A rare oasis effect for forage fauna in oceanic eddies at the global scale.

Oceanic eddies are recognized as pivotal components in marine ecosystems, believed to concentrate a wide range of marine life spanning from phytoplankton to top predators. Previous studies have posited that marine predators are drawn to these eddies due to an aggregation of their forage fauna. In this study, we examine the response of forage fauna, detected by shipboard acoustics, across a broad sample of a thousand eddies across the world's oceans. While our findings show an impact of eddies on surface temperatures and phytoplankton in most cases, they reveal that only a minority (13%) exhibit significant effects on forage fauna, with only 6% demonstrating an oasis effect. We also show that an oasis effect can occur both in anticyclonic and cyclonic eddies, and that the few high-impact eddies are marked by high eddy amplitude and strong water-mass-trapping. Our study underscores the nuanced and complex nature of the aggregating role of oceanic eddies, highlighting the need for further research to elucidate how these structures attract marine predators.

Modeling present and future climate risk of dengue outbreak, a case study in New Caledonia.

BACKGROUND: Dengue dynamics result from the complex interactions between the virus, the host and the vector, all being under the influence of the environment. Several studies explored the link between weather and dengue dynamics and some investigated the impact of climate change on these dynamics. Most attempted to predict incidence rate at a country scale or assess the environmental suitability at a global or regional scale. Here, we propose a new approach which consists in modeling the risk of dengue outbreak at a local scale according to climate conditions and study the evolution of this risk taking climate change into account. We apply this approach in New Caledonia, where high quality data are available. METHODS: We used a statistical estimation of the effective reproduction number (Rt) based on case counts to create a categorical target variable : epidemic week/non-epidemic week. A machine learning classifier has been trained using relevant climate indicators in order to estimate the probability for a week to be epidemic under current climate data and this probability was then estimated under climate change scenarios. RESULTS: Weekly probability of dengue outbreak was best predicted with the number of days when maximal temperature exceeded 30.8°C and the mean of daily precipitation over 80 and 60 days prior to the predicted week respectively. According to scenario RCP8.5, climate will allow dengue outbreak every year in New Caledonia if the epidemiological and entomological contexts remain the same. CONCLUSION: We identified locally relevant climatic factor driving dengue outbreaks in New Caledonia and assessed the inter-annual and seasonal risk of dengue outbreak under different climate change scenarios up to the year 2100. We introduced a new modeling approach to estimate the risk of dengue outbreak depending on climate conditions. This approach is easily reproducible in other countries provided that reliable epidemiological and climate data are available.

The wave regimes of the Central Pacific Ocean with a focus on pearl farming atolls.

Pearl farming sustainability in South Central Pacific (SCP) atolls strongly depends on water quality and renewal. These factors are partly controlled by the wave conditions that impact the lagoon circulation. To characterize the wave conditions around 83 SCP atolls including those hosting pearl farming activities, we used 18 years of WaveWatchIII simulation with a grid refined from 50 to 5 km resolution. Three regional wave regimes are statistically identified: two associated with long distant swells originating from mid-latitude storms, and one with local trade winds. All regimes occur with a relatively high frequency (22-44%), but with a marked seasonality. Wave conditions are also strongly modified locally during their propagation between the archipelagoes. Western and southern isolated atolls generally have a single regime all around their rims. In contrast, central Tuamotu atolls experience different regimes depending on their levels of protection. These results help understanding atoll hydrodynamics, which has implications for their management.

Characterization of south central Pacific Ocean wind regimes in present and future climate for pearl farming application.

In the South Pacific (SP) pearl farming atolls, wind is the main driver of lagoon water circulation, affecting dispersal and survival of pearl oyster larvae. To characterize typical wind conditions in the SP, wind regime classifications are performed from regional climate simulations using the WRF model, for present-day and for the end of the 21st century under RCP8.5 scenario conditions. At the daily time-scale, 4 regimes are identified: a trade-wind, a north-easterly, and two easterly regimes. Their characteristics are driven by large-scale circulation and climate modes of variability. In future projection, all regimes are characterized by a ~15% wind speed increase, while directions and occurrence frequencies undergo marginal changes. At the monthly time-scale that corresponds to pearl oyster pelagic larval duration, nine wind regimes are determined including three regimes with wind reversals. These regimes can be used to model typical lagoon conditions during larval dispersal.

