A comparative study of the toxicity of 1,1,2-trichloroethane,dieldrin, pentachlorophenol and 3,4 dichloroaniline for marine and fresh water organisms

The aquatic toxicity of 1,1,2-trichloroethane, dieldrin, pentachlorophenol and 3,4-dichloroaniline was determined for about 15 marine and fresh water animals and several unicellular algae. Acute, subchronic and chronic tests including reproduction studies, were carried out. The results are summarized in five tables.     

Trace Metals in Fish and Crustaceans - Identifying Heavier Polluted Areas in the Ghanaian Continental Shelf

Abstract

The concentrations of four trace metals, namely copper, lead, cadmium and manganese, were determined in six fish species and three crustaceans collected from five sites spanning over 70% of the Ghanaian coastline.

Copper and lead were determined in Barracuda (Spraena spraena), the Ribbon fish (Trichiurus lepturus), the Sardine (Sardinella spp), the Sole (Cynoflossus senegalensis), the Sea Bream (Pagrus coupei) and the Soldier fish (Cynapastas marmuratus). Cadmium and manganese were analyzed in the Blue Crab (Callinectes sepidus), the Spiny lobster (Panilirus regius) and the edible shrimp (Crago septempinosus). Sampling sites included Takoradi, Elmina, Cape Coast, Accra and Tema.

Lead and copper in the fishes ranged 0.25-0.94 μgg^?1 fresh weight and 0.40-2.54 μgg^?1 dry weight (FW) respectively whilst cadmium and manganese in the crustaceans ranged 0.05-0.083 μgg^?1 FW and 0.554-1.404 μgg^?1 FW respectively.

The Barracuda accumulated the greatest amount of metals whilst the sardine accumulated the least. with the crustaceans, there was a significant difference between the amounts of the metals accumulated. the blue crab accumulated the greatest and the edible shrimp the least.

The analysis showed that: (i) there was a positive correlation between the metals bioconcentrated and the extent of pollution of the marine waters and (ii) along the Ghanaian Continental Shelf, the extent of pollution was of the increasing order as: Elmina = Cape Coast < Takoradi < Accra < Tema. Pollution of the marine waters could be minimized by control of flow of pollutants from land based activities.     

富营养水体浮游植物群落对新型生态浮床的响应

通过围隔水泥池模拟试验,研究了富营养化水体中浮游植物群落对新型组合型生态浮床系统净化水质的响应. 每隔2周对水体中各水质指标、浮游植物及浮游甲壳动物群落进行检测,结果显示:①3种不同覆盖率(以浮床面积计)处理下,组合型生态浮床对氮、磷的去除率表现为39%覆盖率>26%覆盖率>13%覆盖率. ②3种覆盖率下水体中的浮游植物群落结构复杂性和生物多样性指数均显著高于空白对照组,其中,26%和13%覆盖率对浮游植物生物量的抑制效果比39%覆盖率好;同时,26%覆盖率比39%覆盖率水体中的浮游植物生物多样性指数要高,群落结构更复杂,随后是13%覆盖率处理. ③浮游植物生物量的变化与浮游甲壳动物表现出明显的相反时间趋势. 尽管26%覆盖率对氮、磷的去除量不是最大,但却更利于形成较为稳定的浮游植物群落结构,促进水体生态系统的平衡与健康发展;浮游植物生物量与营养盐的显著相关性及与浮游甲壳动物的相反时间趋势显示,生态浮床对浮游植物群落的改善可能是通过营养盐的上行效应与浮游甲壳动物的下行效应等因素得以实现.      

Use of Fully Biodegradable Panels to Reduce Derelict Pot Threats to Marine Fauna

Fishing pots (i.e., traps) are designed to catch fish or crustaceans and are used globally. Lost pots are a concern for a variety of fisheries, and there are reports that 10 – 70% of deployed pots are lost annually. Derelict fishing pots can be a source of mortality for target and bycatch species for several years. Because continual removal of derelict gear can be impractical over large spatial extents, modifications are needed to disarm gear once it is lost. We tested a fully biodegradable panel with a cull or escape ring designed for placement on the sides of a crab pot that completely degrades into environmentally neutral constituents after approximately 1 year. This panel is relatively inexpensive, easy to install, and can be used in multiple fisheries. We used the blue crab (Callinectes sapidus) fishery as a test case because it is a large pot fishery and blue crab pots are similar to traps used in other pot fisheries. We had commercial fishers deploy pots with panels alongside standard pots in Chesapeake Bay (U.S.A.) to assess potential effects of our experimental pots on blue crab catch. We compared the number, biomass, and size of crabs captured between standard and experimental pots and evaluated differences in catch over a crabbing season (March–November) at five locations. There was no evidence that biodegradable panels adversely affected catch. In all locations and time periods, legal catches were comparable in abundance, biomass, and size between experimental and standard pots. Properly designed biodegradable panels appear to be a viable solution to mitigate adverse effects of derelict pots. Uso de Paneles Completamente Biodegradables para Reducir las Amenazas de Vasijas Abandonadas para la Fauna Marina     

Effects of Liming on the Aquatic Fauna in a Norwegian Watershed: Why Do Crustaceans and Fish Respond Differently?

