Analysis,on,the,characteristics,of,domestic,and,foreign,blue,economy,research,based,on,CiteSpace

LIU Yuxi,LIU Yiyang,LIN Xianghong

1.National Marine Data and Information Service,Tianjin 300171,China

2.Ocean Strategic Think Tank Research Center,Shanghai Ocean University,Shanghai 201306,China

Abstract:Blue economy is one of the hot research topics both at home and abroad,which is of great significance to the construction of a strong maritime country and the high-quality development of national economy.This paper summarizes the research highlights and characteristics of blue economy at home and abroad,based on the visual analysis of analyzing 414 literature from Web of Science Core Collection Database(SSCI)and CNKI General Database,using CiteSpace 6.1.R3.The results show that:(1)The number of articles in the field of blue economy at home and abroad is on rise during 2010-2021,and the volume of foreign articles about blue economy is significantly higher than that of domestic ones.The domestic and foreign articles about blue economy were more of a theoretical mechanism research.(2)Domestic blue economy cooperation network is budding,blue economy research in coastal provinces and cities of China has policy support and scientific research advantages,and Ocean University of China is the core institution in the research field of blue economy in China.With close international blue economy network cooperation,the university is the main scientific research unit of blue economic cooperation at home and abroad.United States,the United Kingdom and Australia attach great importance to blue economy and have a good scientific research foundation,holding an absolutely dominant position in the field of blue economy research.(3)Blue industry and blue practice are the hot research topics of China"s blue economy,and the evolution of research topics can be divided into three phases.Among other topics,regional analysis,sustainable blue economy,ocean governance,are the priority research areas of international blue economy research.

Keywords:blue economy,research characteristics,knowledge graph,CiteSpace

In the early stage of international research,blue economy was often used to explore the sustainable use of freshwater runoff and watersheds.In the 1960s,Chinese scholars considered the development of marine industry as blue economy.With the enrichment and development of the connotation of blue economy at home and abroad,at the beginning of the 21st century,the blue economy concept has gradually evolved into a model for the growth of marine economy under the concept of sustainable development integrating ocean economy and green economy[1].In 2012,the European Commission proposed the"Blue Growth"strategy;in 2015,the World Wide Fund for Nature proposed the definition of"a sustainable blue economy"based on the growth of marine economy in the report of"Principles for a Sustainable Blue Economy";in 2017,the World Bank stated in"The Potential of the Blue Economy"that the blue economy seeks to promote economic growth,social inclusion,and the preservation or improvement of livelihoods while ensuring environmental sustainability of the oceans and coastal areas at the same time.

The 21stcentury is the century of the ocean,and the United Nations Sustainable Development Goal 14(SDG14)proposes to conserve and sustainably use oceans and marine resources to promote sustainable development.In the post-epidemic era,the marine economy is no less than one of the growth poles of global economic development.It is proposed in Xi Jinping"s Report at 19th CPC National Congress that"step up efforts to build China into a strong maritime country",and General Secretary Xi Jinping points out that"The oceans are strategically important to high-quality development".The blue economy,as a new concept of the ocean-based economy,has become one of the hot research topics in the field of ocean economy at home and abroad.It is of great significance to the construction of a strong maritime country and the high-quality development of economy.In this context,graph-based visualization and analysis was performed with CiteSpace6.1.R3 on the literature about blue economy at home and abroad in the past 12 years,focusing on the basic situation,development trend and main characteristics of blue economy research at home and abroad,in order to deepen the understanding of blue economy,and provide references for the in-depth research and sustainable development of China"s blue economy.

This paper uses CNKI and Web of Science(WOS)Core Collection database as data sources,and the time span of the studied literature is 2010-2021.The domestic literature on blue economy was sourced from the CNKI database,filtered by the theme of"blue economy".In order to ensure the quality of the articles,the categories of the journals were further refined to"Chinese core journals"and"CSSCI".The English literature about blue economy was sourced from the WOS Core Collection database,with the subject heading set to"blue economy",and the categories of the journals were further refined to"SSCI".The above retrieval results were manually screened,de-duplicated and sorted,and irrelevant entries such as calls for papers,prefaces,and introduction of personal academic achievements were deleted.A total of 521 valid literature were finally obtained,of which 107 were from the CNKI and 414 were from the WOS Core Collection database.

