A Horizon Scan of research priorities to inform policies aimed at reducing the harm of plastic pollution to biota.

Plastic pollution in the oceans is a priority environmental issue. The recent increase in research on the topic, coupled with growing public awareness, has catalyzed policymakers around the world to identify and implement solutions that minimize the harm caused by plastic pollution. To aid and coordinate these efforts, we surveyed experts with scientific experience identified through their peer-reviewed publications. We asked experts about the most pressing research questions relating to how biota interact with plastic pollution that in turn can inform policy decisions and research agendas to best contribute to understanding and reducing the harm of plastic pollution to biota. We used a modified Horizon Scan method that first used a subgroup of experts to generate 46 research questions on aquatic biota and plastics, and then conducted an online survey of researchers globally to prioritize questions in terms of their importance to inform policy development. One hundred and fifteen experts from 29 countries ranked research questions in six themes. The questions were ranked by urgency, indicating which research should be addressed immediately, which can be addressed later, and which are of limited relevance to inform action on plastics as an environmental pollutant. We found that questions relating to the following four themes were the most commonly top-ranked research priorities: (i) sources, circulation and distribution of plastics, (ii) type of harm from plastics, (iii) detection of ingested plastics and the associated problems, and (iv) related economies and policy to ingested plastics. While there are many research questions on the topic of impacts of plastic pollution on biota that could be funded and investigated, our results focus collective priorities in terms of research that experts believe will inform effective policy and on-the-ground conservation.

Microplastics in grey seal (Halichoerus grypus) intestines: Are they associated with parasite aggregations?

Between 2012 and 2015, 13 grey seals were recovered from trammel nets targeting monkfish and rays off the south coast of Ireland. Incidence and distribution of microplastics were investigated along the intestines of bycaught seals. No macrodebris items were found, whereas microplastics were detected in all seals. A total of 363 microplastics items were identified (85% fibers, 14% fragments, 1% films). Estimation of microplastic ingestion based on prey ingestion (245 particles) was lower than the observed data. Acantocephala parasites (n = 1543) were found in 12 seals, with an average of 74.5 ±â€¯67.7 parasites per seal. Distribution of microplastics varied between seals, although microplastics tended to accumulate in areas where more parasites were aggregated; however, there was no significant relationship between the number of parasites and microplastics was found. Seals recovered from nets appear to be a good source to monitor the incidence of microplastic pollution within the coastal food webs.

Tools and constraints in monitoring interactions between marine litter and megafauna: Insights from case studies around the world.

Adverse impacts of marine litter is documented on >1400 species, including marine megafauna (fish, birds, sea turtles and mammals). The primary impacts include ingestion and entanglement, and there is increasing concern about chemical contamination via ingestion. Numerous survey approaches and monitoring programs have been developed and implemented around the world. They may aim to provide data about parameters such as species distribution and interactions with anthropogenic activities. During the Sixth International Marine Debris Conference, a session was dedicated to the tools and constraints in monitoring interactions between litter and megafauna. In the present paper, we summarize 7 case studies which discuss entanglement and ingestion including macro- and micro-debris in several taxa and across multiple geographic regions. We then discusses the importance of tools and standardizing methods for assessment and management purposes, in the context of international environmental policies and marine litter strategies.

Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel.

Microplastics are present in marine habitats worldwide and laboratory studies show this material can be ingested, yet data on abundance in natural populations is limited. This study documents microplastics in 10 species of fish from the English Channel. 504 Fish were examined and plastics found in the gastrointestinal tracts of 36.5%. All five pelagic species and all five demersal species had ingested plastic. Of the 184 fish that had ingested plastic the average number of pieces per fish was 1.90±0.10. A total of 351 pieces of plastic were identified using FT-IR Spectroscopy; polyamide (35.6%) and the semi-synthetic cellulosic material, rayon (57.8%) were most common. There was no significant difference between the abundance of plastic ingested by pelagic and demersal fish. Hence, microplastic ingestion appears to be common, in relatively small quantities, across a range of fish species irrespective of feeding habitat. Further work is needed to establish the potential consequences.

A comparison of handsearching versus MEDLINE searching to identify reports of randomized controlled trials.

This study aims to compare handsearching to a basic MEDLINE search for the identification of reports of randomized trials in specialized health care journals. Twenty-two specialized health care journals, published in the U.K., were handsearched for all reports of controlled trials (as defined by the Cochrane Collaboration). The reports of trials, which were judged to be definitely randomized, were identified from a random sample of three years per journal and form one element of this study. A MEDLINE search using the publication type terms 'randomized controlled trial' and 'controlled clinical trial' was also performed for the same journal years. The reports of trials retrieved by handsearching were then compared against those retrieved from the MEDLINE search, to identify differences in retrieval between the two techniques. Reports of randomized trials identified by the MEDLINE search but not found by handsearching were individually assessed to see if they met the Cochrane eligibility criteria for a report of a randomized trial. A total of 714 reports of randomized trials were found by using a combination of both handsearching and MEDLINE searching. Of these, 369 (52 per cent) were identified only by handsearching and 32 (4 per cent) were identified only by MEDLINE searching. Of the reports identified only by handsearching, 252 had no MEDLINE record, of which 232 (92 per cent) were meeting abstracts or published in supplements; 117 (25 per cent) of the 462 reports of randomized trials which had a MEDLINE record were missed by the electronic search because they did not have either of the publication type terms 'randomized controlled trial' or 'controlled clinical trial'. This proportion varied depending on when the reports of randomized trials were published (that is, before or after the introduction of the MEDLINE publication type terms above). The highest additional yield from handsearching compared to MEDLINE searching was for reports of randomized trials published prior to 1991 and from handsearching the non-MEDLINE indexed parts of a journal. The results of this study suggest that a combination of MEDLINE and handsearching is required to identify adequately reports of randomized trials.

Improving searching skills and evidence retrieval.

OBJECTIVE: To evaluate the effect of a three-hour training session in formulating questions and searching databases. DESIGN: A randomised controlled trial and before and after study, with blinded outcome assessment. SETTING: Oxford University Medical School, first clinical year. SUBJECTS: Altogether 108 medical students were randomly assigned to an experimental group (54) or a control group (54), and all were given the task of searching for evidence around an ulcer related problem or a cardiac problem. Students in the experimental group were randomly allocated to research one of the two problems before training and the remaining problem afterwards. Control students received no training and were randomly allocated to search for evidence around either of these problems. MAIN OUTCOME MEASURES: Searching performance; the quality of evidence retrieved; student satisfaction. RESULTS: Training improved the students' search performance and the quality of evidence retrieved. Students' satisfaction with the training was high. CONCLUSIONS: A three-hour interactive training session improved the students' ability to search databases and retrieve evidence and was well received by the students.