A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk Detecting phenology change in the mayfly

This study explores the ecological effects of a woody bank revetment in an upper reach of the River Manifold, Staffordshire, UK. Significantly higher abundances of macroinvertebrates were recorded immediately downstream of the deciduous bank revetment compared with a reference site, in 3 out of 4 months surveyed. The watercourse at the revetment also had significantly higher species richness of aquatic fauna than the reference site in some months. While there was no evidence of spatial or temporal variation in aquatic species richness within the reference site during the study period, the species biodiversity of the sub-sample collected from the deciduous revetment zone was more varied: there was significantly higher Ephemeroptera/Plecoptera/Trichoptera (EPT) richness close to the woody bank. Additionally, three relatively rare mayfly species were exclusively associated with the woody revetment (Baetis niger, Ameletus inopinatus and Siphlonorus alternatus). Water temperatures were also found to be lower in close proximity to the revetment. These micro-scale effects suggest that revetments could deliver a range of conservation benefits, not least habitat creation and mitigation of rising river temperatures under climate change. Plate 1 The test site (looking up stream) showing a bank side woody revetment in the River Manifold at Ludburn Farm in Staffordshire, UK Plate 2 The reference site (looking up stream)Ecological benefits of creating messy rivers 471

Aquatic macroinvertebrates have been the basis for one of the primary indicators and a cornerstone of lotic biomonitoring for over 40 years. Despite the widespread use of lotic invertebrates in statutory biomonitoring networks, scientific research and citizen science projects, the sampling methodologies employed frequently vary between studies. Routine statutory biomonitoring has historically relied on semi-quantitative sampling methods (timed kick sampling), while much academic research has favoured fully quantitative methods (e.g. Surber sampling). There is an untested assumption that data derived using quantitative and semi-quantitative samples are not comparable for biomonitoring purposes. As a result, data derived from the same site, but using different sampling techniques, have typically not been analysed together or directly compared. Here, we test this assumption by comparing a range of biomonitoring metrics derived from data collected using timed semi-quantitative kick samples and quantitative Surber samples from the same sites simultaneously. In total, 39 pairs of samples from 7 rivers in the UK were compared for two seasons (spring and autumn). We found a strong positive correlation (rs = +0.84) between estimates of taxa richness based on ten Surber sub-samples and a single kick sample. The majority of biomonitoring metrics were comparable between techniques, although only fully quantitative sampling allows the density of the community (individual m-2) to be determined. However, this advantage needs to be balanced alongside the greater total sampling time and effort associated with the fully quantitative methodology used here. Kick samples did not provide a good estimate of relative abundance of a number of species / taxa and, therefore, the quantitative method has the potential to provide important additional information which may support the interpretation of the biological metrics.

The ecological effects of interacting stressors within lotic ecosystems have been widely acknowledged. In particular, the ecological effects of elevated fine sediment inputs and phosphate have been identified as key factors influencing faunal community structure and composition. However, while knowledge regarding adult and larval life stage responses to environmental stressors has grown, there has been very limited research on their eggs. In this study, the eggs of the mayfly Serratella ignita (Ephemerellidae: Ephemeroptera) were collected and incubated in laboratory aquaria to hatching under differing concentrations of inert suspended sediment (SS) and orthophosphate (OP), individually and in combination. Results indicate that SS and OP have greater effects on egg hatching in combination than when either were considered in isolation. SS displayed a greater effect on egg survival than OP in isolation or when OP was added to elevated SS treatments. Egg mortality in control treatments was around 6% compared to 45% in treatments with 25 mg l SS and 52% in 0.3 mg l OP treatments. Even relatively modest levels of each stressor (10 mg l SS; 0.1 mg l OP), below national legal thresholds, had significant effects on egg survival to hatching. The results support calls for legal levels of SS to be reassessed and suggest that more research is required to assess the impacts of pollution on invertebrate egg development given their different sensitivity and exposure pathways compared to other life stages.

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