Marine fungi from the Northwest African upwelling areas and from the Atlantic off Portugal

Quantitative data on lower marine Phycomycetes (fungi) found in the upwelling waters off the West African coast during cruises No. 13 (1968), 19 (1970), 36 (1975) and 44 (1977) of R.V. "Meteor" are reported. The distribution of the total fungi numbers is presented and, as far as possible, the evaluation of the material up to species level is given. Several provisionally named forms and groups of morphologically related, undescribed fungi are included. A correlation between the number of fungi in sediments and the water depth and distance from the coast line is postulated. There are typical distributions of the lower marine fungi in water bodies and sediments. Different values within replicates of the stations in different years show that there is a sequence in development of fungal populations induced by changes in the water bodies. Surface water far from the coast has low numbers of fungi; numbers increase to a maximum nearer to the coast. In the vicinity of the coast the values decrease. The numbers of fungi in the deep sediments are low below 1,200 m. However, there are isolated areas of higher fungal activities, indicated by some deeper grab samples. During two cruises, the "overlying water" in the grab samples was investigated. It was evident that the numbers of fungi lost by stirring of the sediment when the grab was brought up to the surface were small, relatively and absolutely. The seamount "Josephine Bank" has been investigated for the first time with respect to lower marine fungi; the populations are low in the sediments, but one sample of the surface water had a higher number than the water in the surroundings. In some hydrographic series there was a peculiar depth distribution. An increase occurred at a depth greater than 1,000 m. The results are discussed and some correlations to the aging of the fungal populations in the water masses are constructed.本文报道了‘流星号’（R/V Meteor）调查船第13航次（1968年）、第19航次（1970年）、第36航次（1975年）及第44航次（1977年）期间，在西非沿岸上升流海域采集到的海洋低等藻状菌（Phycomycetes，真菌类群）定量数据。文中展示了真菌总丰度的空间分布特征，并尽可能对样本开展了物种级别的分类鉴定与评估。研究纳入了多个暂定命名的类群，以及一批形态特征相近但尚未正式发表描述的真菌类群。本研究推测沉积物中真菌丰度与水深、离岸距离之间存在相关性。海洋低等真菌在水体与沉积物中均存在典型的分布模式。不同年份同一站位重复采样得到的真菌丰度存在差异，这表明水体环境变化会诱导真菌种群发生阶段性演替。离岸较远的表层水体中真菌丰度较低，随着向近岸靠近真菌丰度逐渐升高至峰值，而在近岸区域其数值则会下降。水深超过1200米的深海沉积物中真菌丰度普遍偏低，但部分深海抓斗采泥样本结果显示存在若干真菌活性较高的孤立区域。在其中两个航次中，研究人员对采泥样本的上覆水（overlying water）进行了检测。结果表明，采泥器提升至海面过程中因沉积物搅动而流失的真菌数量，无论相对值还是绝对值均较低。本研究首次针对‘约瑟芬海山（Josephine Bank）’开展海洋低等真菌相关调查，该海山沉积物中真菌种群丰度偏低，但其中一个表层水样的真菌丰度高于周边海域水体。部分水文序列中存在特殊的深度分布模式，在水深超过1000米的区域真菌丰度出现上升。本文对研究结果进行了讨论，并构建了真菌种群在水团中的老化过程与各项环境指标的若干关联关系。