To understand the current state of utilizing phytoplankton to globally evaluate water quality and provide references for future studies, bibliometric methods were used to review the articles on phytoplankton and water quality monitoring published in the Web of Science database between 1996 and 2016. A total of 5850 articles were retrieved, and 93.66% of the retrieved literature comprised research papers. The annual quantity of the published literature increased with time, for instance, 516 papers were published in 2015 which was 3.51 times the number of papers published in 1996 (147 papers). During our study period, the top five literature-publishing countries were the United States, China, Germany, Canada, and France, which published 1477, 490, 471, 465, and 351 articles, with literature growth rates of 25.25, 8.38, 8.05, 7.95, and 6.00%, respectively. All 15,990 authors, including 510 core authors, came from 3851 institutions belonging to 126 countries. The Chinese Academy of Sciences, which published 202 research papers accounting for 3.45% of the total literature published during the study period, was the first institute to publish the largest number of research papers. The total citation frequency of the articles was 130,865. The number of articles with citation frequency more than 100 and between 50 and 99 were 208 and 434, respectively. The average citation frequency of these papers was 22.37, and the H-index was 127. The annual citation of articles was found to be significantly increased, with citation only 33 times in 1996, but 18,127 times in 2015. The top five authors whose papers showed the highest citation frequency were from Germany, the United States, the United States, Australia and Canada, with the citation frequencies of 1203, 875, 698, 653, and 615, respectively. However, 693 articles had not been cited even once. All 5850 papers were published in 983 journals, mainly in the English journals, such as Hydrobiologia, Estuarine Coastal and Shelf Science, and Freshwater Biology, including 83 research subjects and mainly focused on the research fields such as marine freshwater biology, environmental science ecology. A total of 10,182 keywords were extracted from these papers, and 113 keywords appeared more than 20 times. Subsequently, 39 high-frequency effective keywords and 9 core high-frequency keywords were further extracted. The nine core high-frequency keywords, which appeared more than 100 times, were phytoplankton, algae, nutrients, eutrophication, toxicity, microalgae, estuary, phosphorus, and nitrogen, and their appearance frequencies were 442, 289, 196, 192, 137, 135, 134, 114, and 101, respectively. Analysis of the co-occurrence relationship of the high-frequency keywords showed that the keywords algae and nutrients, water eutrophication and nitrogen, phosphorus, and salt co-occurred 120 times; algae and taxonomy, biological diversity, and various groups co-occurred 82 times, algae and primary production, biomass, photosynthesis, chlorophyll, food web and bioenrichment co-occurred 57 times; algae and estuary and lake co-occurred 48 times, algae and water quality, organic matter, bacteria, toxins, and copper co-occurred 40 times; and algae and temperature and climate change co-occurred 28 times. These co-occurrence relationships showed that the relative studies concentrated on the water eutrophication, biodiversity of algae, ecology of phytoplankton, and influence of environmental factors on the phytoplankton community. Water areas of estuaries and lakes were mainly concerned. These results indicated that the amount and citation frequency of the research papers on utilizing phytoplankton to evaluate water quality were rapidly growing, and the developed countries in Europe and America contributed most to the research in this field. The number of papers published by the Chinese researchers ranked second, but there is still a huge gap between China and the developed countries because of the lack of researchers and papers with high impact power in this field of research.
Author(s): Yu-Fang Liu, Li-Chuan Sun, Yan-Liang Jiang
Organization(s): Hunan University of Science and Technology, Chinese Academy of Fishery Sciences
Source: Acta Ecologica Sinica