Le Jolis Research Articles

COMPARATIVE CHARACTERISTICS OF THE LOW MOLECULAR WEIGHT METABOLOME OF MACROPHYTES IN DIFFERENT WATER BODIES IN THE WATER AREA OF THE KANDALAKSHA BAY OF THE WHITE SEA

The Kandalaksha Bay of the White Sea underwent a first-of-its-kind comparative examination of the composition of essential oils of structure-forming macrophytes growing in freshwater and saltwater habitats. The essential oils of the aquatic macrophytes Nuphar lutea (L.) Sm., Ruppia maritima L., Zostera marina L., Fucus vesiculosus L., and Ascophyllum nodosum (L.) Le Jolis were obtained by steam hydrodistillation using the Clevenger apparatus from dried plants. Gas chromatography-mass spectrometry (GC/MS complex SHIMADZU GCMS-QP2010 Ultra) was used to analyze the qualitative and quantitative composition of LMWOCs (low molecular weight organic compounds). The component composition of the low molecular weight metabolome (LM) of macrophytes was shown to depend on both plant species specificity and plant habitat conditions (hydrological features, trophic state). More LMWOCs are found in plants from freshwater habitats than from marine ones. The investigated plants had only a few major compounds, ranging in number from 4 to 14. They accounted for between 70 and 83% of the overall concentration of all compounds in freshwater N. lutea and between 82 and 95% of the total concentration of LMWOCs in marine macrophytes. The most significant (% of the total essential oil) main components in macrophytes were carboxylic acids, specifically hexadecanoic, tetradecanoic, linoleic, and linolenic. The outcomes gained proved that the presence of carboxylic acids is a sign of a healthy macrophyte environment. The composition of LM of plants from northern habitats (marine and freshwater) contains high total concentrations of LMWOCs (including valuable ones from the perspective of economic use), making it possible to consider them as a valuable natural renewable resource for obtaining raw materials for various economic uses.

Ascophyllum nodosum (Linnaeus) Le Jolis from Arctic: Its Biochemical Composition, Antiradical Potential, and Human Health Risk.

Ascophyllum nodosum is a brown seaweed common in Arctic tidal waters. We have collected A. nodosum samples from the Barents Sea (BS), Irminger Sea (IS), and Norwegian Sea (NS) in different reproductive stages and have evaluated their biochemical composition, radical scavenging potential, and health risks. The total content of dominating carbohydrates (fucoidan, mannitol, alginate, and laminaran) ranged from 347 mg/g DW in NS to 528 mg/g DW in BS. The proportion of two main structural monosaccharides of fucoidan (fucose and xylose) differed significantly between the seas and reproductive phase, reaching a maximum at the fertile phase in the BS sample. Polyphenols and flavonoids totals were highest in NS A. nodosum samples and increased on average in the following order: BS < IS < NS. A positive correlation of free radical scavenging activity for seaweed extracts with polyphenols content was observed. The concentration of elements in A. nodosum from the Arctic seas region was in the following order: Ca > Mg > Sr > Fe > Al > Zn > As total > Rb > Mn > Ba > Cu > Co. Seaweeds from BS had the lowest metal pollution index (MPI) of 38.4. A. nodosum from IS had the highest MPI of 83. According to the calculated target hazard quotient (THQ) and hazard index (HI) values, Arctic A. nodosum samples pose no carcinogenic risk to adult and child health and are safe for regular consumption. Our results suggest that the Arctic A. nodosum has a remarkable potential for food and pharmaceutical industries as an underestimated source of polysaccharides, polyphenols, and flavonoids.

Ascophyllum nodosum (L.) Le Jolis, a Pivotal Biostimulant toward Sustainable Agriculture: A Comprehensive Review

