東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Nutrient Drivers of Harmful Cyanobac...

Kausch, Michael Edward,

FindBook

Google Book

Amazon

博客來

Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes /

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes // Michael Edward Kausch.
作者:	Kausch, Michael Edward,
面頁冊數:	1 electronic resource (111 pages)
附註:	Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
Contained By:	Dissertations Abstracts International86-12B.
標題:	Limnology. -
電子資源:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31999513
ISBN:	9798280783386

Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes /
Kausch, Michael Edward,

Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes /Michael Edward Kausch. - 1 electronic resource (111 pages)

Source: Dissertations Abstracts International, Volume: 86-12, Section: B.

Inland waters are susceptible to harmful algal blooms (HABs) through the delivery of excess nitrogen (N) and phosphorus (P) from anthropogenic sources. Freshwater HABs are typically dominated by cyanobacteria and include species capable of producing important toxins. Historically, efforts to mitigate HABs have been based on reducing phosphorus inputs because of the potential of cyanobacteria to fix N2, and thereby dominate lakes with low N:P conditions. My research objectives were to: (1) assess the relative importance of N and P on phytoplankton biomass production and bloom formation in NY area lakes; (2) compare the effects of different forms (NO3-, NH4NO3, urea) of N on cyanobacterial bloom development, species composition, and toxin production; and (3) examine N-limited growth in an understudied cyanobacterium which lacks heterocysts, but forms blooms in low-nutrient lakes and co-occurs with toxic species. Algal (particulate) nutrient measurements revealed equal frequencies of N and P limitation of phytoplankton biomass production in oligotrophic and mesotrophic lakes, but N:P ratios were low in the most productive lakes, suggesting that N limitation was an important factor leading to eutrophic conditions. Using large-scale (5400 L) lake mesocosms, I demonstrated that treatments receiving only phosphorus did not produce a significant increase in phytoplankton biomass, indicating that drivers of maximum productivity were not caused by phosphorus alone. However, addition of both N and P produced blooms of the cyanobacterium Aphanizomenon among all forms of N. Heterocyst production by Aphanizomenon was significantly greater under lower N concentrations. Algal production and stoichiometric ratios were greatest in treatments receiving NH4+ and urea, suggesting a physiological preference for reduced forms of N. Laboratory experiments provided evidence of N2 fixation in Limnoraphis birgei, an understudied bloom-forming cyanobacterium that lacks heterocysts. Limnoraphis biomass increased significantly (> 10-fold) in flasks in zero-N addition controls to levels not significantly different from those receiving added N. My studies indicate that N-limited growth may be especially important in eutrophic systems, and that co-limitation by N and P may be critical for lakes with lower algal biomass. My results also suggest that management efforts to control eutrophication and harmful algal blooms in lakes need to focus on reducing both N and P inputs from human activities.

English

ISBN: 9798280783386Subjects--Topical Terms:

545788
Limnology.
Subjects--Index Terms:

Algae

Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes /
LDR:03901nmm a22004333i 4500 001 2436085
005 20251021115109.5
006 m o d
007 cr|nu||||||||
008 261011s2025 miu||||||m |||||||eng d
020 $a 9798280783386
035 $a (MiAaPQD)AAI31999513
035 $a AAI31999513
040 $a MiAaPQD $b eng $c MiAaPQD $e rda
100 1 $a Kausch, Michael Edward, $e author. $3 3826621
245 1 0 $a Nutrient Drivers of Harmful Cyanobacterial Blooms in New York Lakes / $c Michael Edward Kausch.
264 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2025
300 $a 1 electronic resource (111 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
500 $a Advisors: Wehr, John D. Committee members: Lewis, J. D.; Franks, Steven J.; Hekkala, Evon R.
502 $b Ph.D. $c Fordham University $d 2025.
520 $a Inland waters are susceptible to harmful algal blooms (HABs) through the delivery of excess nitrogen (N) and phosphorus (P) from anthropogenic sources. Freshwater HABs are typically dominated by cyanobacteria and include species capable of producing important toxins. Historically, efforts to mitigate HABs have been based on reducing phosphorus inputs because of the potential of cyanobacteria to fix N2, and thereby dominate lakes with low N:P conditions. My research objectives were to: (1) assess the relative importance of N and P on phytoplankton biomass production and bloom formation in NY area lakes; (2) compare the effects of different forms (NO3-, NH4NO3, urea) of N on cyanobacterial bloom development, species composition, and toxin production; and (3) examine N-limited growth in an understudied cyanobacterium which lacks heterocysts, but forms blooms in low-nutrient lakes and co-occurs with toxic species. Algal (particulate) nutrient measurements revealed equal frequencies of N and P limitation of phytoplankton biomass production in oligotrophic and mesotrophic lakes, but N:P ratios were low in the most productive lakes, suggesting that N limitation was an important factor leading to eutrophic conditions. Using large-scale (5400 L) lake mesocosms, I demonstrated that treatments receiving only phosphorus did not produce a significant increase in phytoplankton biomass, indicating that drivers of maximum productivity were not caused by phosphorus alone. However, addition of both N and P produced blooms of the cyanobacterium Aphanizomenon among all forms of N. Heterocyst production by Aphanizomenon was significantly greater under lower N concentrations. Algal production and stoichiometric ratios were greatest in treatments receiving NH4+ and urea, suggesting a physiological preference for reduced forms of N. Laboratory experiments provided evidence of N2 fixation in Limnoraphis birgei, an understudied bloom-forming cyanobacterium that lacks heterocysts. Limnoraphis biomass increased significantly (> 10-fold) in flasks in zero-N addition controls to levels not significantly different from those receiving added N. My studies indicate that N-limited growth may be especially important in eutrophic systems, and that co-limitation by N and P may be critical for lakes with lower algal biomass. My results also suggest that management efforts to control eutrophication and harmful algal blooms in lakes need to focus on reducing both N and P inputs from human activities.
546 $a English
590 $a School code: 0072
650 4 $a Limnology. $3 545788
650 4 $a Ecology. $3 516476
650 4 $a Microbiology. $3 536250
653 $a Algae
653 $a Cyanobacteria
653 $a Lakes
653 $a Nitrogen
653 $a Phosphorus
690 $a 0793
690 $a 0329
690 $a 0410
710 2 $a Fordham University. $b Biological Sciences. $e degree granting institution. $3 3826622
720 1 $a Wehr, John D. $e degree supervisor.
773 0 $t Dissertations Abstracts International $g 86-12B.
790 $a 0072
791 $a Ph.D.
792 $a 2025
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31999513