3.1 Overall picture of blue economy research publications

3.1.1 The number of published articles about blue economy at home and abroad

The number of articles published each year can visually show an overall picture of blue economy research.There is an obvious difference in the number of literature published on core journals about blue economy at home and abroad.At present,the foreign blue economy research is more in-depth,with a higher number of literature about blue economy in WOS Core Collection database than that in CNKI.As shown in the figure below,the number of domestic blue economy literature saw large fluctuations,with the first peak in 2011.And the number of domestic blue economy literature has showed a fluctuating rising trend in recent years.In contrast,the number of foreign blue economy literature has showed an exponential upward trend.The research on blue economy steeply increased in 2017,and the number of blue economy literature reached 123 in 2021,presumably due to the greater attention from the international community to the field of blue economy in recent years.

3.1.2 Distribution of domestic and foreign blue economy journals cited

In Tab.1,we selects the top 10 journals cited in terms of the number of publications about blue economy from 2010 to 2021 at home and abroad.It can be seen that domestic publications about blue economy are generally more theoretical in nature,with most of the articles being published in comprehensive theoretical journals in humanities and social sciences,such asDongyue TribuneandShandong Social Sciences;some journals focus on ocean economy,marine industry and construction of a strong maritime country,such asPacific JournalandJournal of Ocean University of China(Social Sciences),as well as journals on marine economy and policies from a country’s perspective,such as International Studies and Northeast Asia Forum.

Tab.1 Blue economy journals cited

Fig.1 The number of blue economy literature during 2010-2021

The distribution of foreign blue economy journals cited is more concentrated,with 71 blue economy publications in Marine Policy,accounting for 17.7% of the total number of publications.The foreign journals cited features a slightly broader category than the domestic journals,such as Marine Policy,which focuses on the research of policies about ocean economy,Sustainability,Frontiers in Marine Science,Marine Pollution Bulletin,etc.,which cover marine science,technology and innovation,as well as the sustainable development of marine economy,Ocean & Coastal Management,and Coastal Management,both of which are in the field of comprehensive marine management.

3.2 Analysis on the characteristics of domestic blue economy development

3.2.1 Emerging of blue economy cooperation network

There are more than one hundred institutions conducting blue economy research in China,covering research institutes,universities and government bodies,and their distribution is directly related to the geographical attributes of blue economy and their research power.Tab.2 shows the main institutions with the articles published in the field of blue economy,mainly concentrated in coastal provinces and cities such as Shandong Province,Fujian Province,and Tianjin City.Ocean University of China,a professional institution in the field of marine in China,has published the highest number of articles with 17 blue economy articles,accounting for 15.9%of the total number of articles published.It is followed by Fujian Provincial Committee Party School and Shandong University.

Tab.2 Main issuing organizations of blue economy in China

The co-occurrence knowledge mapping analysis of"research institutions"in CNKI data shows that there are 131 nodes and 59 connecting lines,with a network density of 0.0069(Figure 2).Ocean University of China(OUC)is the core research institution in the field of blue economy in China,and its blue economy partners are mainly divided into three categories.The first is the School of Education of OUC,the Institute of Marine Development of OUC,etc.;the second is the First Institute of Oceanography of the Ministry of National Resources,Shandong Academy of Social Sciences,School of Economics Shandong University and other universities and research institutes in Shandong Province;the third is Xiamen University,Sun Yat-sen University,Nagoya University,Japan and other well-known universities in coastal areas.It can be seen that the domestic blue economy research institutions are distributed dispersedly,with limited cooperation and communication among them,and the research institutions with strong connection are mainly in the same province or affiliated with the same university.

