气候变化对鲑鱼丰富度和繁殖影响的研究进展

鲑鱼是人类重要的食品来源之一,具有巨大的经济价值。同时,鲑鱼资源通过输送营养物质对维持溪流和陆地生态系统的结构、功能和过程等有重要作用。而鲑鱼是对温度极为敏感的冷水性鱼类,对气候变化的反应尤为明显。作者通过文献综述法梳理相关研究,从气候变化引起的温度变化、淡水和海洋环境的变化以及鱼病传播4个方面探讨对鲑鱼丰富度和繁殖的影响,并提出研究展望。研究显示:温度变化对鲑鱼的产卵和迁徙有较大影响;溪流和河流流量的改变会影响鲑鱼的迁徙和幼年鲑鱼的存活数量;温度和二氧化碳浓度的变化使海洋食物供应减少,鲑鱼丰富度降低;水温的升高使病原体增加,鲑鱼死亡率增加。本研究成果可为鲑鱼种群应对气候变化的研究及管理提供一定的理论支持。     

From reductionism to systems thinking: How the shipping sector can address sulphur regulation and tackle climate change

The shipping sector is required to reduce fuel sulphur content to 0.1% in Emission Control Areas by 2015 and to 0.5% globally by 2020. Although this is demanding, a greater challenge for all sectors is climate change. However, the three options to comply with sulphur regulation do little to address this challenge. With a deep-seated change to the type of fuel burnt in marine engines, this should be seen as an opportunity to explore co-benefits of sulphur and carbon reduction – instead of taking a short-sighted approach to the problem. It is argued here that the upcoming sulphur regulations should be postponed and instead, a co-ordinated suite of regulations should be implemented that tackles cumulative CO₂ emissions and localised SO_x emissions in chorus. This would ensure that less developed, yet more radical, step-change forms of propulsion such as wind, battery and biofuels are introduced from the outset – reducing the risks of infrastructure lock-in and preventing the lock-out of technologies that can meaningfully reduce absolute emissions from the sector.     

近百年气候变化及可能的自然影响因素研究进展

就国内外关于近百年的气候变化特征进行综述,并对太阳活动、火山爆发以及海气相互作用等自然因素对近百年气候变化的影响作了详细的总结。结果发现最近100年(1906—2005年)全球平均地表温度上升了0.56—0.92℃,中国的平均气温上升了(0.6±0.1)℃,但是20世纪全球和中国年平均降水没有明显的变化趋势。目前关于太阳活动、火山爆发和气候系统内部海气相互作用对于气候变化的影响,还存在很大的不确定性。     

气候变化背景下海南东寨港红树林生态系统的脆弱性评估

鉴于红树林生态系统对气候变化背景下海平面上升和极端台风事件有高度敏感性,应用1980—2018年的海洋大气观测资料和实地调查数据,分析了海口东寨港地区的海平面、温度和台风最大风速的变化特征,并基于IPCC气候变化综合风险的理论框架,构建了"暴露度-敏感性-适应性"的脆弱性评价指标体系和估算方法,评估了海平面上升和台风事件背景下东寨港红树林生态系统的脆弱性主要特征。结果显示:①东寨港红树林生态系统的致灾影响因子主要为该地区沿海海平面的快速上升,其上升速率可达4. 6 mm/a,远高于全球和中国沿海平均值;其次为1993年之前和2006年之后,在海口地区250 km范围内出现的热带气旋或台风事件;②东寨港红树林脆弱性指数的平均值为0. 31,属于中度脆弱等级,其中三江片区的红树林脆弱性相对最高,演丰片区最低。构建的评价指标体系可较好地反映出海平面快速上升和热带气旋或台风影响下红树林生态系统的脆弱性特征。     

南半球热带外气候变量与两种ENSO的联系

This study uses the Climate Forecast System Reanalysis(CFSR) to investigate the responses of the Southern Hemisphere(SH) extratropical climate to two types of El Ni?o–Southern Oscillation(ENSO)—the eastern Pacific(EP) type and the central Pacific(CP) type in different seasons. The responses are denoted by the anomalies of climate variables associated with one-standard-deviation increase in the Ni?o3 or Ni?o4 index. The results show that in austral spring the differences in the ENSO-related anomaly(ERA) patterns of atmospheric circulation between the EP ENSO period(1979–1998) and CP ENSO period(1999–2010) are mainly associated with the change in the ENSO-PSA2 relationship. Such differences affect the ERA fields of surface air temperature and mixed layer temperature, and finally result in significant differences in sea-ice concentration anomalies in the Atlantic sector. In austral summer, significant correlation exists between the variations of SAM and both of the variations of Ni?o3 and Ni?o4 in 1979–1998, while the correlation between SAM and Ni?o4 disappears in 1999–2010. For all seasons, the strength of the climate ERAs depend on if there are close relationship between ENSO and the major climate variation modes of the SH extratropics. For the climate variables, the ERA patterns of surface air temperature are generally controlled by surface wind anomalies and mirrored by the mixed layer temperature anomalies. The mixed layer depth anomalies are primarily modulated by surface heat flux anomalies and occasionally by anomalous wind. There are strikingly strong anomalies of surface heat flux in the autumn of 1979–1998 related to the Ni?o3 variation, the period when there is only significant correlation between ENSO and PSA2. There are no evidence that the SH extratropical climate variability induced by Ni?o3 variations are stronger in the EP-ENSO period, and that variability induced by Ni?o4 variations are stronger in the CP-ENSO period.     

