DOCSLIB.ORG

Caulerpa Taxifolia in Seagrass Meadows: Killer Or Opportunistic Weed?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Caulerpa Taxifolia in Seagrass Meadows: Killer Or Opportunistic Weed? Biol Invasions DOI 10.1007/s10530-012-0347-1 ORIGINAL PAPER Caulerpa taxifolia in seagrass meadows: killer or opportunistic weed? Tim M. Glasby Received: 28 May 2012 / Accepted: 17 October 2012 Ó Springer Science+Business Media Dordrecht 2012 Abstract Seagrass habitats are being lost throughout been affected by the introduction of C. taxifolia in the the world and the invasive alga C. taxifolia has often embayments studied. A review of literature on effects been implicated in seagrass declines. Although C. taxi- of species of Caulerpa on seagrasses provided limited folia can impact a variety of species, evidence for its experimental evidence for negative impacts of this effects on seagrasses is largely correlative. This study genus on seagrass abundance. combined observational studies and manipulative experiments done over many years to test hypotheses Keywords Invasive species Á Caulerpa taxifolia Á about effects of C. taxifolia on two Australian Marine algae Á Seagrass Á Experimental Á Review seagrasses, namely Posidonia australis and Zostera capricorni. Results indicated that C. taxifolia is not having adverse impacts on the coverage of these seagrasses in the sites studied. Rather, C. taxifolia Introduction appears to be an opportunist, persisting longer and its coverage being greater in previously non-vegetated There are numerous examples of negative correlations sediments than amongst seagrasses. C. taxifolia between abundances of introduced and native species co-existed with P. australis and did not cause reduc- (Parker et al. 1999; Ruiz et al. 1999; Bruno et al. 2005; tions in the cover of the seagrass. Outcomes of Simberloff 2009), but there are fewer instances for experimental manipulations of C. taxifolia amongst which there is experimental evidence that an intro- Z. capriconi were less clear due to losses of Z. capri- duced species has caused the decline of a native (i.e. coni in all plots, regardless of the presence of been the driver of change; MacDougall and Turking- C. taxifolia. It was possible that C. taxifolia may have ton 2005). Removal experiments can be useful for enhanced the decline in canopy cover of Z. capricorni, testing whether an introduced species is driving but the presence of alga did not alter the final fate of ecological change (removal would result in the Z. capricorni. There was also no evidence that long- recovery of the native assemblage, e.g. Bulleri et al. term areal coverage of P. australis or Z. capriconi has 2010), although results could be confused if impacts are long-term (e.g. recovery is slow, Glasby and Underwood 1996), or if there have been historical or T. M. Glasby (&) multiple interacting drivers of change (Didham et al. New South Wales Department of Primary Industries, 2005). Moreover, due to varying degrees of hysteresis, Port Stephens Fisheries Institute, Locked Bag 1, Nelson Bay, NSW 2315, Australia recovery after the removal of an invader might elicit e-mail: [email protected] community responses that are quite different from 123 T. M. Glasby those associated with the initial invasion (Dı´az et al. Various authors have asserted that C. taxifolia can 2003). A more direct test of impacts of invasion, cause the regression of seagrasses (e.g. Boudouresque therefore, is to use experimental additions of an et al. 1995; Glardon et al. 2008; Francour et al. 2009; introduced species, noting that this can potentially Lapointe and Bedford 2010; Peirano et al. 2011), but raise ethical concerns and impacts might still take a most evidence for this comes from correlative studies. long time to manifest. Observations of Posidonia oceanica beds in the Marine macroalgae account for some 20 % of the Mediterranean Sea soon after they were invaded by known