Statistical aspects of heterogeneous population dynamics (38102)

Project Details


A variety of ‘indices’ of distribution are often considered: occurrence, aggregation and geographical range. However, the estimators of these indices are frequently biased and the results often do not reflect changes in distribution, often due to effects of non-random sampling in space and time. Another type of bias in many existing methods results from the assumption that the individual observations of abundance in an area are all independent and spatial correlation is ignored. Methods that do take spatial correlation into account, such as kriging, are often inappropriate because they do not handle the high frequency of zero observations, which are typical of survey data. During this task we will develop new types of models using the so-called “Log Gaussian Cox Process” (e.g. Lewy and Kristensen 2009; Kristensen 2008), which account for spatial correlation and better involve the information from zero observations. These models will further strengthen our ability to detect changes in distribution and provide useful indices of biological aggregation or ‘clumping’ based on the degree of spatial correlation.

24 research institutes and 14 universities are partners in the project.

The project is coordinated by Plymouth Marine Laboratory, UK.

Research area: Marine Living Resources
Effective start/end date01/01/201131/12/2011