Inhibition of nitrification by nitrapyrin,carbon disulphide and trithiocarbonate

We have studied the behaviour of the nitrification inhibitors nitrapyrin (2-chloro-6-trichloromethyl pyridine) and carbon disulphide (CS₂), and of trithiocarbonate ion (CS₃^2?). Solutions of Na₂CS₃ in water or aqueous NH₃ are stable but when added to soil they decompose with evolution of CS₂, which in laboratory tests was complete within hours. In field experiments each material was injected simultaneously with aqueous NH₃ or aqueous urea. Nitrapyrin was held strongly on soil near the centre of the injected band of fertiliser N. It became fully effective only approximately two months after injecting grassland in November (1974 and 1975) with 375 kg N/ha, but approximately one month after injecting winter wheat with 100 kg N/ha in March (1976). In contrast CS₂ itself, or CS₂ generated by CS₃^2?, diffused rapidly from the injected band and markedly inhibited nitrification for up to three months after injecting grassland and up to one month after injecting winter wheat, but had no effect on nitrification later. The main practical implication of the work is that liquid fertilisers supplying NH₄-N may, if mixed with a trithiocarbonate, be injected into grassland in autumn, without risk of substantial nitrate leaching during winter. This extends the period suitable for injection and eases congestion of work normally done in spring.     

Reducing gaseous losses of nitrogen from cattle slurry applied to grassland by the use of additives

Losses of nitrogen (N) through ammonia (NH₃) volatilisation and denitrification were determined following the application of cattle slurry to grassland in autumn or spring. Denitrification was examined on two contrasting soils. A system of small wind tunnels was used to measure NH₃ loss and an acetylene inhibition technique for denitrification. Between 31 and 84% of the ammonium N (NH-N) applied in slurry was lost through NH₃ volatilisation. Acidifying the slurry to pH c 5.5 prior to application reduced these losses to between 14 and 57%. On a freely drained loam soil, denitrification from unacidified slurry applied in the autumn at 80 m³ ha^?1 was continuous throughout the winter, with the maximum rate of 0.91 kg N ha^?1 day^?1 occurring a few weeks after slurry application. The total denitrification losses were equivalent to about 29% of the NH-N applied for this treatment and 41% for the acidified slurry. The nitrification inhibitor dicyandiamide reduced the amount of N lost through denitrification by 70% when applied with the slurry at 25 kg ha^?1, by 55% at 20 kg ha^?1 and by 30% at 15 kg ha^?1. The nitrification inhibitor nitrapyrin did not appreciably reduce denitrification. Denitrification losses were consistently small from slurry applied to the freely drained loam soil in spring, or to a poorly drained, silty clay in autumn or spring. Neither nitrification inhibitor was of benefit in these situations.     

Use of nitrification inhibitors to improve recovery of mineralised nitrogen by winter wheat

Nitrification inhibitors were applied in September 1980, after ploughing of a grass ley, to prevent formation of NO_3-N which could be lost by leaching and denitrification. Laboratory tests indicated that nitrapyrin or etridiazole at 1 μg g soil^?1 and dicyandiamide (DCD) at 10 μg g^?1 could inhibit nitrification by approximately 40%, compared with untreated soil, for 10 weeks at 10°C. In the field, nitrapyrin, etridiazole and DCD had little effect on NH₄ and NO₃ levels in the soil throughout autumn and winter. In April uptake of mineralised N by wheat was greater in plots treated with DCD (but not with nitrapyrin or etridiazole) than in untreated plots. Spring fertiliser N applications (35 or 70 kg N ha^?1) increased ear numbers, as did the two rates of all inhibitors except etridiazole. At harvest, grain and straw yields were increased by both rates of DCD with and without fertiliser N in spring, but there were no consistent increases from nitrapyrin or etridiazole. The mean increases in N uptake by wheat grain plus straw were 12 and 15% for 5 and 20 kg ha^?1 DCD respectively. DCD could be of use in preventing losses of NO₃-N, particularly in situations where large amounts of N may be mineralised during autumn and would be liable to loss prior to crop uptake.     