Incidence and Risk Factors of Reticular Pseudodrusen Using Multimodal Imaging.

Importance: Although retinal multimodal imaging is needed for diagnosing reticular pseudodrusen (RPD), the incidence of RPD in the general population typically has been assessed only using fundus photographs, which may underestimate their incidence. Objectives: To describe the incidence of RPD using retinal color photographs, spectral-domain optical coherence tomography scans, fundus autofluorescence, and near-infrared reflectance images among individuals 77 years of age or older and to analyze the associated risk factors of RPD. Design, Setting, and Participants: The ALIENOR (Antioxydants, Lipides Essentiels, Nutrition et Maladies Oculaires) Study is a cohort of French individuals 77 years of age or older. Data for this study were collected between February 22, 2011, and February 15, 2017, with a mean (SD) follow-up of 3.7 (1.0) years (range, 1.2-5.6 years). At baseline, 501 individuals were eligible to participate. Of 1002 eyes, 197 had prevalent RPD, advanced age-related macular degeneration, or ungradable images. Of the remaining 805 eyes, 333 were missing follow-up data; therefore, the statistical analyses included data from 472 eyes. Data management and statistical analyses were performed between March 15, 2017, and April 5, 2019. Main Outcomes and Measures: Reticular pseudodrusen were considered as present if detected by at least 2 of the following imaging methods: color fundus photographs, fundus autofluorescence, near-infrared reflectance, and spectral-domain optical coherence tomography images. Results: Of the 472 eyes analyzed, 263 (55.7%) were from female participants, and the mean (SD) age was 81.9 (3.2) years. Forty-three eyes developed RPD, corresponding to an annual incidence rate of 2.9% (95% CI, 1.9%-4.4%) per participant and an estimated 5-year risk of 13.5%. In multivariable analysis, 4 risk factors of incident RPD were identified: subfoveal choroidal thinning (hazard ratio [HR], 0.99; 95% CI, 0.99-1.00 per 10-µm decrease in thickness; P = .02) and the presence of the minor allelic variants rs10490924 for ARMS2 (HR, 3.57; 95% CI, 1.80-7.10; P < .001), rs1061170 for CFH (HR, 2.12; 95% CI, 1.02-4.41; P = .04), and rs10468017 for LIPC (HR, 2.57; 95% CI, 1.37-4.82; P = .003). Lipophilic statin therapy was associated with a lower incidence of RPD (HR, 0.13; 95% CI, 0.02-0.74; P = .02). Conclusions and Relevance: With the use of multimodal imaging, the RPD incidence rate was higher than previously reported in other population-based studies using fundus color images. Individuals with subfoveal choroidal thinning or carrying minor allelic variants for ARMS2, CFH, or LIPC had an increased risk for RPD, whereas lipophilic statin therapy was associated with a lower incidence.

Whales in warming water: Assessing breeding habitat diversity and adaptability in Oceania's changing climate.

In the context of a changing climate, understanding the environmental drivers of marine megafauna distribution is important for conservation success. The extent of humpback whale breeding habitats and the impact of temperature variation on their availability are both unknown. We used 19 years of dedicated survey data from seven countries and territories of Oceania (1,376 survey days), to investigate humpback whale breeding habitat diversity and adaptability to climate change. At a fine scale (1 km resolution), seabed topography was identified as an important influence on humpback whale distribution. The shallowest waters close to shore or in lagoons were favored, although humpback whales also showed flexible habitat use patterns with respect to shallow offshore features such as seamounts. At a coarse scale (1° resolution), humpback whale breeding habitats in Oceania spanned a thermal range of 22.3-27.8°C in August, with interannual variation up to 2.0°C. Within this range, both fine and coarse scale analyses of humpback whale distribution suggested local responses to temperature. Notably, the most detailed dataset was available from New Caledonia (774 survey days, 1996-2017), where encounter rates showed a negative relationship to sea surface temperature, but were not related to the El Niño Southern Oscillation or the Antarctic Oscillation from previous summer, a proxy for feeding conditions that may impact breeding patterns. Many breeding sites that are currently occupied are predicted to become unsuitably warm for this species (>28°C) by the end of the 21st century. Based on modeled ecological relationships, there are suitable habitats for relocation in archipelagos and seamounts of southern Oceania. Although distribution shifts might be restrained by philopatry, the apparent plasticity of humpback whale habitat use patterns and the extent of suitable habitats support an adaptive capacity to ocean warming in Oceania breeding grounds.