introductions of marine species globally C. taxifolia indicated that the seagrass showed signs of (Schaffelke et al. 2006). The ecological effects of etiolation, chlorosis and had reduced numbers of leaves introduced marine macroalgae have been reviewed compared to an uninvaded site (Meinesz et al. 1993;de comprehensively over the last few years (e.g. Schaff- Ville`le and Verlaque 1995). After C. taxifolia invaded elke et al. 2006; Williams and Smith 2007; Thomsen sites in southern California, Williams and Grosholz et al. 2009) and the consensus is that there is a dearth of 2002) documented considerably reduced biomass experimental data and hence limited understanding of of the seagrass Ruppia maritima in patches where their impacts. The few high profile invasive macroal- C. taxifolia was abundant. Manipulative experiments gae that have been studied experimentally can have in Italy demonstrated that the shoot density of negative effects on native biota, but impacts are not the seagrass Cymodocea nodosa was decreased by always detected (Williams and Smith 2007; Thomsen C. taxifolia over a period of 4 months (Ceccherelli and et al. 2009). In comparison to other marine habitats, Cinelli 1997), but a subsequent 13 month study the effects of introduced species in seagrass has indicated no significant effects (Ceccherelli and Sechi received relatively little attention (Williams 2007). 2002). When seagrass beds are invaded, it is often by There is evidence that abundances of seagrasses at macroalgae and in situations where the seagrass beds some sites in the Mediterranean declined prior to the have already been disturbed (Williams 2007). Species introduction of C. taxifolia (Chisholm et al. 1997) and of the genus Caulerpa are the best known macroalgal that seagrass coverage has not in fact declined since invaders of seagrass beds and one of the better studied the introduction of the alga (Jaubert et al. 1999; species is Caulerpa taxifolia. Ceccherelli and Sechi 2002). Given the limited Much has been written about C. taxifolia since its experimental evidence for impacts of C. taxifolia on rise to prominence in the mid 1980s. C. taxifolia is a seagrasses (see Table 1), it is quite possible that the highly invasive green alga, capable of spreading alga may, at least in some cases, be responding rapidly over large areas and creating dense mats opportunistically to reductions of seagrass that are (Meinesz et al. 2001; Wright and Davis 2006). caused by some other disturbance. What seems clear is C. taxifolia can invade sheltered or exposed marine that it is inappropriate to generalise about any impacts habitats (Meinesz et al. 1993), including seagrass beds of C. taxifolia on seagrasses. (Ceccherelli and Cinelli 1998), non-vegetated soft Caulerpa taxifolia was first discovered in the sediments (Jaubert et al. 1999) and rocky reefs temperate waters of New South Wales (NSW), Aus- (Bellan-Santini et al. 1996; Ceccherelli et al. 2002). tralia, in 2000 and is currently present in 13 estuaries or Beds of C. taxifolia can affect the feeding behaviour coastal lakes. It appears that the strain of C. taxifolia in and distribution of benthic fishes (Levi and Francour NSW is different from that in the Mediterranean 2004; Longepierre et al. 2005) and support assem- (Meusnier et al. 2004), although genetic data suggest blages of fish (York et al. 2006) and invertebrates there have been several introductions of C. taxifolia (McKinnon et al. 2009; Gribben et al. 2009a) that into NSW (Schaffelke et al. 2002). C. taxifolia was differ from those in adjacent native habitats. The declared noxious in NSW after its appearance in recruitment of clams can be enhanced in beds of isolated patches some 750 km south of native sub- C. taxifolia relative to non-vegetated habitats, but the tropical populations in Queensland, and its subsequent growth, survivorship and reproductive capacity of rapid spread (Glasby and Creese 2007). Observations