Effects of nitrification inhibitors on uptakes of mineralised nitrogen and on yields of winter cereals grown on sandy soil after ploughing old grassland

An old grass sward on a sandy loam soil (Cottenham series) was ploughed-down in summer 1981 and winter wheat, winter oats and winter wheat respectively were grown on the site for the next 3 years. Nitrification inhibitors (dicyandiamide (DCD), nitrapyrin or etridiazole) were applied to the seedbed in all 3 years. In spring, the cereals were given 0, 35 or 70kg N ha^?1 as “Nitro-Chalk”. Inhibitors had little effect on the amounts or distribution of mineralised nitrogen in the soil profile or on the uptake of mineralised nitrogen during autumn and winter. Much mineralised nitrogen was leached during the autumn and winter 1981/82 and 1982/83, but amounts of available mineralised nitrogen were sufficient to meet the crop requirements. In these 2 years nitrogen fertiliser decreased yields and inhibitors had no consistent effect on yields or nitrogen uptakes. In 1984, winter wheat responded to spring-applied nitrogen fertiliser, while DCD or nitrapyrin increased yields and nitrogen uptakes. There was no evidence that yield increases were due solely to the increased availability of mineralised nitrogen caused by the inhibition of nitrification.     

Influence of nitrogen form on yield and nitrate content of subirrigated early potato

Potato is classified among the vegetables with low nitrate content but, in diet, it contributes most to the daily intake of nitrate, because of its high per capita consumption. Two trials were carried out in winter–spring and autumn–winter cycles using a trough bench subirrigation system. Potato seedlings were transplanted into pots containing peat, pumice and vermiculite in a 3:1:1 volume ratio. Both trials were carried out to compare three nutrient solutions having the same nitrogen concentration (6.4 mM ), but different ammonium:nitrate (NH₄‐N:NO₃‐N) percentage ratios (100:0, 50:50 and 0:100). In the winter–spring cycle, tubers were lower in weight and were more numerous than in the autumn–winter cycle. The tuber yield of ammonium‐fed plants was lower than with the mixed form and 100% NO₃‐N, but only in the trial carried out in the winter–spring period. Nitrate‐fed plants yielded a number of tubers almost 3‐fold higher than ammonium‐fed plants. The NO₃ content of tubers harvested in spring in the presence of 100% NH₄‐N in the nutrient solution was a 25% of that in nitrate‐fed plants (44 vs 169 mg kg^?1 of fresh mass); in tubers harvested in winter, with worse light conditions, nitrate content increased with increasing NO₃‐N in the nutrient solution (26, 109, and 225 mg kg^?1 of fresh mass with NH₄‐N:NO₃‐N 100:0, 50:50 and 0:100, respectively). The substrate electrical conductivity increased with increasing ammonium concentration in the nutrient solution, and was higher in the upper layer of the substrate. Copyright © 2004 Society of Chemical Industry     

Nitrogen nutrition,yield and quality of spinach

When grown in solution culture spinach plants confirmed the preference toward NO₃⁻ nutrition and showed heavy toxicity to NH₄⁺. In open field condition the highest yield was achieved with the ammonium sulphate in Bari (autumn–winter cycle—110 days) and with calcium nitrate in Policoro (winter–spring cycle—64 days). By increasing N level, yield, nitrates and oxalates leaf content increased. Oxalate content was not affected by nitrogen form. Remarkable differences were observed between leaf petiole and blade in nitrate (4062 vs 925 mg kg⁻¹ of fresh mass) and oxalate (1051 vs 6999 mg kg⁻¹ of fresh mass). © 1998 SCI.     

Pungency levels of white radish (Raphanus sativus L.) grown in different seasons in Australia

White Radish, or daikon (Raphanus sativus) is a popular root vegetable in East Asian countries but there are increasing export opportunities for lower cost agricultural countries such as Australia. The Japanese processing white radish cultivar, Hoshiriso, was grown in spring, summer, autumn and winter on the Central Coast of New South Wales, Australia and accumulation of the characteristic pungent flavour component, 4-methylthio-3-trans butenyl isothiocyanate (MTBITC) during growth was determined. MTBITC concentration was found to be higher in roots grown in autumn and spring than in winter and summer. There was considerable change in MTBITC concentration during growth in all seasons with a maximum concentration occurring 9 weeks after sowing for roots grown in autumn and winter, and after 13 weeks for spring- and summer-grown roots.     

