First report of Ciguatoxins in two starfish species: Ophidiaster ophidianus and Marthasterias glacialis

Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk.

First report of Ciguatoxins in two starfish species: Ophidiaster ophidianus and Marthasterias glacialis

Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk.

Sei whale (Balaenoptera borealis) ecology and management in the North Atlantic

Tese de Doutoramento em Ciências do Mar, especialidade em Ecologia Marinha.

Cephalopoda as prey of juvenile Southern elephant seals at Isla 25 de Mayo/King George, South Shetland Islands

The aim of the present study was to enhance the knowledge of the feeding habits of the juvenile component of the population of Southern elephant seals [Mirounga leonina (Linnaeus, 1758)] from Isla 25 de Mayo, South Shetland Islands, age class whose diet information is scarce. A total of 60 individuals were stomach lavaged in the spring - summer seasons of three consecutive years (2003, 2004 and 2005) of which 53.3 % (n = 32) presented food remnants. The Antarctic glacial squid Psychroteuthis glacialis Thiele, 1921 was the dominant prey taxon in terms of frequency of occurrence (68.7%), numerical abundance (60.1%) and biomass (51.5%), contributing 84.1% to the total relative importance index. Other squid prey species of importance were Slosarczykovia circumantartica Lipinski, 2001 in terms of occurrence (37.5%) and numerical abundance (14%) and Moroteuthis knipovitchi Filippova, 1972 in terms of biomass (16%). All identified cephalopod prey taxa are distributed south of the Antarctic Polar Front, except for the squid Martialia hyadesi Rochebrune & Mabille, 1889 which has a circumpolar distribution associated to the Polar Frontal Zone. No significant differences in the sizes of P. glacialis preyed upon by elephant seals were found between sexes and years. However, significant interannual differences were found in the taxonomical composition of their diet. This would be associated with temporal changes in food availability at the foraging areas of seals, which in turn may have been influenced by changes in oceanographic conditions as a result of the El Niño Southern Oscillation (ENSO) phenomenon that occurred during part of the study period. Furthermore, a differential response of males and females to this temporal variation was observed, with the former being also associated to a predation on octopods. This would suggest a sexual segregation in foraging habits of this species from the early stages of its life cycle.

Comportamiento nictemeral del fitoplancton frente al Callao (12°S), Perú

El estudio se realizó entre el 18 y 21 abril 2006, en dos estaciones frente a la costa central del Perú (12°S). Se colectaron muestras cada 6 horas para evaluar la distribución vertical del fitoplancton hasta los 75 m de profundidad, y se determinó la composición y abundancia del fitoplancton en relación a las concentraciones de oxígeno disuelto. Se discute el diferente comportamiento de las especies más abundantes en la columna de agua, como la diatomea Asterionellopsis glacialis, del dinoflagelado Akashiwo sanguinea, y de los fitoflagelados en la estación más costera. Las dos primeras especies profundizaron su distribución hasta los 25 m durante la noche, pero los fitoflagelados presentaron focos de concentración máximos en la Zona de Mínimo Oxígeno tanto en el día como en la noche en la estación ubicada a 30 mn.

A wolf in sheep"s clothing: carnivory in dominant sea urchins in the Mediterranean

Arbacia lixula and Paracentrotus lividus are the dominant sea urchins in the Mediterranean sublittoral, where they are key structuring species due to their grazing activity. It has been commonly accepted that competition between both species is minimized by specializing in different algal foods. A. lixula is considered to feed mainly on encrusting coralline algae, while P. lividus prefers fleshy macroalgae. We used stable isotope analysis to test if these species occupy different trophic positions at 3 locations in the western Mediterranean and one in Macaronesia. Our results show unambiguously that A. lixula always occupies a higher trophic level than P. lividus, with a δ15N comparable in some locations to strict carnivores such as Actinia schmidti or Marthasterias glacialis. A temporal monitoring at one locality showed that this signature of a higher trophic level is consistent throughout the year. These results are incompatible with the current belief of an herbivorous diet for A. lixula and suggest that it must be considered an omnivore tending to carnivory in Mediterranean ecosystems, feeding at least partially on sessile animals such as Cirripedia, Hydrozoa or Bryozoa. A parallel analysis of gut contents showed a predominance of vegetal items in both species, although A. lixula consistently had a higher abundance of animal components than P. lividus. Our results challenge the validity of using gut content observations alone for characterizing the trophic behaviour of omnivorous marine invertebrates that feed on a variety of food sources with different digestibility.

