yields a substantially stronger photoresponse than predicted by the classical plasma-wave self-mixing and other mechanisms

A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter

Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority

Long-Term Effects of the Cleaner Fish Labroides dimidiatus on Coral Reef Fish Communities

Cleaning behaviour is deemed a mutualism, however the benefit of cleaning interactions to client individuals is unknown. Furthermore, mechanisms that may shift fish community structure in the presence of cleaning organisms are unclear. Here we show that on patch reefs (61–285 m2) which had all cleaner wrasse Labroides dimidiatus (Labridae) experimentally removed (1–5 adults reef−1) and which were then maintained cleaner-fish free over 8.5 years, individuals of two site-attached (resident) client damselfishes (Pomacentridae) were smaller compared to those on control reefs. Furthermore, resident fishes were 37% less abundant and 23% less species rich per reef, compared to control reefs. Such changes in site-attached fish may reflect lower fish growth rates and/or survivorship. Additionally, juveniles of visitors (fish likely to move between reefs) were 65% less abundant on removal reefs suggesting cleaners may also affect recruitment. This may, in part, explain the 23% lower abundance and 33% lower species richness of visitor fishes, and 66% lower abundance of visitor herbivores (Acanthuridae) on removal reefs that we also observed. This is the first study to demonstrate a benefit of cleaning behaviour to client individuals, in the form of increased size, and to elucidate potential mechanisms leading to community-wide effects on the fish population. Many of the fish groups affected may also indirectly affect other reef organisms, thus further impacting the reef community. The large-scale effect of the presence of the relatively small and uncommon fish, Labroides dimidiadus, on other fishes is unparalleled on coral reefs

2016 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1003/thumbnail.jp

Investigating spatial aspects of the community-based management of a small-scale artisanal grouper fishery

