广西废弃虾塘红树林恢复时的纳潮生态混养探索研究

An Exploratory Study on the Tide Driving Eco Polyculture in an Abandoned Shrimp Pond with Mangrove Restoration in Guangxi,China

为了在废弃虾塘红树林恢复中获得一定的经济效益,2017年2月到2020年1月在广西防城港1.1927 hm^(2)的废弃虾塘内进行7种肉食性和2种杂食性鱼类的纳潮生态混养试验研究。在塘底挖掘0.8-1.2 m深的庇护沟、水面设置植物遮阴浮床、塘内设红树林造林监测样地。在塘底基础水位设为0.5 m深的条件下,年均渔获生物量为691 kg/(hm^(2)·a),饵料综合效率为35.09%。3年中9种鱼类成活率、占渔获总尾数和占总生物量比例最高的均是黄鳍鲷(Sparus latus),分别达到38.16%、65.2%和35.28%。2020年1月的全捕渔获显示,鲻鱼(Mugil cephalus)、斑鰶(Clupanodon punctatus)和灰鳍鲷(Sparus berda)等野生经济鱼苗可随潮水进入塘内生长,个体数可占渔获总尾数的16.9%。在全日潮15 d的潮汐周期中,塘底淹水日数小于6 d时木榄幼苗可正常生长,成活率93.5%。扩大废弃虾塘红树林恢复及生态养殖的规模可有效降低成本,提高社会对红树林良好环境及高质量产品的认识,可显著增加经济效益。

In order to obtain certain economic benefits in the mangrove restoration in abandoned shrimp ponds,a tide driving eco polyculture experiment of seven carnivorous and two omnivorous fishes was conducted in an abandoned shrimp pond of 1.1927 hm^(2) in Fangchenggang,Guangxi from February 2017 to January 2020.A 0.8-1.2 m deep shelter ditch was excavated at the bottom of the pond,a plant shading floating bed was set on the water surface,and a mangrove afforestation monitoring plot was set up in the pond.The average annual catch biomass was 691 kg/hm^(2)·a,and the comprehensive feed efficiency was 35.09%under the condition of 0.5 m deep essential water level.In the three years,Sparus latus had the highest survival rate,the highest proportion of total catch tails and the highest proportion of total biomass of nine species of fish,which reached 38.16%,65.2%and 35.28%,respectively.The total catch in January 2020 showed that wild economic fish such as Mugil cephalus,Clupanodon punctatus and Sparus berda could grow in ponds with tides,and the number of individuals could account for 16.9%of the total catch.In the 15 d tidal cycle of diurnal tide,the Bruguiera gymnorhiza seedlings could grow normally and the survival rate was 93.5%when the flooding days were less than 6 days.Expanding the scale of mangrove restoration and ecological breeding in abandoned shrimp ponds can effectively reduce costs,improve social understanding of mangrove good environment and high quality products,and significantly increase economic benefits.