During the last decade, the marine oil-and-gas industry has been actively developing in Russia, thus becoming an additional source of oil hydrocarbon pol-.
ISSN 1063-0740, Russian Journal of Marine Biology, 2008, Vol. 34, No. 2, pp. 131–134. © Pleiades Publishing, Ltd., 2008. Original Russian Text © O.V. Stepaniyan, 2008, published in Biologiya Morya.
ECOLOGY
Effects of Crude Oil on Major Functional Characteristics of Macroalgae of the Barents Sea O. V. Stepaniyana, b aDepartment bAsov
of Marine and Ecosystem Research, Southern Scientific Center RAS, Rostov-on-Don, 344001 Russia Branch, Murmansk Marine Biological Institute, Kola Science Center RAS, Rostov-on-Don, 344006 Russia Accepted September 13, 2007
Abstract—On the basis of experimental research on the influence of crude oil on basic functional characteristics (growing speed, photosynthesis, and breadth) of macroalgae of the Barents Sea (Laminaria saccharina, Fucus vesiculosus, Ascophyllum nodosum, Porphyra umbilicalis, Palmaria palmata, and Enteromorpha prolifera) it was shown that kelp are more resistant to the influence of oil carbohydrates while red and green algae are less resistant. Under the short-term influence of oil toxins photosynthesis is depressed and respiration increases, under long-term influence the rate of growth is reduced. Key words: oil, photosynthesis, respiration, growth rate, macroalgae, Laminaria saccharina, Fucus vesiculosus, Ascophyllum nodosum, Porphyra umbilicalis, Palmaria palmata. DOI: 10.1134/S1063074008020077
During the last decade, the marine oil-and-gas industry has been actively developing in Russia, thus becoming an additional source of oil hydrocarbon pollution in the marine environment. Almost the entire Russian shelf zone is rather promising for oil and gas extraction. At present, in the shelf of the Barents Sea oil and gas fields are under development and the coastal infrastructure of the oil-and-gas complex is under construction; however, this increases the risks of pollution of intertidal and subtidal zones [5]. Inevitable oil spills could negatively affect attached macroscopic algae that form highly productive coastal communities [7]. On the other hand, an analysis of literature data performed earlier showed that macroalgae, especially fucoids, are resistant to the effects of oil hydrocarbons due to functional reorganizations and adaptations in different levels of organization [2, 8]. In this project we studied responses in the major functional parameters of macroalgae (growth, photosynthesis, and respiration) on exposure to emulsions of low-sulphur, low-tarry, paraffine oil (Barents Sea, Kolguev Island). MATERIAL AND METHODS We used common species of macroalgae of the Barents Sea, belonging to either brown (Laminaria saccharina, Fucus vesiculosus, and Ascophyllum nodosum) or red algae (Porphyra umbilicalis and Palmaria palmata). The algae were collected in the intertidal and upper subtidal zones of DalOne-Zelenetskaya Guba Bay (69°07'N, 36°05'E), in July–August 2002–2003. The experiments were performed in the Laboratory of
Algology of the Murmansk Marine Biological Institute (MMBI), Cola Science Center RAS (DalOnie Zelentsy Village). Preparation of a crude oil emulsion in seawater. We placed 400 ml of filtered seawater (the water salinity and temperature were 32–33‰ and 8.0 ± 1.0°C respectively) into a vial with a ground glass stopper and introduced the oil, so that the resulting volume concentration of oil in seawater was 5, 10, 20, or 30 mg/l. The mixture was agitated in an electric shaker for 30 min, at a rate of 3.6 rotations per minute, at an air temperature of 9.0°C. During preliminary experiments we found that the greatest volume of oil (the sum of water-soluble and emulsified fractions) that can be emulsified without development of a film on the water surface (under the tested experimental conditions) was 30 mg/l, thus the latter was the greatest concentration used in the experiments. Studies of oil effects on the relative growth rate of microalgae. We used cuttings from the intercalary growth zone of L. saccharina (at an age of 0+); apical parts of thalluses of F. vesiculosus (at an age of 1+) and A. nodosum (at an age of 2+); prolifications of P. palmata; and entire thalluses of P. umbilicalis (10–12 cm long). Prior to the experiments these parts of the algal thalluses were adapted to conditions in a temperatureregulated room for 3 days. After determination of the wet weight of the entire material and the dry weight of a certain portion of the sample, the thalluses or their parts (20 specimens in each subsample) were placed into 400–600 ml glass beakers and flooded with 300– 400 ml of oil emulsion. To exclude effects of mutual shading, the contents of the beakers were stirred
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RESULTS AND DISCUSSION
Growth rate, % per day 7 6 5 4
1
3 4
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1 2 0 Control
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Fig. 1. Effects of a crude oil emulsion on the relative growth rate in macroalgae. (1) Laminaria saccharina, (2) Porphyra umbilicalis, (3) Fucus vesiculosus, (4) Ascophyllum nodosum, (5) Palmaria palmata.
