Loss of an ecological baseline through the eradication of oyster reefs from coastal ecosystems and human memory

Oyster reefs form over extensive areas and the diversity and productivity of sheltered coasts depend on them. Due to the relatively recent population growth of coastal settlements in Australia, we were able to evaluate the collapse and extirpation of native oyster reefs (Ostrea angasi) over the course of a commercial fishery. We used historical records to quantify commercial catch of O. angasi in southern Australia from early colonization, around 1836, to some of the last recorded catches in 1944 and used our estimates of catch and effort to map their past distribution and assess oyster abundance over 180 years. Significant declines in catch and effort occurred from 1886 to 1946 and no native oyster reefs occur today, but historically oyster reefs extended across more than 1,500 km of coastline. That oyster reefs were characteristic of much of the coastline of South Australia from 1836 to 1910 appears not to be known because there is no contemporary consideration of their ecological and economic value. Based on the concept of a shifted baseline, we consider this contemporary state to reflect a collective, intergenerational amnesia. Our model of generational amnesia accounts for differences in intergenerational expectations of food, economic value, and ecosystem services of nearshore areas. An ecological system that once surrounded much of the coast and possibly the past presence of oyster reefs altogether may be forgotten and could not only undermine progress towards their recovery, but also reduce our expectations of these coastal ecosystems. La Pérdida de una Línea de Base Ecológica por Medio de la Erradicación de Arrecifes de Ostión de los Ecosistemas Costeros y la Memoria Humana     

太湖苏州三山岛旅游资源议论

本文对太湖苏州三山岛旅游区的区位、自然景观、文化内函和科学潜能作了初步评论．同时提出三山岛旅游业应瞄准国际旅游业趋势、四大热点，以高的起点将可持续性旅游作为三山岛立足之本，建议开展从旅游学研究，加大宣传力度提高三山岛的知名度。     

"How near were we to Ruine": the effects in England of the earthquake of 8th September 1692

This paper attempts to Illustrate some of the advantages and disadvantages of using contemporary evidence in the study of historical seismicity. The event considered here is doubly significant—it was a large event by British standards, as well as arguably the best documented earthquake to have occurred before the mid-eighteenth century. At a time when an interdisciplinary approach to historical seismicity is still in its infancy this paper identifies those areas where the available sources can assist in the evaluation of early macroseismic data.     

Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments

The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000 years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution.     

Catastrophic Decline in Mollusc Diversity in Eastern Tasmania and Its Concurrence with Shellfish Fisheries

Abstract:  We used historical patterns of deposition of mollusc shells to infer changes to inshore benthic assemblages in the southeastern Tasmanian region over the past 120 years. We identified and counted shells in slices embedded within 1m long ²¹⁰Pb-dated sediment cores were collected at 13 sites in water depths of 8–16 m. Declines in mollusc species richness and shell production occurred during the past century at all sites studied, with a mean decline per 5-cm sediment slice from 21 species in 1890 to 7 species in 1990 and in shell abundance from 150 to 30 individuals over the same period. The time course of decline notably corresponded with the history of the scallop dredge fishery, presumably either because scallop dredging caused general declines in populations of mollusc species or because other factors caused a catastrophic regional decline in molluscs that included scallops. As a consequence, the fishery was forced to close. Of major concern is that losses had not previously been recognized but extended throughout the 100-km coastal span of the study. Given that fishing and other anthropogenic impacts, as well as a lack of observational data, are virtually ubiquitous for the coastal zone, major recent losses in mollusc biodiversity may be globally widespread but have gone unnoticed.     

基于电力历史应急大数据的应急情景规则分析与发现方法研究

为了解决电力突发事件演化过程难于预测,进而导致事件应急缺少针对性,较为被动的问题,提出在现有应急预案指导、事故模拟仿真、事故案例经验总结等方法基础上,引入基于电力历史大数据分析与预测的应急情景规则分析与发现方法,将电力应急突发事件情景构建的结果与相关大数据预测模型（汇总统计、分类与预测）相结合,提出科学、合理且具有良好操作性的情景演化规则的获取方法与技术路线,为进一步提高复杂电力突发事件的应急处置与指挥能力提供技术支撑。     

公路工程施工安全事故致因模型构建

为了探究公路施工安全事故诱因及其影响关系,基于"4M"理论和事故致因"2-4"模型,识别公路工程施工安全事故致因因素并确定模型框架,运用SPSS Modeler软件对2007~2017年426起事故进行关联规则挖掘,采取路径分析与重要度分析,构建出公路工程施工安全事故致因模型。结果表明:施工单位内外部原因共同引发公路工程施工安全事故,外部原因来源于建设单位、监理单位和勘察设计单位的安全管理缺失,而施工单位内部影响因素中,人的不安全动作、物的不安全因素、不良的生产环境和自然环境是事故发生的直接原因,无效的安全监管和作业层安全素质及能力不强是间接原因,根本原因是施工程序和技术方案存在缺陷,根源原因是决策层和管理层的安全素质及能力有待提高。该模型系统展现了工程施工项目安全事故致因因素的影响关系和重要程度,为公路工程施工安全事故预防提供指导。     

水污染环境损害鉴定评估的因果关系判定方法研究

因果关系判定包括环境暴露与环境损害间因果关系判定和环境污染物从源到受体的暴露路径的建立与验证两个部分.因果关系判定是环境损害鉴定评估的重点和难点,因果关系的判定对环境损害案例的结果起着十分重要的作用.在结合印染企业水环境污染事件案例实践基础上,对水环境污染事件环境损害鉴定评估的因果关系判定方法进行了探讨,为环境污染损害鉴定评估方法研究提供技术支持.     

Disasters and ‘conditions of possibility’: rethinking causation through an analysis of earthquakes in Nepal

What causes a disaster's aftermath? Scholars have increasingly turned to historical approaches that link outcomes to pre-disaster sociopolitical dynamics. Disasters lead to ‘critical junctures’ that ‘trigger’ events that unfold in the wake of the initial phenomenon. This paper argues that the ‘critical junctures’ paradigm shares limitations with ‘path dependency’ theory from which it is derived, namely a tendency towards historicism—a functionalist teleology better able to explain continuity than change. As an alternative, this analysis draws on Michel Foucault's understanding of ‘conditions of possibility’ as a way of rethinking agency/causation, moving away from individual subjects, events, or even historical conditions towards, instead, the new, radically destabilised ‘epistemological field’ emerging in the disaster's aftermath. This paper examines a series of devastating earthquakes in Nepal to consider how post-disaster ‘epistemological fields’ present new ‘conditions of possibility’ within which new ideas, actions, and outcomes become thinkable and possible in ways that pre-disaster historical conditions could not have predicted.