Algae are existing macroscopic materials with substantial benefits, including as important growth regulators and macronutrients and micronutrients for the growth of healthy crop plants. Biofertilizers obtained from algae are identified as novel production fertilizers or innovative biofertilizers without the detrimental impacts of chemicals. Seaweeds contain many water-soluble minerals and nutrients that plants can easily absorb and that are valuable for crop plants’ growth. At present, Ascophyllum nodosum (L.) Le Jolis extract outperforms chemical fertilizers in terms of increasing seed germination, plant development, and yield, as well as protecting plants from severe biotic and abiotic stresses. A. nodosum contains bioactive compounds that exhibit an array of biological activities such as antibiotic, anti-microbial, antioxidant, anti-cancer, anti-obesity, and anti-diabetic activities. A. nodosum extract (AnE) contains alginic acid and poly-uronides that improve soil’s water-carrying ability, morsel structure, aeration, and capillary action, stimulating root systems in plants, increasing microbial activity in soil, and improving mineral absorption and availability. The scientific literature has comprehensively reviewed these factors, providing information about the different functions of A. nodosum in plant growth, yield, and quality, the alleviation of biotic and abiotic stresses in plants, and their effects on the interactions of plant root systems and microbes. The application of AnE significantly improved the germination rate, increased the growth of lateral roots, enhanced water and nutrient use efficiencies, increased antioxidant activity, increased phenolic and flavonoid contents, increased chlorophyll and nutrient contents, alleviated the effects of abiotic and biotic stresses in different crop plants, and even improved the postharvest quality of different fruits.

Range‐edge populations of seaweeds show niche unfilling and poor adaptation to increased temperatures

AbstractAimGlobal warming is affecting the distribution of species worldwide, but the level of adaptation of edge populations to warmer temperatures remains an open question. Here, we assess the thermal tolerance of populations of two habitat‐forming seaweeds along their latitudinal range, using thermal niche unfilling to assess their resilience to global warming.LocationEuropean Atlantic coastline.TaxonAscophyllum nodosum (Linnaeus) Le Jolis (Phaeophyceae) and Chondrus crispus Stackhouse (Rhodophyta).MethodsWe studied the ecotypic variation in upper survival temperatures (USTs) by measuring survival and growth of adults representing populations under a gradient of seawater temperature (12–30°C). Comparing the USTs with maximum seawater temperatures obtained from satellites, we investigated safety margins and niche unfilling states, both in recent history and under future climate scenarios.ResultsUSTs (≈24°C) did not differ significantly between populations, except for higher values (27.9°C) for the northernmost populations (cold edge) of A. nodosum. Populations of both species had thermal safety margins over the last few decades (from 1982 to 2021). However, projections based on USTs showed that in several years these margins have been eliminated and will completely disappear in the Bay of Biscay under RCP4.5 and RCP6.0 2090–2100 IPCC scenarios for C. crispus and under RCP8.5 for both species, threatening the populations there.Main ConclusionsSouthern marginal populations were not better adapted to global warming than populations elsewhere. Both seaweed species tolerated higher temperatures than the ambient maxima, suggesting a thermal niche unfilling state with thermal safety margins in their recent history. However, those are being depleted by ongoing climate change and this trend is predicted to increase. Marine heat waves are important threats to these habitat‐forming species, transiently reducing or even eliminating safety margins in the hottest parts of the European Atlantic coastline, contributing to explaining the distributional gap there.

A novel approach reveals underestimation of productivity in the globally important macroalga, Ascophyllum nodosum

Ascophyllum nodosum (L.) Le Jolis (Fucales, Fucaceae) is a modular intertidal brown alga that has the particularity of forming an air bladder once a year at the apical tip of the growing shoots. This characteristic provides a means for aging and estimating the growth of individuals. While it has long been recognized that growth can occur in older parts of the frond, this has not been properly assessed until now and has largely been overlooked when calculating the productivity of the species. Recent studies have suggested that the growth and elongation of older segments is minimal and thus has been used to infer past environmental conditions. Here we assessed the length and mass of successive internodal segments from 25 sites spread over both sides of the North Atlantic, covering a wide portion of the distribution of the species. By calculating the ratio of the mass and length of a segment divided by the segment produced the following year, we established that internodal segments continue accumulating mass for 1–5 years and increase in length for 1–3 years at most sites. Segments can almost triple their mass during their second year and more than double their length. These results indicate that previous productivity and growth estimates for A. nodosum based on apical growth alone greatly underestimate the true productivity of the species and its role in coastal carbon cycling. Furthermore, because they grow over several years, internodal segments should not be used to infer past environmental conditions or to reconstruct growth patterns over time.

The nomenclatural history of Phormium colensoi Hook.f.