UV-LED -lamppujen soveltuminen laivojen painolastivesien käsittelyyn

Painolastivesien mukana kulkeutuvien lajien leviäminen on yksi vakavimmista globaaleista ympäristöuhkista. Kansainvälinen merenkulkujärjestö IMO määritteli vuonna 2004 kansainvälisen painolastivesiyleissopimuksen, jonka tarkoituksena on ehkäistä laivojen painolastivesien mukana kulkeutuvien lajien leviämistä. Sopimus velvoittaa aluksia käsittelemään niiden painolastivedet ja se sisältää myös käsittelyjärjestelmiltä edellytetyt vaatimukset. Vaikka sopimus ei ole vielä astunut voimaan, painolastivesien käsittelyyn löytyy markkinoilta jo useita kymmeniä IMO:n hyväksymiä käsittelyjärjestelmiä, jotka hyödyntävät erilaisia mekaanisia, fysikaalisia ja kemiallisia menetelmiä. Yksi yleisimmin käytetyistä menetelmistä on UV-säteilytys. UV-säteily tuotetaan elohopealampuilla, jotka kuitenkin kuluttavat paljon energiaa ja sisältävät myrkyllistä elohopeaa. Tämän työn tarkoituksena oli selvittää, voisiko elohopealamput korvata lähitulevaisuudessa UV-LED -lampuilla. UV-LED –lamppujen etuja ovat muun muassa energiatehokkuus, kestävä rakenne ja myrkyttömyys. Työn tärkeimpänä tavoitteena oli tutkia laboratoriomittausten avulla, millainen UV-annosmäärä 10-50 µm kokoisten kasviplanktonien inaktivoimiseen tarvitaan. Mittausjärjestelyt vastasivat suurelta osin IMO:n vaatimuksia. Laboratoriomittauksissa käytettiin 265 nm:n aallonpituudella toimivia UV-LED -lamppuja. Näytteiden analysoinnissa käytettiin sekä PAM-fluorometriä että virtaussytometriä. Saatujen tulosten perusteella tutkimuksessa käytettyjen lajien Asterionellopsis glacialis ja Thalassiosira sp. täydelliseen inaktivoitumiseen tarvittiin noin 600 mJ/cm2 suuruinen UV-annos. Tulos vastasi ennakko-odotuksia ja se oli vertailukelpoinen muiden aiheesta tehtyjen tutkimusten kanssa. Koska nykyisten UV-LED –lamppujen teho on hyvin alhainen, ne eivät vielä sovellu painolastivesien käsittelyyn. UV-LED –lamppujen kehitystyö on kuitenkin käynnissä ja on arvioitu, että niitä voitaisiin käyttää suurten virtaamien käsittelyssä 5-10 vuoden kuluttua.

Microfitoplâncton de águas costeiras amazônicas: Ilha Canela (Bragança, PA, Brasil)

Variações sazonal e nictemeral do microfitoplâncton foram estudadas em uma estação fixa (00º46'37,2''S-046º43'24,5''W), localizada em uma área costeira próxima à ilha Canela (Norte do Brasil), durante os meses de setembro e dezembro/2004 (período seco) e março e junho/2005 (período chuvoso). As amostras destinadas à análise qualitativa do fitoplâncton foram obtidas a partir da filtragem de 400 L de água, através de uma rede planctônica (65 μm de abertura de malha), durante marés de sizígia, em intervalos regulares de três horas, por um período de 24 horas. O material coletado foi fixado com formol neutro a 4%. Paralelamente a essas coletas foi medida a salinidade da superfície da água. A salinidade apresentou variação significativa ao longo do período de estudo, variando entre 26,1 (junho/2005) e 39,0 (dezembro/2004), caracterizando o ambiente como eualino-polialino. Foram identificados 130 táxons incluídos nas divisões Cyanophyta (dois táxons), Bacillariophyta (115 táxons) e Dinophyta (13 táxons). As diatomáceas dominaram o microfitoplâncton da área, sendo Asterionellopsis glacialis, Dimeregramma minor, Skeletonema sp. e Thalassiosira subtilis os táxons mais freqüentes e abundantes. Os altos valores de salinidade condicionaram a maior representatividade das espécies marinhas neríticas, polialóbias. Os processos de ressuspensão provocados pelos ventos e arrebentação das ondas promoveram intercâmbios entre as populações planctônicas e ticoplanctônicas, dentre as quais as espécies Dimeregramma minor, Triceratium biquadratum e T. pentacrinus representaram novas ocorrências para as águas costeiras do litoral amazônico.

