Abstract
Phosphorus accumulation rates in depositional zone sediments of Lake Okeechobee were determined in 11 mudzone cores and two peat-zone cores dated by 210Pb. Although difficulties were encountered in interpreting 210Pb data from some sites, reliable dating of sediments from the mud zone of this shallow lake is possible. Sediment accumulation rates in this zone have increased during the present century by an average of about twofold, and accumulation of organic sediments in the lake during pre-settlement times apparently was much slower than during the past century. Concentrations of all forms of sedimentary P but especially nonapatite inorganic-P and organic-P also have increased since pre-settlement times and especially since about 1940. Annual P accumulation rates in the lake's sediments have increased about fourfold during the 1900s, with most of the increase occurring in the past 40-50 years. The recent accumulation rate of sedimentary P (past ~ 10 years) agrees within a factor of 1.5 with the net retention of P in the lake calculated from published input-output mass balances.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 31-46 |
| Number of pages | 16 |
| Journal | Journal of Paleolimnology |
| Volume | 20 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1998 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank Mark Brenner, Dan Conley, Matt Fisher and Scott King for assistance in collecting sediment cores, the South Florida Water Management District for field logistic support, Peter Appleby for dating assistance, and Tiekang Huang and Shen Zhisong for analysis of sediment phosphorus forms. This work was supported by the South Florida Water Management District through a subcontract from the University of Florida.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
Keywords
- Eutrophication
- Lake Okeechobee
- Lead-210 dating
- Phosphorus
- Phosphorus loading