© 1997 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
A new software system for the PIROP database: data flow and an approach for a seabird-depth analysis
Atlantic Co-operative Wildlife Ecology Research Network (ACWERN), Faculty of Forestry and Environmental Management, University of New Brunswick P.O. Box 44555, Fredericton, New Brunswick, Canada, E3B 6C2
Environment Canada, Canadian Wildlife Service Atlantic Region, Queen Square 45 Alderney Drive, Dartmouth, Nova Scotia, Canada, B2Y 2N6
Correspondence to F. Hüttmann: tel: +5064526033; fax: +5064533538; email: k9wk{at}unb.ca
PIROP (Programme Intégré des Recherches sur les Oiseaux Pélagiques) is a well-known and unique database for seabird observations collected from the whole eastern Canadian coast, from the Gulf of Maine to the Canadian Arctic, and some other regions, between 1966 and 1992. Although several major seabird studies have already used the PIROP data, the potential exists for further data analysis. This is particularly true for statistical analyses of seabird distribution in relation to oceanographic data. Collection of field data for PIROP has evolved and improved over a period of 20 years, and new software for data entry has been developed that allows for quick and efficient entry of data on seabird observations made at sea. Thus, advanced data analysis, including spatial analyses using Geographical Information Systems (GIS), can now be done. Data may be analysed, imported and exported, and previously compiled data-sets can also be implemented into the PIROP scheme using data conversion algorithms in the import feature of the new PIROP software system. Using the new software system, an example of an analysis of the PIROP data is presented. Positive sightings of northern gannets (Sula bassana) and northern fulmars (Fulmarus glacialis) in the month of August were extracted and analysed in relation to sea depth data derived from a digital database (ETOPO5). A Classification and Regression Tree (CART) was used as an exploratory data analysis method, indicating how a distri-bution model for gannets versus fulmars in relation to sea depth may be derived from these data-sets. The model suggests that fulmar observations occur north of 51.57°N latitude over both shallow and deep waters. South of 51.57°N latitude, fulmars are found over waters deeper than 203 m, while gannets are found over shallow regions less than 203 m deep. This result is probably due to the preponderance of non-breeding birds among the observed fulmars, whereas gannets are confined to the vicinity of breeding colonies, which are situated on the continental shelf.
Keywords: bathymetry, CART, classification and regression tree, data entry mask, Fulmarus glacialis, geographical information system, GIS, seabird, software, Sula bassana, PIROP database