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181.
182.
Matthiessen P Allen Y Bamber S Craft J Hurst M Hutchinson T Feist S Katsiadaki I Kirby M Robinson C Scott S Thain J Thomas K 《Marine environmental research》2002,54(3-5):645-649
This paper summarises results of the EDMAR programme which is investigating oestrogenic and androgenic endocrine disruption in UK coastal waters. Most of the data concern fish. Four species (flounder, viviparous blenny and two sand gobies) are experiencing feminisation in industrialised estuaries. In males this includes vitellogenin (VTG) synthesis, ovotestis induction and/or feminised sexual characteristics. Although reproductive success may be impaired in some cases, implications for fish populations are still unclear. Suspected causative contaminants include natural oestrogenic substances and synthetic oestrogen mimics. The majority of the oestrogenic activity is adsorbed to sediments, and routes of exposure may include benthic food chain transfer. Some natural androgenic substances are also being discharged to estuaries, but their activity appears low. 相似文献
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185.
Benedetti-Cecchi L Bertocci I Micheli F Maggi E Fosella T Vaselli S 《Marine environmental research》2003,55(5):95-458
Marine protected areas (MPAs) are increasingly used as a management tool to preserve species and habitats. Testing hypotheses about the effectiveness of MPAs is important for their implementation and to identify informative criteria to support management decisions. This study tested the general proposition that MPAs affected assemblages of algae and invertebrates between 0.0 and 0.5 m above the mean low water level of rocky coasts on two islands in the Tuscan Archipelago (northwest Mediterranean). Protection was concentrated mainly on the west coasts of the islands, raising the possibility that neither the full range of assemblages nor the relevant scales of variation were properly represented within MPAs. This motivated the comparison of assemblages on opposite sides of islands (habitats). The effects of MPAs and habitat were assessed with a multifactorial sampling design; hypotheses were tested about differences in structure of assemblages, in mean abundance of common taxa and in univariate and multivariate measures of spatial variation. The design consisted of three replicate shores for each condition of protected and reference areas on the west side of each island and three unprotected shores on the eastern side. Assemblages were sampled independently four times on each island between June 1999 and January 2001. At each time of sampling two sites were selected randomly at each of two tidal heights to represent midshore and lowshore assemblages on each shore. Estimates of abundance were obtained using non-destructive sampling methods from five replicate 20x20 cm quadrats at each site. Results indicated differences among habitats in structure of assemblages, in mean abundance of common taxa and in univariate and multivariate measures of spatial variation at the scale of shores. Most of these patterns were inconsistent with the predicted effect of management through MPAs. The data suggest that designation of MPAs in the Tuscan Archipelago should proceed through management of multiple shores and types of habitat selected to guarantee protection to a representative sample of assemblages and to the processes responsible for maintenance of spatial patchiness at different scales. This study also shows that considerations of spatial heterogeneity are important to underpin management decisions about the number, size and location of MPAs. 相似文献
186.
The sublethal effects of stormwater runoff from sections of a plum orchard treated with esfenvalerate or diazinon were evaluated in 7-day-old Sacramento splittail (Pogonichthys macrolepidotus) larvae. Fish were exposed to eight runoff samples using the USEPA standard static renewal method for 96 h acute toxicity testing, then transferred to clean water for three-month to assess the survival, growth, histopathological abnormalities, and heat stress proteins (hsp). No significant mortality was observed at 96 h in exposed fish. At one week, histopathological abnormalities included severe glycogen depletion, cytoplasmic protein droplets, vacuolar degeneration, and cell necroses in liver of all exposure groups. Pyknotic nerve cells were seen in brain of one exposure group. Significantly higher cumulative mortality, lower condition factor, and elevated hsp60 and hsp70 levels (p < 0.05) were occurred in several exposure groups. No histopathological abnormalities were observed after three months in any exposure group. This study confirms that standard acute toxicity tests have underestimated the toxicity of stormwater runoff, and although splittail larvae survived the 96 h exposure, they exhibited reduced survival and growth and showed signs of cellular stress even after a three month recovery period. 相似文献
187.