Population histories of right whales (Cetacea: Eubalaena) Inferred from Mitochondrial Sequence Diversities and Divergences of Their Whale Lice (Amphipoda: Cyamus)

Right whales carry large populations of three ‘whale lice’ (Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales (Eubalaena glacialis, Eubalaena japonica, Eubalaena australis) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population sizes of right whales. We found high levels of nucleotide diversity but almost no population structure within oceans, indicating large effective population sizes and high rates of transfer between whales and subpopulations. North Atlantic and Southern Ocean populations of all three species are reciprocally monophyletic, and North Pacific C. erraticus is well separated from North Atlantic and southern C. erraticus. Mitochondrial clock calibrations suggest that these divergences occurred around 6 million years ago (Ma), and that the Eubalaena mitochondrial clock is very slow. North Pacific C. ovalis forms a clade inside the southern C. ovalis gene tree, implying that at least one right whale has crossed the equator in the Pacific Ocean within the last 1–2 million years (Myr). Low-frequency polymorphisms are more common than expected under neutrality for populations of constant size, but there is no obvious signal of rapid, interspecifically congruent expansion of the kind that would be expected if North Atlantic or southern right whales had experienced a prolonged population bottleneck within the last 0.5 Myr.

Baleen Whales: Conservation Issues and The Status Of The Most Endangered Populations

Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions; populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right Whales Eubalaena glacialis, Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations, western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and, where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling, existing data indicate strong recovery in most studied populations of these species.

Comparison of epifaunal assemblages between Cymodocea nodosa and Caulerpa prolifera meadows in Gran Canaria (eastern Atlantic)

Máster en Oceanografía

Adattamento e acclimatazione a diverse temperature di lieviti psicrofili obbligati e facoltativi e di lieviti mesofili. Studio della produzione di acidi grassi polinsaturi omega-3 e omega-6 per via fermentativa.

Adaptation and acclimation to different temperatures of obligate psychrophilic, facultative psychrophilic and mesophilic yeasts. Production of ω-3 and ω-6 polyunsaturated fatty acids by fermentative way. Obligate psychrophilic, facultative psychrophilic and mesophilic yeasts were cultured in a carbon rich medium at different temperatures to investigate if growth parameters, lipid accumulation and fatty acid composition were adaptive and/or acclimatory responses. Acclimation of facultative psychrophiles and mesophiles to lower temperature negatively affected their specific growth rate. Obligate psychrophiles exhibited the highest biomass yield (YX/S), followed by facultative psychrophiles, then by mesophiles. The growth temperature did not influence the YX/S of facultative psychrophiles and mesophiles. Acclimation to lower temperature caused the increase in lipid yield (YL/X) in mesophilic yeasts, but did not affect YL/X in facultative psychrophiles. Similar YL/X were found in both facultative and obligated psychrophiles, suggesting that lipid accumulation is not a distinctive character of adaptation to permanently cold environments. The extent of unsaturation of fatty acids was one major adaptive feature of the yeasts which colonize permanently cold ecosystems. Remarkable amounts of α-linolenic acid were found in obligate psychrophiles at the expenses of linoleic acid, whereas it was generally scarce or absent in all the others strains. Increased unsaturation of fatty acids was also an acclimatory response of mesophiles and facultative psychrophiles to lower temperature. It’s well known that omega-3 polyunsaturated fatty acids (PUFAs) display a variety of beneficial effects on various organ systems and diseases, therefore a process for the microbial production of omega-3 PUFAs would be of great interest. This work sought also to investigate if one of the better psychrophilic yeast, Rhodotorula glacialis DBVPG 4785, stimulated by acclamatory responses, produced omega-3 PUFAs. In fact, the adaptation of psychrophilic yeasts to cold niches is related to the production of higher amounts of lipids and to increased unsaturation degree of fatty acids, presumably to maintain membrane fluidity and functionality at low temperatures. Bioreactor fermentations of Rhodotorula glacialis DBVPG 4785 were carried out at 25, 20, 15, 10, 5, 0, and -3°C in a complex medium with high C:N ratio for 15 days. High biomass production was attained at all the temperatures with a similar biomass/glucose yield (YXS), between 0.40 and 0.45, but the specific growth rate of the strain decreased as the temperature diminished. The coefficients YL/X have been measured between a minimum of 0.50 to a maximum of 0.67, but it was not possible to show a clear effect of temperature. Similarly, the coefficient YL/S ranges from a minimum of 0.22 to a maximum of 0.28: again, it does not appear to be any significant changes due to temperature. Among omega-3 PUFAs, only α-linolenic acid (ALA, 18:3n-3) was found at temperatures below to 0°C, while, it’s remarkable, that the worthy arachidonic acid (C20:4,n-6), stearidonic acid (C20:4,n-3) C22:0 and docosahexaenoic acid (C22:6n-3) were produced only at the late exponential phase and the stationary phase of batch fermentations at 0 and -3°C. The docosahexaenoic acid (DHA) is a beneficial omega-3 PUFA that is usually found in fatty fish and fish oils. The results herein reported improve the knowledge about the responses which enable psychrophilic yeasts to cope with cold and may support exploitation of these strains as a new resource for biotechnological applications.

