As populations and human activities increase in coastal watersheds, an understanding of the connections of aquatic ecosystems to the adjacent terrestrial landscape is necessary to identify, monitor, and protect vulnerable coastal habitats. This study investigates the relationships between land-use patterns and δ15N values of aquatic organisms in coastal ecosystems, across a defined watershed gradient for the U.S. portion of the Great Lakes shoreline. δ15N measured in plankton and benthic invertebrates reflects a range of basin wide land-use gradients and demonstrates a strong connection between watershed-based anthropogenic activities and exposure in aquatic biota. For example, benthos δ15N values range over 12‰ across sites in our study, but regression analyses suggest that over 50% of the variability is explained by the regional landscape. Further, multiple taxa at comparable trophic position showed similar patterns in relation to watershed-scale land use. Our results suggest that within the coastal environment, the expression of landscape in aquatic biota is stronger in habitats such as embayments and wetlands than open nearshore. These results support the use of δ15N in Great Lakes coastal biota as an exposure indicator of watershed-scale N loading.
|Original language||English (US)|
|Number of pages||15|
|Journal||Journal of Great Lakes Research|
|Issue number||SPEC. ISS. 3|
|State||Published - 2007|
Bibliographical noteFunding Information:
Assistance in the field and laboratory was provided by Captain Sam Miller of the R/V Lake Explorer, Mario Picinich, Lee Anderson, Tim Corry, Steve Skolasinski, Charlie Butterworth, Evan Slocum, Jon Van Alstine, Matthew Able, and Anne Cotter. We thank Ted Angradi and Cathleen Wigand and the journal reviewers for their highly constructive and critical manuscript reviews. This experimental design was made possible with help from collaborators with the Great Lakes Environmental Indicator project, funded by the U.S. EPA Agreement EPA/R-8286750. The information in this document was wholly funded by U.S. EPA and has been approved for publication after review by agency’s National Health and Environmental Effects Research Laboratory. Approval does not signify that the contents reflect the views of the agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
- Coastal habitat
- Great Lakes
- Landscape disturbance gradient
- Stable nitrogen isotope