Population Ecology

Population ecology is the study of how and why populations change over time and how a given population interacts with the environment and other populations. In other words, how and why the population size of species changes over time and space.

A mud crab parasitized by the barnacle Loxothylacus panopaei. Photo by Monaca Noble 

In the marine Invasions lab we focus on biological invasions and how new species change the recipient communities they invade. Specifically how nonnative species affect native populations. Predation, competition for limiting resources, and the introduction of parasites are some of the ways that nonnative species can change native populations. Examples of our research on each of these include our work on the European Green Crab (Carcinus maenas), an introduced predator, in Seadrift Lagoon where they were introduced in the 1990s (December 2011 Feature Story). In 2007 Julia Blum and others at our satellite lab in Tiburon, CA published their study on the impact of introduced tunicate Ciona intestinalis and how it depressed species diversity through competition (Blum et al, 2007). Lastly our research on the introduced parasitic barnacle Loxothylacus panopaei on native mud crabs in Chesapeake Bay shows the impact of new parasites over time (September 2012 Feature Story).

In addition, several studies started in the mid-2000s compared the biology of native and non-native populations of the same species across broad geographic scales. We investigated Atlantic (native) and Pacific (introduced) populations of the mud crab, Rhithropanopeus harrisii, the amethyst gem clam Gemma gemma, and the rough periwinkle, Littorina saxatilis, to quantify differences in size-specific fecundity, reproductive schedule, and other demographic characters. We also conducted extensive studies with the European Green Crab (Carcinus maenas) during the late 1990s and early 2000s covering several factors that impact populations over time, including environmental tolerances and effects of invertebrate and shorebird populations. Details of some of these experiments can be found here.

Understanding the ecological and biological underpinnings of the invasion process is vital to understanding how best to prevent new introductions and how to effectively manage existing invasions.

Updated July 2013