those clams can be reduced by the alga (Gribben and in NSW indicated that, as in the Mediterranean Wright 2006; Wright et al. 2007; Gribben et al. 2009b; (Ceccherelli and Cinelli 1999), there were negative Byers et al. 2010). associations between abundances of seagrasses 123 Caulerpa taxifolia in seagrass meadows Table 1 Putative effects of Caulerpa spp. on seagrasses based on mensurative studies Seagrass Putative Evidence Apparent response of seagrass Reference species effect Posidonia -ve C Shorter, narrower leaves at one site with C. taxifolia cf another without. de Ville`le and oceanica Necrosis of leave base where C. taxifolia smothering seagrass Verlaque (1995) -ve C P. oceanica leaves produced more phenolic compounds (presumed to be a Cuny et al. stress response) at one site with C. taxifolia cf another without (1995) -ve C Longevity of P. oceanica leaves reduced where C. taxifolia was dense. At Dumay et al. some times of sampling, shorter leaves at one site with C. taxifolia cf (2002) another without. Leaf productivity greater (thought to be a stress response) in presence of C. taxifolia n C Areal coverage of seagrass unchanged 8 years after invasion of Jaubert et al. C. taxifolia (2003) n C Number of leaves similar in areas with or without C. taxifolia Dumay et al. (2002) n C No indication that rhizome growth or shoot density where C. taxifolia Peirano et al. present were worse than uninvaded sites (2005) -ve C Tendency for reduced meristematic activity in P. oceanica when mixed Garcias-Bonet with C. taxifolia or C. prolifera et al. (2008) -ve C Leaves of P. oceanica smaller (and leaf turnover enhanced) when in the Pergent et al. presence of C. taxifolia (2008) -ve C More plagiotropic shoots (thought to be a stress response) at one seagrass Molenaar et al. site with C. taxifolia cf another without (2009) -ve C Negative associations between P. oceanica shoot density and biomass of Holmer et al. three species of Caulerpa (C. prolifera, C. racemosa, C. taxifolia) (2009) Posidonia n E Cover of seagrass not affected by C. taxifolia Current study australis Cymodocea -ve E Reduced seagrass shoot density in presence of C. taxifolia (over 4 months) Ceccherelli and nodosa Cinelli (1997) -ve E Reduced seagrass shoot density in presence of C.
Load more

Recommended publications
  • Predicting Risks of Invasion of Caulerpa Species in Florida
    University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2006 Predicting Risks Of Invasion Of Caulerpa Species In Florida Christian Glardon University of Central Florida Part of the Biology Commons Find similar works at: https://stars.library.ucf.edu/etd University of Central Florida Libraries http://library.ucf.edu This Masters Thesis (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Electronic Theses and Dissertations, 2004-2019 by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Glardon, Christian, "Predicting Risks Of Invasion Of Caulerpa Species In Florida" (2006). Electronic Theses and Dissertations, 2004-2019. 840. https://stars.library.ucf.edu/etd/840 PREDICTING RISKS OF INVASION OF CAULERPA SPECIES IN FLORIDA by CHRISTIAN GEORGES GLARDON B.S. University of Lausanne, Switzerland A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Biology in the College of Arts and Sciences at the University of Central Florida Orlando, Florida Spring Term 2006 ABSTRACT Invasions of exotic species are one of the primary causes of biodiversity loss on our planet (National Research Council 1995). In the marine environment, all habitat types including estuaries, coral reefs, mud flats, and rocky intertidal shorelines have been impacted (e.g. Bertness et al. 2001). Recently, the topic of invasive species has caught the public’s attention. In particular, there is worldwide concern about the aquarium strain of the green alga Caulerpa taxifolia (Vahl) C. Agardh that was introduced to the Mediterranean Sea in 1984 from the Monaco Oceanographic Museum.
