Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. The release of phosphorus (P) from bed sediments to the overlying water can delay , 2012;Spears et al., 2012;Sharpley et al., 2014). (over 3 days, as slurry from a pontoon) to control internal P loading, in an effort to Loch Flemington (Table 1) and likewise, being shallow, does not thermally stratify.
189This site also has sufficient data available and satisfies the BACI requirements for 190 the differences between sites to be relatively constant in the before period and not 191 subject to localised long-term random influences (e.g. large storms) during the study.
192The phytoplankton community in Loch Leven is, primarily, P limited and the loch has and cyanobacterial bloom intensity (using cyanobacteria biovolume) (see also , 1986). The null hypothesis is that there is no change in the difference in 262 the two time periods i.e. no effect of the La-bentonite application and where a 263 significant difference in the differences in the two time periods is detected at the 5% evidence that a large-scale driver i.e. weather, was influencing changes at both sites.
422Hence the increase in annual mean TP concentration may have been due to 423 enhanced internal P loading, associated with the drier and warmer than average 424 summer of 2013, when compared across the five year monitoring period (Table 4) essential and could potentially be discerned using long-term monitoring data.
441The phytoplankton compositional metric (PTI EQR) showed a sustained
Implications of the results for future eutrophication management in lakes 468We have demonstrated the use of a BACI approach for detecting responses in shallow lake ecosystems (Hosper & Jagtman, 1990;Søndergaard et al., 2000; 532 Wichelen et al., 2007;Mehner et al., 2002 Mehner et al., & 2008 Duras & Dziaman, 2010).
533Controlling catchment-derived nutrient loading is a prerequisite for lasting lake 534 restoration efforts, otherwise internal stocks of nutrients will be replenished and 535 recovery periods protracted through their sediment release (Cooke et al., 2005).
536We have presented the first comprehensive assessment, using a BACI
546• This initial cyanobacterial response was not sustained beyond post-application 547 year two, implying a short lived reduction in internal P loading as a result of capping 548 sediment release.
549• The resumption in annual mean TP concentration, suggests that the La-bentonite 550 application was insufficient to control internal P loading for longer than two years.
551• Continual improvements in the phytoplankton compositional and abundance 552 metrics, not observed at the control site, may reflect a response to the sustained 553 reduction in annual mean FRP concentration following La-bentonite application.
554• The cyanobacterial bloom intensity metric is sensitive to inter-a...