Ammonia emissions from dairy production in Wisconsin

Ammonia gas is the only significant basic gas that neutralizes atmospheric acid gases produced from combustion of fossil fuels. This reaction produces an aerosol that is a component of atmospheric haze, is implicated in nitrogen (N) deposition, and may be a potential human health hazard. Because of the potential impact of NH₃ emissions, environmentally and economically, the objective of this study was to obtain representative and accurate NH₃ emissions data from large dairy farms (>800 cows) in Wisconsin. Ammonia concentrations and climatic measurements were made on 3 dairy farms during winter, summer, and autumn to calculate emissions using an inverse-dispersion analysis technique. These study farms were confinement systems utilizing freestall housing with nearby sand separators and lagoons for waste management. Emissions were calculated from the whole farm including the barns and any waste management components (lagoons and sand separators), and from these components alone when possible. During winter, the lagoons’ NH₃ emissions were very low and not measurable. During autumn and summer, whole-farm emissions were significantly larger than during winter, with about two-thirds of the total emissions originating from the waste management systems. The mean whole-farm NH₃ emissions in winter, autumn, and summer were 1.5, 7.5, and 13.7% of feed N inputs emitted as NH₃-N, respectively. Average annual emission comparisons on a unit basis between the 3 farms were similar at 7.0, 7.5, and 8.4% of input feed N emitted as NH₃-N, with an annual average for all 3 farms of 7.6 ± 1.5%. These winter, summer, autumn, and average annual NH₃ emissions are considerably smaller than currently used estimates for dairy farms, and smaller than emissions from other types of animal-feeding operations.     

Seasonal changes in the fatty acids of gilthead sea bream (<Emphasis Type="Italic">Sparus aurata</Emphasis>) and white sea bream (<Emphasis Type="Italic">Diplodus sargus</Emphasis>) captured in Iskenderun Bay,eastern Mediterranean coast of Turkey

Seasonal variations in the fatty acid compositions of gilthead sea bream (Sparus aurata) and white sea bream (Diplodus sargus), captured in Iskenderun Bay, Eastern Mediterranean of Turkey, were investigated. Results from studying the composition over all seasons showed that the basic saturated, monounsaturated and polyunsaturated fatty acids for gilthead sea bream and white sea bream were palmitic acid (16:0), oleic acid (18:1) and docosahexaenoic acid (DHA, 22:63). The other main fatty acids for both species were myristic acid (14:0), stearic acid (18:0), palmitoleic acid (16:1), linoleic acid (18:26) (especially in autumn and winter for gilthead sea bream), and eicosapentaenoic acid (EPA, 20:53). Gilthead sea bream and white sea bream exhibited seasonal fluctuations in their fatty acid contents. EPA ratios in gilthead sea bream in the autumn, winter, spring and summer were 5.42%, 4.69%, 5.20% and 4.27%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 5.03%, 4.53% and 6.97%, respectively. DHA ratios in gilthead sea bream in autumn, winter, spring and summer were 15.37%, 14.16%, 9.51% and 7.07%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 11.49%, 20.17% and 7.74%, respectively. The present study suggests that the daily consumption of either 100 g of gilthead sea bream captured in any season or 100 g white sea bream captured in spring or summer could meet peoples needs for EPA+DHA fatty acids.     

The distribution in the soil of aqueous ammonia injected under grass

In an experiment with grassland, aqueous ammonia containing about 28% N was injected in rows 305 mm apart either in the autumn or in the spring. Two treatments supplied 126 and 502 kg N ha^?1. Soil representing a cross-section of one row was taken 3 days after injecting the ammonia in autumn and 8 or 9 days after injecting in spring. The plots receiving ammonia in the autumn were resampled in spring. The soil was divided into 51 × 51 mm sections and for the samples at the time of injection those sections close to the point of injection were further subdivided. Each section or sub-section was analysed for NH_4?N and NO_3?N. The array of values was used to produce a computer printout from which lines of equal concentration could be drawn by the procedure described in the appendix. With 126 kg N ha^?1 applied, maximum concentrations found were 900–1440 μg N g^?1, and these had decreased to 100 μg g^?1 at 20–30 mm from the area of maximum concentration. Similarly with 502 kg N ha^?1 maximum concentrations were 2360–3340 μg N g^?1 and the concentration had decreased to 100 μg g^?1 at 50 mm from the zone of maximum concentration. Therefore even with the very large application of fertiliser only a small part of the surface rooting zone contained a concentration of ammonia large enough to damage roots or adversely affect root growth. The zone of maximum concentration was always above the point of injection and usually to the side of the centre of the slit indicating that the aqueous ammonia tended to flow up and to one side of the slit, presumably because the soil closed rapidly behind the narrow injection tine. This shows that aqueous ammonia may not necessarily be effectively injected as deeply as the depth of slit might indicate. The soils resampled in the spring showed that much ammonium nitrogen remained, mostly concentrated round the zone of maximum concentration near the point of injection. Some ammonium had nitrified and nitrate was distributed more uniformly than ammonium, some had moved 300 mm deep. Soil containing most ammonia also contained more water than the bulk of soil. This soil was also plastic and structureless and the clay was deflocculated. The extra water may initially have come from the injected aqueous ammonia but was retained because of the changed structure.     

