A decline in benthic algal production may explain recent hypoxic events in Lake Erie's central basin

نویسندگان

  • Soren Brothers
  • Yvonne Vadeboncoeur
  • Paul Sibley
چکیده

Article history: Received 23 November 2016 Accepted 19 March 2017 Available online 6 April 2017 Since the late 1990s, the central basin of Lake Erie has reputedly experienced an increase in the frequency and severity of hypoxic events. However, total phosphorus (TP) loading, in-lake TP concentrations, chlorophyll a (Chl a), and sediment oxygen demand (SOD) have all declined in the central basin since the 1970s.Water clarity in this basin has declined from the 1970s to 2000s despite the invasion of dreissenid mussels around 1990. In shallow lakes, declines in benthic primary production (PP) can generate positive feedback loops between the internal loading of nutrients/dissolved organic carbon and hypoxic/anoxic conditions in the water column. Such a hypoxia-inducingmechanism driven by declines in benthic PP has not been explored in Lake Erie. To test if a decline in benthic PPmight explain hypoxic events in the central basin of Lake Erie, we calculated the inter-decadal changes in benthic and planktonic algal production in this basin from the 1970s to the 2000s. Primary production models using water column Chl a concentrations and light attenuation indicated that benthic PP represents roughly 10% of the basin's total areal PP. However, our calculations show that benthic PP declined from approximately 540 to 200 g C/m y since the 1970s. We propose that a decline in benthic PP may have played a key mechanistic role in the transition from externally-induced hypoxia (i.e. watershed nutrient loading fueling phytoplankton production) in the 1970s and 80s to internally-induced hypoxia (sediment resuspension and internal loading) since the late 1990s. © 2017 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Record-breaking Lake Erie hypoxia during 2012 drought.

Hypoxia has been observed in the central basin of Lake Erie for decades. To understand the impact of various controlling factors, we analyze a record of hypoxic extents for Lake Erie for 1985–2012 and develop a parsimonious model of their interannual variability. We find that the 2012 North American drought and accompanying low tributary discharge was associated with a record-breaking hypoxic e...

متن کامل

Internal loading of phosphate in Lake Erie Central Basin.

After significant reductions in external phosphorus (P) loads, and subsequent water quality improvements in the early 1980s, the water quality of Lake Erie has declined considerably over the past decade. The frequency and magnitude of harmful algal blooms (primarily in the western basin) and the extent of hypoxic bottom waters in the central basin have increased. The decline in ecosystem health...

متن کامل

Increased benthic algal primary production in response to the invasive zebra mussel (Dreissena polymorpha) in a productive ecosystem, Oneida Lake, New York.

Increased water clarity associated with zebra mussel (Dreissena polymorpha) populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplankton production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates be...

متن کامل

Benthic Algae of Lake Erie (1865-2006): A Review of Assemblage Composition, Ecology, and Causes and Consequences of Changing Abundance

Peer-reviewed literature and published reports were used to summarize knowledge of benthic algal assemblage composition and ecology in Lake Erie, and causes and consequences of temporal variation in algal abundance. Macroalgal assemblages in rocky littoral and so— substrate habitats have been reasonably well described and studied, as has the epiphyte/ metaphyte assemblage associated with rocky ...

متن کامل

Impacts of the zebra mussel (Dreissena polymorpha) on large lakes: influence of vertical turbulent mixing

Vertical mixing processes and thermal structure of large lakes can impact the biological processes both through vertical transport processes and the exponential decay of light with depth. I investigated the role of these issues in algal consumption, production and influence on oxygen dynamics. The impact of a benthic filter feeder limited by physical transport of algae to the benthos. Hydrodyna...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2017