From the time of publication,Ocean University of China has the longest time span of publication(2010-2019),and Fujian Provincial Committee Party School and Shandong Academy of Social Sciences have higher volume of publications in 2013-2015.Since 2019,National Marine Data and Information Service,Wuhan University and Liaocheng University have become the research institutions with higher volume of blue economy publications.

Fig.2 Blue cooperation network of economic publishing organizations in China

In terms of financial support,there were 59 blue economy articles with fund support in China,accounting for about 55.1% of the total number(Table 3).These publications were mostly supported by the National Social Science Fund of China,the National Natural Science Foundation of China and received grants as provincial social science planning projects,21 of which received funding from the National Social Science Fund of China.In addition,Shandong province makes outstanding contribution to the funding support at the prefectural level,with 12 articles receiving funding support as social science or natural science projects in Shandong province.It can be seen that China"s coastal provinces and cities pay more attention to the development of blue economy,and the universities and research institutions in these regions have more research advantages and policy support in blue economy research and cooperation and exchange.

3.2.2 Research focusing on blue industry and blue practice

The"keywords"of data on CNKI were processed by CiteSpace software to get the word frequency,centrality and co-occurrence knowledge map of keywords,so as to further analyze the hot research topics of domestic blue economy.Tab.4 shows the statistics of keyword frequency and centrality,indicating that the themes of blue economy from 2010 to 2021 are mainly ocean economy(11),land and sea coordination(5),maritime power country(2),ocean environment(2),and the Belt and Road initiative(2).The centrality of ocean economy is 0.41,reflecting that the research of domestic blue economy focuses on the sustainable development of ocean economy.

Tab.3 Top10 funds with publish articles in blue economy

Tab.4 Word frequency and centrality of blue economy keywords in China

Combined with the keyword co-occurrence map,sorting literature themes and keywords,and reading key literature,the hot research topics in the field of blue economy are further analyzed and summarized.As shown in Fig.3 below,"blue economy"and"ocean economy"are the two most prominent nodes.The literature at the node of"blue economy"is branching out,and the derived sub-nodes are blue industry,regional development,Shandong Peninsula and Qingdao.This indicates that China"s blue economy research has been extended to the industry level[2,3],and the concept of coordinated development between regions has been introduced into the blue economy research[4],and Shandong Province and Qingdao City[5]play a pioneering role in the field of development of the blue economy.The node of"ocean economy"is also branching out,and the sub-nodes are land and sea coordination,ocean environment,countermeasure and suggestions,and marine potestatem,with a small blue financial network appears at the sub-node of ocean environment,mainly involving in the study of blue bonds to support the development of the blue economy[6].At the same time,one of the important models for the development of blue economy in China is the integration of land and sea[7],and the strategic goal of marine potestatem complements the development of blue economy[8].The"ocean economy"and its sub-nodes are studied at a more macro level,focusing on the practice and development of the blue economy.

Fig.3 Blue economy keywords of China

3.2.3 Evolutionary analysis on research topics of the blue economy

From 2010 to 2021,the theme of blue economy research has evolved and its research content has been enriched and improved.The following figure shows the prominent word spectrum of key words in blue economy articles.According to the transition phenomenon of key words in blue economy articles,the research hotspots and research frontiers in different periods are determined.As shown in Fig.4,the maximum value of the two keywords(salient words)of China and Africa is 1.14;Second is ocean governance,strategy,and the Indian Ocean.The emergence of the name of Africa and other international regions or countries as key words in 2019 indicates that the research scope of blue economy has expanded from domestic to international.With the construction of China-Africa"Blue Partnership"and global ocean governance becoming the hot research topics in this time period[9,10].In terms of keyword duration,ocean governance,strategy,and the Indian Ocean feature a longer duration,reflecting that ocean governance gradually became a highlight for academics and the international community in 2016,and was also proposed as an important research topic of the core areas for the development of the 21st Century Maritime Silk Road[11].

