2009, COWRIE, Comparison of design and model-based estimates of seabird abundance derived from visual, digital still transects and digital video aerial surveys in Carmarthen Bay series https://portal.medin.org.uk/portal/start.php?tpc=015_7b0fe22a-9c9a-4041-92ec-4a7f8d03fc4a The report in this series describes design-based and model-based estimates of abundance for a group of seabirds who reside in large aggregations (scoters) and another group of seabirds that are less consistently clumped (‘gulls’) from three types of aerial surveys in Carmarthen Bay. Each type of survey was conducted on four dates during the month of March 2009 using different amounts of effort. This work explores patterns in estimates derived from different data collection and data analysis methods for both types of seabird groups. The work follows on from an examination of a portion of this data set conducted by Rexstad and Buckland (2009). 20071001 20070101