    [Show full text]
  • Posidonia Oceanica Beds Caulerpa Taxifolia
    SciENTiA M arina73(2) June 2009, 329-335, Barcelona (Spain) ISSN: 0214-8358 doi: 10.3989/scimar.2009.73n2329 Alterations of the structure ofPosidonia oceanica beds due to the introduced algaCaulerpa taxifolia HEIKE MOLENAAR, ALEXANDRE MEINESZ and THIERRY THIBAUT EA 4228 ECOMERS, Laboratoire Environnement Marin Littoral, Université de Nice-Sophia Antipolis, Faculté des Sciences, Parc Valrose, 06108 Nice cedex 02, France. E-mail: [email protected] SUMMARY: The impact of Caulerpa taxifolia on the structure of shallow Posidonia oceanica beds was studied in perma­ nent quadrats from 1995 to 2005 at the invaded site of Cap Martin and the control site of Cap d’Antibes (French Riviera, France). The cover of C. taxifolia, shoot density, number of orthotropic and plagiotropic shoots and proportion of ramifica­ tions of P. oceanica were measured yearly. The cover of C. taxifolia in the invaded zone rapidly reached a maximum of in­ festation in 2000 with 93% of the quadrats covered by the alga. In 2001 an unexplained phenomenon led to a sharp decrease in the infestation and in the following years the colonisation remained low. Within the 10 years of the study, P. oceanica did not disappear from the permanent quadrats, but we observed a drastic change in the structure of the meadow invaded by C. taxifolia. Between 1999 and 2000 a decrease in the shoot density observed at both sites was probably related to the warm temperature event recorded in 1999 (from 636 to 143 shoots n r2 at the invaded site and from 488 to 277 at the control site). At the invaded site, the seagrass never recovered its initial density even after a sharp decrease in C.
    [Show full text]
  • Invasive Species: Killer Algae (Caulerpa Taxifolia) Archida Korat BIOL 115 SPRING 2019
    Invasive Species: Killer Algae (Caulerpa taxifolia) Archida Korat BIOL 115 SPRING 2019 ABSTRACT IDENTIFICATION ECOLOGY GOVERNMENT REGULATIONS Caulerpa taxifolia, famously known as “killer algae” Caulerpa taxifolia colonizes the environment it lives in is a strain of green algae native to the Indian Ocean. Its classification is as follows: Phylum Chlorophyta, and becomes the “dominant form of plant life” (Cotton Many countries around the world have Been affected Class Ulrophycea, Order Caulerpales, Family Due to its neat presentation and arrangement, it is 2005). Since it creates a “dense algal expanse across the by the killer algae as demonstrated in Figure 4. In often used in aquariums. As a result of an accident, the Caulerpaceae, Genus Caulpera, and Species Caulpera sea floor” as seen in Figure 3, the oxygen consumption order to reduce the risk of re-introduction in eradicated taxifolia (Agardh 2001). It is a siphonalean alga mutant form was introduced to the Mediterranean Sea. in that particular area increases (Cotton 2005). As a areas, the public was educated and made aware of the (coenocytic morphology) which can grow up to 5-65 It grows at a rapid rate in undesiraBle conditions such result, the marine species (various fishes and potential risk and threats of the killer algae to the as polluted waters, low light levels, and extreme cm in length. As it is illustrated in Figure 2, the non- inverteBrates) that once thrived and relied on food and marine ecosystem. Additionally, under the Noxious vascular algae are anchored to the substrate with root- temperatures. Though it does not possess any threat to shelter in the Mediterranean have Been greatly reduced.
    [Show full text]
  • Algae Sheets-Invasive Elsewhere
    ALGAE: NATIVE, INVASIVE ELSEWHERE Caulerpa taxifolia (Vahl) C. Agardh 1822 Caulerpa taxifolia has gained worldwide attention and the nickname killer algae because of its great success in coastal Mediterranean waters. It is a native species in Hawaii where it has not exhibited invasive tendencies. Division: Chlorophyta Class: Ulvophyceae Order: Bryopsidales Family: Caulerpaceae Genus: Caulerpa PHOTO: A. MEINESZ IDENTIFYING FEATURES HABITAT DESCRIPTION In Hawaii, small patches grow in sandy areas of tidepools and reef flats. In its maximum invasive Branches, feather-like, flattened, and upright, 3 - 10 cm state, it can cover all favorable available substrates, high, rising from a creeping stolon (runner), 1 - 2 mm including rock, sand, and mud. in diameter, anchored by rhizoids to the substrate. Branchlets oppositely attached to midrib, flattened, slightly curved upwards, tapered at both base and tip, and constricted at point of attachment. Midrib is slightly flattened, appearing oval in cross-section. This species resembles another Hawaiian Caulerpa species, C. sertularioides. C. sertularioides is more delicate and the branchlets are rounded, compared to the flattened branchlets of C. taxifolia. The rising branches are also more rounded toward apices, compared to the more angular, squared-off branches of C. taxifolia. COLOR PHOTO: A. MEINESZ Mediterranean Sea Dark green to light green. STRUCTURAL Thallus non-septate, coenocytic, traversed by trabecu- lae, which are extensions of cell wall; reproduction vegetative and sexual, latter anisogamous. Gametes liberated through papillae that develop on frond or occasionally on frond. Caulerpa taxifolia herbarium sheet © Botany, University of Hawaii at Manoa 2001 A-43 Caulerpa taxifolia DISTRIBUTION QUARANTINES HAWAII The Mediterranean clone or strain of Caulerpa taxifolia has been designated a U.S.
