Evidence of sewage-driven eutrophication and harmful algal blooms in Florida's Indian River Lagoon
Evidence of sewage-driven eutrophication and harmful algal blooms in Florida's Indian River Lagoon
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DOI：
10.1016/j.hal.2015.01.004
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发表时间：
2015-03-01
期刊：
影响因子：
6.6
通讯作者：
Vogel, Margaret A.
中科院分区：
文献类型：
--
作者：
Lapointe, Brian E.;Herren, Laura W.;Vogel, Margaret A.
营养物污染是全球河口和沿海水域富营养化和有害藻华的主要驱动因素。2011-2012年，对分布在251 km长的印度河泻湖（IRL）上的20个样点进行了3次采样，对溶解营养物（DIN、SRP、TON、TDP）和叶绿素a进行了评估。对底栖大型藻类的δ C-13、δ N-15和C:N:P含量进行了分析，以确定潜在的营养来源，并判断N和P限制的类型和程度。整个IRL的DIN和SRP平均浓度较高，平均分别为4.24 +/- 0.45 μ M和0.68 +/- 0.06 μ M，解释了研究期间赤潮的广泛发生。低冲水的IRL北部、蚊子湖和香蕉河段的高TDN浓度（高达152亩）和TDN:TDP比（bbb100:1）反映了富氮地下水输入的积累和循环，产生了磷限制。这些丰富的营养条件与前所未有的叶绿素a浓度（100 μ g/L）有关，其中以2011年在香蕉河的Resultor sp. O. Moestrup和2012年在蚊子泻湖和IRL北部的Aureoumbra lagunensis D.A. Stockwell, DeYoe， Hargraves和P.W. Johnson为主。大型藻的C:N、C:P和N:P比值在整个IRL期间平均分别为15.9、698.9和40.6；IRL北部段的C:P和N:P比值显著升高，表明富氮水体的磷限制较强。大藻δ N-15值在整个IRL中都富集（+6.3 ppm），与其他受污水污染的沿海水域的大藻报告的值相似。由于进入IRL的点源污水输入在很大程度上通过1990年的IRL法案被消除，这些结果表明，化粪池（类似于30万）的非点源氮富集代表了IRL的一个重要且在很大程度上被忽视的N源。IRL的污水氮污染程度高，加上最近的有害藻，包括有毒生态型的红巨藻，海草损失和野生动物死亡，表明迫切需要改善污水收集和处理，包括营养物去除。(C) 2015 Elsevier B.V.版权所有
Nutrient pollution is a primary driver of eutrophication and harmful algal blooms (HABs) in estuaries and coastal waters worldwide. In 2011-2012,20 sites evenly distributed throughout the 251-km long Indian River Lagoon (IRL) were assessed during three sampling events for dissolved nutrients (DIN, SRP, TON, TDP) and chlorophyll a. Benthic macroalgae were also analyzed for delta C-13, delta N-15, and C:N:P contents to identify potential nutrient sources and gauge the type and degree of N and P limitation. The mean DIN and SRP concentrations throughout the IRL were high, averaging 4.24 +/- 0.45 and 0.68 +/- 0.06 mu M, respectively, explaining the widespread occurrence of HABs during the study. High TDN concentrations (up to 152 mu M) and TDN:TDP ratios (>100:1) in the poorly flushed northern IRL, Mosquito Lagoon and Banana River segments reflected the accumulation and cycling of N-rich groundwater inputs that produce P-limitation. These enriched nutrient conditions were associated with unprecedented chlorophyll a concentrations (>100 mu g/L), dominated by Resultor sp. O. Moestrup in the Banana River in 2011 and Aureoumbra lagunensis D.A. Stockwell, DeYoe, Hargraves and P.W. Johnson in the Mosquito Lagoon and northern IRL in 2012. C:N, C:P, and N:P ratios in macroalgae averaged 15.9, 698.9, and 40.6, throughout the IRL, respectively; significantly higher C:P and N:P ratios in the northern IRL segments suggested strong P-limitation in these N-enriched waters. Macroalgae delta N-15 values were enriched throughout the IRL (+6.3 parts per thousand) and similar to values reported for macroalgae from other sewage-polluted coastal waters. Because point-source sewage inputs to the IRL were largely eliminated through the IRL Act of 1990, these results suggest that non-point source N enrichment from septic tanks (similar to 300,000) represents a significant and largely ignored N-source to the IRL. The high degree of sewage N contamination of the IRL, combined with recent HABs, including toxic ecotypes of the red macroalga Gracilaria tikvahiae McLachlan, seagrass loss, and wildlife mortality, indicates a critical need for improved sewage collection and treatment, including nutrient removal. (C) 2015 Elsevier B.V. All rights reserved.