Observations on the effects of germanium dioxide on the growth of macro-algae and diatoms

Markham, James W.; Hagmeier, Erik

doi:10.2216/i0031-8884-21-2-125.1

Cited by 58 publications

(33 citation statements)

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“…Ambient irradiance was 87 to 145 µE m -2 s -1 , provided by full spectrum (GE Chroma 50) and cool white (Sylvania) fluorescent bulbs on a 12:12 h photoperiod. Germanium dioxide treatments of 0.15 mg l -1 were conducted weekly for diatom control for the duration of the experiment (Markham & Hagmeier 1982).…”

Section: Methodsmentioning

confidence: 99%

Population ecology of the invasive kelp Undaria pinnatifida in California: environmental and biological controls on demography

Thornber

Kinlan²,

Graham³

et al. 2004

Mar. Ecol. Prog. Ser.

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We combined field monitoring and laboratory experiments to examine the population ecology of both the microscopic and macroscopic stages of a new invasion of Undaria pinnatifida in California. Over the course of 1 yr, we observed 2 distinct recruitment pulses of individuals in the Santa Barbara harbor; the appearance of these pulses was strongly correlated with a 4°C drop in ocean temperature approximately 2 mo prior to recruitment. Cultures of zoospores and successive microscopic stages revealed thermal tolerances consistent with field recruitment data; individuals grown at 13°C had significantly higher survivorship than individuals grown at higher temperatures (harbor temperatures annually ranged from 12 to 21°C). The 2 cohorts also differed greatly in individual size, growth rate, and survival to maturity. Grazing by herbivores, predominately the native kelp crab Pugettia producta, effectively prevented nearly all individuals in the second cohort from reaching reproductive maturity. Grazer control was effective despite far higher rates of recruitment during the second recruitment pulse. Our results highlight the potential for extreme variability in U. pinnatifida demography mediated by local oceanographic and biotic factors. Understanding controls on U. pinnatifida demography helps to explain variation in the spread and impact of this invader worldwide, and allows better prediction of when and where U. pinnatifida may continue its invasion along the west coast of North America.

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Section: Methodsmentioning

confidence: 99%

Population ecology of the invasive kelp Undaria pinnatifida in California: environmental and biological controls on demography

Thornber

Kinlan²,

Graham³

et al. 2004

Mar. Ecol. Prog. Ser.

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“…Prior to each renewal of growth medium, the slides were carefully sprayed with seawater to remove necromass and dross. To reduce growth of diatoms and prokaryotes, germanium dioxide (0.2 mg l -1 , a concentration recommended by Markham & Hagmeier 1982) and penicillin (2 mg l -1 ) were added to the cultures.…”

Section: Methodsmentioning

confidence: 99%

Interspecific competition between Enteromorpha (Ulvales: Chlorophyceae) and Fucus (Fucales: Phaeophyceae) germlings: effects of nutrient concentration, temperature, and settlement density

Steen¹

2004

Mar. Ecol. Prog. Ser.

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The increased abundance of ephemeral algae and corresponding decline in perennial fucoids observed in eutrophic (nutrient-rich) waters could be caused by eutrophication-driven shifts in the competitive relationship between the 2 groups as early as the germling stage. During the initial post-settlement period germlings are exposed to large temporal variations in temperature, which may influence their performance and competitive interactions. Effects of temperature, nutrient concentration, and settlement density on the competitive relationship between germlings of Fucus serratus L. and F. evanescens C. Agardh and of the ephemeral alga Enteromorpha compressa (Linnaeus) Greville were examined using factorially designed culture experiments. In monocultures, germling growth of both Fucus species and E. compressa was generally stimulated by nutrient enrichment (32 µmol nitrate/ammonia and 2 µmol phosphate l -1 seawater) and high temperature (17°C compared to 7°C), and negatively related to settlement density (10 to 50 germlings cm -2 for Fucus, 30 to 130 germlings cm -2 for E. compressa). In mixed cultures, interspecific competition effects of E. compressa on F. serratus and F. evanescens germlings increased with increasing nutrient and temperature levels. In the nutrient-enriched cultures, interspecific competition from E. compressa suppressed the yield of Fucus spp. by 80 to 100% at 17°C, with F. evanescens being more suppressed than F. serratus, whereas the suppressive effects of E. compressa on Fucus germlings were < 60% at 7°C. These results suggest that competition from ephemeral algae at early life stages may be a reason for the decline of fucoids in eutrophic waters and that reproduction at low temperatures, as in species like F. serratus and F. evanescens, may shield the vulnerable initial germling stages from the severest competition pressure by ephemeral algae. KEY WORDS: Fucus spp. · Enteromorpha compressa · Germlings · Competition · Nutrients · TemperatureResale or republication not permitted without written consent of the publisher