    [Show full text]
  • The Spread of the Native Macroalga Caulerpa Filiformis
    University of Technology Sydney The spread of the native macroalga Caulerpa filiformis By Sofie Voerman A thesis submitted in partial fulfilment for the degree of Doctor of Philosophy School of the Environment, Faculty of Science February 2017 CERTIFICATE OF ORIGINAL AUTHORSHIP I c ertify that the work in this thes is has not previous ly been s ubmitted for a degree nor has it been s ubmitted as part of requirements for a degree except as part of the collaborative doctoral degree and/or fully ac knowledge d within the text. I als o certify that the thes is has been written by me. Any help that I have rec eived in my research work and the preparation of the thesis itself has been acknowledged. In addition, I certify that all information s ourc es and literature us ed are indic ated in the thes is . S ignature of S tude nt: Date: Acknowledgements There are many people to thank who supported me along this journey. Without you this work would not have been possible. First and foremost, I owe my sincerest thanks to my primary advisor Paul Gribben. I am extremely grateful to Paul, in the first place to putting his trust in me and have me come over to this country. From day one, Paul has been incredibly supportive, pushing me to pursue paths with always my best interest in mind. Thank you for allowing me the freedom to pursue my ideas, and for always being there to back me up, no matter where they led. It was a privilege to be able to pick your brain on things, with your great knowledge on all things ecology, and inspiring views of “the bigger picture” on things.
    [Show full text]
  • National Management Plan for the Genus Caulerpa
    National Management Plan for the Genus Caulerpa Photo by R. Woodfield, Merkel and Associates Submitted to the Aquatic Nuisance Species Task Force Prepared by the Caulerpa Working Group Draft - October, 2004 Executive Summary A variety of surveys have confirmed at least twenty-one species and varieties of Caulerpa with populations in different regions of the United States (U.S.). Three species of Caulerpa are thought to be invasive due to their historic and ongoing invasions of U.S. and Deleted: species have warranted special foreign waters; Caulerpa taxifolia (Aquarium or Mediterranean strain), Caulerpa brachypus and concern Caulerpa racemosa. Deleted: to which they are not native In June 2000 divers detected C. taxifolia (Mediterranean strain) in Agua Hedionda Lagoon located in Carlsbad, CA and a second population in Huntington Harbor, CA. Divers first discovered non-native C. brachypus off the coast of southern Florida in 1999. Concerns have Deleted: The spread of C. brachypus also been raised by scientists about C. racemosa, which has spread rapidly in the Mediterranean, has raised concerns because of its potential impact on the reef ecosystem off but has not yet produced any problematic populations in U.S. waters. the southeastern coast of Florida. The impact of Caulerpa on natural systems in U.S. waters is unknown. It is possible to Deleted: Introduction and spread of infer likely impacts based on documented impacts in similar ecosystems in other regions of the Caulerpa species into world, where non-native Caulerpa species have become established. Deleted: remain largely unstudied so Documented impacts of invasive Caulerpa species include competition with marine plants and the likely impacts on U.S.