ABSTRACT The complicated nomenclatural history of Phormium colensoi Hook.f. is reviewed. The name and a very brief validating description, both attributed to Joseph Dalton Hooker, were published in 1848 in an article by Le Jolis. The brevity of the description does not affect the validity of the publication, and the name is here accepted as validly published. Indirect references to gatherings by Banks & Solander and by Colenso are discussed to identify original material. Plants seen during this study at localities close to those visited by Colenso have a diverse range of phenotypes, and Banks & Solander specimens also seem to show more than a single phenotype. A lectotype is therefore not designated at this time. Possible synonyms for P. colensoi are also discussed. Phormium cookianum Le Jol. is the name currently recognised by New Zealand botanists, but this has not historically always been the case. A Le Jolis specimen at Kew is designated as lectotype for P. cookianum. The possibility that P. cookianum is a provisional name, and is therefore invalid, is rejected. Phormium forsterianum Colenso is a validly published synonym, but is superfluous and illegitimate. Phormium hookeri Gunn ex Hook.f., commonly regarded as a subspecies of P. cookianum, may not be sufficiently different from phenotypes of P. colensoi to justify the same rank under that species. The conclusion by New Zealand botanists is that European writers on Phormium were greatly misled by the limited material they had to hand. An open question remains as to whether some or all the original specimens of P. colensoi and P. cookianum might be of hybrid origin. Until the necessary taxonomic work (genetic and population studies) has been done, the nomenclature of Phormium species should be regarded as an open question rather than being decided purely on publication dates.

ИЗМЕНЕНИЕ ПРОФИЛЯ МИКОТОКСИНОВ В БУРЫХ ВОДОРОСЛЯХ ИЗ ШТОРМОВЫХ ВЫБРОСОВ

Brown algae Fucus vesiculosus Linnaeus, Fucus serratus Linnaeus, Ascophyllum nodosum (Linnaeus) Le Jolis and Saccharina latissima (Linnaeus) C.E. Lane, C. Mayes, Druehl &amp; G.W. Saunders collected from natural substrates and from storm emissions in one of the ecotopes of the Kandalaksha Bay of the White Sea (66°31' N 33°11' E) were used for comparative assessment of the content of low-molecular metabolites of micromycetes beloning to the genera Fusarium Link, Alternaria Nees, Penicillium Link, Aspergillus P. Micheli ex Haller, Myrothecium Tode, Cladosporium Link and others. After drying, the samples were crushed in a laboratory mill, a mixture of acetonitrile and water was used for extraction in a volume ratio of 84:16 with a consumption rate 10 mL per 1 g specimen. Extracts after 10-fold dilution with the buffer solution were analyzed using a set of certified enzyme-linked immunosorbent assay systems (Russia). The lower limit of quantitative measurements corresponded to an 85% level of antibody binding. All analyzed compounds – T-2 toxin, diacetoxiscirpenol, deoxynivalenol, zearalenone, fumonisins, alternariol, ochratoxin A, citrinin, PR-toxin, mycophenolic acid, aflatoxin B1, sterigmatocystin, cyclopiazonic acid, emodin, roridin A and ergot alkaloids – were found in the fresh thalli of F. vesiculosus, F. serratus, and A. nodosum. In the samples from the emissions, the profile of mycotoxins has been significantly changed. In F. vesiculosus and F. serratus the content of mycotoxins decreased sharply and uniformly and, as a result, the incidence of detection reduced to 8% and 15%. In A. nodosum, alternariol, aflatoxin B1 and mycophenolic acid were revealed in 17% of samples near the limits of determination of methods, and the other components of the complex could not be found. The mycotoxins were absent in the fresh thalli of S. latissima, and only some of the samples from the emissions had weak contamination with mycophenolic acid and emodin.

