diversity Article The Significance of New Records of Benthic Red Algae (Rhodophyta) for Hainan Island (and China) between 1990 and 2016 Tamara V. Titlyanova 1, Eduard A. Titlyanov 1,*, Xiubao Li 2, Inka Bartsch 3 and Bangmei Xia 4 1 National Scientific Centre of Marine Biology, Far Eastern Branch of the Russian Academy of Sciences, Palchevskogo 17, Vladivostok 690041, Russia; [email protected] 2 Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; [email protected] 3 Alfred-Wegener-Institute Helmholtz-Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; [email protected] 4 Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; [email protected] * Correspondence: [email protected] Academic Editor: Rupert Ormond Received: 3 March 2017; Accepted: 25 May 2017; Published: 31 May 2017 Abstract: We present an annotated list of new finds of red algae from Hainan Island, Southern China, including those found in 1990 and 1992 during the German-Chinese expeditions to Hainan Island and in 2008–2016 by Titlyanova, Titlyanov, and Li. Between 1990 and 1992, a total of 64 taxa of red algae were newly recorded for Hainan Island. Of these 15 species were new records for China. During the period 2008–2016, a further 54 taxa were newly recorded for Hainan Island, of which 20 were new records for China. The full list of new taxa includes taxonomic forms, dates, and locales, together with known biogeographical distributions. During both periods, the apparent enrichment of red algal marine flora has occurred in a similar way—mainly at the expense of epiphytes with filamentous, thin-filamentous, and finely branched forms. We believe that the changes in the flora of Hainan Island have been influenced by both anthropogenic and natural factors including in particular exploitation of herbivores, nutrient pollution, and coral bleaching. Keywords: new records; Rhodophyta; Hainan Island; China 1. Introduction Hainan Island is located at the subtropical northern periphery of the Indo-Pacific in the South China Sea (18◦100–20◦90 N, 108◦370–111◦10 E) (Figure1). The island has an area of about 33,920 km 2 and a coastline of more than 1000 miles. The annual mean sea surface temperature (SST) is 26 ◦C with an average seasonal range of 12.1 ◦C[1]. The annual SST maximum (30.8 ◦C) and minimum (18.7 ◦C) commonly occur in July and January, respectively. Mean sea surface salinity (SSS) in the South China Sea fluctuates between 33.3 and 34.0 practical salinity units (PSU). The mean tidal range is mostly less than 1.5 m [2,3]. Shallow areas along Hainan Island coastline are occupied by coral reefs. Seagrass beds and mangroves are also present, but to a lesser extent [4]. The species diversity on the coral reefs appears to have been declining, as does that of the seagrass beds, mainly because of increasing tourism, aquaculture, sediment loads, pollutions from land, and the coastal engineering associated with development [4–11]. The marine algal flora of Hainan Island has been studied by a number of phycologists over the period from 1933 to 2016. The first sampling of marine seaweeds on the island was performed by mainly Chinese algologists [12], from 1933 to the 1980s, at sites covering all coasts of the island (Figure1). Diversity 2017, 9, 24; doi:10.3390/d9020024 www.mdpi.com/journal/diversity Diversity 2017, 9, 24 2 of 13 Diversity 2017, 9, 24 2 of 14 Diversity 2017, 9, 24 2 of 13 Figure 1. AlgalFigureFigure collection 1. Algal 1. Algal collection sites collection at Hainan sites sites at Hainan Island: at HainanIsland: ( )—collection Island: ( )—collection ( )—collection sites of sites Tsengsites of Tsengof and Tseng andcoworkers and coworkers coworkers in the in the 1930s–1980s1930s–1980sin the (old 1930s–1980s (old spellings spellings (old of of spellingssites sites names) names); of sites; ( names))—collection )—collection; ( )—collection sitessites ofof two sitestwo German-Chinese ofGerman-Chinese two German-Chinese expeditions expeditions during October–December 1990 and March–April 1992; ( )—collection sites of expeditionsduring during October–December October–December 1990 1990 and March–Apriland March–April 1992; (+)—collection1992; ( )—collection sites of Titlyanova, sites of Titlyanov, Titlyanova, Titlyanov, and Li between 2008 and 2016. Titlyanova,and Titlyanov, Li between and 2008Li between and 2016. 