【作者】 陈应华；

【导师】 杨宇峰；

【作者基本信息】 暨南大学 ， 水生生物学， 2009， 博士

【摘要】 为了修复大亚湾海域的生态环境和增殖渔业资源,2002年12月-2004年8月,广东省海洋与渔业局在大亚湾大辣甲岛南面6.8km²海域内,分两期投放了1829个钢筋混凝土礁体,总空方为60178m³。本文根据投礁前（2002年11月）和投礁后（2004年7月、2005年8月、2006年11月）对大辣甲南人工鱼礁海域综合调查的结果,首次将生态系统健康评价和生态系统服务功能价值评估的理论和方法应用于人工鱼礁的综合效应分析。结果表明:1)投礁后,礁区内海水的COD、DIN和PO₄^3--P含量均比投礁前高,COD比投礁前增加了73-149%,DIN比投礁前增加了172-224%,PO₄^3--比投礁前增加了14-129%,悬浮物含量降低。采样站点各项指标均达到第一类海水水质标准,表明投放人工鱼礁可以调节海水水质。N/P比上升幅度明显（投礁前为16.29,投礁后介于39.63-116.17之间）,且显著大于Redfield比,浮游植物生长受P限制突出。水体的富营养化趋势仍在继续,但由于受到磷限制,总体上还处于潜在性富营养化阶段。2)礁区表层沉积物为粘土质粉砂和砂质粉砂。投礁后,礁区内表层沉积物的pH值和Hg含量降低,有机质、Cu、Pb、Zn、Cd的含量都有一定程度增加,并高于对照点。2004年7月,有一站位的铅含量超过第一类沉积物质量标准（超标0.78倍）;2006年11月,有机质（超标率50%）和一个站位的铅（超标0.52倍）含量略超过第一类沉积物质量标准。Cu、Pb、Zn、Cd、Hg的潜在生态危害程度极轻微。3)浮游植物种类和密度组成均以硅藻为主。投礁后,礁区内浮游植物的细胞密度逐年递增,但增幅不大（441.05×10⁴-711.1×10⁴ cell/m³）,礁区内浮游植物的细胞密度与同期对照点差异不大。优势种全为硅藻,优势种组成变化明显,群落结构年际变化大。礁区内的叶绿素a含量以投礁前最高,初级生产力以2004年7月最高,表层略高于底层。4)投礁后,礁区内浮游动物的种类和生物量逐年递增,密度明显高于投礁前,礁区内浮游动物的密度和生物量高于同期对照点,浮游动物优势种更替频繁,群落结构不稳定。2005年8月,礁区内浮游动物的密度（1260.2 ind./m³）超过了大亚湾海域浮游动物密度的历史较高水平（1013.4 ind./m³）,但生物量较低（154.2 mg/m³）,低于历史较高水平（472.8 mg/m³）,浮游动物小型化现象严重。5)投礁后,礁区内鱼类浮游生物的种类和数量均比投礁前多,且多于同期对照点,2006年11月鲷科鱼类鱼卵占60.89%,人工鱼礁对仔稚鱼的庇护效果明显。6)底栖动物的主要类群为软体动物、甲壳动物和环节动物,以热带、亚热带暖水种和近岸广布种为主。投礁2-3年后,礁区内底栖生物的栖息密度和生物量比投礁前有了大幅增加,并高于同期对照点,人工鱼礁对底栖动物的增殖效果较明显。7)投礁后,礁区内虾拖网渔获种类比投礁前增加了64-91%,资源密度比投礁前增加了12.13-21.22倍;流刺网渔获种类比投礁前增加了13.33-46.67%,渔获率比投礁前增加了36.96-70.80倍。礁区内的渔获种类、资源密度和渔获率均高于同期对照点。主要优势种的资源密度和渔获率明显增加,人工鱼礁资源养护效果明显。8)大亚湾大辣甲南人工鱼礁生态系统健康状况保持良好,随着投礁时间的推移,人工鱼礁生态系统的健康状况有望得到进一步改善。9)大亚湾大辣甲南人工鱼礁生态系统服务功能总价值为2.03亿元,单位面积服务价值为99.69万元/km²-a。投资回收期为2年。30年寿命期内产生的净效益为1.90亿元,投入产出比为1:15.6。更多还原