Screening on the Presence of Plant Growth Regulators in High Biomass Forming Seaweeds from the Ionian Sea (Mediterranean Sea)

The use of seaweed as plant biostimulants is a solution for sustainable agriculture. The present study aims to quantify and compare the presence of plant growth regulators (PGRs) in four genetically labeled macroalgae growing in the Ionian Sea. Species were selected because they produce abundant biomass, disturbing ecological equilibrium and anthropic activities. We measured the content of gibberellic acid (GA3), kinetin (KN), indoleacetic acid (IAA), abscisic acid (ABA) and indole butyric acid (IBA). The method applied was modified from the literature to obtain simultaneously different PGRs from seaweed biomass in a shorter period of time. Among results, it is notable that Hypnea corona Huisman et Petrocelli (Rhodophyta) showed higher GA3 concentration, while in Spyridia filamentosa (Wulfen) Harvey (Rhodophyta), higher KN, IBA, IAA and ABA contents were recorded. The latter species displayed an interesting profile of PGRs, with an IAA value comparable with that reported in Ascophyllum nodosum (Linnaeus) Le Jolis (Ochrophyta), which is currently used as a source of plant biostimulants in agriculture. Macroalgae thrive abundantly in nutrient-rich environments, such as anthropized coastal areas affecting human economic activities. Consequently, environmental agencies are forced to dredge algal thalli and discard them as waste. Any use of unwanted biomass as an economic product is highly desirable in the perspective of ecosustainable development.

Natural Deep Eutectic Solvents as Alternatives for Extracting Phlorotannins from Brown Algae

Natural deep eutectic solvents (NADES) are promising green solvents for extracting biologically active compounds from plant raw material. This is the first study in which NADES were used to extract phlorotannins from brown algae Fucus vesiculosus L. and Ascophyllum nodosum (L.) Le Jolis. The extraction efficiency of polyphenols was evaluated using 10 NADES based on choline chloride, lactic acid, betaine, and glucose in various mole ratios. The effect of H2O in aqueous solutions of NADES on extraction of phlorotannins was studied. Algae were extracted by maceration for 120 min at 50°C with a 1:5 raw-material:extractant ratio. Phlorotannins were quantified by spectrophotometry using the Folin–Ciocalteu method. The maximum extraction of phlorotannins (60 – 72%) was achieved using aqueous NADES solutions (50 – 70%) based on choline chloride with added lactic or malic acid and also on malic acid and betaine. The NADES had efficiencies comparable to Me2CO and EtOH.

Increased freezing stress tolerance of Nicotiana tabacum L. cv. Bright Yellow-2 cell cultures with the medium addition of Ascophyllum nodosum (L.) Le Jolis extract

The study of bioactive components of the brown alga Ascophyllum nodosum (L.) Le Jolis has shown that they promote growth and increase productivity of plants. However, a standardized model system providing consistent responses to such bioactive components has yet to be established. Given that freezing stress, especially in northern climates, reduces plant growth and productivity, a technique was developed to protect plant cells under freezing stress using the natural products made from the abundant A. nodosum as a cell culture supplement. In this study, a homogenous cell culture system of Nicotiana tabacum L. cultivar Bright Yellow-2 (BY-2) suspension cells was used to investigate the bioactivity and protection level of this alga extract under freezing temperatures, and BY-2 cell growth, physiology, and molecular changes were measured in the presence or absence of the extract. The results indicated that A. nodosum extract significantly improved BY-2 cell survival after exposure to freezing temperatures. Inclusion of alga extract also improved cell growth, membrane stability, and nuclear integrity, and reduced cell death of cold-stressed BY-2 suspension cultures. It was concluded that A. nodosum extract influenced cellular and molecular regulation and triggered mechanisms, such as osmolyte accumulation and antioxidant activity, to combat freezing stress in BY-2 suspension cells.

Природные глубокие эвтектические растворители как альтернативные экстрагенты для извлечения флоротанинов бурых водорослей

Природные глубокие эвтектические растворители (ПГЭР) являются перспективными «зелеными» растворителями для экстракции биологически активных веществ из растительного сырья. Это первое исследование, в котором ПГЭР использованы для извлечения флоротанинов из бурых водорослей Fucus vesiculosus L. и Ascophyllum nodosum (L.) Le Jolis. На основе холина хлорида, молочной кислоты, бетаина и глюкозы с различными молярными соотношениями 10 ПГЭР применены для оценки эффективности экстракции полифенолов. Изучено влияние воды в составе водных растворов ПГЭР на извлечение флоротанинов при экстракции. Водоросли экстрагировали методом мацерации в течение 120 мин при 50 °C, соотношение сырье : экстрагент было 1:5. Количественное содержание флоротанинов определяли спектрофотометрически по методу Фолина — Чокальтеу. Максимальное извлечение флоротанинов (60 – 72 %) было достигнуто с использованием 50 – 70 % водных растворов ПГЭР на основе холина хлорида с добавлением молочной или яблочной кислоты, а также яблочной кислоты и бетаина. ПЭГР по эффективности были сравнимы с ацетоном и этанолом.

