PARENT SESSION
Contributed Oral Session 147: Aquatic Communities, Disturbance, and Dispersal
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 511a, Level 5, Palais des congrès de Montréal

Surviving in a warmer, more urban world: a process-based, temporally explicit habitat model for fish.

Nelson, Karen^*,1, Palmer, Margaret¹, ¹ University of Maryland, College Park, MD, USA

ABSTRACT- As topological low points, we know that streams integrate the effects of stressors felt throughout the landscape -- but there is little consensus on how the interactions of novel stressors will affect stream ecosystem structure and function. Our goal is to predict the impact of urbanization and climate change on fish communities. To that end, we are building a process-based habitat suitability model for Piedmont fish responding to a variety of stressors, including water temperature, light levels, siltation, and invertebrate abundance. The model takes into account such disparate processes as stream warming due to impervious surface, removal of riparian vegetation, and/or increased air temperatures; increased productivity and decomposition; loss of cooler water for spawning; flashier hydrology; and higher sedimentation rates affecting both feeding and spawning. At the heart of our model are 1) timeseries predictions from a variety of disciplines, including climate change, economics, hydrology, and geomorphology, and 2) an extensive matrix of characteristics of individual fish species, including habitat, temperature, food preferences, and breeding characteristics. Depending on assumptions about levels of urbanization and climate change, our model for small streams in a Chesapeake Bay watershed suggests that up to one-fourth of current fish species could be highly stressed within the next 100 years.

Key words: urbanization, climate change, modelling, stream ecology