Modelling the water balance in the glacierized Parón Lake basin (White Cordillera,Peru) / Modélisation du bilan hydrique du bassin versant englacé du Lac Parón (Cordillère Blanche,Pérou)

Abstract

The White Cordillera (northern Peru), with a glacial surface of 631 km², is the largest glacierized mountain range in the Tropics. Due to the lack of physical data from most of its sub-basins, it is difficult to build a physical model to estimate the water resource flowing from the glaciers at the present time and a fortiori for the future. The most recent GCM simulations indicate a significant increase in the temperature and an accelerated shrinking of the glaciers. Consequently, we sought a model that would be based on the data available within instrumented sub-basins. A theoretical/conceptual water model makes it possible to quantify the local glacier contribution, which could then be applied to the other non-instrumented sub-basins. A total of 43.6% of Parón Lake's instrumented sub-basin area (47.4 km²) corresponds to glacial surfaces. Within this sub-basin, a smaller watershed (8.8 km²), called Artesón, with 72.9% glacierized area, has been accurately observed over a 5-year hydrological period (September 2000–August 2005). This information allowed us to calibrate the model over the Artesón sub-basin. The parameters obtained were applied to the entire Parón basin using the same modelling approach.     

Marine radiocarbon reservoir effect along the northern Chile-southern Peru coast (14-24°S) throughout the Holocene

Through an extensive sampling and dating of pairs of associated shells and charcoal fragments combined with reanalysis of all the available previous data, we reconstruct the evolution throughout the Holocene of the regional marine radiocarbon reservoir effect (ΔR) values along the northern Chile-southern Peru area (14°-24°S). After elimination of the cases in which the terrestrial component yielded older ages than the marine shells to which they were associated, the study is based upon data from 47 pairs of associated marine and terrestrial material.Our results suggest major changes in both the magnitude and variability range of ΔR during the whole Holocene Period: (1) between 10,400 and 6840 cal yr BP, high values (511 ± 278 yr) probably result from a strengthened SE Pacific subtropical anticyclone and shoaling of equatorial subsurface waters during intensified upwelling events; (2) between 5180 and 1160 cal yr BP, lower values (226 ± 98 yr) may reflect a major influence of subtropical water and diminished coastal upwelling processes; (3) during the last ~ thousand years, high values (between 355 ± 105 and 253 ± 207 yr) indicate an increased influence of ¹⁴C-depleted water masses and of ENSO. For the early twentieth century a ΔR value of 253 ± 207 yr was calculated.     

多种糖类添加物对秘鲁鱿鱼(Loliginidae)肌原纤维蛋白抗冻保水效果及构象变化影响研究

为探索海藻糖类对于冷冻水产品的抗冻保水效果,以秘鲁鱿鱼(Loliginidae)鱼糜为研究对象,以焦磷酸钠保水处理为对照,研究海藻糖、海藻胶寡糖及海藻胶对秘鲁鱿鱼鱼糜蛋白质抗冻保水的作用效果。结果表明,–18°C冻藏6周后,1.0%海藻糖和海藻胶寡糖(500—600Da)处理效果最好,可显著降低冷冻鱿鱼鱼糜解冻汁液流失(5.00%—5.54%),其与焦磷酸钠保水效果无显著性差异(5.02%—5.48%,P0.05)。整个冻藏期内,随着冻藏时间延长,不同处理鱿鱼鱼糜盐溶性蛋白、Ca2+-ATPase活性及总巯基均呈逐渐下降趋势,其中海藻糖、海藻胶寡糖对鱿鱼鱼糜蛋白质特性的保护效果,显著优于蒸馏水、焦磷酸钠处理(P0.05)。本研究可为开发一种安全、高效、节能、环保,适用于冷冻鱿鱼的海藻糖类抗冻保水剂提供参考。     

Lasting Legacies: Conservation and Communities at Huascaran National Park,Peru

This article uses a case-study approach to investigate the challenges of protected area (PA) management for Huascaran National Park in the Peruvian Andes. The park is analyzed by situating the timing of establishment of the park boundaries within the context of two historical Peruvian events: agrarian reform (1969) and an earthquake (1970). Interviews and narratives from community members and stakeholders associated with park delimitation and management were used for the study. Analysis of narratives revealed that the establishment of park boundaries, the legal definition used for the park, and land use restrictions contribute to diminished support for the park from surrounding communities. Community and national institutions negotiate the spatial boundary of conservation in Huascaran National Park while engaging with historical narratives that invoke environmental constraints and acts of resistance.     

CONTESTING PISCO: CHILE,PERU, AND THE POLITICS OF TRADE*

This article examines the geography of pisco, a South American brandy claimed as the national drink of both Peru and Chile. The historic tension between these two nations—based notably on the nineteenth‐century War of the Pacific—is used as a backdrop to understanding the cultural and political contestation over the “ownership” of this beverage. Although both countries see exportation of pisco as a means of agricultural development, much of the animosity of this trade dispute is couched in cultural and historical terms. International trade policies, including the use of geographical indications (labels of geographical origin) for the purposes of trademarking, and the physical geography that makes pisco production possible are discussed.     

