Ghép và trồng từng phần của cụm san hô thuộc các loài scleractinian khác nhau trên rạn san hô ở việt nam

Hoi thao khoa hoc - Hgp tac Ouic ti diiu ha, nghien ciru tai nguyen va m6i trudng biin TRANSPLANTATION AND CULTIVATION OF FRAGMENTS OF CORAL COLONIES OF VARIOUS SCLERACTINIAN SPECIES ON A REEF IN VIETNAIM Yu Ya LatvDov' N.I Selin', IM.L Bui^ L.Q.Pham' A.V Zhirmunsky Institute of Marine Biology, Far East Division, Russian Academy of Sciences, Vladivostok, 690059 Russia Nha Trang Institute of Technology Research and Application, Vietnam Academy of Science and Technology Institute of Natural Products Chemistry - Hanoi, Vietnam Academy of Science and Technology The economy of Vietnam is developing rapidly The coastline of Vietnam has become a site of intense house- and road-building; dozens of new hotels and diving centers have recently appeared here, and sea farming is developing extensively This intensification has become a cause of increased terrigenous effluent into waters of local bays Local coral reefs are subjected to deposition of 70-100 g/m2 a day, and this estimate grows one order higher during typhoons (Vo, Hodgson, 1997; JlaTbinOB, 2003) Erosion processes along the coastal line at the city and port of Nha Trang, as well as developing sea farming in coastal waters of neighboring islands, aggravate the sedimentation and eutrophication impact in Nha Trang Bay (An et al., 2000; riaBJioB H flp., 2004) An increased amount of microparticles of different origins increases water turbidity caused by deposition, leads to impairment of photosynthetic abilities of reef building corals and other benthic organisms, and reduces physical and biological processes in the sea (Soong, Chen, 2003) As a result, coral cover of the substrate reduces to 20-40%, while the portion of substrate cover by macrophytes Chnoospora and Halimeda grows to 60-80% General reduction of the area of coral reefs has recently been documented (Latypov, 2006) Many publications are available on transplantation and cuUivation of coral fragments; they cover various methodical, physical and biological problems connected whh coral cultivation A majority of researchers believe that the attention of those engaged in the matter should be focused on the size of coral fragments, the season of their transplantation, orientation in the place of transplanting, and selection of substrate These factors are most important for restoration of reproductive abilities of new coral colonies reared from fragments (Okubo, 2005) Based on our positive experience in cultivation of corals, we analyzed presumably species-specific peculiarities of regeneration of fragments and growth of new coral colonies of the genera Acrbpora and Porites, belonging to the families Acroporidae and Poritidae Yu Ya Latypov 341 "3 Workshop: 'international Cooperation on Investigation and Research of Marine Natural Resource and Envimnnv.wi.'^ More 20 species of genera Acropora, Isopora, Pocillopora, Porites common scleractinian were studied; which predominate in reef communities of the Indian and Pacific oceans, including also the area of Viemamese waters Experimental facilities were placed on the reef slopes of Mun Island in Nha Trang and Cam Ranh Bay, beyond the activity of open seawaters Judging from the presence of a natural reef in this locality at a depth below 12 m, the experimental installation was illuminated by sufficient light, which is crhically important for viability of hermatypic corals As compared to other localities, water turbidity and intensity of sedimentation were relatively low during our experiment The water transparence and intensity of water exchange in coral settlements were 1.48 times higher at the island than at other islands along the coast (An et al., 2000) Altogether, about 150 fragments were selected from 30 donor colonies tliat were 1-1.5 m high and 2.5-4 m in diameter All but one donor colony grew at a depth of 2-3 m Peripheral parts of coral colonies with to 17 branches were used for the experiment The length of fragments was measured with a slide gage anii three size groups were distinguished: small (40±.05 and 7±0.06 cm), medium'fll 12±0.09 cm), and large (20-21±0.41 cm) Survival and growth rates of transplanted coralftagnen^ver^nves% with respect to (I) species, (2) orientation at • " • " • ^ • • ' • ' • • • • • ^ attachment, (3) transplantation season, and (4) size of transplants Transplanted fiagments were fixed to the frame of the facility either vertically, horizontally, or with a growing distal tip downwards The frames were installed on vertical supports, 30-40 cm above the bottom, in order to prevent covering of the