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“…En estudios previos realizados por otros autores, se demostró también que bajo condiciones de laboratorio el dióxido de germanio no afecta el crecimiento de ciertas macroalgas como Polysiphonia urceolata, Porphyra umbilicalis y Chondrus crispus (Rhodophyta) [15]. Sin embargo, en la gran mayoría de los casos el efecto observado sobre las algas es claramente inhibidor [16][17][18].…”

Section: Resultados Y Discusiónunclassified

Efecto inhibidor del dióxido de germanio sobre el biofouling del puerto de Mar del Plata

et al. 2018

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RESUMENLa fijación del biofouling sobre cualquier tipo de materiales sumergidos acarrea graves pérdidas económicas como consecuencia del deterioro y la salida de servicio de las distintas estructuras. Este asentamiento de organismos que afecta principalmente a embarcaciones, muelles, boyas, granjas de cultivo y tuberías ocurre de forma secuencial, rápida e inmediata después de la inmersión. En principio se asientan organismos microscó-picos ("microfouling") sobre un film preformado de macromoléculas orgánicas adsorbidas sobre la superficie sumergida; la exudación de polímeros extracelulares de las bacterias forma una especie de malla que sirve de anclaje, sostén y nutrición para las esporas algales y larvas de organismos macroscópicos que arriban más tarde. Esta comunidad denominada biofouling alcanza un espesor considerable en poco tiempo y por esta razón, se busca para su control formulaciones antifouling eficaces cuyos componentes sean ecológicamente aceptables. La inhibición que ejerce el dióxido de germanio sobre el desarrollo de organismos del microfouling (principalmente diatomeas, hongos y bacterias) plantea la posibilidad de su utilización como compuesto antiincrustante. En este sentido se estudió el efecto del dióxido de germanio incluido en una pintura antiincrustante expuesta en el puerto de Mar del Plata durante el período de verano. Los resultados obtenidos indican que la formulación con dióxido de germanio inhibió no solo el asentamiento de diatomeas sino que también afectó la fijación de especies conspicuas del macrofouling (ascidias solitarias y coloniales, gusanos tubícolas y cirripedios). Sobre la base de estos estudios se puede concluir que el dióxido de germanio puede ser empleado como compuesto antifouling dado que demostró alta efectividad sobre un amplio espectro de organismos integrantes de la comunidad.Palabras clave: dióxido de germanio, biofouling, pinturas antifouling amigables con el ambiente. ABSTRACTMarine biofouling on any new material immersed in seawater can lead to extra costs due to increased maintenance, or/and even mechanical wear, and/or biodeterioration that require costly antifouling measures. Fouling organisms growing on immersed manmade surfaces affect hulls, piers, buoys, aquaculture and pipes mainly. Following adsorption of a conditioning film of macromolecules, microorganisms which are the primary colonizers ("microfouling"), are found on unprotected surfaces after only a few minutes of immersion. Extracellular polymeric material exudates from bacteria forms a net that permits anchorage and protection for spores of macroalgae and macroinvertebrate larvae which arrive later. This community is called "biofouling" and develops a thick layer rapidly. As a consequence, the search is orientated to new efficient compounds to formulate environmental friendly antifouling paints.It is well known the inhibitory effect of germanium dioxide on microfouling organisms (diatoms, fungi and bacteria, mainly) and this property promotes its use as antifouling compound. In this sense, g...

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Observations on the effects of germanium dioxide on the growth of macro-algae and diatoms

Cited by 58 publications

References 0 publications

Population ecology of the invasive kelp Undaria pinnatifida in California: environmental and biological controls on demography

Population ecology of the invasive kelp Undaria pinnatifida in California: environmental and biological controls on demography

Interspecific competition between Enteromorpha (Ulvales: Chlorophyceae) and Fucus (Fucales: Phaeophyceae) germlings: effects of nutrient concentration, temperature, and settlement density

Efecto inhibidor del dióxido de germanio sobre el biofouling del puerto de Mar del Plata

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