Fig.4 Top 10 blue economy keywords with the strongest citation bursts

To further analyze and investigate the evolution of research topics of the blue economy in China,a timeline view of keywords for blue economy articles from 2010-2021 was generated and verified with the descriptive statistics of the literature.The period of China"s blue economy research can be summarized into the following 3 phases:

Phase I(2010-2015),the focus of this phase included the connotation of blue economy,blue industry development,blue economic zone,etc.In 2010,the connotation of blue economy was defined through the analysis and research of blue economy development thinking and typical cases at home and abroad(Jiang,2010),which believed that blue economy,with dimensions of time and space,not only contains both sustainable development and intergenerational equity of marine resources,but also contains the optimization and integration of sea and land layout[12];meanwhile,taking Shandong Province and Rizhao City as examples,the construction of blue industrial belt was explored(Sun,2010)[3],the promotion of industrial network and industrial cluster on the blue economy was also explored(Zhao,2015)[2];taking Fujian Province(Zheng,2013)[13],Shandong Province[4],Qingdao City(Wang,2011)[5]and other provinces and cities as research areas,the development model of the blue economic zone in coastal areas was explored(Ao,2015)[14],and the characteristics of blue economic zone was summarized as innovation,sustainable development,and land and sea coordination[4].In addition,blue carbon sink was proposed as a new idea for the development of blue economy as early as 2011(Xu,2011)[15].

Phase II(2016-2019),the blue economy research in this phase had been extended to the international field,with the research contents mainly involving global ocean governance,the"21st Century Maritime Silk Road"and the"Ice Silk Road".The"21st Century Maritime Silk Road"is considered as an important blue corridor connecting China and the countries along the Road,by which countries(regions)cooperate to jointly advance the sustainable development of marine resources and marine industry cooperation(Chen and Han,2016)[16].In 2018 the"Ice Silk Road",i.e.,the Arctic maritime routes,was incorporated into the overall layout of the"Belt and Road"to further expand the space of the"21st Century Maritime Silk Road"(Yang,2018)[17];in the field of global ocean governance,emphasis is placed on China"s ocean governance system and modernization capacity to promote the construction of China"s"blue partnership"with African countries and countries in other regions(He,2019)[18].

Phase III(2020-present),this phase has a shorter time span,and the research contents mainly include blue bonds,blue economic passages and other international innovation efforts in blue economy.Blue bonds,as a product of blue economy,have great potential for growth,whose research direction is mostly to promote the development of China"s blue bonds by drawing on international experience such as Seychelles"(Guo,2020;Li,2021)[19],[20];"blue economic passage"is an emerging concept in recent years,which is considered to be a maritime corridor for the sustainable use of marine resources and sustainable development for all countries in the world,including Small Developing Island States(Liang,2021)[21],and existing studies include the foundation and challenges of building a blue economic passage which connects China to the Indian Ocean(Wang,2021)[22];international organizations,innovation initiatives for sustainable development of marine economy in typical marine countries[23],and influence factors of blue economy development[24](Lin,2020)are also some of the current research priorities of blue economy.

Fig.5 Blue economy timeline from 2010 to 2021 in China

3.3 Analysis on the characteristics of international blue economy research

3.3.1 Close network of blue economy cooperation

The cooperation map of foreign countries(regions)in which blue economy literature have published provides a general picture of the research situation and the degree of importance of each country in the field of blue economy research(Fig.6).The top 5 countries in terms of the volume of publications are the United States,the United Kingdom,China,Australia,and Canada in order.The United States had published the most literature with 101 articles,accounting for 25.2%,followed by the United Kingdom,China,Australia,and Canada with 93,57,50,and 39 articles,respectively,showing obvious gradient disparity in the volume of blue economy publications between countries(regions).

