鼠尾藻池塘秋冬季栽培生态观察

Ecological observations on Sargassum thunbergii cultivated in ponds during autumn and winter

中文关键词: 鼠尾藻  环境因子  气囊  生殖托  次生分枝

英文关键词: Sargassum thunbergii  Environment factors  Air sac  Receptacle  Secondary branch

中文摘要:

      2010年10月~2011年3月对鼠尾藻池塘秋冬季栽培的生长情况进行了观察与分析。选择池塘水温、光强、盐度和pH，研究其对鼠尾藻1年苗、两年苗在不同水层的养殖效果。结果表明，1）40~60 cm水层鼠尾藻生长最好；其次是80~100 cm水层； 0~20 cm水层生长最慢；2）1年苗、2年苗在整个试验期间均未发现生殖托。其中部分两年苗藻体生长出1~2cm左右次生分枝，而1年苗均未发现次生分枝；1年苗于11月中旬开始生长出气囊，两年苗于试验开始时就有气囊，12月中旬鼠尾藻气囊开始腐烂脱落，至翌年1月上旬池塘水温降至0℃以下，池塘水体表层出现结冰现象，此时鼠尾藻气囊已大部分脱落，同时有腐烂脱落现象，藻体缩短、变瘦，湿重降低，体色呈黑褐色。2月下旬随着水温的逐渐回升，鼠尾藻又有生长现象，体长及湿重均有增长，至3月上旬发现气囊。3）鼠尾藻两年苗生长情况比1年苗略好，其同一时期测量的藻体平均体长和单株藻体平均湿重均比1年苗大，鼠尾藻两年苗S值（S=单株藻体平均湿重（g）/藻体平均体长（cm））大于1年苗。

英文摘要:

      High-density pond culture leads to water quality deterioration and wastewater discharge, which may result in pollution of pond and even coastal waters, and affect the sustainable development of pond culture. Domestic and foreign scholars generally believe that large-scale seaweeds cultivation is one of the effective ways to absorb and utilize nutrients and relieve the eutrophication.Sargassum thunbergii can rapidly absorb harmful substances in seawater, such as arsenic,zinc and cadmium, as well as NH+4-N,NO-3-N, P， etc.Therefore， it is suitable to cultivate this algae in cofferdam or artificial reef pond in co-culture with sea cucumber or abalone. S.thunbergi cultivation during spring and summer have been widely reported, however, culture during autumn and winter is still very limited.To investigate the growth characteristics of S.thunbergi in different stages and the impact of environmental factors, such as temperature, light intensity, salinity or pH, on both one year old (1-y algae) and two years old (2-y algae)seedlings, S.thunbergi were cultivated at different depths in pond from October 2010 to March 2011. Morphological observation was done and growth rate was determined on the seaweed.It was found that: 1)best growth was achieved at water-depths of 40~60cm, followed by that of 80~100cm,and the slowest growth was found at 0~20 cm;2) no receptacle was seen during the experiment, and 2-y algae set forth some 1~2 cm secondary branches, while 1-y algae did not; 1-y algae produced air sac in mid-November, while 2-y algae did the same at the beginning of the experiment; from mid-December, air sac began to decay and rot off, when water temperature was below 0℃ and pond was frozen in mid-January of the next year, most air sac fell off and the thalli began to rot with shortened length, thin frond, decreased fresh weight and black brown body;as water temperature gradually rose in late February, S. thunbergii began to grow, with increasing length and weight; some thalli produced air sac gradually in early March;3) during this experiment, 2-y algae grew better than 1-y algae, showing greater length and weight, It was found that factor S, which is the ratio of fresh weight to length of a single algae,was also greater in 2-y algae than 1-y algae.