    [Show full text]
  • Occurrence of Caulerpa Taxifolia (Vahl) C
    BioInvasions Records (2015) Volume 4, Issue 1: 9–16 Open Access doi: http://dx.doi.org/10.3391/bir.2015.4.1.02 © 2015 The Author(s). Journal compilation © 2015 REABIC Research Article It was only a matter of time: occurrence of Caulerpa taxifolia (Vahl) C. Agardh var. distichophylla (Sonder) Verlaque, Huisman and Procaccini in the Maltese Islands (Chlorophyta, Ulvophyceae, Caulerpaceae) Patrick J. Schembri1*, Jacqueline Barbara1, Alan Deidun2, Edwin Lanfranco3 and Sandro Lanfranco1 1Department of Biology, University of Malta, Msida MSD2080, Malta 2Physical Oceanography Unit, University of Malta, Msida MSD2080, Malta 3Institute of Earth Systems, University of Malta, Msida MSD2080, Malta E-mail: [email protected] (PJS), [email protected] (JB), [email protected] (AD), [email protected] (EL), [email protected] (SL) *Corresponding author Received: 18 August 2014 / Accepted: 24 November 2014 / Published online: 15 December 2014 Handling editor: Darren Yeo Abstract A new alien species of Caulerpa, corresponding morphologically to Caulerpa taxifolia (Vahl) C. Agardh var. distichophylla (Sonder) Verlaque, Huisman and Procaccini, already known from Turkey, Sicily, and Cyprus, was first discovered in Malta in June 2013. The original record was of but a few fronds, and surveys made during winter at the same site did not locate any plants. A survey conducted during July 2014, however, located two patches of the alga occupying a total area of ca 125m2 in the 4–6m depth range, with a mean frond density of 276.3 (± 51.21 SD) per m2. Also in July 2014, two patches with a total of 520 fronds in an area of 0.37m2 at 14–15m depth were found at a second site ca 7.4 km along-coast distance from the first site.
    [Show full text]
  • The Introduced Green Alga Caulerpa Taxifolia Continues to Spread in the Mediterranean
    Biological Invasions 3: 201–210, 2001. © 2002 Kluwer Academic Publishers. Printed in the Netherlands. Invasion note The introduced green alga Caulerpa taxifolia continues to spread in the Mediterranean Alexandre Meinesz1,∗, Thomas Belsher2, Thierry Thibaut1, Boris Antolic3, Karim Ben Mustapha4, Charles-Franc¸ois Boudouresque5, Daniele` Chiaverini1, Francesco Cinelli6, Jean-Michel Cottalorda1, Aslam Djellouli7, Amor El Abed3, Carla Orestano8, Antoni M. Grau9, Ljiljana Ivesa10, Andrej Jaklin10, Habib Langar6, Enric Massuti-Pascual9, Andrea Peirano11, Leonardo Tunesi12, Jean de Vaugelas1, Nevenka Zavodnik10 & Ante Zuljevic3 1Laboratoire Environnement Marin Littoral, Universite´ de Nice-Sophia Antipolis, 06108 Nice Cedex 2, France; 2IFREMER, Centre de Brest, Departement´ d’Ecologie cotiˆ ere,` BP 70, 29280 Plouzane´ Cedex, France; 3Laboratory of Benthos, Institute of Oceanography and Fisheries, I. Mestrovica 63, 21000 Split, P.P. 500, Croatia; 4Institut National des Sciences et des Technologies de la mer (INSTM) 2025 Salammbo,ˆ Tunisia; 5Centre d’Oceanologie´ de Marseille, UMR CNRS 6540, Campus de Luminy, 13288 Marseille Cedex 9, France; 6Dipartimento di Scienze dell’Uomo e dell’Ambiente, Universita` di Pisa, Via A. Volta, 6, 56121 Pisa, Italy; 7Faculte´ des Sciences de Tunis, Campus Universitaire, 1060 Tunis, Tunisia; 8Laboratorio di Ecologia Acquatica, Dipartimento di Scienze Botaniche, Universita` degli studi di Palermo, Via Archirafi, 38, 90123, Palermo, Italy; 9Conselleria d’Agricultura i Pesca, C/. dels Foners, 10, 07006 Palma de Mallorca,
    [Show full text]
  • Species in Depth: Caulerpa
