Wednesday 14 September 2016 at 3:00pm

Title: “Urban Fish: Sure they are tough, but can they tell us anything about the future of fishes faced with climate disruption?”

Speaker:
Jay Nelson, Towson University

Abstract:
One of the least appreciated impacts of humans is how urbanization has altered the biota of urban streams. Increased impervious surface cover (ISC) in cities decreases the fraction of precipitation that enters groundwater. Thus surface run-off is much greater in cities following rainfall or melting events and urban stream flow rises dramatically often changing temperature rapidly. The loss of groundwater also produces lower flows between precipitation in urban streams and can alter natural thermal regimes. Urban fishes in Baltimore have been increasingly exposed to these radical changes of flow and temperature over the past 200 years. Interestingly, these changes to the hydrologic regime wrought by urbanization are identical to the predicted changes expected from climate disruption in many regions. This talk will explore the idea that we can use the physiology of urban fish populations to better understand how fishes will respond to coming climate change. The blacknose dace is an urban-tolerant species that exists in some of the most degraded streams around Baltimore, often to the point of being the only fish species left in a stream. However, this fish is also abundant in nearby, rural stream communities with a diverse fish fauna. This gradient of urbanized streams at similar latitude, altitude and stream order, sets up an intraspecific comparative experiment from which one can test hypotheses concerning how urbanization has changed this species, possibly revealing characteristics necessary for fish survival in a changing world.

Host: Dr. Sook Chung, Ph.D.