fragments with sediments, Fig Plastic installation Coral fragments were fixed to horizontal rods of witii transplanted coral the facility with „ plastic-covered copper wire fragments on the reef slope of (Fig 1) In order to avoid attacks of crawling Mun Island predators, e.g., Drupella rugosa Results Survival of transplants All fragments that survived after transplantation recovered and formed new finl" f ' „ " ? ' " ' T * ' " * ' ' "^^'^ intemionally injured also recovered About du/o ot all fragments fused over 6-8 months with their bases onto horizontal rods unrecovTrTd"' " " " ^ ^ ' " '"'"''^*^- '^'^^ fragments sized lOO-l 10 mm died Formation of new branches t e s t l m i i " ™ ' " " " I ' ' ' ^^^^ •'^"splantetion, new branches and their buds in all o w e r n n ! " " ' , , " ' " °" * ' '"''^''^^ of surviving fragments, including the 60 new b t , " ' ' ' ^ ' ' ' ' ' ^ " ' ' " ' ' * " ^ P^'^^" from the donor colony Fron,3 60 new branches grew on fragments of different coral species over 12-18 342 Yu Ya Latypov , Hpi thao khoa hoc - Hcrp tac Qu6c ti diiu tra nghian cihi tai nguygn va mfli trudng biin months Very branchy fragments of ^ elseyi and A valida of different size groups with numerous ranches formed the highest number of new branches and subbranches Every transplanted fragment this species developed five to nine new basic branches and about 24-32 subbranches of different levels It is worth noting that the average monthly accretion of medium- and large-sized fragments and the number of new branches was of fragments 1.20- to 1.37-fold higher at spring transplantation than at autumn transplantation This was especially characteristic of P cylindrica and A valida fragments Linear accretion Linear accretion of coral fragments was 70-160 mm during the period of the experiment The grovrth rate depended on the species, fragment size, and season of transplantation Morphologically different fragments of A palifera, P cylindrical, Pocillopora verrucosa, A valida and A valenciennesi had different grovrth rates Among these species, higher linear accretion was found in fragments of more branchy A valenciennesi (Fig.2) Within the same species, fragments of larger sizes grew 1.3- to 1.5-fold longer than medium-sized fragments Prolongation of the period of cultivation from one to one-and a-half years enhanced the linear accretion 1.2- to 1.4-fold The study showed the efficiency of transplantation of fragments of branchy corals onto an artificial construction installed in the natural environment on a reef slope and elevated over the bottom Fragments with numerous branches formed more new branches of the X xii 11 IV in vu IX X xii u in j ^ ^ g arrangement as in the - O - A palifcia —a-P cyliltdrica -*—A valenciennesi donor colony; they had a greater surface area of live polyp (jsjue per unit of the total fragment length Their ability to obtain energy at the expense of photosynthesis or captured food particles is appreciably higher than in small fragments with smaller surfaces (Soong, Chen, 2003) The relatively high grovrth rates of fragments of all species niight be explained by their displacement to a new well-illuminated location which is less populated by other benthic organisms It is also important that the installation was elevated 30-40 cm over the silty bottom, since silty deposits often limit coral grovrth and are sometimes even the cause of their death The location of fragments over the bottom reduces the probability of their covering with silt (Ocubo et al., 2005) Fig Growth rates of transplanted fragments of different coral species Large-sized fragments of all coral species survived better and had higher growth Yu.Ya Latypov 343 Workshop: "International Coopeiation on Investigation and Research of Marine Nahiral Resource and Environmenr rates They formed agreater number of new branches and then- buds and formed new large-sized colonies This agrees well with the opinion of many researchers who correlate the size of recovered colonies with the size of original iragmenfs (Soong, Chen, 2003) Large-sized coral colonies reared from fiagments had the best fecundity It was documented that the percent of spawning colonies obtained fi-om transplanted fiagments depended on the size of the transplants (Ocubo et aL 2005) Growth of corals from fiagments is an important natural process, at least, in corals with branchy forms of colonies Colony fiagments first anchor somehow occasionally on the bottom, then adhere to the substrate through regeneration and outgrowth of soft tissues and skeleton (IIpeoSpaKeHCKHH, JlaxtinoB, 1980' Heyward, Collins, 1985) Our results not contradict the conclusion of Okubo et al (Ocubo et aL, 2005) who concluded that attachment to the substrate is a precondition of a successful long-term process of transplantation All fragments of Acropora and Porites that survived in our experiment fused to the wire that fixed them onto the experimental Inltiiil dimensions and accreticnof frasments.mm installation Two-thirds of fiagments 40tlr adhered to horizontal rods of the installation and blended to them with the basal part of their colony body A high rate of blending to an artificial substrate can testify to a good state of the colonies formed from V.M vm X xn n IV V.05 recovered fragments -*-i.fimatg -B-A.