光裸方格星虫增养殖对滩涂底质的影响

摘要

基于2016年春、秋两个季节的现场实验数据,研究光裸方格星虫(Sipunculus nudus Linnaeus)滩涂增养殖对滩涂底质的影响.实验对方格星虫单养区(S组)、方格星虫-贝类混养区(P组)和无星虫对照区(C组)进行了有机质、粒径组成、氧化还原电位(ORP)等指标测定, 结果表明: 1) 秋季S组20~30cm层次有机质含量和细沙比例均显著高于春季, 而C 组仅表层物质有所增加, 表明方格星虫具有较强的表层物质迁移能力, 且其迁移深度为20~30cm.2) 秋季 C 组各层氧化还原电位值(ORP)均无明显降低趋势, 而S组仅10~20cm层次有一定程度降低, 表明方格星虫增养殖并不会明显降低滩涂底质状况.3) P 组各层有机质以及细沙含量增加, 表明皱肋文蛤的过滤沉积作用可以提高滩涂颗粒物质的积累,且方格星虫混养会加速颗粒物质的向下迁移; P组皱肋文蛤的栖息层次(0~3cm、3~10cm) ORP明显低于S组(p0.05), 表明高密度的皱肋文蛤代谢活动会加剧0~10cm 的底质恶化.4) 方格星虫与皱肋文蛤具有生态互补作用, 在同一区域进行增养殖可以提高滩涂物质利用率及碳汇功能; 方格星虫扰动引入富氧水可以缓解皱肋文蛤栖息层次的底质.%To study the effects of culturing and proliferation of Sipunculus nudus on tidal flat sediment, we carried out an investigation in a culturing zone located in Suixi, Beibu Gulf, China in spring and autumn 2016. The organic matter content (OM),grain size and oxidation reduction potential(ORP)of the sediment were determined in the S group(Sipunculus nudus monoculture),P group(polyculture of S.nudus and Meretrix lyrata)and C group(blank zone without S.nudus).The OM and fine sand of the layer (20~30 cm) in the S group accumulated obviously, but only the surface layer (0~3 cm) in the C group had a similar tendency, which indicated that S. nudus can migrate down the surface sediment, and the migration depth was about 20~30 cm in the tidal flat. The ORP of the pore water in the C group had no significant decrease, and most of the layers in the S group had similar changing trends except that the layer of 10~20 cm decreased to some extent, which indicated that the culture of S. nudus in tidal flat will not result in significant deterioration of sediment. The OM and fine sand of the five layers in the P group increased significantly than those in the S and C groups, which indicated that the Meretrix lyrata had strong filter feeding and deposition ability,and the bioturbation of S.nudus can accelerate the migration of OM and fine sand. The ORP value of the two layers (0~3, 3~10 cm) in the P group decreased significantly than that in the S group (p<0.05), and the results indicated that the high density of Meretrix lyrata will result in significant deterioration of their habitat.S.nudus can migrate down and bury surface organic matter, and M. lyrata can promote the deposition of particulate matter; the complementary functions of the two animals help improve the nutrient utilization and carbon sequestration function of the tidal flat.