Ren J. Wang J. Jenkinson I. Xu D. L. Yang J. B. 《中国海洋工程》2007,21(3):371-388
This paper presents a new approach for offshore risk analysis that is capable of dealing with linguistic probabilities in Bayesian networks(BNs).In this paper,linguistic probabilities are used to describe occurrence likelihood of hazardous events that may cause possible accidents in offshore operations.In order to use fuzzy information,an f-weighted valuation function is proposed to transform linguistic judgements into crisp probability distributions which can be easily put into a BN to model causal relationships among risk factors.The use of linguistic variables makes it easier for human experts to express their knowledge,and the transformation of linguistic judgements into crisp probabilities can significantly save the cost of computation,modifying and maintaining a BN model.The flexibility of the method allows for multiple forms of information to be used to quantify model relationships,including formally assessed expert opinion when quantitative data are lacking,or when only qualitative or vague statements can be made.The model is a modular representation of uncertain knowledge caused due to randomness,vagueness and ignorance.This makes the risk analysis of offshore engineering systems more functional and easier in many assessment contexts.Specifically,the proposed f-weighted valuation function takes into account not only the dominating values,but also the α-level values that are ignored by conventional valuation methods.A case study of the collision risk between a Floating Production,Storage and Off-loading(FPSO) unit and the authorised vessels due to human elements during operation is used to illustrate the application of the proposed model. 相似文献
188.
Gülcan BOZKAYA Nurullah HANIL?I Ivan A. BAKSHEEV Vsevolod Yu. PROKOFIEV David A. BANKS 《《地质学报》英文版》2014,88(Z2):520-521
Please refer to the attachment(s) for more details 相似文献
189.
Anastasia V.Arzhannikova Elena I.Demonterova Marc Jolivet Ekaterina A.Mikheeva Alexei V.Ivanov Sergey G.Arzhannikov Valentin B.Khubanov Vadim S.Kamenetsky 《地学前缘(英文版)》2022,13(1):101254
The Late Paleozoic–Early Mesozoic Mongol-Okhotsk Ocean extended between the Siberian and Amur–North China continents.The timing and modalities of the oceanic closure are widely discussed.It is largely accepted that the ocean closed in a scissor-like manner from southwest to northeast(in modern coordinates),though the timing of this process remains uncertain.Recent studies have shown that both western(West Transbaikalia)and eastern(Dzhagda)parts of the ocean closed almost simultaneously at the Early–Middle Jurassic boundary.However,little information on the key central part of the oceanic suture zone is available.We performed U-Pb(LA-ICP-MS)dating of detrital zircon from wellcharacterized stratigraphic sections of the central part of the Mongol-Okhotsk suture zone.These include the initial marine and final continental sequences of the East Transbaikalia Basin,deposited on the northern Argun-Idemeg terrane basement.We provide new stratigraphic ages for the marine and continental deposits.This revised chronostratigraphy allows assigning an age of~165–155 Ma,to the collisionrelated flexure of the northern Argun-Idemeg terrane and the development of a peripheral foreland basin.This collisional process took place 5 to10 million years later than in the western and eastern parts of the ocean.We demonstrate that the northern Argun-Idemeg terrane was the last block to collide with the Siberian continent,challenging the widely supported scissor-like model of closure of the MongolOkhotsk Ocean.Different segments of the ocean closed independently,depending on the initial shape of the paleo continental margins. 相似文献
190.
Introductions of non-indigenous species (NIS) are mostly discussed through their impact on biodiversity. However, NIS can also act as ecosystem engineers, influencing the habitat itself, positively or negatively, directly or indirectly, which should be included when making risk assessments. Special concern should be given to changes in ecological services provided by the ecosystem. Physically, NIS may affect the substrate itself, or alter habitat architecture, indirectly influencing water movements, sediment accumulation, and light conditions. Chemical changes brought upon by NIS occur both on small and large scales, some having positive effects on ecosystem services, others can perturb epibionts. Furthermore, NIS may negatively affect natural resources, aquaculture or create fouling communities, all resulting in a negative impact on economics. However, if removed, already established NIS can be used as bioremediators, having a positive effect on different ecosystems. Using NIS for habitat management may be economically profitable, but could affect the habitat adversely. 相似文献