title: Long-term trend of Ulva prolifera blooms in the western Yellow Sea.
abstract: Blooms of the green macroalga Ulva prolifera in the western Yellow Sea occurred every year since 2008, and they have been reported and studied extensively using a variety of means including remote sensing. However, to date, long-term bloom patterns have not been reported except for a few case studies showing examples in different years. Here, using MODIS observations and an objective method to perform statistical analysis, mean Ulva coverage in the western Yellow Sea has been derived and analyzed between 2007 and 2015 at both monthly and annual scales. On annual scale, mean Ulva coverage decreased after 2008, but increased rapidly after 2012 from 8km2in 2012 to 116km2in 2015 (the largest ever reported in history for this region). In the month of June the mean coverage increased from 18km2in 2012 to 363km2in 2015. Other than 2009 and 2010, the month of June showed maximum Ulva coverage in every year. These coverage estimates are significantly lower than previously reported values as they represent "pure" algae coverage after taking into account of partial pixel coverage. Several environmental factors were examined in an attempt to determine the reasons behind such long-term changes, yet the results are inconclusive, suggesting a strong necessity of further coordinated and multi-disciplinary researches.
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qi
authors.affiliation: College of Marine Science, University of South Florida, 140 Seventh Avenue, South, St. Petersburg, FL 33701, USA. Electronic address: huc@usf.edu.
authors.forename: Chuanmin
authors.initials: C
authors.lastname: Hu
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Laishan District, Yantai, Shandong 264003, China.
authors.forename: Qianguo
authors.initials: Q
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
authors.forename: Shaoling
authors.initials: S
authors.lastname: Shang
mesh_terms: D002681:China; D004784:Environmental Monitoring; D005068:Eutrophication; D009792:Oceans and Seas; D011157:Population Dynamics; D058998:Remote Sensing Technology; D013995:Time; D044445:Ulva / Q000502:physiology*
keywords: Aquaculture; Eutrophication; Green tide; MODIS; Remote sensing; Ulva prolifera