Fresh biomass of macroalgae collected at Hansneset, Kongsfjorden, Spitsbergen in 1996/1998

We surveyed macroalgae at Hansneset, Blomstrand in Kongsfjorden, Svalbard, down to 30 m depth between 1996 and 1998. In total, 62 species were identified: 16 Chlorophyta, 25 Phaeophyceae, and 21 Rhodophyta. The majority of species (53.5%) belonged to the Arctic cold-temperate group, followed in frequency by species distributed from the Arctic to the warm-temperate region (25.9%). Four endemic Arctic species (Laminaria solidungula, Acrosiphonia flagellata, A. incurva, and Urospora elongata) were found. Two species (Pogotrichum filiforme and Mikrosyphar polysiphoniae) were new to Svalbard. Chlorophyta, Phaeophyceae, and Rhodophyta extended from the eulittoral zone down to 11, 21, and >30 m depths with maximum biomasses at 1-5 m, 5-10 m, and 5-30 m depths, respectively. Annual and pseudoperennial species had highest biomasses in the upper 5 m, while perennials were distributed deeper. The highest biomass (8600 g/m**2 wet weight) at 5 m depth comprised mainly L. digitata, Saccorhiza dermatodea, Alaria esculenta, and Saccharina latissima. The biogeographic composition of macroalgae at Hansneset was rather similar to that of northeastern Greenland, but different from that of northern Norway, which has a higher proportion of temperate species. Climate warming and ship traffic may extend some of the distribution ranges of macroalgae from mainland Norway to Svalbard.

我们于1996年至1998年间，在斯瓦尔巴群岛国王湾布隆斯特兰德的汉斯内塞特海域开展了大型藻类（macroalgae）调查，调查水深范围至30米。本次调查共计鉴定出62个物种：其中绿藻门（Chlorophyta）16种、褐藻纲（Phaeophyceae）25种、红藻门（Rhodophyta）21种。53.5%的物种属于北极冷温类群，其次为分布于北极至暖温带区域的物种，占比25.9%。本次调查还发现了4种北极特有物种：Laminaria solidungula、Acrosiphonia flagellata、A. incurva和Urospora elongata；另有Pogotrichum filiforme和Mikrosyphar polysiphoniae 2个物种为斯瓦尔巴群岛新记录种。绿藻门、褐藻纲和红藻门的分布范围均从真潮带（eulittoral zone）向下延伸至11米、21米和30米以上水深，其生物量峰值分别出现在1-5米、5-10米和5-30米水深区域。一年生和假多年生物种的生物量峰值均出现在5米以浅水域，而多年生物种则分布于更深海域。5米水深处的生物量最高，达8600克/平方米鲜重，主要优势物种为Laminaria digitata、Saccorhiza dermatodea、Alaria esculenta和Saccharina latissima。汉斯内塞特海域大型藻类的生物地理区系组成与格陵兰东北部较为相似，但与挪威北部存在显著差异——挪威北部温带物种占比更高。气候变暖和船舶航运活动可能促使部分大型藻类的分布范围从挪威本土向斯瓦尔巴群岛扩张。