Entwicklung und Anwendung eines Verfahrens zur Bestimmung von halogenierten Kohlenwasserstoffen in Luft mittels anreichernder Probenahme,Thermodesorption und GC,MS mit negativer chemischer Ionisation

Flüchtige organische Halogenverbindungen übernehmen in der Chemie der Troposphäre eine Schlüsselrolle. Photolytisch gebildete Halogenatome reagieren mit troposphärischem Ozon und können durch Oxidation, vor allem von Iod, zur Neubildung von Partikeln beitragen. Auf diese Weise beeinflussen Halogenalkane den Strahlungshaushalt der Atmosphäre. Aus analytischem Blickwinkel ist es wichtig die Konzentration der einzelnen Spezies zu untersuchen um Rückschlüsse auf deren biotische oder abiotische Quellen ziehen und die Emissionswege besser verstehen zu können. Im Rahmen der vorliegenden Arbeit wurde daher eine sensitive Methode zur Untersuchung von halogenierten Kohlenwasserstoffen entwickelt, basierend auf anreichernder Probenahme mit anschließender Thermodesorption und der Analyse mittels Massenspektrometrie mit negativer chemischer Ionisation. Die Kennwerte der Methode sind: Nachweisgrenzen zwischen 0.11 pg und 5.86 pg bzw. zwischen 1.0 ppqV und 44.7 ppqV, Linearität zwischen R2=0.993 und R2=1.000, Reproduzierbarkeit (Triplikate) RSD < 15 % und ein sicheres Probenahmevolumen von 10 L. Die Methode wurde im Anschluss im Rahmen von zwei Feldmessungen, in Mace Head, Irland und auf einer Schiffskampagne im antarktischen Amundsen-Meer, angewendet. Durch die Ergebnisse aus Irland kann gezeigt werden, dass die Mischungsverhältnisse der Iodalkane mit denen früherer Studien vergleichbar sind, und dass die verschiedenen untersuchten Algenarten deutlich unterschiedliche Emissionsraten zeigen. Die Ergebnisse der Kampagne im Amundsen-Meer zeigen einen großen Einfluss der Windrichtung auf die Halogenalkan-Konzentrationen. So sind die Mischungsverhältnisse der Halogenalkane deutlich höher, wenn der Wind zuvor über die antarktischen Eisflächen strömt. Für die biotischen Quellen wurden die Emissionsraten ausgewählter Makroalgen unter dem Einfluss von Ozon untersucht. Die Emissionsrate der Iodalkane zeigt einen exponentiellen Zusammenhang, sowohl zur I2-Emission als auch zum Gesamtiodgehalt der Algen. Unter oxidativen Bedingungen zeigt L. Digitata eine linear steigende Iodalkanemission. Mit diesem Verhalten wird die These der Bildung von Iodalkanen als Nebenprodukt beim Abbau reaktiver Sauerstoffspezies unterstützt. Neben den Makroalgen wurden auch Mikroalgen als biotische Quellen untersucht. Hierbei können zwei unterschiedliche Emissionsmuster der Halogenalkane für Diatomeen und Phaeocystis sp. gezeigt werden. Im Gegensatz zur Iodalkan-Emission hängt die I2 Emission der Mikroalgenproben von der Ozonkonzentration der Luft ab. Durch die lineare Korrelation der I2-Emission mit der Iodid-Konzentration der wässrigen Phase einerseits, und dem Ozonverbrauch andererseits, kann die Bildung von I2 durch Oxidation von Iodid durch Ozon bestätigt werden. Für das Emissionsverhalten der Mikroalgenprobe aus dem Sylter Wattenmeer, welche keine Korrelation mit dem verbrauchten Ozon zeigt, gibt es zwei Erklärungen: Zum einen kann I2 durch den hohen Gehalt an organischen Verbindungen an diesen adsorbiert bzw. chemisch gebunden werden und wird dann nicht mehr in die Gasphase emittiert. Zum anderen können aktive organische Verbindungen das Gleichgewicht zwischen HOI und I2 in Richtung HOI verlagern. Im Versuch zur abiotischen Bildung von Iodalkanen aus Partikeln, bestehend aus I2O5 und verschiedenen Alkoholen, kann gezeigt werden, dass die Bildung von Iodmethan und Diiodmethan abläuft, dass jedoch die Emission bis zu zwei Größenordnungen kleiner ist als die von I2. Somit trägt die Bildung von Iodalkanen nur in einem sehr eingeschränkten Rahmen zum Recycling des Iods in der Atmosphäre bei. Der vorgestellte abiotische Bildungsweg hängt sowohl vom pH-Wert als auch vom Mischungsverhältnis im Partikel ab.