Nitrogen fractions and soluble carbohydrates in Italian ryegrass II.—Effects of light intensity,form and level of nitrogen

S.22 Italian ryegrass grown in a glasshouse during June on clay loam soil at three light intensities (100, 68 and 44% of daylight), was given 6 amounts of N (0–500 ppm) as NH₄⁺-N or NO₃^?-N. Grass grew best in 100% daylight, and with NH₄⁺-N yields were most at 500 ppm and with NO₃^?-N at 200 ppm. Total-N, total soluble-N and nitrate-N, were much more, and protein-N, amide-N (psrticularly asparagine-N) and α-amino-N much less in grass given NO₃^?-N than in grass given NH₄⁺-N. These differences increased with increasing amounts of applied N. Shading, or increasing the amount of N increased total-N, total soluble-N, soluble organic-N and nitrate-N, and decreased protein-N and soluble carbohydrates. Light intensity had most effect on the amount of solyble carbohydrates in grass given 100 ppm of N and the effect decreased with increasing amounts of N. ‘N-Serve’ indirectly influenced the chemical composition of grass by maintaining N in the soil in the NH₄⁺-N form.     

Effect of the application of cow slurry to grassland on nitrate levels in soil and soil water contents

The effect of a single heavy dressing of unamended cow slurry, applied to grassland in early spring (March), on nitrate levels and moisture contents in the soil profile have been examined for a 12 month period after the application. The slurry was allowed to remain on the soil surface until late autumn, when it was cultivated and a pasture re-established. Nitrate accumulated in the slurry and surface soil over spring, summer and autumn: the amount found in the slurry and 0–20 cm depth of soil in October (172 kg N/ha) accounted for 9% of the total-N originally added in the slurry. Significant leaching of nitrate into the subsoil did not occur until the soil was subsequently rewetted to field capacity in late autumn and winter. The layer of slurry on the soil surface restricted moisture losses from the soil during summer to less than one half of those under untreated grassland. Restricted aeration under the slurry is considered to be an important factor in delaying nitrification and stimulating anaerobic activity in the soil so that deep leaching of nitrate may not be likely for several months after a heavy application.     

Determination of the seasonal changes on total fatty acid composition and ω3/ω6 ratios of carp (Cyprinus carpio L.) muscle lipids in Beysehir Lake (Turkey)

The muscle lipid and fatty acid composition of carp, Cyprinus carpio in Beysehir Lake the largest freshwater lake in Turkey, was determined. Polyunsaturated fatty acids (PUFA) of carp, the most abundant fish species in Beysehir Lake, were found to be higher than those of saturated fatty acids (SFA) in spring, summer and autumn and also the monounsaturated fatty acids (MUFA) in spring and summer. Palmitic acid was the major SFA (14.6–16.6%) in all seasons. Oleic acid was identified as the major MUFA (15.1–20.3%). Docosahexaenoic acid (DHA) was the major PUFA in summer and winter, whereas linoleic acid (LA) was the major PUFA in spring and autumn. The percentages of total ω3 fatty acid were higher than those of total ω6 fatty acid in the fatty acid composition of carp in winter. It was shown that the fatty acid composition in the muscle of carp was significantly influenced by feeding period and seasons.     