A comparison of three marine ecosystems surrounding the Korean peninsula: Responses to climate change

This study uses a comparative approach to examine responses of marine ecosystems to climatic regime shifts. The three seas surrounding the Korean peninsula, the Japan/East Sea, the East China Sea and the Yellow Sea represent three contiguous but distinct ecosystems. Sampling has been carried out by the National Fisheries Research and Development Institute of South Korea since 1965, using the same methods in all three seas. Sampling was generally synoptic. Amplitude time series of 1st EOF modes for temperature, salinity, zooplankton biomass and concentrations of four major zooplankton taxa were used to determine whether the three marine ecosystems respond in a similar manner to climate variations. Temporal patterns of the variables were strongly similar among the three seas at decadal time scales, but very weakly similar at interannual scales. All three seas responded to a climatic regime shift that occurred in 1989. Temperature, zooplankton biomass and copepod concentrations increased in the late 1980s or early 1990s in all three seas. Concentrations of amphipods, chaetognaths and euphausiids also increased in the Japan/East Sea and the East China Sea, but not the Yellow Sea. The Yellow Sea ecosystem differs strongly from the other two seas, and water exchange between the Yellow Sea and the East China Sea is much weaker than that between the East China Sea and Japan/East Sea. Spatial patterns of zooplankton determined by the EOF analysis were closely related to currents and fronts in each of the three seas.     

Non-stationary extreme value models to account for trends and shifts in the extreme wave climate due to climate change

The extreme values of wave climate data are of great interest in a number of different ocean engineering applications, including the design and operation of ships and offshore structures, marine energy generation, aquaculture and coastal installations. Typically, the return values of certain met-ocean parameters such as significant wave height are of particular importance. There exist many methods for estimating such return values, including the initial distribution approach, the block maxima approach and the peaks-over threshold approach. In a climate change perspective, projections of such return values to a future climate are of great importance for risk management and adaptation purposes. However, many approaches to extreme value modelling assume stationary conditions and it is not straightforward how to include non-stationarity of the extremes due to for example climate change. In this paper, various non-stationary GEV-models for significant wave height are developed that account for trends and shifts in the extreme wave climate due to climate change. These models are fitted to block maxima in a particular set of wave data obtained for a historical control period and two future projections for a future period corresponding to different emission scenarios. These models are used to investigate whether there are trends in the data within each period that influence the extreme value analysis and need to be taken into account. Moreover, it will be investigated whether there are significant inter-period shifts or trends in the extreme wave climate from the historical period to the future periods. The results from this study suggest that the intra-period trends are not statistically significant and that it might be reasonable to ignore these in extreme value analyses within each period. However, when it comes to comparing the different data sets, i.e. the historical period and the future projections, statistical significant inter-period changes are detected. Hence, the accumulated effect of a climatic trend may not be negligible over longer time periods. Interestingly enough, such statistically significant shifts are not detected if stationary extreme value models are fitted to each period separately. Therefore, the non-stationary extreme value models with inter-period shifts in the parameters are proposed as an alternative for extreme value modelling in a climate change perspective, in situations where historical data and future projections are available.     

Joint distributions of wave height and period: A critical comparison

Three theoretical joint distributions of wave height and period are compared with data. Both crest-to-trough waves and zero-upcrossing waves are considered. The data consist of two long Waverider records (of 12 and 8 hr) and a shorter record taken from a reservoir. It is found that a distribution based on the theory of Gaussian processes fits the crest-to-trough waves well in all cases. In contrast, the two narrow band approximations only fit the data from the reservoir, which is more narrow band. The effect of high frequency cut-off on the distribution of height and period are considered.     