Optical coherence tomography angiography and choroidal neovascularization in multifocal choroiditis: A descriptive study.

PURPOSE: To analyze the ability of optical coherence tomography angiography to identify choroidal neovascularization in multifocal choroiditis and to describe active and inactive choroidal neovascularization findings. METHODS: Retrospective study of consecutive patients with multifocal choroiditis and choroidal neovascularization examined between January and November 2016. In addition to usual exams, optical coherence tomography angiography (AngioPlex™ CIRRUS™ HD-OCT model 5000; Carl Zeiss Meditec, Inc., Dublin, CA, USA) images were assessed for morphological analysis: choroidal neovascularization size, choroidal neovascularization margin (well or poorly circumscribed), choroidal neovascularization shape (tangled or interlacing), choroidal neovascularization core (feeder vessel) and dark ring around the choroidal neovascularization. RESULTS: A total of 10 eyes were included. Optical coherence tomography angiography identified all choroidal neovascularization. Active choroidal neovascularization had well-circumscribed margins (67%), interlacing shape (83%), and a surrounding dark ring (83%). Inactive choroidal neovascularization had rather poorly circumscribed margins (75%), tangled shape, and "dead tree" appearance (50%) with less frequently a surrounding dark ring (50%). CONCLUSION: Optical coherence tomography angiography is adapted to confirm the diagnosis of choroidal neovascularization complicating multifocal choroiditis, but it is still insufficient to differentiate active and inactive lesions.

Spontaneous rupture of chorioretinal coloboma in an 8-year-old child is treated by temporal fascia graft.

We report the rare case of an 8-year-old boy with spontaneous scleral perforation secondary to an isolated congenital chorioretinal coloboma. Visual acuity was 20/200 and examination revealed severe hypotony with subcapsular cataract, complete exudative retinal detachment, hypotonous optic nerve swelling, and hypotony retinal fold. In the temporal periphery, there was a chorioretinal coloboma with a central full-thickness defect. The scleral defect was successfully treated with an autologous temporalis fascia graft. One year later, and after cataract surgery, visual acuity had improved to 20/20, with normal intraocular pressure.

Mass mortality events in atoll lagoons: environmental control and increased future vulnerability.

Coral reefs and lagoons worldwide are vulnerable environments. However, specific geomorphological reef types (fringing, barrier, atoll, bank for the main ones) can be vulnerable to specific disturbances that will not affect most other reefs. This has implications for local management and science priorities. Several geomorphologically closed atolls of the Pacific Ocean have experienced in recent decades mass benthic and pelagic lagoonal life mortalities, likely triggered by unusually calm weather conditions lasting for several weeks. These events, although poorly known, reported, and characterized, pose a major threat for resource sustainability. Based on a sample of eleven events on eight atolls from the central South Pacific occurring between 1993 and 2012, the conservative environmental thresholds required to trigger such events are identified using sea surface temperature, significant wave height and wind stress satellite data. Using these thresholds, spatial maps of potential risk are produced for the central South Pacific region, with the highest risk zone lying north of Tuamotu Archipelago. A regional climate model, which risk map compares well with observations over the recent period (r=0.97), is then used to downscale the projected future climate. This allows us to estimate the potential change in risk by the end of the 21st century and highlights a relative risk increase of up to 60% for the eastern Tuamotu atolls. However, the small sample size used to train the analysis led to the identification of conservative thresholds that overestimated the observed risk. The results of this study suggest that long-term monitoring of the biophysical conditions of the lagoons at risk would enable more precise identification of the physical thresholds and better understanding of the biological processes involved in these rare, but consequential, mass mortality events.