    SPECIES IN DEPTH CaulerpaCaulerpa NATIVE AND INVASIVE RANGE Caulerpa taxifolia is native to northern Australia, the Indian Ocean, the east African coast, the western Pa­ cific, Indonesia and the southwest Pacific, Hawaii, and the Caribbean. The potential for Caulerpa to invade the Gulf, southern Atlantic, and California coasts is high, due to its ability to tolerate a wide range of conditions and effective methods of dispersing into new areas. In 1984 the aquarium strain of Caulerpa taxifolia was accidentally released from the Oceanographic Museum in Monaco. Its subsequent invasion of the Mediterranean Sea has gained significant attention over the past decade. By 2001 the aquarium strain of Caulerpa covered over 30,000 acres of Mediterranean seafloor off the coasts of France, Spain, Italy, Croatia, and Tunisia. Rachel Woodfield Rachel Woodfield Several outbreaks of the aquarium strain have oc­ curred in southeastern Australia. Eradication efforts Caulerpa have failed, and Caulerpa is spreading through coastal Caulerpa taxifolia areas in a pattern similar to that of the Mediterranean invasion. In some areas off Australia, hybridization Caulerpa taxifolia is an invasive marine alga that is with native populations is possible. widely used as a decorative plant in aquaria. Although unicellular, Caulerpa develops pseudo organs similar WEST COAST DISTRIBUTION to roots, shoots, and leaves of more complex plants. In 2000 the aquarium strain of Caulerpa was first The plant consists of a horizontal, stem-like rhizome that produces a series of colorless, root-like rhizoids identified in Agua Hedionda Lagoon and Huntington that extend downward, anchoring the plant to the Harbor in southern California. These colonies were sea floor and absorbing food, water, and nutrients.
    [Show full text]
  • Green Alga Caulerpa Taxifolia Introduced To
    MARINE ECOLOGY PROGRESS SERIES Vol. 172: 275-280, 1998 Published October 22 Mar Ecol Prog Ser Molecular evidence for the aquarium origin of the green alga Caulerpa taxifolia introduced to the Mediterranean Sea 0. ~ousson~~~~*,J. ~awlowski'~~, L. Zaninetti', A. ~einesz~,C. F. ~oudouresque~ 'Departement de Zoologie et Biologie animale, Universite de Geneve, CH-1224 Chene-BougeriesIGenBve. Switzerland 'Centre d'Oceanologie de Marseille. UMR CNRS 6540, F-13288 Marseille, France 3Mus6um d'Histoire Naturelle. CH-1211 Geneve 6, Switzerland "aboratoire Environnement Marin Littoral, Universite de Nice-Sophia Antipolis, Parc Valrose. F-06108 Nice Cedex 2, France ABSTRACT. Here, we present the first molecular evidence that the trop~calgreen alga Caulerpa taxi- folia, which is quickly spreading in the Mediterranean and out-competing natlve species, escaped to the sea from a public or private equarium. Our data show that this alga is genetically identical to the strain cultivated in western European aqudria since the early 1970s The facillty with which this strain is obtained world-wide represents a potential danger of additional biological invasions. KEY WORDS: Caulerpa taxifolja Mediterranean . Aquaria . ITS rDNA INTRODUCTION In the mid-1980s, an alga similar to the Caulerpa tax- ifolia strain cultivated in public aquaria was observed The genus Caulerpa (Ulvophyceae) comprises about for the first time in the Mediterranean Sea, off the coast 70 species ubiquitous in coastal marine environments. of Monaco (Meinesz & Hesse 1991). Since then, the One of these species, C. taxifolia (Vahl) C. Agardh, is species has rapidly spread in the Northwestern common in tropical seas and has been reported along Mediterranean, invading most of the sublittoral envi- the Atlantic American coast (from Brazil to the ronments and competing with native benthic species Caribbean), in the African Atlantic (Gulf of Guinea), (Verlaque & Fntayre 1994, Villele & Verlaque 1995, the Indian Ocean and the Pacific Ocean (Taylor 1977, Bellan-Santini et al.
