Species responses to contaminated marine sediments: An in situ experiment to inform benthic indices
Background
One of today’s largest scientific challenges is to understand how natural and anthropogenic disturbances affect the structure and functioning of marine ecosystems and the services they provide with the aim for sustainable future development. Important anthropogenic stressors to marine environments include organic enrichment and inputs of contaminants such as heavy metals and polycyclic aromatic hydrocarbons (PAHs), which accumulate in sediments of bays, estuaries, and near shore coastal zones. Benthic macroinvertebrates living in, and feeding on these sediments are commonly used to provide a biologically meaningful measure of ecological quality or ecosystem health. Several characteristics of these organisms have contributed to their establishment as important bioindicators. Being generally sedentary ensures prolonged and maximum exposure to disturbances/stressors; having a relatively short life cycle enables a rapid response to changing environmental conditions; they occupy a key position in marine food webs affecting the success of many commercially important fish; and they are trophically diverse exhibiting species-specific tolerances or sensitivity to organic enrichment, eutrophication, and chemical contaminants. As such they have become an essential component of national and international biological monitoring and assessment programs/policies.
Project Aims
This project develops/employs a relatively novel field experiment specifically designed to provide a mechanistic approach and unconfounded data to better understand species responses to different levels/types of sediment contamination and assign much needed species sensitivity/tolerance designations for benthic indices currently used in national and international biomonitoring programs.
Recolonization tray experiment deployed on the seafloor.