2011-2013, RPS, Lincs Offshore Wind Farm, Boat-based Ornithological Monitoring series https://portal.medin.org.uk/portal/start.php?tpc=015_40377e1e-2736-464a-b28c-dc7bb6d695ff Since 2007 a boat-based monitoring programme has been undertaken for the Lincs/LID6 offshore wind farm to collect information on seabird species during the pre-construction (2007-2010) and construction (2011- 2012) periods. Pre-construction surveys identified 12 key species which either occurred in (regionally) important numbers or were considered potentially sensitive to the construction and operation of the offshore wind farm. The main aim of this report is to determine whether the effects of construction related activities have had a measurable influence on the populations of each of the key species. To that end information is presented to explore changes in abundance, seasonal and spatial distribution of birds recorded within the Study Area between pre-construction and construction periods. Results from surveys during the construction period indicated the continued presence of all key species, generally at similar levels of abundance compared to the pre-construction period. However, most of these species occurred in insufficient numbers to allow for robust statistical analysis. In order to explore potential disturbance effects of construction activities, ultimately three species, reflecting high, moderate and low levels of susceptibility to disturbance respectively, were chosen for inclusion in analysis: red-throated diver, guillemot and great black-backed gull. Statistical analysis of population estimates of these three species did not reveal significant differences between pre-construction and construction periods of the Lincs/LID6 offshore wind farm. 2013