SOURCES OF VARIATION IN RADIOCESIUM LEVELS BETWEEN INDIVIDUAL FISH FROM A CHERNOBYL CONTAMINATED NORWEGIAN LAKE
SOURCES OF VARIATION IN RADIOCESIUM LEVELS BETWEEN INDIVIDUAL FISH FROM A CHERNOBYL CONTAMINATED NORWEGIAN LAKE
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DOI：
10.2307/2405101
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发表时间：
1995-05-01
影响因子：
5.7
通讯作者：
NJASTAD, O
中科院分区：
文献类型：
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作者：
UGEDAL, O;FORSETH, T;NJASTAD, O
1. 我们评估了受切尔诺贝利事故沉降物污染的挪威湖泊中的北极红点鲑 (Salvelinus alpinus) 和褐鳟 (Salmo trutta) 的 Cs-137 个体变异来源。 1986年7月至1989年10月期间共采集了14次样品。2。 Cs-137浓度与鱼体重、年龄和生长速度之间的关系随时间而变化。 1986年，北极红点鲑中的Cs-137浓度与年龄呈负相关，与生长速度呈正相关。后来，经过一个过渡期，北极红点鲑中的 Cs-137 浓度与体重和年龄呈正相关，与生长速度呈负相关。这种变化的时间与猎物相对于鱼类放射性的变化有关。3。从 1987 年 9 月开始，在整个研究过程中，Cs-137 浓度随鱼体重的增加可以通过幂函数来描述，北极红点鲑和褐鳟鱼的体重指数分别为 0.39 和 0.11。我们没有发现褐鳟的饮食随体型的变化而变化，而北极红点鲑的饮食随着年龄和体重的增加而从浮游动物转向底栖动物。这种饮食变化可能是红点鲑中 Cs-137 浓度随体重增加幅度比鳟鱼更大的原因。4。北极红点鲑和褐鳟鱼的 Cs-137 浓度个体差异中，鱼体重的差异分别占 29% 和 11%。铯浓度的大部分变化可归因于与体型无关的因素，其中饮食成分的个体变化被认为是最重要的一个。5。鱼类中 Cs-137 浓度的频率分布呈正偏态、尖峰状，与正态分布显着不同，但与对数正态分布无显着差异。铯浓度的个体差异相当大，北极红点鲑比褐鳟更大，这可能是因为北极红点鲑比褐鳟对生态位的利用更广泛。如果要获得群体的 Cs-137 浓度代表值，这些较大的个体差异就需要较大的样本量。
1. We evaluate sources of individual variation in Cs-137 Of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) from a Norwegian lake contaminated by fall-out from the Chernobyl accident. Samples were collected on 14 occasions between July 1986 and October 1989.2. The relationship between Cs-137 concentration, and fish weight, age and growth rate, changed with time. In 1986 the Cs-137 concentration in Arctic charr was negatively correlated with age and positively correlated with growth rate. Later, after a transition period, Cs-137 concentration in Arctic charr became positively correlated with weight and age, and negatively correlated with growth rate. The timing of this change was associated with changes in prey relative to fish radioactivity.3. From September 1987 and throughout the study, the increase in Cs-137 concentration with fish weight could be described by a power-function with weight exponents of 0.39 and 0.11 for Arctic charr and brown trout, respectively. We could detect no diet changes with size in brown trout, while Arctic charr showed a diet shift from zooplankton to zoobenthos with increasing age and weight. This diet shift probably accounted for the larger increase in Cs-137 concentration with weight in charr than trout.4. Variation in fish weight accounted for 29 and 11% of the individual variation in Cs-137 concentration in Arctic charr and brown trout, respectively. Most of the variation in caesium concentrations can be attributed to size independent factors, of which individual variation in diet composition is suggested to be the most important one.5. Frequency distributions of Cs-137 concentration in fish were positively skewed, leptokurtic and differed significantly from the normal distribution, but not from the log-normal distribution. Individual variation in caesium concentration was rather large, and larger in Arctic charr than in brown trout, probably because of a wider niche utilization by Arctic charr than by brown trout. These large individual variations necessitate large sample sizes if representative values of Cs-137 concentration for the populations shall be obtained.