Biogeography is the study of the distribution of species and ecosystems in space and time. Biological invasions result in major shifts in the geographic distributions of species and species assemblages. As invasions have increased due to human transfers, the temporal and spatial pattern of invasions has changed dramatically.

Our research explores the biogeography of marine organisms from several vantage points, with particular emphasis on bays and estuaries:

Patterns of biological invasions

Patterns of invasions refers the both the distribution of species and the ways in which they are spread (vectors). Using data collected from the Fouling Community Survey as well as historical records from a range of sources, including literature and museum collections, we can start to understand how invasions occur, spread, and change the invaded region. The fouling survey is an intensive survey of marine fouling communities that provides standardized measures of non-native species across sites and over time, for more on this survey and the fouling community see the July 2012 Feature Story.

Shipping is a major vector in the species of marine and estuarine species. We use data on ship traffic and ballast water discharge collected by the National Ballast Information Clearinghouse (NBIC) help us understand the patterns of past invasion and help predict future ones. Learn more about how ballast water data are used in the July 2011 Feature Story. Specific examples of how data from NBIC are being used include the creation of a model to predict changes in shipping patterns with the expansion of the Panama Canal and an analysis of vessel traffic entering the Great Lakes and their subsequent movements within the Great Lakes to quantify and describe the patterns of vessel movement and resulting ballast water movements, find more on these projects here.

Range limits of native and non-native species

An example of a distribution map in the National Exotic Marine and Estuarine Species Information System (NEMESIS) showing the all the locations where the European Green Crab (Carcinus maenas) has been found. An interactive version of the map is found here under occurrences.

We explore that factors that influence the range limit of species living along the coastline. Our research is designed to (a) characterize the distribution of both native and non-native populations, (b) test hypotheses about factors that limit distribution and spread, and (c) develop predictions about the potential and realized range of species. A major focus of this work is on non-native populations, but we are also interested in comparisons between native and non-native populations. Some examples of this include the salinity and temperature trials that were conducted on the European Green Crab (Carcinus maenas) in the early 2000s (available here). More recent examples include the study done by Dr. Canning Clode in 2011 on the Northern spread of the Green Porcelain Crab (Petrolisthes armatus), described in the January 2012 Feature Story and the citizen science effort in Alaska to monitor and detect European Green Crabs as they more north, described in the March 2013 Feature Story

Updated August 2013