【Abstract】 In order to rehabilitate the ecological environment and increase fisheries resources of Day Bay, Guangdong Ocean and Fisheries Administration has deployed 1829 reinforced steel-concrete hollow reefs in Daya Bay during the period of December 2002-August 2004. All modular reefs were cast in two batches within an area of 6.8 km² in the southern part of Dalajia Island, with a total volume of 60178m³.Four comprehensive surveys in the reef area were made including one cruise prior to casting reef （November 2002） and other three cruises post-cast in July 2004, August 2005 and November 2006. The ecological effects of artificial reefs were analyzed ecosystem-based using ecosystem health evaluation and ecosystem services valuation, through characterization of shifts in nutrients and the main biota of the area. The results showed that:1) Following deployment of the artificial reefs, concentration of COD, DIN, andPO₄^3- -P in the reef area were higher than those pre-deployment of reef, COD, DIN andactive phosphate increased by 73-149%, 172-224% and 14-129% respectively. Suspended solids concentrations were reduced. These indicators for all sites reach the first category water quality standards of China. Hence, artificial reefs appear to improve water quality. The N:P ratio before reef placement approximated Redfield （16.29） indicating no P limitation, while N/P ratio significantly increased and substantially greater than the Redfield ratio after reef placement （ranged from 39.63 to 116.17） suggesting P-limitation. Consequently, growth of phytoplankton was limited prominently by phosphorous. With these increases, potential eutrophic conditions still prevailed.2) Surface sediments of reef areas were principally clay-silt and sandy-silt. Following reef deployment, pH and Hg content in surface sediments of the reef area decreased, while contents of organic matter, Cu, Pb, Zn and Cd increased to some degree, withmeans appearing higher than those of control site. In July 2004, lead content of a station was a little more than the first category sediment quality standards of China （levels exceeded standards by 78 percent）. In November 2006, organic matter content of three stations and Lead content of one station （exceeded standards by 0.52-fold） were slightly more than China’s first category sediment quality standards. Cu, Pb, Zn, Cd and Hg in surface sediment were so minimal that potential ecological risks of these elements were low.3) The species and density of phytoplankton in the reef area were mainly diatoms as all dominant species belonged to Bacillariophyta. Seasonal changes in dominant species were obvious. Additionally, an inter-annual variation in phytoplankton community structure was evident. After reef deployment, densities of phytoplankton slightly increased year after year （ranged from 441.05×10⁴ cell/m³ to 711.1×10⁴cell/m³）. There was little difference in phytoplankton densities between reef areas and control site during the survey period. The maximum concentration of chlorophyll a in the reef area was noted prior to artificial reef casts. However, maximum primary productivity after reef deployment occurred in July 2004, with slightly higher in the surface layer than that of bottom layer.4) The post-deployment period was also typified by an increased in species and biomass of zooplankton in the reef area year by year. Densities of zooplankton were significantly higher than before the reefs were deployed, and densities and biomass of zooplankton were higher in the reef area than noted at the control site. The dominant species of zooplankton were quite variable, with no consistent community structure pattern for the zooplankton. In August 2005, the density of zooplankton in the reef area （1260.2 ind/m³） exceeded a relatively high historical level （1013.4 ind/m³ in 2004）, but biomass （154.2 mg/m³） was lower than historical levels （472.8 mg/m³ in 2004）. This shift reflected a switch to dominance of small-sized zooplankton.5) Following reef deployment, species and quantities of ichthyoplankton in the reef area exceeded those noted prior to deployment. Further, there were more species and numbers of ichthyoplankton in the reef area than in the control site during the same period. Fish eggs of family Sparidae, the main taxon accounted for 60.9% of the total fish eggs found in November 2006. We concluded that artificial reefs have an apparent protective performance on fish eggs and larval and juvenile fish.6) The main groups of benthic invertebrates in the reef area were molluscs, crustaceans and annelids, most of which belong to tropical and subtropical warm water species and inshore widely distributed species. 2-3 years after reef deployment, the biomass and densities of macrobenthos in the reef area had substantially increased compared to pre-deployment levels, and levels at the reef areas were higher than observed at the control site. Hence, proliferation performances of artificial reefs on zoobenthos are obvious.7) Nekton species increased by 64-91% and densities increased by 12.13-21.22 fold in the reef area surveyed by trawl net. Nekton species increased by 13.33-46.67% and catch rates increased by 36.96-70.80 fold in the reef area investigated by gill-net. Species, resource densities and catch rates within reef area were higher than those of the control site. The densities and catch rates of the dominant species markedly increased. Hence, artificial reefs played an important role in resource conservation.8) The southern Dalajia Island artificial reef ecosystem remained healthy throughout the survey period. With increasing time, it is anticipated that ecosystem health, through the parameters described above, will be further improved.9) The southern Dalajia Island artificial reef ecosystem services are valued at 203 million yuan RMB, the services value per unit area was estimated at 996,900 yuan RMB km^-2.a^-1. The initial investment of 13 million yuan RMB should be recovered in 2 years. Net benefit for a 30-year life span is 190 million yuan RMB, a ratio of input to output is 1:15.6.更多还原