Evaluation of the acetylene-inhibition technique for the measurement of denitrification in grassland soils

The acetylene inhibition technique has been evaluated for its suitability for routine field measurements of denitrification in two soils under grass. Acetylene was introduced into the soil air by radial diffusion from probes inserted vertically into the soil and, using a soil cover, total denitrification was determined as the loss of nitrous oxide (N₂O) from the acetylene-treated soil. Acetylene concentrations of 0.1–1.0% (v/v), which are effective in inhibiting the reduction of N₂O, were established within 1–2 h of commencing the supply of acetylene to soil at field capacity; the N₂O flux equilibrated within the same period. Treatment and equilibration times were longer after rainfall on to a soil at field capacity and shorter in spring, summer and autumn when soil water content was less than field capacity. Spatial variability in N₂O flux from acetylene-treated soil was generally ±25% and was probably associated with variability in air-filled pore spaces in the soil. Repeated treatments, as required in routine measurements of denitrification, did not affect the distribution of soil inorganic N between NH₄+ and NO₃- which suggests that concurrent inhibition of nitrification by acetylene was not a significant constraint in the field application of the technique. The efficiency with which acetylene inhibits the reduction of N₂O was not affected by repeated treatments of soil nor was there any evidence for acetylene decomposition. Repeated treatments did not affect dry matter yield or mineral contents of herbage. The findings of this study suggest that the acetylene-inhibition technique may be applied to routine measurements of denitrification in both small and large plot studies of the fate of fertilizer N.     

Unused fertiliser nitrogen in arable soils—its contribution to nitrate leaching

Nitrate present in arable soils in autumn is at risk to leaching during the following winter. To see whether unused nitrogen fertiliser was a major source of this nitrate, ¹⁵N-labelled fertiliser was applied to 11 winter wheat crops at rates of between 47 and 234 kg N ha^?1in spring. The experiments were on three contrasting soil types in south-east England. On average, 17′% of the N from spring-applied labelled fertiliser remained in the 0–23 cm soil layer at harvest (range, 7–36%) but only a small proportion was in inorganic forms (ammonium + nitrate). This was never more than 5 kg N ha^?1and averaged only 1·3% of the fertiliser N applied (range, 0·4–3·6 %). Between 79 and 98% of the inorganic N in soils at harvest was unlabelled, being derived from the mineralisation of organic N rather than from unused fertiliser. The amount of unlabelled N was much greater where wheat was grown after ploughing up grass or grass/clover leys than where it was grown in all-arable rotations. When wheat was grown without N fertiliser, soil inorganic N content at harvest was no lower than in plots given fertiliser at rates up to 234 kg N ha^?1. This work indicates that, for soil growing winter wheat, almost all of the nitrate at risk to leaching over the winter period comes from mineralisation of organic N, not from unused fertiliser applied in spring. Consequently, even a drastic reduction in N fertiliser use would have little effect on nitrate leaching.     

Seasonal changes in the proximate chemical compositions and fatty acids of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) from the north eastern Mediterranean Sea

The effects of seasonal variations on the proximate chemical compositions and fatty acid profiles of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) captured in the north‐eastern Mediterranean Sea were investigated. Protein fluctuations were observed in two species for all seasons. The lipid content of both species was lower in winter than in autumn and spring. In all seasons, the major fatty acids in both species were observed to be palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1 ω9), eicosapentaenoic acid (20:5 ω3) and docosahexaenoic acid (20:6 ω3). Chub mackerel and horse mackerel exhibited seasonal fluctuations in their fatty acid contents. The fatty acid profile of the two species had a higher degree of unsaturation during winter. The levels of EPA in chub mackerel in winter, spring and autumn were 5.96%, 4.86% and 4.33%, respectively, while those of DHA were 24.94%, 18.75% and 17.12%, respectively. The levels of EPA in horse mackerel in winter, spring and autumn were 5.42%, 5.03% and 4.86%, respectively, while those of DHA were 14.96%, 13.31% and 11.10%, respectively. The PUFA (polyunsaturated fatty acids) values and ω3/ω6 ratios in the two species were highest in winter. The results indicate that chub mackerel and horse mackerel captured in the north‐eastern Mediterranean Sea, which are among the most important fish in Turkey and of international commercial value, are a good source of nutrition for human consumption in terms of their proximate chemical composition and fatty acids.     

