Abstract
Phosphorus and chlorophyll a (Chl a) concentrations in 1997 decreased from the west basin, which receives most of the lake's nutrient loading, to the central and eastern basins. By contrast, average areal primary production varied little between basins, because higher Chl a concentrations in the west basin were offset by poorer light penetration. Sub-epilimnetic production in the deeper central and east basins, which might be favored by trends to greater water clarity over recent decades, was a minor contributor to total primary production. With additional data from the literature, it was shown that pre-dreissenid Lake Erie produced significantly less Chl a relative to total phosphorus (TP) than did other Great Lakes or smaller inland lakes. Chl a:TP ratios did not change significantly consequent to dreissenid colonization. Despite the continued low yield of Chl a, Lake Erie in post-dreissenid years had areal primary production relative to TP as high as other, dreissenid-free, Great Lake locations and much higher than comparably oligotrophic inland lakes. Absolute concentrations of TP and Chl a have decreased over the decades of nutrient controls and, in the west basin, in parallel with dreissenid colonization. The lake nonetheless remained highly efficient at translating TP into primary production up to 1997, revealing little or none of the depression associated with dreissenid impacts in shallower systems.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.