From the international research cooperation network,Fig.6 shows 83 nodes and 462 connecting lines,with a network density of 0.135 8,indicating a close blue economy cooperation and exchange among countries/regions.The top 5 countries in terms of network centrality are UK(0.27),USA(0.19),Germany(0.15),Denmark(0.12)and the Netherlands(0.12).Combined with the volume of publications,it shows that USA and UK,as traditional maritime powers,have strong scientific research strength in the field of blue economy and maintain close cooperation and exchange with research institutions in other countries(regions).Although China has a relatively high volume of blue economy publications,its centrality only ranked 21st.

Fig.6 Major countries(regions)of international blue economy

Tab.5 shows the main institutions in the field of international blue economy.The international institutions in the field of blue economy research are mainly top universities in UK,Australia,USA and Canada,among which University of British Columbia and University of Wollongong have published the largest numbers of literature,each with 10 articles;Ocean University of China also holds a place in the field of international blue economy research,with 9 articles.The University of Exeter in the UK has the highest network centrality,followed by Queensland University of Technology and Stanford University.In general,the developed western countries generally attach importance to blue economy research,maintain close cooperation and exchange,and occupy an absolutely dominant position in the field of blue economy research.

Tab.5 Main issuing organizations of blue economy

3.3.2 Research focusing on impacts of blue economy and sustainable development

The keyword frequency,centrality and clustering map of keywords were obtained by processing the"Keywords"of WOS data with CiteSpace software.Tab.6 shows the statistics of keyword frequency and centrality.It can be seen that the highlights in the field of blue economy includes"management(48)","impact(37)","climate change(36)"and"sustainability(33)"during 2010-2021.The centrality is 0.23 for"impact",and 0.17 for"economy",showing that the impacts of blue economy on macroeconomy,climate change and ecosystem are the key direction of international blue economy research.

Tab.6 Word frequency and Centrality of International blue economy keywords

After comprehensive comparison,the LLR algorithm was selected to conduct keyword clustering of international blue economy literature.There are 378 nodes and 1 354 connecting lines in the graph,with a density of 0.019,Q value of 0.5384(greater than 0.3)and S value of 0.8013(greater than 0.7).The clustering results are significant,efficient and obviously related.This analysis reveals that the keywords for international blue economy research from 2010 to 2021 have obvious clustering characteristics,forming a total of 14 clusters intersecting or in parallel with each other(Fig.7).The clustering results can be classified into the following categories:the first is the blue economy and its impact,such as"blue economy","economic impact",and"climate change";the second is the concept of the sustainable development of the blue economy,such as"carbon storage","small-scale fishery",and"sustainable development";the third is the blue economy-related public social issues such as"corporate social responsibility"and"social licence to operate".From the overlap between the clusters,"blue economy","economic impact"and"sustainable development"are the core of international blue economy research;blue economy is considered in many literatures to be sustainable,socially equitable,conducive to ecosystem protection and improvement of livelihoods,while science,technology and innovation are favorable supports for the development of the blue economy.

Fig.7 International blue economy keywords clustering

3.3.3 Co-citation analysis of blue economy literature

The co-citation analysis of WOS data was conducted,and the titles of articles were selected for clustering of literature cited together,from which a total of 17 hotspot literature and 4 significant research issues were obtained.As the knowledge base of academic research,cited literature can reflect the development trend of a discipline,and it can be seen that regional analysis,flexible ocean management,ocean governance transformation,sustainable blue economy,etc.are the hot topics of international blue economy research and future trends in recent years.

The articles about blue economy were mainly published in 2015,three of which with the hottest topics elaborated and analyzed the concepts of blue economy,ocean grabbing,and blue growth,respectively.The blue economy,influenced by the concept of green economy,was first proposed at the United Nations Conference on Sustainable Development in 2012,which mainly included four aspects,i.e.oceans as natural capital,oceans as good business,and oceans as integral to Small Developing Pacific Island States,and oceans as small-scale fisheries livelihoods(Silver,2015)[25].The concept of ocean grabbing focuses on ocean governance and is used to describe exploitation,protection,and fisheries management,aiming to avoid the destruction of human security and social-ecological well-being in the exploitation and utilization of marine resources(Bennett,2015)[26].Blue growth is an extension of the concept of sustainable development in the ocean economy,and is applied internationally in such fields as comprehensive marine management,marine spatial planning,and innovation in marine industries(Eikeset,2018)[27].