气候变化背景下海-气CO_2通量获取方法综述

综述了国内外海-气CO2通量测量和估算方法的研究进展,对各方法的原理、应用及优缺点做了简要介绍,着重介绍了海洋碳循环数值模式的研究现状、原理方法等,并对海-气CO2通量研究的发展趋势作了展望。     

Using stochastic population process models to predict the impact of climate change

More than ten years ago a paper was published in which stochastic population process models were fitted to time series of two marine polychaete species in the western Wadden Sea, The Netherlands (Van der Meer et al., 2000). For the predator species, model fits pointed to a strong effect of average sea surface winter temperature on the population dynamics, and one-year ahead model forecasts correlated well with true observations (r = 0.90). During the last decade a pronounced warming of the area occurred. Average winter temperature increased with 0.9 °C. Here we show that despite the high goodness-of-fit whilst using the original dataset, predictive capability of the models for the recent warm period was poor.     

Vulnerability to impacts of climate change on marine fisheries and food security

Assessment of fisheries vulnerability to climate change is an important step for enhancing the understanding and decision-making to reduce such vulnerability. This study aimed to provide an analysis of country level vulnerability focusing on food security implications of climatic disturbances on marine fisheries. The comparative magnitude and distribution of potential food security impacts of climatic disturbances on marine fisheries were assessed for 109 countries by scoring and ranking countries against a set of vulnerability criteria including metrics of national exposure, sensitivity and adaptive capacity, highlighting the contribution of marine fisheries to national food and nutrition security. Results showed that developing countries in Africa, Asia, Oceania, and Latin America appeared to be most vulnerable, and the key sources of vulnerability differed considerably among the countries. For countries most vulnerable to climate-induced effects on marine fisheries, more than two-thirds of them depended on domestic marine fisheries as a main source of fish supply. Developing appropriate adaptation policies and management plans to reduce the impacts of changing climate is of great importance to sustain food security in these highly vulnerable and heavy marine fisheries-dependent countries.     

Preparedness of key coastal and marine sectors in Ireland to adapt to climate change

Preparedness to adapt to the impacts of climate change was assessed for three important sectors of activity within the Irish coastal and marine environment, namely tourism, fisheries, and conservation of biodiversity. Information on the current status of each sector is a valuable point of reference in terms of accessing contribution to the implementation of future national adaptation efforts. A modified version of the National Adaptive Capacity (NAC) framework developed by the World Resources Institute was used to assess the three sectors of activity. This framework is structured around five functions: assessment, prioritisation, coordination, information management, and climate risk reduction; results of the assessment suggest that all three sectors are at the nascent stages of the climate change adaptation process. Currently there is no dedicated national policy guidance or legal support mechanism on adaptation in Ireland; hence there is no national financial commitment to support implementation of adaptation actions for any of the sectors assessed. Subjecting these three selected sectors of activity to such an assessment enables identification of existing actions that can potentially support current adaptation, as well as where issues such as knowledge gaps and lack of policy support hinder progress.     

Relation of ice conditions to climate change in the Bohai Sea of China

1NTRODUcrIONThe bohai As is a seasonally ice-covered sea and is located in the lowest latitudes (37' -4l'N), where sea ice occurs. The bohai ffea is nearly enclosed by land in the south, the northand the west, and only connects to the Huanghai ffea through the bohai Strait in the east.The width of the strait is abeut l06 km. The boai ffea is very shallow basin with the meandepth of l8 m and the maximum depth of 78 m. The topography of the sea bottom and thecoastal regions has an importan…     

Environmental change and oyster colonization within the Hudson River estuary linked to Holocene climate

Geophysical mapping and sampling data provide a record of changing environmental and faunal conditions within the Hudson River estuary during the mid- to late Holocene. On the shallow, broad marginal flats of the mesohaline Hudson, fossil oyster beds (Crassostrea virginica) are found exposed on the river bottom and buried by sediment. The shallowest beds are well imaged in chirp sub-bottom and side-scan sonar data and form discrete flow-perpendicular bands, 0.6–1.0 km wide and up to 3 km long, which cover 30% of the river bottom. Radiocarbon-dated sediment cores indicate oysters thrived within two time periods from ~500–2,400 and ~5,600–6,100 cal. years b.p. Sediment and physical property data indicate a changing depositional regime consistent with the oyster chronology. Similar changes in oyster presence are found in local shell midden sites of the Lower Hudson Valley as well as elsewhere along the Atlantic coast, and may reflect climatic controls associated with warm–cool cycles during the Holocene. Oysters flourished during the mid-Holocene warm period, disappeared with the onset of cooler climate at 4,000–5,000 cal. years b.p., and returned during warmer conditions of the late Holocene. The most recent demise of oysters within the Hudson at 500–900 cal. years b.p. may have accompanied the Little Ice Age.