2−3 times per day, thus providing a homogeneous distribution of the algae throughout the bottom of the bakers. The duration of each experiment was 10 days. Then the above listed parameters were measured again. To calculate the relative growth rate (RGR), the following equation was used [10]: RGR = (lnA2 – lnA1)/T × 100%, where A1 and A2 are the initial and final size of the tested object and T is the time (in days) between the first and the last measurements. Studies of oil effects on the intensity of photosynthesis and respiration in macroalgae. A portion of algal thalluses or their parts (n = 10 for the control and each experimental concentration of oil emulsion) from the preceding experiment was used to determine visible photosynthesis and dark respiration. Prior to the beginning of the experiments and during 10 days of exposure to medium including oil hydrocarbons, we measured the level of visible photosynthesis and dark respiration of macroalgae using Winkler’s iodometric method. The intensity of photosynthesis was determined as the difference between visible photosynthesis and respiration [1]. The amount of oxygen produced by the algae was recalculated for 1 g of dry weight, as the latter parameter, according to the results of our preliminary experiments, appeared to be the less variable one over time (compared with the wet biomass or surface area of algal thalluses). The experiments were performed in a temperatureregulated room, at an air temperature of 9.0 ± 1.0°C, a photoperiod of 24 h, and illumination of 3–6 W/m2. The temperature of the seawater was 8.0 ± 1.0°C. Each of the experiments was repeated twice; each measurement was repeated three times.
The results of our experiments showed that the growth of the brown algae Laminaria saccharina and Fucus vesiculosus was not arrested under all tested concentrations of crude oil in the water (Fig. 1). In the brown alga Ascophyllum nodosum and red algae Porphyra umbilicalis and Palmaria palmata active growth was seen only at oil concentrations of 5–10 mg/l. Increasing concentrations of oil emulsion in the water caused a significant decrease in the relative growth rate of these species. The photosynthetic activity of the examined species decreased as follows: A. nodosum—L. saccharina— F. vesiculosus—P. palmata—P. umbilicalis (Fig. 2). The indices of photosynthesis in all algae except A. nodosum decreased with an increase in the concentration of oil hydrocarbons, whereas the intensity of respiration was variable (Fig. 2). Complete suppression of photosynthetic activity by the end of exposure at oil concentrations of over 10 mg/l was recorded in P. umbilicalis and P. palmata, although at oil concentrations below 10 mg/l we found the same or even greater values of photosynthesis intensity than in the control in these species. In A. nodosum we recorded the stimulation of photosynthetic activity at all tested oil concentrations. Decreasing photosynthetic activity was accompanied by deformations and changes in the coloration of thalluses, such phenomena have also been observed in the past [9, 12, 13]. These results corroborate the existing opinion that the intensity of the functional response to toxic oil effects is different in taxonomically different groups of macroalgae [13, 15]. This is probably due to structural peculiarities of the thalluses and the functional activities of the photosynthetic system in macroalgae. Penetrating into the cell, oil hydrocarbons could destroy the plasmalemma, causing disturbances in the ion balance, reducing intracellular pressure, and decreasing the amount of phycoerythrin and chlorophylls [15, 16]. However, such changes could be reversible and restoration of the photosynthetic function in macroalgae is possible after the effects of toxicants cease or decrease [12]. The increasing intensity of respiration observed in the experiments obviously is due to the necessity to compensate energy losses appearing as a result of the suppression of photosynthetic function with the toxicants [3]. The changes in the functional parameters of macroalgae under the effects of crude oil show a non-linear pattern (Figs. 1, 2). It is known that disbalance in the functioning of the biochemical adaptation system of algae is accompanied by changes in the major functional indices, which are revealed as gradually damped oscillations [4]. Due to the time lag in the system of biochemical responses, the results of the effects are somewhat delayed relative to the time of the initial stimulus.
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EFFECTS OF CRUDE OIL 2.0 0
Porphyra umbilicalis î Ñ 0
5
Palmaria palmata 4.0 2.0 0
10 20 30
–2.0
–1.0
–4.0 –6.0
–0.2
–8.0 Fucus vesiculosus
2.0 1.5 1.0 0.5 0 –0.5
0
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–1.0
7.0 6.0 5.0 4.0 3.0 2.0 30 1.0 0 –1.0
5.0 4.0 3.0 2.0 0 5 10 20 30 1.0 0 –1.0 –2.0 –3.0 –4.0 –4.0 Ascophyllum nodosum
0
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133 Laminaria saccharina
0
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10 20 30
10 20 30
Fig. 2. Dependencies between photosynthetic activity (F) and respiration (R) of algae and the effects of crude oil emulsion. Abscissa—concentration of oil hydrocarbons, mg/l; ordinate—photosynthesis and respiration, mg O2.
