Global assessment of marine plastic exposure risk for oceanic birds

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

Global assessment of marine plastic exposure risk for oceanic birds

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

Comment on 'Silicone oil removal after rhegmatogenous retinal detachment: comparing techniques' Response

We thank Drs Wong, Lee and Shunmugam1 for their interest in our paper.2 Dr Wong et al state that the number of cases with less than 2 months of tamponade is disproportionally low. The reason for the unequal distribution is that we consider 3 months as the minimum period of tamponade. This potentially introduces confounding, as the reason for early silicone oil removal could be related to worse outcome. Thus, although we revealed a statistically significant influence of tamponade duration, further study is needed to determine a causal relation, preferably using a controlled design, comparing equally sized groups. We thank Dr Wong et al for pointing out an error in the manuscript. The number of cases with tamponade of less than 2 months was not 10, as stated in the paper, but was 14. Of these 14 cases, 6 redetached, which amounts to 43% as depicted in the paper correctly. Dr Wong et al describe a perceived discrepancy between the exclusion of cases with clinically apparent macular pucker and the performance of membrane peeling. The peelings performed were for membranes located outside the macula, for instance, along the retinectomy edges. The indication for peeling of these membranes was not standardized, and was mainly dependent on intraoperative assessment of the presence of traction after staining by membrane blue. The underlying idea was that prophylactic removal of dormant retinal traction could improve the outcome. Our study was a retrospective, uncontrolled case series. The objective was to describe the transition from a two-port to a three-port technique. The reason for our transition was our hypothesis that the ability to perform an internal search could identify more retinal breaks, and that membrane removal could release dormant peripheral traction. Despite these theoretical advantages of the three-port technique, our results could not show any influence on outcome. Because of the retrospective, uncontrolled design of our study, there is plenty of room for confounding. But unless better equipped studies can show better results from a more expensive technique, we still feel that adherence to the traditional technique of oil removal is preferable

Silicone oil removal after rhegmatogenous retinal detachment: comparing technique

Purpose: To assess the outcome of silicone oil removal after rhegmatogenous retinal detachment (RRD) surgery, and to compare results of a two-port (infusion-extraction) versus a three-port (full vitrectomy) approach. Methods: Primary outcome measure was the rate of redetachment. Secondary outcome measures were visual acuity, rate of intraoperative and postoperative epiretinal membrane removal and complications. Results: We included 147 consecutive cases. There were 15 cases of giant retinal tear, 26 cases of RRD without proliferative vitreoretinopathy (PVR) and 106 cases of RRD with PVR. The overall redetachment rate after silicone oil removal was 17.7%. In the group treated with the two-port technique (n=95), the retina redetached in 16 cases (16.8%), and in the group treated with the three-port technique (n=52), redetachment occurred in 10 cases (19.2%). This difference was not statistically significant (P=0.717; χ 2-test). There was a significantly higher redetachment rate in cases with a short oil tamponade duration of <2 months. Conclusion: We reconfirm a relatively high redetachment rate after silicone oil removal. The risk of redetachment is not lower with the three-port compared with the two-port approach

A teaser made simple: a didactic measurement of the spectral answer of a human eye calibrated luxmeter

A simple didactic experiment has been designed and realized, in order to illustrate to undergraduate students in scientific faculties some basic concepts lying behind the fundamentals of geometrical optics. The spectral response of a human-eye-calibrated lux meterwas measured using a very trivial experimental arrangement. The white light of a halogen lamp was decomposed into its spectral components through a diffraction grating, so that collecting the radiation at different dispersion angles allowed one to measure the intensity as a function of wavelength. The experiment can be used to effectively illustrate the concepts of spectral distribution, the radiometry versus photometry conversion and photopic response, and the famous historical experience by Herschel on the ‘temperature of colours’