2008 and 2016. This collection has been deposited in the herbarium of the Institute of Oceanology of the Chinese This collectionThisAcademy collectionhas beenof Sciences deposited has been [12]. deposited inAll the records herbarium in based the herbarium onof thethese Institute collections of the of Institute Oceanology were considered of Oceanology of the in Chineseour of previous the Chinese AcademyAcademy of Sciencespapers of [13–18]. [12]. Sciences All In thisrecords [12 early]. All collectionbased records on (EC), basedthese a totalcollections on theseof 310 collectionsmacroalgal were considered taxa were and considered their in our forms previous inwere our found, previous papers [13–18].papersof In [which 13this–18 early ].178 In collectionspecies this early (57%) (EC), collection were a total Rhodophyta of (EC), 310 amacroalgal total(Rh), of64 310(21%) taxa macroalgal andPhaeophyceae their forms taxa (Ph), andwere and their found, 68 forms (22%) were Chlorophyta (Ch). The next major algal sampling on Hainan was conducted in 1990 and 1992 during of which found,178 species of which (57%) 178 were species Rhodophyta (57%) were (R Rhodophytah), 64 (21%) (Rh), Phaeophyceae 64 (21%) Phaeophyceae (Ph), and 68 (Ph), (22%) and 68 (22%) the German-Chinese expeditions (IC) to Hainan Island (Figure 1). The results of these expeditions ChlorophytaChlorophyta (Ch). The (Ch).next major The next algal major sampling algal samplingon Hainan on was Hainan conducted was conducted in 1990 and in 1992 1990 during and 1992 during the German-Chinesewere partially expeditions published (IC) [13,16–18], to Hainan with Is land203 taxa (Figure collected, 1). Theincluding results 105 of red these (52%), expeditions 32 brown (16%), the German-Chineseand 66 green (32%) expeditions algal taxa. A (IC) third to sampling Hainan Islandwas performed (Figure 1during). The 20 results08–2016 of (LC) these (Figure expeditions 1). were partially published [13,16–18], with 203 taxa collected, including 105 red (52%), 32 brown (16%), wereSome partially of the published results of this [13, 16algal–18 inventory], with 203 have taxa also collected, been published including [13–15,17,19,20], 105 red (52%), with 32 301 brown species (16%), and 66 green (32%) algal taxa. A third sampling was performed during 2008–2016 (LC) (Figure 1). and 66being green recorded (32%) including algal taxa. 163 (54%) A third Rhodophyta, sampling 50 was (17%) performed Phaeophyceae, during and 2008–2016 88 (29%) Chlorophyta. (LC) (Figure 1). Some of theSome resultsThis of the furtherof resultsthis paperalgal of thisinventorypresents algal an inventory have annotated also havebeen list of alsopublished new been findings published [13–15,17,19,20], of red [algae13–15 for, 17with ,Hainan19 ,30120], speciesIsland with 301 made species being recordedbeingduring including recorded the includingcourse163 (54%) of this 163Rhodophyta, study. (54%) On Rhodophyta, the 50 (17%)basis of Phaeophyceae, 50 this (17%) new Phaeophyceae,list with and data 88 (29%) in and the Chlorophyta. 88literature, (29%) Chlorophyta.decadal This furtherThis paper furtherchanges presents paperin the benthican presents annotated flora an of annotated thelist island of new between list findings of new the 1930sof findings red and algae 2000s of redfor are algaeHainan analyzed for Island Hainan. made Island made during theduring course the of course this study. of this On study. the On basis the basisof this of new this newlist with list with data data in inthe the literature, literature, decadal decadal changes 2. Materials and Methods changes inin the the benthic benthic flora flora of of the the island island between between the the 1930s 1930s and and 2000s 2000s are are analyzed analyzed.. 2.1. Study Sites and Times of Sampling in 1990 and 1992 2. Materials2. Materials and Methods and Methods IC algal sampling was conducted during the German-Chinese expeditions in October–December 2.1. Study2.1. Sites Study 1990and Timesand Sites in andofMarch–April Sampling Times of Samplingin1992. 1990 During and in 1992 1990 these and expedi 1992tions, algal samples were processed as herbarium specimens by Xia and Bartsch with colleagues. New findings of red algae were documented from the IC algal samplingICfollowing algal samplingwas sites: conducted Haikou was and conducted during Qukou the on during Germ the Northan-Chinese the German-Chinesecoast, Qingnan expeditions Gang expeditions inand October–December Shalao in on October–December the East coast, 1990 and 1990in March–April andTielu in Gang, March–April 1992.Yalong During Wan, 1992. Dadong these During expedi Hai, these Luhuitou,tions, expeditions, algal Xiaodong samples algal Hai, were samples Ximao processed Zhou, were and processed as herbariumTian Ya as Hai herbarium Jiao specimensspecimens by Xiaon theand bySouth Bartsch Xia coast, and with Bartschand colleagues. Linchang, with colleagues. Meixia, New findings and NewNanmai of findings red on thealgae ofNorth-West redwere algae documented coast were (Figure documented from 1). the from the followingfollowing sites: HaikouAt sites: Linchang, and Haikou Qukou Luhuitou, and on Qukou the Dadong North on the Hai,coast, North Xiaodong Qingnan coast, Hai, Gang Qingnan Yalong and Gang Wan,Shalao and on Tian Shalao the EastYa onHai coast, the Jiao, East the coast, Tielu Gang,Tielu Yalongintertidal/infralittoral Gang, Wan, Yalong Dadong Wan, reefDadongHai, flat Luhuitou, was Hai, characterized Luhuitou, Xiaodong Xiaodongby Hai,mobile Ximao blocks Hai, Zhou, Ximao of dead and Zhou, corals, Tianand typically Ya Tian Hai on YaJiao a Hai rocky Jiao on on the Souththe Southcoast,substratum and coast, Linchang, andinterspersed Linchang, Meixia, with Meixia, an sandyd Nanmai and areas.