The effect of global climate change on the future distribution of economically important macroalgae (seaweeds) in the northwest Atlantic

An increase in greenhouse gas emissions has led to a rise in average global air and ocean temperatures. Increased sea surface temperatures can cause changes in species’ distributions, particularly those species close to their thermal tolerance limits. We use a bioclimate envelope approach to assess potential shifts in the range of marine macroalgae harvested in North American waters: rockweed ( Fucus vesiculosus Linnaeus, 1753), serrated wrack ( Fucus serratus Linnaeus, 1753), knotted wrack ( Ascophyllum nodosum (Linnaeus) Le Jolis, 1863), carrageen moss ( Chondrus crispus Stackhouse, 1797), and three kelp species ( Laminaria digitata (Hudson) J.V. Lamouroux, 1813; Saccharina latissima (Linnaeus) C.E. Lane, C. Mayes, Druehl et G.W. Saunders, 2006; and Saccharina longicruris (Bachelot de la Pylaie) Kuntze, 1891). We determined species’ thermal limits from the current sea surface temperatures associated with their geographical distributions. Future distributions were based on sea surface temperatures projected for the year ∼2100 by four atmosphere-ocean general circulation models and earth system models for regional concentration pathways (RCPs) 4.5 and 8.5. Future distributions based on RCP 8.5 indicate that the presence of all but rockweed ( F. vesiculosus) is likely to be threatened by warming waters in the Gulf of St. Lawrence and along the Atlantic coast of Nova Scotia. Range retractions of macroalgae will have significant ecological and economic effects including impacts on commercial fisheries and harvest rates and losses of floral and faunal biodiversity and production, and should be considered in the designation of marine protected areas.

Managing disturbance: the response of a dominant intertidal seaweed Ascophyllum nodosum (L.) Le Jolis to different frequencies and intensities of harvesting

The rockweed Ascophyllum nodosum is a dominant component of intertidal communities across the North Atlantic Ocean, providing both habitat and primary productivity to nearshore ecosystems. Commercial exploitation of this species is widespread and typically involves cutting the distal portion of fronds thereby permitting regrowth by lateral branching and generation of new fronds from the perennial holdfast. Two key management parameters for determining the sustainability of this resource are the cutting height and the recovery period between successive harvests. Here, we assess the influence of these two parameters on several indicators of exploitation, including harvested biomass, remaining biomass, annual harvest yield, and biomass recovery. Over a 28-year period, treatments of two levels of cutting height (15 and 30 cm) and five levels of recovery period (1, 2, 3, 4, and 5 years) were applied to individual 25-m2 plots. This study provides unique observations of the long-term impacts of different management scenarios on Ascophyllum biomass. In general, indicators were lower for shorter recovery periods of 1 and 2 years. Surprisingly, longer recovery periods of 4 and 5 years rarely increased indicators, suggesting that a 3-year recovery period maximizes harvested biomass. Moreover, a longer cutting height did not consistently result in increased indicators, and indeed, the 15-cm cutting height often provided higher values (e.g., annual harvest rates), than the 30-cm cutting height, especially at longer recovery periods. Other impacts of harvesting beyond effects on biomass (e.g., reproductive capacity, canopy structure, scale of harvested areas) were not measured but are discussed and merit further investigation to better determine harvesting regulations.

