Plastic photodegradation under simulated marine conditions

Ocean plastic pollution is a problem of increasing magnitude; yet, the amount of plastic at the sea surface is much lower than expected. Solar ultraviolet (UV) radiation can induce photodegradation, but its importance in determining the longevity of floating plastic remains unconstrained. Here, we measured photodegradation rates of different plastic types slightly larger than microplastics (virgin polymers and floating plastic debris) under simulated marine conditions. UV irradiation caused all plastic types to leach dissolved organic carbon, and to a lesser degree carbon dioxide, carbon monoxide, methane, and other hydrocarbon gases. The release of photodegradation products translates to degradation rates of 1.7–2.3 % yr−1 of the tested plastic particles normalized to conditions as found in the subtropical surface ocean. Modelling the accumulation of floating plastic debris, our results show that solar UV radiation could already have degraded 7 to 22 % of all floating plastic that has ever been released to the sea

Plastic photodegradation under simulated marine conditions

Ocean plastic pollution is a problem of increasing magnitude; yet, the amount of plastic at the sea surface is much lower than expected. Solar ultraviolet (UV) radiation can induce photodegradation, but its importance in determining the longevity of floating plastic remains unconstrained. Here, we measured photodegradation rates of different plastic types slightly larger than microplastics (virgin polymers and floating plastic debris) under simulated marine conditions. UV irradiation caused all plastic types to leach dissolved organic carbon, and to a lesser degree carbon dioxide, carbon monoxide, methane, and other hydrocarbon gases. The release of photodegradation products translates to degradation rates of 1.7–2.3 % yr−1 of the tested plastic particles normalized to conditions as found in the subtropical surface ocean. Modelling the accumulation of floating plastic debris, our results show that solar UV radiation could already have degraded 7 to 22 % of all floating plastic that has ever been released to the sea

NIOZ3: independent temperature sensors sampling yearlong data at a rate of 1 Hz

International audienceSome 110 independent sensors form the NIOZ3-thermistor “string” to study waves in the ocean interior sampling at a rate of 1 Hz during at least one year. The string operates without connecting cables between the newly designed sensors, which are programmed and synchronized via induction. The accuracy of previous custom-made high-sampling rate thermistor strings is maintained, being better than 1 mK. This is demonstrated here using data from three recent field trials, two above seamounts and one in the ocean interior that occasionally show vigorous (nonlinear) internal wave motions

二南斎智角編『はい諧水いらす』翻刻と解題 : 不角の弟子の撰集

Many trace elements like Mn, Fe, Co, Ni, Cu and Zn are essential for marine life, some trace elements are of concern as pollutants, e.g. Pb and Hg, while others, together with a diverse array of isotopes, are used to assess modern-ocean processes and the role of the ocean in past climate change. GEOTRACES is an international program that aims to measure the distribution of trace elements and isotopes throughout the world oceans to improve our understanding of their marine biogeochemical cycles. To contribute to GEOTRACES a new sampler system was developed at NIOZ allowing efficient sampling of large volumes of seawater under ultraclean conditions. The 24 "PRISTINE" samplers each with a volume of 24.4 L are made of a high-purity polymer Polyvinylidene Fluoride (PVDF) and are opened and closed using a butterfly-valve closing mechanism. The samplers are mounted on an all-titanium frame and deployed using a poly-aramide hydrowire (Super Aram) with internal power/signal conductors. Upon recovery the complete frame is immediately placed in its own clean-air laboratory unit. Samplers are (i) always closed when onboard, (ii) always mounted on the frame without the need for hand-carrying heavy samplers, and (iii) can be deployed again with minimal (manual) preparation. The PRISTINE ultraclean sampling system was used for the first time during the GA02 GEOTRACES cruises in the West Atlantic Ocean (2010-2012). During 60 full ocean depth stations all 24 samplers closed with a 100% success rate. Sampling proved to be much faster, less labor intensive, and ultraclean. A comparison of salinity, temperature, nutrient and oxygen data collected with the rectangular titanium frame with PRISTINE samplers and a traditional CTD frame with Niskin samplers showed that the CTD systems functioned equally well, that the PRISTINE samplers took discrete seawater samples without any inward leakage of seawater during the up-cast, and that no atmospheric oxygen contaminated the seawater samples in the PRISTINE samplers after return on deck. The excellent agreement between 13 trace elements sampled with PRISTINE and sampled during the cross over occupation of US-GEOTRACES at the Bermuda BATS site (32 degrees N, 64 degrees W) shows its suitability for ultraclean trace element and isotope sampling (see accompanying paper). (C) 2015 Elsevier B.V. All rights reserved

Plastic photodegradation under simulated marine conditions

Ocean plastic pollution is a problem of increasing magnitude; yet, the amount of plastic at the sea surface is much lower than expected. Solar ultraviolet (UV) radiation can induce photodegradation, but its importance in determining the longevity of floating plastic remains unconstrained. Here, we measured photodegradation rates of different plastic types slightly larger than microplastics (virgin polymers and floating plastic debris) under simulated marine conditions. UV irradiation caused all plastic types to leach dissolved organic carbon, and to a lesser degree carbon dioxide, carbon monoxide, methane, and other hydrocarbon gases. The release of photodegradation products translates to degradation rates of 1.7–2.3 % yr−1 of the tested plastic particles normalized to conditions as found in the subtropical surface ocean. Modelling the accumulation of floating plastic debris, our results show that solar UV radiation could already have degraded 7 to 22 % of all floating plastic that has ever been released to the sea.</p