We studied the effects of liming on fish and crustaceans in a watershed which is in a region known to have one of the highest diversity of aquatic biota in Norway. This watershed, Enningdal, is shared between Norway (1/3) and Sweden (2/3) and includes 61 lakes  >  1.0 ha in Norway. Liming started on a large scale in the 1980s. Currently, a total of 26 of lakes (43%) are limed, covering 93% of the total lake area. The mean value ± S.D. of pH and the concentration of inorganic labile Al in these lakes is 6.62 ± 0.35 and 3 ± 4 μg l⁻¹, respectively. Historical data of fish communities have been obtained from surveys, while test-fishing and sampling of crustaceans were conducted in 24 lakes in recent years (2002–2004). The present study shows that crustaceans to a greater extent than fish has responded to improved water quality after more than 20 years of liming. Of a total of 120 fish populations, 42 (35%) have gone extinct. Only five of the lost fish populations (12%) have been re-established, all due to human re-introductions. Physical barriers are considered to be the main factor preventing fish from invading limed lakes. In contrast, crustaceans have been re-established in most limed lakes. This may be mainly due to their good spreading capacity. However, they might also have survived in refuges within the watershed, or as resting-eggs in the sediment.     

Prognosis of the State of Aquatic Animal Populations under Conditions of Disturbed Ionic Composition of Water

In the crustacean Eudiaptomus gracilisSars, relationships between mortality (D) and the ratio of main cations (R, the ratio of the sum of potassium and sodium equivalent concentrations to the sum of calcium and magnesium equivalent concentrations) were studied. The calculated regression equation D= 315 – 355/Rwas used for predicting the state of E. gracilispopulation in Lake Poppalijarvi (Karelia) polluted with mining waste. At R< 0.47, the population will survive; at R> 1.53, its extinction should be expected. The results of hydrobiological observations on Lake Poppalijarvi confirmed the prognosis based on the equation.     

水质基准甲壳类受试生物筛选

为筛选我国甲壳类基准受试生物, 依据其分布范围、 生态学意义等选出具有代表性的本土甲壳类生物, 从ECOTOX数据库及公开发表的文献中搜集其毒性数据, 采用物种敏感度分布法分别对浮游甲壳类和底栖甲壳类的物种毒性数据进行敏感性分析. 结果表明: 溞科的溞属(大型溞、 蚤状溞、 僧帽溞和透明溞)、 低额溞属(锯顶低额溞)和网纹溞属(模糊网纹溞)可作为浮游甲壳类基准受试生物; 钩虾科的钩虾属(蚤状钩虾和淡水钩虾)、 长臂虾科的沼虾属〔日本沼虾(青虾)〕和方蟹科的绒螯蟹属(中华绒螯蟹)可作为底栖甲壳类基准受试生物. 此外, 由于甲壳类生物对不同污染物的敏感性排序存在差异, 溞属(大型溞、 蚤状溞、 僧帽溞和透明溞)、 低额溞属(锯顶低额溞)、 钩虾属(蚤状钩虾)和沼虾属(日本沼虾)适用于推导重金属污染物的水生生物基准; 溞属(蚤状溞)、 网纹溞属(模糊网纹溞)、 钩虾属(蚤状钩虾和淡水钩虾)、 绒螯蟹属(中华绒螯蟹)适用于推导各种有机污染物和氨氮的水生生物基准.      

Pesticide effects on crabs: How environmental concentrations of endosulfan and chlorpyrifos affect embryos

The objectives of this work were to evaluate the effects of environmentally relevant chlorpyrifos and endosulfan, concentrations in the incubation period, effective hatching and survival of embryos and neonates of the freshwater burrowing crab, Zilchiopsis collastinensis (Decapoda, Trichodactylidae). Both pesticides were prepared from commercial and technical grade products. The exposure to about 100, 200, and 400 ng endosulfan L^?1, and 48, 240, and 1,200 ng chlorpyrifos L^?1 did not cause differences in the incubation period or in effective hatching but decreased survival of neonates, especially in the concentrations prepared from the technical grade product. Even if these concentrations are below the median lethal concentration (LC₅₀) values for embryos, these caused a significant decrease in the survival of neonates, i.e. when crabs are outside the egg and not protected by chorion. The decrease in the neonate population caused by these concentrations, which could be found in the environment, might impact aquatic communities.