Fisheries are increasingly understood as complex social-ecological systems (Folke 2006). Fisheries management thus requires an understanding of key processes that underpin both the resource (i.e., fish) and the resource users (i.e., fishers) (Cinner et al. 2009b). These processes invariably operate over differing spatial and temporal scales, and one of the primary challenges facing fisheries management is adequately matching the scale of management institutions and actions to all key social and ecological processes (Cumming et al. 2006). Failure to adequately match the scale of management to these processes can have severe consequences. For example, regional scale management in the northern Altantic was unable to stop the serial depletion of numerous relatively discrete spawning stocks of cod and other groundfish leading to catastrophic and sustained population collapses (Wilson et al. 2013). Such 'problems of fit' have long been a central concern of fisheries management, most notably through Hardin's (1968) 'tragedy of the commons'. For small-scale artisanal fisheries problems of fit are particularly troubling, as key social processes such as patterns of fishing and marine tenure boundaries often operate over very restricted spatial scales (McClanahan et al. 2006). Recognition of this has led to an increasing global proliferation of community-based management of small-scale fisheries (Govan et al. 2006, 2009). However, critics suggest that problems of fit with the spatial scales of key ecological processes may drastically diminish the ability of community-based management to achieve conservation goals (Foale and Manele 2004; Mills et al. 2010). This thesis examines potential problems of fit for community-based management, through the case study of two vulnerable grouper species, Epinephelus polyphekadion and E. fuscoguttatus, targeted within a multi-species artisanal coral reef fishery in Papua New Guinea. Specifically I ask: What are the spatial problems of fit between community-based governance institutions, relatively mobile target fishes, and the fishers that target them within small-scale artisanal fisheries? Many aspects of this study drew upon the local knowledge, advice, and participation of community fishers of Dyual Island, Papua New Guinea. A range of social science and ecological research methods were employed to assess the spatial scales of operation and governance of the local fishery, and key life history processes for the focal species. Local stakeholders were intrinsically involved in the work, with research questions and methods greatly influenced by community input. Data were collected during extended field seasons within the communities of Dyual Island, Papua New Guinea, and by trained local stakeholders throughout the study period. The specific scientific objectives of this study were to (1) determine the spatial patterns of settlement, clan affiliation, access rights, and fishing effort within the local fishery, and the spatial scales of the governance institutions most relevant to its management; (2) detail the key demographic and reproductive characteristics of the two focal species of grouper; (3) examine changes in the spatial distributions of the focal species throughout their post-settlement life histories (i.e., ontogenetic shift); (4) examine the reproductive migrations of populations of the focal species associated with a multi-species transient fish spawning aggregation; and finally (5) investigate the level of spatial fit between community-based governance institutions and these key social and ecological processes. The focal fishery of this study was governed through two complementary systems –Papua New Guinea's relatively recent Westminster governance system and the enduring system of customary ownership which has much older origins. The study region was under the statebased jurisdiction of the Leon Village Planning Committee encompassing approximately 45 km² of shallow sub-tidal and inter-tidal habitat. The customary ownership of this area was divided between three clan groups, with individual tenure over areas of 7 – 19 km². Local inhabitants had access rights across the entire study area, regardless of clan affiliation. However, fishing effort was highly concentrated around human settlements, such that half of fishing effort was concentrated within just 10% of the study area. Both E. polyphekadion and E. fuscoguttatus exhibited relatively typical epinephelid life histories which make them intrinsically vulnerable to overfishing. They had long lifespans (with maximum ages of 22 and 27 yrs, respectively), relatively slow grow rates, and relatively late reproductive maturity. Females of both species reached sexual maturity between 4 – 8 yrs of age. Epinephelus fuscoguttatus reached greater lengths and exhibited faster growth. As such, female E. polyphekadion entered the reproductive population between 278 – 380 mm in length (with 50% mature at 330 mm), whereas female E. fuscoguttatus entered the reproductive population between 370 – 480 mm in length (with 50% mature at 430 mm). These ages and sizes at maturity were used to investigate the habitat requirements of these species throughout their post-settlement life histories. Habitat suitability modelling indicated that ontogenetic shift was similar for both species. Juveniles (i.e., individuals under the age/size at 50% female maturity) were restricted to habitat directly adjacent to land, particularly around mangroves and freshwater inputs. Both species occupied broader ecological niches throughout their post-settlement life histories. Adult (i.e., individuals above the age/size at 50% female maturity) habitat included patch and barrier reef habitats characterised by high live coral cover, as well as the fringing habitat preferred by juveniles. Acoustic telemetry revealed that the fish spawning aggregation currently under community-based management drew E. fuscoguttatus individuals from a 'catchment area' (i.e., the total area inhabited by the entire spawning population throughout the non-spawning season) of at least 16 km². Further analysis however, indicated that reproductive migrations were skewed toward shorter distances. As a result, 30 – 50% of the spawning population resided within the 1-2 km² directly adjacent to the aggregation site throughout the non-spawning season. Finally, I brought together all of the key social and ecological scales considered throughout this thesis, and demonstrated that at western Dyual, community-scale governance institutions presented a good spatial fit to manage the artisanal fishery for these commercially valuable grouper. The ecological processes considered here (ontogenetic shift in habitat suitability and reproductive migration to and from fish spawning aggregations) could be effectively managed at the scale of individual tenure areas. Individual spawning stocks would best be managed at this scale to avoid serial depletions. However, social processes were poorly aligned with tenure areas. Common access to resources and variable patterns of settlement resulted in highly variable fishing effort between tenure areas. Management opportunities within the most heavily fished tenure area were particularly restricted. Thus, the larger scale of community-based governance considered here, encompassing approximately 45 km², provided a better spatial fit with social processes, primarily due to its alignment with stakeholders (i.e., resource users). However, fishing effort varied at extremely fine spatial scales here. This could produce serial depletion of grouper stocks here, even within these spatially restricted management areas. This thesis demonstrates that community-based management institutions can provide a good spatial fit for managing key social and ecological processes that underpinning the persistence of relatively mobile coral reef fisheries. However, nested governance institutions may be required, even at these restricted spatial scales

Fish and fisher behaviour influence the\ud vulnerability of groupers (Epinephelidae)\ud to fishing at a multispecies spawning\ud aggregation site