Ultrasound assisted methods for enhanced extraction of phycobiliproteins from marine macro-algae, Gelidium pusillum (Rhodophyta)

Extraction of phycobiliproteins (R-phycoerythrin, R-PE and R-phycocyanin, R-PC) from macro-algae is difficult due to the presence of large polysaccharides (agar, cellulose etc.) present in the cell wall which offer major hindrance for cell disruption. The present study is aimed at developing most suitable methodology for the primary extraction of R-PE and R-PC from marine macro-algae, Gelidium pusillum(Stackhouse) Le Jolis. Such extraction of phycobiliproteins by using ultrasonication and other conventional methods such as maceration, maceration in presence of liquid nitrogen, homogenization, and freezing and thawing (alone and in combinations) is reported for the first time. Standardization of ultrasonication for different parameters such as ultrasonication amplitude (60, 90 and 120µm) and ultrasonication time (1, 2, 4, 6, 8 and 10mins) at different temperatures (30, 35 and 40°C) was carried out. Kinetic parameters were estimated for extraction of phycobiliproteins by ultrasonication based on second order mass transfer kinetics. Based on calorimetric measurements, power, ultrasound intensity and acoustic power density were estimated to be 41.97W, 14.81W/cm2 and 0.419W/cm3, respectively. Synergistic effect of ultrasonication was observed when employed in combination with other conventional primary extraction methods. Homogenization in combination with ultrasonication resulted in an enhancement in efficiency by 9.3% over homogenization alone. Similarly, maceration in combination with ultrasonication resulted in an enhancement in efficiency by 31% over maceration alone. Among all the methods employed, maceration in combination with ultrasonication resulted in the highest extraction efficiency of 77 and 93% for R-PE and R-PC, respectively followed by homogenization in combination with ultrasonication (69.6% for R-PE and 74.1% for R-PC). HPLC analysis was carried out in order to ensure that R-PE was present in the extract and remained intact even after processing. Microscopic studies indicated a clear relation between the extraction efficiency of phycobiliproteins and degree of cell disruption in a given primary extraction method. These combination methods were found to be effective for extraction of phycobiliproteins from rigid biomass of Gelidium pusillum macro-algae and can be employed for downstream processing of biomolecules also from other macro-algae.

Extrato da alga Ascophyllum nodosum (L.) Le Jolis na produção de porta-enxertos de Anonna glabra L.

The use of bio-stimulant-based extract of seaweed is increasingly entering the agricultural scenario, allowing its use in organic agriculture because of the need for fertilizers, pesticides and natural hormones. The aim of this study was to test the efficiency of the use of the commercial product (Acadian®) based seaweed Ascophyllum nodosum (L.) Le Jolis in the production of rootstock Anonna glabra L. The work was conducted in a greenhouse with 50% shade. The experimental design was completely randomized with five doses of the extract (0, 2, 4, 6 and 8 ml L-1) with six replications. At 150 days after sowing characteristics were evaluated: number of leaves (pcs. / plant), length of the aerial, root and total dry matter (cm), diameter (mm), shoot dry weight of the root system and total (g), and the quality index Dickson. The extract of Ascophyllum nodosum seaweed at a dose 2 ml L-1 produced positive results in the agronomic performance of araticum rootstocks (Anonna glabra L.).

Effect of Bio-Algeen&lt;sup&gt;®&lt;/sup&gt; preparation on growth and mycorrhizal characteristics of Norway spruce seedlings

In this paper, the effect of the Bio-Algeen® product (bio-alginate from the seaweed Ascophyllum nodosum (Linnaeus) Le Jolis) was evaluated in relation to basic mycorrhizal and growth characteristics of Norway spruce (Picea abies (Linnaeus) H. Karsten) seedlings. The seedlings were planted in a forest nursery in 5 different treatments: 4 treatments with the Bio-Algeen® product in different regimes (soaking, granulate, soaking + granulate, irrigation) and control. Compared to the control, mycorrhizal characteristics of the treated seedlings differed significantly for soaking treatment only, but they were less favourable for all treatments with this product. Among the growth characteristics, the height of aboveground parts was significantly taller compared to the control for soaking and granulate treatments, while the shoot dry weight was significantly higher for granulate treatment only. Both of these characteristics showed higher values across all treatments compared to the control. Although treated seedlings showed worse mycorrhizal characteristics, their growth was not affected by these characteristics. Thus, Bio-Algeen® can be used for an improvement of seedling growth in forest nurseries.

