CURRENT PROJECTS
A. Causes and consequences of biodiversity
We are looking to develop a quantitative vision of how and why the biodiversity of hard substrate benthic communities has changed over the past 3 decades and to predict conditions influencing their stability.
B. Influence of oceanographic climate change on subtidal benthic ecosystems
A fundamental unknown required to predict the impacts of climate change how climate change will impact ecosystems is whether communities respond to physical disturbance in a linear (ie all negative or positive responses) or non-linear (leveling off) fashion where thresholds come into play. As recurrent, large scale shifts in oceanographic climate, El Niño's (ENSO’s) represent a good proxy for studying some aspects of future climate change in the ocean.
C. Long term change in the Gulf of Maine: overfishing, species invasions and climate change
The Gulf of Maine (GOM) has been impacted by overfishing, species invasions, and rising ocean temperatures. In this way, it is probably typical of many coastal-offshore marine ecosystems in the 21st century. Witman's baseline on fish populations, physical disturbance and patterns/processes in rocky subtidal communities (invertebrates, macroalgae) of the GOM extends back to the late 1970's, and we are using it to test theory and ask key questions about how subtidal ecosystems are being altered by these drivers.
We are looking to develop a quantitative vision of how and why the biodiversity of hard substrate benthic communities has changed over the past 3 decades and to predict conditions influencing their stability.
- Effects of predator diversity on the strength of trophic cascades in an oceanic benthic ecosystem (Galapagos Islands)
- The effects of biodiversity on the temporal stability and resilience of subtidal marine communities: a global evaluation
B. Influence of oceanographic climate change on subtidal benthic ecosystems
A fundamental unknown required to predict the impacts of climate change how climate change will impact ecosystems is whether communities respond to physical disturbance in a linear (ie all negative or positive responses) or non-linear (leveling off) fashion where thresholds come into play. As recurrent, large scale shifts in oceanographic climate, El Niño's (ENSO’s) represent a good proxy for studying some aspects of future climate change in the ocean.
C. Long term change in the Gulf of Maine: overfishing, species invasions and climate change
The Gulf of Maine (GOM) has been impacted by overfishing, species invasions, and rising ocean temperatures. In this way, it is probably typical of many coastal-offshore marine ecosystems in the 21st century. Witman's baseline on fish populations, physical disturbance and patterns/processes in rocky subtidal communities (invertebrates, macroalgae) of the GOM extends back to the late 1970's, and we are using it to test theory and ask key questions about how subtidal ecosystems are being altered by these drivers.
