Temporal distribution and seasonal fluxes of microplastics in the sediments of UK rural and urban lakes

<p>Microplastics (<5 mm) are persistent environmental pollutants characterised by heterogeneous physico-chemical properties and a broad range of shapes, sizes, colours and composition. Microplastics may be directly released into the environment at this size (i.e. pellets and cosmetic microbeads) when they are known as primary microplastics. However, the majority of microplastics are secondary, i.e. they originate from the degradation of larger plastic items. An important source of secondary microplastics is represented by fibres released during washing of synthetic garments. Although microplastic contamination is thought to be ubiquitous in aquatic ecosystems, very little is known about the scale, the extent of inputs as well as rates of change in rivers and lakes. In particular lake sediments, may represent an important sink for microplastics as well as providing a means to assess historical trends.  </p><p>To assess microplastic abundance, distribution, historical records and composition in the sediments of UK urban and rural lakes, sediment cores have been collected at representative locations in two ponds on Hampstead Heath, in the Borough of Camden, London, and in three lakes in the Norfolk Broads National Park, in eastern England. Microplastics extracted from sediment cores have been identified, and variation in polymer-type analysed through sediment chronostratigraphy. Sediment chronologies can help quantify the historical flux of microplastics from terrestrial environments to freshwaters, reflecting changes in microplastic production over time.</p><p>To highlight seasonal fluxes and variations in microplastic distribution and abundance in the lakes examined, new-design sediment traps were built at UCL Geography Laboratories and anchored to the bottom of the study sites to collect material sinking from the water column. The traps are being monitored, emptied, cleaned and redeployed every three months over about a 2-year period.</p><p>This study presents the results about temporal distribution and seasonal fluxes of microplastics in sediments from Hampstead Heath ponds in London (urban sites) and from the Norfolk Broads National Park (rural sites). The identification of plastic polymers, together with the assessment of microplastic temporal distribution and seasonal patterns of accumulation in lakes will help identify factors influencing microplastic distribution and pollution sources for lakes. The results from this project will deliver a better understanding of the number and scale of sources of microplastics in urban and rural lakes, improving future risk assessments and prevention strategies.</p>

Insights into toxic Prymnesium parvum blooms: the role of sugars and algal viruses

Prymnesium parvum is a toxin-producing microalga that causes harmful algal blooms globally, which often result in large-scale fish kills that have severe ecological and economic implications. Although many toxins have previously been isolated from P. parvum, ambiguity still surrounds the responsible ichthyotoxins in P. parvum blooms and the biotic and abiotic factors that promote bloom toxicity. A major fish kill attributed to P. parvum occurred in Spring 2015 on the Norfolk Broads, a low-lying set of channels and lakes (Broads) found on the East of England. Here, we discuss how water samples taken during this bloom have led to diverse scientific advances ranging from toxin analysis to discovery of a new lytic virus of P. parvum, P. parvum DNA virus (PpDNAV-BW1). Taking recent literature into account, we propose key roles for sialic acids in this type of viral infection. Finally, we discuss recent practical detection and management strategies for controlling these devastating blooms.

Arthur Ransome and the Dialect of Norfolk

Arthur Ransome provides information about the dialect of the English county of Norfolk as it was actually spoken in the 1930s. Two of his novels (Coot Club and The Big Six) are set on the Norfolk Broads. In these he offers some Norfolk vocabulary within the reported speech of some of his characters, along with some direct reflection on the dialect. However his masterpiece of Norfolk dialect is within Coots in the North (his unfinished novel, not published during his lifetime) where he presents what is in effect an extended Norfolk dialogue of over two-hundred lines. Ransome was an astute observer of language, and records the Norfolk dialogue with apparent accuracy and without contrivance.