    [Show full text]
  • BIOLOGICAL CONTROL of IOLLER ALGAE, CAULERPA TAXIFOLIA '' Lars WJ Anderson USDA- ARS Exotic and Invasive Weed Research Davis, CA
    '. BIOLOGICAL CONTROL OF IOLLER ALGAE, CAULERPA TAXIFOLIA '' Lars WJ Anderson USDA- ARS Exotic and Invasive Weed Research Davis, CA ABSTRACT Caulerpa taxifolia, a marine alga, has invaded Mediterranean subtidal ecosystems from small founder populations in 1984 to present expanse of about 6,000ha, including coasts of France, Monaco, Italy, Spain and I, Croatia, and Tunisia. It was recently found in Australia and Southern California in 2000. It has successfully displaced several native, benthic communities and can establish on a variety of substrates from sand to rocky shores. Reproduction and spread is clonal via stolons supporting fronds from 0.2 to 3 meters long. The small, California populations have been under vigorous containment and eradication since their discovery under the direction of the Southern California Caulerpa Action Team (SCCAT). Four species of herbivorous gastropods (mollusks) have been examined in Europe for potential reduction of th extensive Mediterranean C. taxifolia populations ( Oxytnoe azuropunctata, Elysia subornatat, Oxynoe olivacea and Lobiger serradifalci) E. suboranata, a tropical species, though unable to survive below 15C, has direct, benthic development (no pelagic larvae), feeds well at higher (e.g.>20C) temperatures, and appears to be the best candidate. However, since it is not native, further testing of host-specificity and potential for switching is required. L, serraedifalci, a native to the Mediterranean, feeds on C. taxifolia, but also tends to produce fragments, which can spread the population further. At present, there is no ' ' proven, effective biological control agent for C. taxifolia. INTRODUCTION Nearly 20 years ago, one of the most interesting and aggressive marine invasive species, Caulerpa taxifolia, entered Mediterranean waters off Monaco and began its dominance of subtidal habitats there (Meinesz, 1999).
    [Show full text]
  • Caulerpa Taxifolia Conference Proceedings
    UC San Diego Conference Proceedings Title International Caulerpa taxifolia Conference Proceedings Permalink https://escholarship.org/uc/item/16c6578n Authors Williams, Erin Grosholz, Edwin Publication Date 2002-12-31 eScholarship.org Powered by the California Digital Library University of California International Caulerpa taxifolia Conference Proceedings January 31 – February 1, 2002 San Diego, California, U.S.A. This publication was supported in part by the National Sea Grant College Program of the U.S. Department of Commerce’s National Oceanic Published by the California Sea Grant and Atmospheric Administration under NOAA College Program Grant #NA06RG0142, project number A/P-1, University of California, San Diego through the California Sea Grant College La Jolla, California 92093 Program. The views expressed herein do not www.csgc-ucsd.edu necessarily reflect the views of any of those 2002 organizations. Cover photo by A. Meinesz International Caulerpa taxifolia Conference Proceedings January 31–February 1, 2002 San Diego, California U.S.A. Hosted by the University of California Cooperative Extension With Support From: California Department of Fish & Game California Sea Grant College Program U.S. Fish & Wildlife Service, Aquatic Nuisance Species Task Force Proceedings Assistance Provided by: California Sea Grant College Program Edited by: Erin Williams Outreach Coordinator Department of Environmental Science & Policy University of California, Davis Edwin Grosholz Associate Specialist in Cooperative Extension Department of Environmental Science & Policy University of California, Davis California Sea Grant College Program University of California La Jolla, California 92093-0232 www-csgc.ucsd.edu Publication No. T-047 ISBN 1-888691-11-5 Acknowledgments First, we would like to thank the scientists, managers, and educators for their participation during the workshop and for the considerable time invested both before and after the workshop.
    [Show full text]