A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China ...A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identifi ed, and D. caudat a was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×10 2 cells/L in surface water and 1.25×10 2 cells/L in bottom water(<10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid(OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit(20 μg OA eq./100 g meat). Ten out of fi fteen wild samples(66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat(more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities(80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.展开更多
Harmful algal blooms, which frequently occur in different tributaries, have become a serious water quality problem of the Three Gorges Reservoir (TGR) since its initial filling. A three-year monitoring campaign from 2...Harmful algal blooms, which frequently occur in different tributaries, have become a serious water quality problem of the Three Gorges Reservoir (TGR) since its initial filling. A three-year monitoring campaign from 2008 to 2010 was conducted to identify the controlling factors of algal blooms and effective preventive measures. The following results were obtained: 1) Layered and bidirectional currents, called intrusive density currents, dominate the tributary bays of the TGR year round; 2) continuously increasing water level can make the intruding density current shift from the middle to the surface, and surface intrusive water can reduce the surface water temperature and break the stable stratification of the tributary; 3) the appearing or fading away of algal blooms is closely associated with fluctuations in the TGR water level. Thus, the water level fluctuation patterns of different "tide-types" may prevent the occurrence of algal blooms in the spring and summer, and the "stair-type" tides may control autumn blooms during the impounding period. These methods were feasible and effective throughout the actual TGR's operation in 2009 2011. These patterns formed an eco-environmentally friendly operation (EEFO) to mitigate algal blooms. As an in situ treatment with easier operation and less negative impact and loss, compared with chemical and filter-feeding fish methods, the EEFO is currently considered as the most feasible remedial measure to remit the eco-environmental problems at the Three Gorges Dam (TGD).展开更多
基金Supported by the National Marine Public Welfare Research Project of China(No.201305010)the National Natural Science Foundation of China(No.41106090)+5 种基金the Open Foundation of Key Laboratory of Marine Bio-resources Sustainable Utilization,Chinese Academy of Sciences(No.LMB111003)the Special Fund for Basic Scientific Research of Central Universities(No.21612401)the Natural Science Foundation of Guangdong Province(No.S2011040003113)the National Basic Research Program of China(973 Program)(No.2013CB956503)the Special Project for Science and Technology of Environmental Protection of Zhejiang Province(No.2011A31)the Wenzhou Science and Technology Plan Program(No.S2006A007)
文摘A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identifi ed, and D. caudat a was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×10 2 cells/L in surface water and 1.25×10 2 cells/L in bottom water(<10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid(OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit(20 μg OA eq./100 g meat). Ten out of fi fteen wild samples(66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat(more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities(80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51179095, 51179205, 51009081 and 51209123)
文摘Harmful algal blooms, which frequently occur in different tributaries, have become a serious water quality problem of the Three Gorges Reservoir (TGR) since its initial filling. A three-year monitoring campaign from 2008 to 2010 was conducted to identify the controlling factors of algal blooms and effective preventive measures. The following results were obtained: 1) Layered and bidirectional currents, called intrusive density currents, dominate the tributary bays of the TGR year round; 2) continuously increasing water level can make the intruding density current shift from the middle to the surface, and surface intrusive water can reduce the surface water temperature and break the stable stratification of the tributary; 3) the appearing or fading away of algal blooms is closely associated with fluctuations in the TGR water level. Thus, the water level fluctuation patterns of different "tide-types" may prevent the occurrence of algal blooms in the spring and summer, and the "stair-type" tides may control autumn blooms during the impounding period. These methods were feasible and effective throughout the actual TGR's operation in 2009 2011. These patterns formed an eco-environmentally friendly operation (EEFO) to mitigate algal blooms. As an in situ treatment with easier operation and less negative impact and loss, compared with chemical and filter-feeding fish methods, the EEFO is currently considered as the most feasible remedial measure to remit the eco-environmental problems at the Three Gorges Dam (TGD).