«l»}t' The results of the experiment revealed a certain relationship between growth of transplants and their species The row of coral species A palifera, A formosa, A valida, A valenciennesi, and P cylindrica distinctly represent a growing complication of colonial stmcture The presence of numerous branches of different levels and axial and radial corallites makes for a more rapid and more successfiil growth of new colonies fi'om the fragments (Figs 2,3) Fig Growth rates of coralfragmentsof the genus Acropora in different size groups \ \Wm Artificial growled sixmonth colonies of A.valida Thus, our study showed that survival of coral fiagments in ambient conditions of a natural coral reef depends on various factors; the main factors are coral species and size of fragments The relatively high growth rates of fragments of all species can probably be explamed by their ttansplanting to a well-illuminated medium less populated with other benthic organisms The obtained data can be used for successfiil recovery of natural settlements of corals or Yu Ya Latypov Hpi thao khoa hoc - Hgp tie Qu6c ti dieu tra nghien cuu tai nguygn va mil tnrfmg biin for cultivation of corals to satisfy the requirements of coral-hunters; effective coral cultivation could relieve the present pressure on natural coral reefs Acknowledgment: The author extends his sincere thanks to Khanh Hoa Salanganest Nest Company (Sanest group) and Open Russian-Vietnamese Laboratory of Biochemistry of A.V Zhirmunsky Institute of Marine Biology Far East Division Russian Academy of Sciences (IBM, Vladivostok) and Nha Trang Institute of Technology Research and Application Viemam (NITRA, VAST Nha Trang) and Institute of natural Products Chemistry -Hanoi (INPC-VAST), for financial support of this research, as well as to p.T Luong, H.D Lu, L.N Hau, N.B Khoa and V.T Trung employees of these Institutions, for their help during field survey REFERENCES Latypov Yu Ya.flee/-buildingcorals and ree6 of Vietnam: The Gulf of Thailand // Russian J Mar Biol 2003 Vol 29, no p.p S22-S33 Latypov Yu Ya Changes in the composhion and structure of coral communities of MJu and Moon Islands, Nha Trang Bay, South China Sea // Russian J Mar Biol 2006 Vol 32, no p.p 269-275 Pavlov, D.S., Smurov, A.V., Ilyash, L.V et al., Cun'ent State of Coral Reefs in Nha Trang Bay (South Vietnam) and Probable CaLses of Adverse Habitat of Scleractinians, Bioi Morya, 2004, vol 30, no 1, pp 60-67 Preobrazhensky, B.V., Latypov, Yu.Ya., Regeneration Processes in Coral Reef Ecosystems, Biologiya koralovykh rifov Morphologiya, systematika, ekologiya (Biology of Coral Reefs Morphology, Systematics, Ecology), M.: Nauka, 1980, pp 512 An N T., Son V.D., Thu P.M., Huan N.H Tracing sediment transport and bed regime in Nha Trang Bay // Coll Mar Res Works 2000 Vol 10 P 63-69 Heyward A J., Collins J.D Fragmentation in Montipora ramosa: the genet and ramet concept applied to a reef coral // Coral Reefs 1985 Vol P 35^0 Ocubo N Hiroki T., Motokawa T Successful methods for transplanting fragments of Acropora formosa and Acropora hyacinthus // Coral Reefs 2005 Vol 24 P 333-342 Soong K T., Chen T-an Coral transplantation: regeneration and growth of Acropora fragments in a Nursery//Restor Ecol 2003 Vol U P 1-10 Vo S.T., Hodgson G Coral reefs of Vietnam: Recruitment limitation and physical forcing// Proc 8th Int Coral Reef Symp 1997 P 477-482 Yu Ya Latypov 345 ... Acknowledgment: The author extends his sincere thanks to Khanh Hoa Salanganest Nest Company (Sanest group) and Open Russian-Vietnamese Laboratory of Biochemistry of A.V Zhirmunsky Institute of Marine Biology... Ilyash, L.V et al., Cun''ent State of Coral Reefs in Nha Trang Bay (South Vietnam) and Probable CaLses of Adverse Habitat of Scleractinians, Bioi Morya, 2004, vol 30, no 1, pp 60-67 Preobrazhensky,... for their help during field survey REFERENCES Latypov Yu Ya.flee/-buildingcorals and ree6 of Vietnam: The Gulf of Thailand // Russian J Mar Biol 2003 Vol 29, no p.p S22-S33 Latypov Yu Ya Changes