季节变化对杂交鲟鱼肉营养成分的影响

采集春、夏、秋、冬四个季节的杂交鲟鱼(Huso dauricus ♀ × Acipenser schrenckii ♂) 样品,分析比较肌肉基本营养成分、氨基酸组成、脂肪酸组成、矿物元素组成的差异。结果表明:鲟鱼肉脂肪含量季节变化特点明显,以秋季鲟鱼肉脂肪含量为最高（P<0.05）,而后依次为冬季、春季、夏季的鲟鱼肉;蛋白质含量以冬季鲟鱼肉最高,春季、夏季、秋季鲟鱼肉依次下降;春季鲟鱼肉必需氨基酸、鲜味氨基酸及总氨基酸含量最高,但秋季鲟鱼肉必需氨基酸占总氨基酸比例最高,冬季鲟鱼肉鲜味氨基酸占总氨基酸比例最高;夏季、秋季鲟鱼肉多不饱和脂肪酸及二十碳五烯酸和二十二碳六烯酸含量显著高于冬季、春季（P < 0.05）,脂肪酸不饱和度受季节影响差异并不显著（P>0.05）;矿物元素含量在春、夏两季鲟鱼肉中较高。季节对鲟鱼肉的营养组成影响明显,分析不同季节杂交鲟鱼肉的营养组成,可为后续开发加工提供理论依据,在加工中可根据需要选择适宜季节的养殖鲟鱼。     

Seasonal variations of total lipid and fatty acid contents in muscle,gonad and digestive glands of farmed Jade Tiger hybrid abalone in Australia

The lipid and fatty acid (FA) contents of muscle, gonad and digestive glands (DG) of Jade Tiger hybrid abalone were studied over the four seasons. Higher contents of total lipid and saturated fatty acids (SFA) were found in summer from muscle. For gonad the higher total lipid content was found in summer and spring whereas the SFA content peaked in summer only. For DG the higher contents of total lipid and SFA were recorded in all seasons except autumn. Winter samples showed significantly higher content of PUFA in all three types of tissue. High contents of eicosapentaenoic acid (EPA, 20:5 n−3), docosapentaenoic acid (DPA, 22:5 n−3) and docosahexaenoic acid (DHA, 22:6 n−3) were recorded in winter from muscle, although no marked variations were observed from gonad. For DG the high content of DHA was also observed in winter whilst EPA and DPA maintained high levels in all seasons except summer.     

Comparison of Gel-forming Properties of Silver Carp (Hypophthalmichthys molitrix) Surimi Prepared in Different Seasons

ABSTRACT: The gel-forming properties of silver carp surimi made in different seasons were compared. Surimi prepared in winter and spring formed gel at 30°C, while autumn and summer surimi required a higher temperature of 40°C for gel formation. All surimi showed marked disintegration when incubated at 60°C. Ca²⁺-ATPase inactivation rate of myofibrils prepared from 4 surimi samples showed that myofibrils in autumn and summer surimi were much more stable than those in winter and spring surimi by about 10°C. These results demonstrated a close relationship between the gel-forming temperature of surimi and the thermal stability of myofibrils in surimi, namely that autumn and summer surimi containing stable myofibrils required higher temperature than winter and spring surimi for the gel formation.     

Amino acid and fatty acid composition of wild sea bass (Dicentrarchus labrax): a seasonal differentiation

Seasonal variations in the amino acid and fatty acid compositions of wild sea bass (Dicentrarchus labrax) captured in the north eastern Mediterranean were investigated. In all seasons, the major amino acids in sea bass fillets were determined to be aspartic acid, glutamic acid and lysine. Methionine, tyrosine and histidine composition of the fillets were lower than those of the other amino acids in all seasons. The ratios of essential (E, g amino acid/16 g N)/nonessential (NE, g amino acid/16 g N) amino acids were observed to be 0.75 for winter, 0.76 for autumn, 0.77 for both spring and summer. Results showed that, sea bass fillets are well-balanced food source in terms of E/NE ratios in all seasons. In addition, seasonal differences in polyunsaturated fatty acid (PUFA) composition of the fillets were observed in all seasons. The major fatty acids of sea bass fillets were observed to be palmitic acid (16:0), oleic acid (18:1ω9), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). The amounts of EPA+DHA in autumn, winter, spring and summer were determined as 0.16, 0.12, 1.14 and 1.02 g/100 g wet weight, respectively.