Copyright © 2010 IOC HAB Programme.During summer 2008, surveys were carried out around São Miguel island in the Azores archipelago (36–39ºN, 25–31ºW). [...]. Species of Ostreopsis were morphologically characterized with an Olympus BX50 equipped with epifluorescence, following Penna et al. [...].Governo Regional dos Açores

Brotas, Vanda

Neto, Ana I.

Orive, E.

Silva, A.

Repository of the University of the Azores

First records of Ostreopsis heptagona, O. cf. siamensis and O. cf. ovata – in the Azores archipelago, Portugal

Repositório da Universidade dos Açores

1The Intergovernmental Oceanographic Commission of UNESCOHARMFUL ALGAE NEWSAn IOC Newsletter on toxic algae and algal bloomsNo. 42August 2010www.ioc-unesco.org/hab(Cont’d on p.2)(Cont’d on p. 3)The publication of Harmful Algae News is sponsored by the Spanish Institute of Oceanography, Vigo,and the Department of Biology, University of Copenhagen.First records of Ostreopsis heptagona, O. cf. siamensisand O. cf. ovata – in the Azores archipelago, PortugalDuring summer 2008, surveys werecarried out around São Miguel island inthe Azores archipelago (36–39ºN, 25–31ºW) (Fig. 1). The sampling area islocated between the main paths of theAzores Current (AC) and North AtlanticCurrent. The average SST around theisland, was above 21ºC, denoting agreater influence of the AC. Seawatersamples were collected with a Niskinbottle, and preserved with neutralizedformalin, for phytoplankton observationsand cell counting. Species of Ostreopsiswere morphologically characterized withan Olympus BX50 equipped withFirst records of Ostreopsis cf. siamensis in MoroccanAtlantic upwelling watersWe report the first records ofOstreopsis cf. siamensis Schmidtdetected in the NE Africa Atlanticupwelling system by the MoroccanHAB and phycotoxins nationalmonitoring programme. The species wasidentified by phase contrast (Fig. 1) andepifluorescence microscopy during theMorocco-Portugal project of scientificcooperation on HABs and marinebiotoxins. Identification was confirmedby sequencing the 5.8S –ITS and LSUribosomal genes [1].Ostreopsis blooms were firstobserved in seawater samples from theCape Ghir region (30°N, 9°W) on 5October 2004, reaching 3.7 x 103 cellL-1. Blooms recurred in the followingyears, and increased in concentrationand duration, reaching 9.8 x 103 to1.2 x 104 cell L-1 in 2008, and a maximumof 105 cell L-1 observed in August 2009.In 2007, O. cf. siamensis cells wereobserved from late summer to earlyautumn, in 2008 from early summer tolate autumn, and in 2009 from spring tolate autumn. The blooms occurred withsurface temperatures ranging from 20to 24°C, with maxima recorded in Augustand September. In parallel, the detectionof toxins by mouse bioassay in musselscollected from the same area indicatedthe presence of neurotoxins.Four monitoring stations weresampled in the Agadir area (Fig. 2).Highest Ostreopsis concentrationswere always observed in samples fromCape Ghir and a station further north,at Tamri, both sites located on a rockycoastline highly exposed to northerly(upwelling favourable) winds and wavesepifluorescence, following Penna et al.[1]. The three Ostreopsis species werefound together in the water, exclusivelyon the north side of the island wherethe waters were warmer. The highestconcentration of Ostreopsis spp. was90 cells L-1.The measurements (Table 1) andplate patterns observed suggest thepresence of three species of Ostreopsis:O. heptagona Norris, Bomber etBalech, 1985 (Fig. 2), O. cf. siamensisSchmidt, 1982 (Fig. 3) and O. cf. ovataFukuyo, 1981 (Fig. 4).Since sampling was not focussed on1’3’’5’’6’’Po7’’Fig. 2. O. heptagona, LM, epithecal view (scalebar = 20 µm). The distinct feature of plate 5’’,pentagonal, in contact with 1’, can beobserved.Fig. 1. Ostreopsis cf. siamensis from a sample off Cape Ghir. Light microscopy– phase contrast(a). Epitheca (b) and hypotheca (c) views. (right). a b c2(Cont’d from p. 1) Dorsoventral  diameter (µm) Transverse diameter (µm) O. heptagona (Fig. 2) 80–83 53–55 O. cf. siamensis (Fig. 3) 60–70 34–42 O. cf. ovata  (Fig. 4) 49–51 22–30  Table 1. Dorsoventral and transversal measurements. 3’’’ 4’’’ 5’’’ 1’ 2’’ 6’’ 3’ 4’ ’ 7’’  1’’ Po Fig. 3. O. cf. siamensis, LM, epithecal (top)and hipotechal views (center) (scale bar =20 µm).Fig. 4. O. cf. ovata, LM, epithecal view (top)(scale bar = 10 µm). 