Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments
We estimated the net exchange of nitrogen and phosphorus species using core incubations under light and dark conditions in estuarine lakes that are the aquatic interface between the freshwater Everglades and marine Florida Bay. These lakes and adjacent shallow water Florida Bay environments are site...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-06-01
|
| Series: | Journal of Marine Science and Engineering |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2077-1312/9/6/626 |
| _version_ | 1797531378443616256 |
|---|---|
| author | Michael S. Owens Stephen P. Kelly Thomas A. Frankovich David T. Rudnick James W. Fourqurean Jeffrey C. Cornwell |
| author_facet | Michael S. Owens Stephen P. Kelly Thomas A. Frankovich David T. Rudnick James W. Fourqurean Jeffrey C. Cornwell |
| author_sort | Michael S. Owens |
| collection | DOAJ |
| description | We estimated the net exchange of nitrogen and phosphorus species using core incubations under light and dark conditions in estuarine lakes that are the aquatic interface between the freshwater Everglades and marine Florida Bay. These lakes and adjacent shallow water Florida Bay environments are sites where the restoration of hydrological flows will likely have the largest impact on salinity. Sediment respiration, measured by oxygen uptake, averaged (±S.D.) −2400 ± 1300, −300 ± 1000, and 1900 ± 1400 μmol m<sup>−2</sup> h<sup>−1</sup> for dark incubations, light incubations, and gross photosynthesis estimates, respectively, with dark incubations consistent with oxygen uptake measured by microelectrode profiles. Although most fluxes of soluble reactive phosphorus, nitrate, and N<sub>2</sub>–N were low under both light and dark incubation conditions, we observed a number of very high efflux events of NH<sub>4</sub><sup>+</sup> during dark incubations. A significant decrease in NH<sub>4</sub><sup>+</sup>flux was observed in the light. The largest differences between light and dark effluxes of NH<sub>4</sub><sup>+</sup> occurred in lakes during periods of low coverage of the aquatic macrophyte <i>Chara hornemannii</i> Wallman, with NH<sub>4</sub><sup>+</sup> effluxes > 200 μmol m<sup>−2</sup> h<sup>−1</sup>. Increasing freshwater flow from the Everglades is expected to expand lower salinity environments suitable for <i>Chara</i>, and therefore, diminish the sediment NH<sub>4</sub><sup>+</sup> effluxes that may fuel algal blooms. |
| first_indexed | 2024-03-10T10:42:56Z |
| format | Article |
| id | doaj.art-6564b2bebe744d50a0e00d177d94f43a |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-10T10:42:56Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-6564b2bebe744d50a0e00d177d94f43a2023-11-21T22:47:17ZengMDPI AGJournal of Marine Science and Engineering2077-13122021-06-019662610.3390/jmse9060626Controls on Nutrient Cycling in Estuarine Mangrove Lake SedimentsMichael S. Owens0Stephen P. Kelly1Thomas A. Frankovich2David T. Rudnick3James W. Fourqurean4Jeffrey C. Cornwell5Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USASouth Florida Water Management District, West Palm Beach, FL 33406, USAInstitute of Environment, Florida International University, Miami, FL 33131, USASouth Florida Natural Resources Center, Everglades National Park, Homestead, FL 33030, USAInstitute of Environment, Florida International University, Miami, FL 33131, USAHorn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USAWe estimated the net exchange of nitrogen and phosphorus species using core incubations under light and dark conditions in estuarine lakes that are the aquatic interface between the freshwater Everglades and marine Florida Bay. These lakes and adjacent shallow water Florida Bay environments are sites where the restoration of hydrological flows will likely have the largest impact on salinity. Sediment respiration, measured by oxygen uptake, averaged (±S.D.) −2400 ± 1300, −300 ± 1000, and 1900 ± 1400 μmol m<sup>−2</sup> h<sup>−1</sup> for dark incubations, light incubations, and gross photosynthesis estimates, respectively, with dark incubations consistent with oxygen uptake measured by microelectrode profiles. Although most fluxes of soluble reactive phosphorus, nitrate, and N<sub>2</sub>–N were low under both light and dark incubation conditions, we observed a number of very high efflux events of NH<sub>4</sub><sup>+</sup> during dark incubations. A significant decrease in NH<sub>4</sub><sup>+</sup>flux was observed in the light. The largest differences between light and dark effluxes of NH<sub>4</sub><sup>+</sup> occurred in lakes during periods of low coverage of the aquatic macrophyte <i>Chara hornemannii</i> Wallman, with NH<sub>4</sub><sup>+</sup> effluxes > 200 μmol m<sup>−2</sup> h<sup>−1</sup>. Increasing freshwater flow from the Everglades is expected to expand lower salinity environments suitable for <i>Chara</i>, and therefore, diminish the sediment NH<sub>4</sub><sup>+</sup> effluxes that may fuel algal blooms.https://www.mdpi.com/2077-1312/9/6/626nutrient fluxesEvergladessediment<i>Chara</i>water management |
| spellingShingle | Michael S. Owens Stephen P. Kelly Thomas A. Frankovich David T. Rudnick James W. Fourqurean Jeffrey C. Cornwell Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments Journal of Marine Science and Engineering nutrient fluxes Everglades sediment <i>Chara</i> water management |
| title | Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments |
| title_full | Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments |
| title_fullStr | Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments |
| title_full_unstemmed | Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments |
| title_short | Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments |
| title_sort | controls on nutrient cycling in estuarine mangrove lake sediments |
| topic | nutrient fluxes Everglades sediment <i>Chara</i> water management |
| url | https://www.mdpi.com/2077-1312/9/6/626 |
| work_keys_str_mv | AT michaelsowens controlsonnutrientcyclinginestuarinemangrovelakesediments AT stephenpkelly controlsonnutrientcyclinginestuarinemangrovelakesediments AT thomasafrankovich controlsonnutrientcyclinginestuarinemangrovelakesediments AT davidtrudnick controlsonnutrientcyclinginestuarinemangrovelakesediments AT jameswfourqurean controlsonnutrientcyclinginestuarinemangrovelakesediments AT jeffreyccornwell controlsonnutrientcyclinginestuarinemangrovelakesediments |