Targeted fishing of spawning aggregations is a major contributor to extinction risk in numerous species of grouper (Epinephelidae). Marine reserves are often used to protect spawning aggregation sites, including multispecies sites shared by several species of grouper. However, marine reserves may be biologically, socioeconomically or culturally unviable in some fisheries, and alternative management actions must be explored. Implementing effective management actions that control rather than prohibit fishing requires an improved understanding of how species vary in their vulnerability to fishing gears and respond to changes in fishing effort. To estimate sources of variability in vulnerability to fishing (i.e. catchability), catch-per-unit-effort (CPUE) and other fisheries data were collected in parallel with underwater visual census-derived estimates of aggregation size at a multispecies spawning site of Epinephelus fuscoguttatus and E. polyphekadion. Despite having similar abundances, E. polyphekadion was eightfold more vulnerable to capture by hook-and-line gear, clearly outcompeting its congener for bait. Contrasting with the common assumption of a proportional relationship, the CPUE of both species was unrelated to the size of their respective aggregations. Moreover, the CPUE of each species was unrelated to hook size and depth fished. However, E. polyphekadion CPUE declined as the density of fishing effort increased at the site, with gear saturation identified as the likely mechanism for this effect. E. fuscoguttatus CPUE was negatively related to the size of aggregations formed by its congener, stemming from the superior competitiveness and therefore higher selectivity of the gear for E. polyphekadion. Our findings demonstrate that CPUE is an unreliable indicator of spawning aggregation status. The other sources of variation in CPUE that we identify have implications for gear-based management, which must be based on understanding of gear selectivity for aggregating species, and fishing effort controls, which must consider the potential for effort-dependent patterns in catchability

Long-term cleaner fish presence affects growth of a coral reef fish

Cleaning behaviour is considered to be a classical example of mutualism. However, no studies, to our knowledge, have measured the benefits to clients in terms of growth. In the longest experimental study of its kind, over an 8 year period, cleaner fish Labroides dimidiatus were consistently removed from seven patch reefs (61-285 m(2)) and left undisturbed on nine control reefs, and the growth and parasite load of the damselfish Pomacentrus moluccensis determined. After 8 years, growth was reduced and parasitic copepod abundance was higher on fish from removal reefs compared with controls, but only in larger individuals. Behavioural observations revealed that P. moluccensis cleaned by L. dimidiatus were 27 per cent larger than nearby conspecifics. The selective cleaning by L. dimidiatus probably explains why only larger P. moluccensis individuals benefited from cleaning. This is the first demonstration, to our knowledge, that cleaners affect the growth rate of client individuals; a greater size for a given age should result in increased fecundity at a given time. The effect of the removal of so few small fish on the size of another fish species is unprecedented on coral reefs

Effects of the cleaner fish Labroides dimidiatus on grazing fishes and coral reef benthos

Territorial and roving grazing fishes farm, and feed on, algae, sediment, or detritus, thus exerting different influences on benthic community structure, and are common clients of cleaner fish. Whether cleaners affect grazing-fish diversity and abundance, and indirectly the benthos, was tested using reefs maintained free of the bluestreak cleaner wrasse Labroides dimidiatus for 8.5 yr (removals) compared with controls. We quantified fish abundance per grazing functional group, foraging rates of roving grazers, cleaning rates of roving grazers by L. dimidiatus, reef benthos composition, and fouling material on settlement tiles. Abundances of 'intensive' and 'extensive' territorial farmers, non-farmers, parrotfishes and Acanthurus spp. were lower on removal than control reefs, but this was not the case for 'indeterminate' farmers and Ctenochaetus siriatus. Foraging rates of Acanthurus spp. and C. striatus were unaffected by cleaner presence or cleaning duration. This suggests some robustness of the grazers' foraging behaviour to loss of cleaners. Acanthurus spp. foraged predominantly on sediment and detritus, whereas C. striatus and parrotfishes grazed over algal turfs. Nevertheless, benthic community structure and amount of organic and inorganic material that accumulated over 3.5 mo on tiles were not affected by cleaner presence. Thus, despite greater abundances of many roving grazers, and consequently higher grazing rates being linked to the presence of cleaners, the benthos was not detectably affected by cleaners. This reveals that the positive effect of cleaners on fish abundance is not associated with a subsequent change in the benthos as predicted. Rather, it suggests a resilience of benthic community structure to cleaner-fish loss, possibly related to multiple antagonistic effects of different grazer functional groups. However, losing cleaners remains a problem for reefs, as the lack of cleaning has adverse consequences for fish physiology and populations