Fig.8 International blue economy article co-citation analysis

In this paper,CiteSpace was used as a research tool to process and analyze a total of 414 literature from Web of Science Core Collection Database(SSCI)and CNKI General Database(Core Journal of Peking University,CSSCI)during 2010-2021;analysis and study was conducted on blue economy research in terms of the volume of publications,journal distribution,cooperation network,and hot research topics,respectively,and the conclusions are as follows:

(a)From the perspective of the volume of publications,the trend of domestic and foreign articles on blue economy published from 2010 to 2021 is on the rise,and the volume of foreign articles about blue economy is significantly higher than that of domestic ones,maintaining a high growth trend since 2017.The domestic and foreign articles on blue economy were more theoretical in nature,mostly published in journals such asMarine Policy,Ocean & Coastal Management,Journal of Ocean University of China(Social Sciences)and other professional journals on marine economy and policies.

(b)From the perspective of cooperation network,international blue economy research features have closer and more mature cooperation than the domestic research community.Developed countries such as the United States,the United Kingdom and Australia attach great importance to blue economy and have a good scientific research foundation,holding an absolutely dominant position in the field of blue economy research.Blue economy research in domestic coastal provinces and cities has more policy support and scientific research advantages,and universities are the main scientific research units undertaking domestic and foreign blue economy cooperation research.

(c)From the perspective of domestic hot research topics,the domestic blue economy research sees a gradual development and has research potential and space for development.Blue industry and blue practice are the hot research topics of China"s blue economy,and the evolution of research topics can be divided into three phases:from 2010 to 2015,it was focused on the connotation of blue economy,blue industry development,blue economic zone,etc.And in this phase,innovation and sustainable concept were incorporated into the development of blue economy;from 2016 to 2019,key research perspective were extended to the international field,such as global ocean governance,the"21st Century Maritime Silk Road"and so on,indicating the importance of blue economy in the international community;from 2020 to present,China"s blue economy research has been more in-depth,and the research focuses on the new concept of blue economic passage,international innovation efforts in blue economy,etc.From the perspective of international hot research topics,attention is paid to the blue economy sustainability research in the international community,exploring the blue economy and its impact,focusing on the blue economy-related social issues,emphasizing the important support of science and technology and innovation for the growth of the blue economy,while regional analysis,sustainable blue economy,ocean governance and so on are the priority research areas of international blue economy research.

On the whole,the accumulation of blue economy research is abundant in China.With the connotation of blue economy being systematically sorted out and studied,and the research areas have been expanded with the enrichment and development of blue economy.However,domestic research still has the problems of insufficient cooperation and exchange in blue economy research,limited research directions,insufficient empirical literature,etc.which leaves potential for improvement compared with the current international blue economy research.Firstly,it is suggested to strengthen the exchanges and cooperation in the field of blue economy among domestic universities and research institutions,especially to develop the blue economy research potential of scientific research institutions in non-coastal provinces and cities,to establish a cooperation and exchange mechanism on a regular basis and make efforts to build an international academic exchange platform for the blue economy.Second,it is suggested to enrich and improve blue economy research from a multi-disciplinary perspective,such as comprehensive management,ecological environmental protection,digital economy,etc.,to break the disciplinary barriers,bring out the capacities of scientific innovation to drive the blue economy,and put blue economy research into practice.Third,it is suggested to diversify the methods of blue economy research,to learn from excellent blue economy cases of international organizations and developed maritime countries in combination with China"s national conditions and development needs,and to apply empirical methods in blue economy research,so as to provide scientific support for China"s development of blue economy and construction of maritime power country.