Estuarine Conservation and Restoration in the 21st century: Using Stable Isotopes to Turn the Red Dots Green Again

Wednesday October 10 at 3 p.m.
William-Olsson salen, level 1, Geovetenskapens hus
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by Professor Brian Fry
Australian Rivers Institute, Griffith University

 link to Prof. Brian Fry's page 

 

Estuarine Conservation and Restoration in the 21st century: Using Stable Isotopes to Turn the Red Dots Green Again

Human population growth is increasingly concentrated along coasts and in urban centers located along estuaries at the land-sea interface. Many types of downstream pressures result from the human activities in local watersheds, and what were once “green” ecozones in our estuaries are now becoming “red” problem spots. The theme of this talk is that isotopes can help in attempts to reverse these problematic trends, especially because extended forensic-type isotope profiles can be developed to distinguish natural system function vs. dysfunction.  A review of tradition non-isotope ecosystem evaluations shows that these evaluations typically focus on bottom-up effects of nutrient loading and sediment delivery, leaving out fisheries mostly because fish seem to be too mobile for easy monitoring. However, stable isotopes are strong recorders of integrated food web fisheries interactions, and this talk considers top-down or “fish-based” perspectives of ecosystem integrity. There are at least five different ways that isotopes can help evaluate estuarine functioning for fisheries food webs: 1) geolocation and residency of consumers within isoscape maps, 2) metabolic growth status and trophic level of key consumers, 3) productivity of fish measured from lipid profiles, 4) terrestrial and upland catchment-level subsidies to food webs via detrital materials, and 5) fisheries support from benthic vs planktonic sources. This talk will consider examples of these five factors within the context of the GENIE project, the Global Excellent Network of Isotopes in Estuaries. So far, GENIE is only an idea of a network rather than an actualized fact. It will take a community of isofolks to make GENIE work well and help turn those red dots green again.

 

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