During our experiments it was shown that the growth of the tested brown and red algae was not arrested under the effects of oil hydrocarbons in concentrations of 10–30 mg/l. Some scientists believe that stimulation of algal growth under conditions of oil intoxication is due to the presence of naphthenic acids and metals in the oil; together with several other oil hydrocarbons, naphthenic acids function as growth factors, while the metals perform the function of microelements in the metabolism of the algae [6, 11]. An alternative explanation of the growth of macroalgae in oil-containing seawater could be the exogenous input of low- and high-molecular organic substances into algal thalluses [14]; these substances appear during the destruction of oil in water and then are involved in metabolic (heterotrophy) or energetic (organotrophy) processes. Exogenous input of oil hydrocarbons is possible in the case of their adsorption on the cell surface and contacts with the microperiphyton community; as a result complex hydrocarbons could be reduced to simple substances. This is a scheme that could obviously explain the resistance of fucoid algae to the effects of crude oil [8]. ACKNOWLEDGMENTS The project was partially supported by Federal Goal-Oriented World Ocean Program via the Integrated Studies of Processes, Characteristics, and Resources of Russian Seas of the North European Basin project. The author is deeply indebted for methodical recommendations and discussion of the results of the RUSSIAN JOURNAL OF MARINE BIOLOGY
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experiments to the Head of Department of Algology MMBI, G.M. Voskoboinikov; colleagues from MMBI, M.V. Makarov and C.I. Bardan and scientist of the Biological Department of Moscow State University, I.V. Tropin. The author is thankful to the anonymous referees for helpful critical analysis of the results of the investigations. REFERENCES 1. Baslavskaya, S.S. and Trubetskaya, O.M., Praktikum po fiziologii rastenii (Practical Training on Plant Physiology), Moscow: Moscow State University, 1964. 2. Voskoboinikov, G.M., Matishov, G.G., Bykov, O.D., et al., On the Resistance of Macrophytes Against Oil Pollution, Doklady RAN, 2004, vol. 397, no. 6, pp. 842– 844. 3. Golovko, T.K., Dykhanie rastenii (fiziologicheskie aspekty) [Respiration of Plants (Physiological Aspects)], St.-Petersburg: Nauka, 1999. 4. Egorov, V.N. and Erokhin, V.E., An Empirical Model of the Kinetics of Macrophyte Pigment System Adaptive Resistance during Intoxication with Phenol, Ekologiya morya, 1998, issue 47, pp. 91–94. 5. Patin, S.A., Neft’ i ekologiya morya (Oil and Ecology of the Sea), Moscow: VNIRO, 2001. 6. Ecological-Toxicological Aspects, Problemy khimicheskogo zagryazneniya vod Mirovogo okeana (Problems of Chemical Pollution of Waters of the World Ocean), Leningrad: Gidrometeoizdat, 1985, vol. 5, pp. 1–115. 7. Stepan’yan, O.V. and Voskoboinikov, G.M., MorphoFunctional Condition of Macrophytes and Forecast of Phytocenosis Development in the Barents Sea under No. 2
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134
8.
9. 10. 11.
STEPANIYAN Conditions of Oil Pollution, Sovremennye tekhnologii v polyarnykh issledovaniyakh (Modern Technologies in Polar Researches), Moscow: Nauka, 2005, pp. 235–255. Stepan’yan, O.V. and Voskoboinikov, G.M., Effect of oil and oil products on morphofunctional parameters of marine macrophytes, Biologiya Morya, 2006, no. 4, pp. 241–248. Clendenning, K.A. and North, W.J., Effects of Wastes on the Giant Kelp Macrocystis pyrifera, Proc. Int. Conf. Waste Dispos. Mar. Envir., 1960, pp. 82–91. Coombs, J., Hall, D.O., Long, S.P., and Scurlock, J.M.B., Eds., Techniques in Bioproductivity and Photosynthesis, Pergamon Press, Oxford, 1985. Hsiao, S.T.C., Kettle, D.W., and Foy, M.G., Effect of Crude Oils and the Oil Dispersant Corexit on Primary Production of Arctic Marine Phytoplankton and Seaweed, Environ. Pollut., 1978, vol. E15, no. 3, pp. 209– 221.
12. Kusk, K.O., Effects of Crude Oil and Aromatic Hydrocarbons on the Photosinthesis of Three Species of Acrosiphonia Grown in the Laboratory, Bot. Mar., 1980, vol. 23, pp. 587–593. 13. Lobban, S.C., Harrison, P.T., and Duncan, M.T., The Physiological Ecology of Seaweeds, Cambridge University Press, 1985. 14. Markager, S. and Sandjiensen, K., Heterotrophic Growth of Ulva lactuca (Chlorophyceae), J. Phycol., 1990, vol. 26, pp. 670–673. 15. O’Brien, P.Y. and Dixon, P.S., The Effects of Oils and Oil Components on Algae: A Review, Brit. Phycol. J., 1976, no. 11, pp. 115–142. 16. Reddin, A. and Prendeville, G.N., Effect of Oils on Cell Membrane Permeability in Fucus serratus and Laminaria digitata, Mar. Poll. Bull., 1981, vol. 12, no. 1, pp. 339–342.
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