1’ 3’ 4’’ 5’’ 6’’ 7’’ 1’’ 2’’   Fig. 1. The Azores archipelago: São Miguel (oriental group).the study of this genus, the fixative useddid not allow complementaryphylogenetic analysis. Future researchwill comprise genotyping Ostreopsisstrains by PCR based assay.This preliminary work in Azoreswaters is expected to contribute to thebiogeographical distribution of HABspecies, and to clarify their role asenvironmental tracers in Atlantic watersand as climate indicators.AcknowledgementsV. Veloso for technical assistancewith the epifluorescence andphotography. R. Ferreira Patarra, N.Álvaro and A. Prestes for the fieldsampling, SRAM/DROTRH, GovernoRegional dos Açores for financialsupport.Reference:1. Penna A et al 2005. J Phycol 41: 212–225A. Silva1, V. Brotas1, E. Orive2 & A.Neto31Centro de Oceanografia, Fac.Ciências, Univ. Lisboa, CampoGrande, 1749-016 Lisbon,Portugal.2Dep. Plant Biology and Ecology,Univ. Basque Country, Apdo. 644,48080 Bilbao, Spain.3CIMAR & Dep. Biologia, Univ.Açores, 9501-801 Ponta Delgada,São Miguel, Açores, Portugal.See you in Hersonissos, Crete, in November!3(Fig. 2). In contrast, other dinoflagellatespecies were favoured at stations southof Agadir, in the shadow of the Cape,on a sandy coast with calmer waters.This suggests that turbulent conditionsnorth of the cape favoured resuspensionof this epiphytic species in the watercolumn although not dispersing the cells.Villa et al. [2] also pointed out thatOstreopsis sp. prefers more turbulentconditions than other benthicdinoflagellates such as Coolia monotis.In contrast, the abundance ofOstreopsis ovata in the Adriatic Seawas significantly higher in sheltered sitescompared with exposed ones, indicatinga major role of hydrodynamism inregulating bloom dynamics [3].According to a recent study of thephylogeography of Ostreopsis speciesbased on several strains isolated fromthe Mediterranean and NortheastAtlantic [1], O. cf. siamensis was, untilnow, only observed in theMediterranean, while O. cf. ovata wasfound both in the Mediterranean and NEAtlantic, e.g. in Madeira and the CanaryIslands. However, neither species wasobserved on the upwelling coasts ofIberia, such as the Galician rías(Santiago Fraga, pers. com.), or NWAfrica where the species was notinvestigated before. Simultaneously,during the Morocco blooms, a strain ofO. cf. siamensis was isolated frommacroalgae off the SW coast ofPortugal [4]. It is possible that this speciesis actually spreading in this region of theAtlantic due to an exchange betweenthe Atlantic and the Mediterraneanbasins or even to a warming of thesecoastal upwelling waters [5]. However,it is not yet clear whether this apparentbiogeographical expansion is real sinceHAB monitoring only became routineon the Agadir coast after 2002, and thereis still no monitoring programme formicrophytobenthic communities alongthe Moroccan coast. After theseOstreopsis blooms and due to theirannual re-occurrence, the HABmonitoring programme has included thisgenus among the potentially harmfulspecies of the Atlantic andMediterranean coasts of Morocco.(Cont’d from p. 1)References:1. Penna A et al 2010. J Biogeogr 37: 830–8412. Vila M et al 2001. Aquat Microb Ecol 26:51–603. Totti C et al 2010. Harmful Algae 9: 233–2394. Amorim A et al 2010. Harmful Algae News(this issue)5. Relvas P et al 2009. Geophys Res Lett 36:L22601, doi:10.1029/2009GL040504A. Bennouna1, J. El Attar1,R. Abouabdellah1, S. Palma2,A. Penna3 & M.T. Moita21National Institut of MarineResearch (INRH), Regional Centerof Agadir, Aghsdis, Nouveau Port,Agadir, Morocco.Email: bennouna5@hotmail.com2INRB-IPIMAR, Av. Brasília,1449-006 Lisbon, Portugal.Email: tmoita@ipimar.pt3Sez. Environmental Biology, Dep.Biomolecular Sciences, Univ.Urbino, Vle. Trieste 296, 61121Pesaro, Italy.Email: antonella.penna@uniurb.itAtlanticMoroccoAfrica          Fig. 2. Location of Moroccan monitoring stations in Agadir region and photo of Cape Ghir (lowerleft) and Sidi Rbat (lower right) monitoring sites.Harmful Algae Newsonly exists if the Editor getsinput from YOU!Write the Editor NOW with newson your work, HAB events inyour country or region, or anyother matter you wish to sharewith HAB scientists and manag-ers worldwide. Harmful AlgaeNews has more than 2000subscribers.PHYCOTOXINSYou can also get news onHAB research and events at thePhycotoxins-list at the internet.The address of this list is:phycotoxins@www.agr.caTo join the list, send“subscribe phycotoxins” to: listserv@www.agr.caArchives are located atw w w . a g r . c a / a r c h i v e s /phycotoxins.html

http://repositorio.uac.pt/bitstream/10400.3/1200/7/Silva2010FirstRecordsOstreopsisAzoresHAN42.pdf

First records of Ostreopsis heptagona, O. cf. siamensis and O. cf. ovata – in the Azores archipelago, Portugal

Abstract

Similar works

Full text

Available Versions

Repository of the University of the Azores

Repositório da Universidade dos Açores