ALGAS MARINAS BENTICAS INDICADORAS DE UN AREA AFECTADA POR AGUAS DE SURGENCIA FRENTE A LA COSTA CARIBE DE COLOMBIA

The present paper is the result of a study undertaken to establish the relationship of certain marine envlromental factors and the benthic flora of the Caribbean littoral of Colombia. For the purpose of this study this coastal bands has been divided in two Areas. Area 1 is found between Cabo Tiburón and the mouth of the Río Magdalena, and is characterized by warm waters with very small fluctuations of the surface temperature. Area 2 ranges from the mouth of the Río Magdalena to Castilletes, and its waters are affected by a coastal upwelling with a locality of maximum intensity at the West of Península de Guajira. As a result of the presence of this upwelling there are considerable variations in the physical and chemical factors acting upon the benthic flora, there established for very short periods or all year round, as well as determining the absence of some genera and species typical of these latitudes. The parameters used for detecting this oceanographic phenomenon are given by Díaz-Piferrer (1967 a) for Venezuela. To the biological indicators cited by this author for Venezuela, the present writer adds the brown alga Ectocarpus confervoides (Roth) Le Jolis, which was found in the area of upwelling in Colombia. A comparative study of these indicators plants with those of Venezuela is given in the present paper. Similarities and differences were found to be caused by the over-run of the warm counter current on the Colombian upwelling; by the different forces of the Caribbean Current and Guayana Current, all of which lead to the related oceanographic phenomenon; tfie climatic factors; the topography of the sea bottom and the influence of the continental waters over these upwelling.

Effects of periodic air-exposure and nutrients on the competition of Ascophyllum nodosum and Fucus vesiculosus germlings

To examine the relationship between competition and environmental factors, the germlings of Ascophyllum nodosum (L) Le Jolis and Fucus vesiculosus L. were cultured in monocultures and mixtures of the two species under two different exposure and nutrient levels. Both intra- and inter-specific competition were examined in comparison of the mortality and growth of germlings in monocultures and mixtures of the two species. The mortality of germlings increased with increasing density and emergence periods both in the monoculture and mixtures of the two species, and the mortality of Ascophyllum was significantly higher than that of Fucus both in submerged and emerged treatments. The growth of germlings of both species reduced with increasing density but F. vesiculosus always grew faster than Ascophyllum. The values of log output ratio were more than 0.1, indicating that Fucus ‘won’ in the competitive battles with Ascophyllum under two nutrient- and air-exposure levels. Log output ratio was greater in high than in low nutrients, indicating that the growth of Fucus is more enhanced than that of Ascophyllum in high nutrients. In the present study, the outcome of inter specific competition between germlings of Fucus vesiculosus and Ascophyllum nodosum was slightly altered by duration of emergence and nutrient concentration, but not to such an extent as to change the outcome.

ОСОБЕННОСТИ МИНЕРАЛЬНОГО СОСТАВА БУРЫХ ВОДОРОСЛЕЙ БЕЛОГО И БАРЕНЦЕВА МОРЕЙ

The contents of macro (Mg, Na, Ca, K, Cl, S) and trace elements (I, Br, Fe, Cr, Ti, P, Si, Sr, Zn, Cu, Al), as well as toxic heavy metals (Pb, Hg) was analyzed in 25 samples of four brown algae (Laminaria saccharina (Linnaeus) J.V.Lamouroux, Laminaria digitata (Hudson) J.V.Lamouroux, Fucus vesiculosus Linnaeus, Ascophyllum nodosum (Linnaeus) Le Jolis), harvested during the complex research expedition "The Arctic Floating University 2012", in the White and Barents Seas. Conclusions are drawn on the patterns in the accumulation of elements in brown algae depending on family and growth conditions, and also regarding the nutritional value of brown algae.

Amino-Acid Composition of Arctic Brown Algae

The amino-acid composition and total nitrogen content in 25 samples of four commercial Arctic brown algae Saccharina latissima (L.) C. E. Lane, C. Mayes, Druehl & G. W. Saunders; Laminaria digitata (Hudson) J. V. Lamouroux; Fucus vesiculosus (L.); and Ascophyllum nodosum (L.) Le Jolis were studied. The use of brown algae not only as raw material for producing mono- and polysaccharides but also as a source for obtaining amino acids for the production of drugs and functional foods was recommended. Factors for calculating total nitrogen in protein that differed from the commonly accepted ones were proposed.