Valuing seafood: The Peruvian fisheries sector

There are tradeoffs in managing fisheries, and ideally such tradeoffs should be known when setting fisheries policies. An aspect of this, which is rarely considered, is the spin-off effect of different fisheries: the economic and social benefits that fisheries generate through processing through distribution and on to the end consumer. This study evaluated the benefits generated in the Peruvian marine fisheries sector through a comprehensive value chain analysis, based on a newly-developed combined ecosystem-economic modeling approach, which was integrated in the widely-used Ecopath with Ecosim approach and software. The value chain was parameterized by extensive data collection through 35 enterprise types covering the marine fisheries sector in Peru, including the world's biggest single-species fishery for anchoveta. While anchoveta is what is known about Peruvian fisheries, the study finds that anchoveta accounts for only 31% of the sector contribution to GDP and for only 23% of the employment. Thus, while anchoveta indeed is the fundamental fish species in the Peruvian ecosystem, there are other fisheries to be considered for management. The study indicates that the economic multipliers for Peruvian fisheries were 2.9 on average over the industry, and that these varied surprisingly little between fleets and between seafood categories indicating that the multipliers can be used beyond Peru to generalize the spin-off effect of the value chain. Employment multipliers vary much more across types of fisheries, but also around an average of 2.9; here it was clear that longer value chains result in more employment.     

Oxygenation episodes on the continental shelf of central Peru: Remote forcing and benthic ecosystem response

The interplay between the oxygen minimum zone and remotely-forced oxygenation episodes determines the fate of the benthic subsystem off the Central Peruvian coast. We analyzed a 12 year monthly time-series of oceanographic and benthic parameters at 94 m depth off Callao, Central Peru (12°S), to analyze: (i) near-bottom oxygen level on the continental shelf in relation to dynamic height on the equator (095°W); and (ii) benthic ecosystem responses to oxygen change (macrobiotic infauna, meiofauna, and sulphide-oxidizing bacteria, Thioploca spp.). Shelf oxygenation episodes occurred after equatorial dynamic height increases one month before, consistent with the propagation of coastal trapped waves. Several but not all of these episodes occurred during El Niños. The benthic biota responded to oxygenation episodes by undergoing succession through three major ecological states. Under strong oxygen deficiency or anoxia, the sediments were nearly defaunated of macro-invertebrates and Thioploca was scarce, such that nematode biomass dominated the macro- and meiobiotas. When frequency of oxygenation events reduced the periods of anoxia, but the prevailing oxygen range was 10–20 μmol L⁻¹, mats of Thioploca formed and dominated the biomass. Finally, with frequent and intense (>40 μmol L⁻¹) oxygenation, the sediments were colonized by macrofauna, which then dominated biomass. The Thioploca state evolved during the 2002–2003 weak EN, while the macrofauna state was developed during the onset of the strong1997–1998 EN. Repeated episodes of strong oxygen deficiency during the summer of 2004, in parallel with the occurrence of red tides in surface waters, resulted in the collapse of Thioploca mats and development of the Nematode state. Ecological interactions may affect persistence or the transition between benthic ecosystem states.     

秘鲁外海茎柔鱼渔场分布与表温及表温距平值关系的初步探讨

根据2006年6~11月我国远洋船队秘鲁茎柔鱼生产统计及其表温(SST)、表温距平值(SSTA)数据,利用GIS软件ArcGIS9.0,对各月平均日产量(CPUE)和SST、SSTA关系的分布图进行绘制并分析,计算作业渔场重心。结果表明,6~8月的产量和CPUE比其他月份高。6~11月作业渔场在80°W~85°W,10°S~15°S,渔场重心在81°W~84°W,11°S~14°S。产量主要集中在12°~14°S海域,约占年总产量的72.72%,与2004-2005年有较大差异。6月作业渔场的SST为21~23℃,7、8月分别为19~21℃和18~20℃,9~11月为18~21℃。6月作业渔场的SSTA为0.1~0.2℃,7、8月分别为0.5~0.7℃,9~11月分别为0.2~0.6℃、1.0~1.4℃和0.4~0.7℃。研究认为,茎柔鱼渔场分布与SST、SSTA关系密切,可作为寻找中心渔场的海洋环境指标。     

An individual-based model study of anchovy early life history in the northern Humboldt Current system

We used an individual-based model of anchovy (Engraulis ringens) early life history coupled with hydrodynamic outputs from the regional oceanic modeling system (ROMS) to investigate the factors driving variability in egg and larval survival rates in the northern Humboldt upwelling region off Peru. Individuals were released within a coastal area and followed for a period of 30 days. Those that were still in the coastal area at that time were considered as retained. We investigated the spatial and temporal variability in the release locations of the individuals retained, and compared these to observed egg concentration patterns reconstructed from a 40-year period of monitoring. A first set of simulations using passive particles to represent anchovy eggs and larvae revealed a large sensitivity of the results to the initial vertical distribution of particles. We then conducted two additional sets of simulations that included the effect of egg buoyancy, larval vertical swimming behavior and lethal temperature. We obtained (1) maximal coastal retention close to the surface in winter and in deeper layers in summer, (2) a large influence of egg buoyancy and of larval vertical behavior on coastal retention in all seasons, (3) a partial match between dates and locations of enhanced retention and observed egg concentration patterns and (4) a low effect of lethal temperature on survival except when associated with high egg density. The model suggests that an optimal temporal spawning pattern for maximizing coastal retention would have two maximums, the most significant in austral winter and the second in summer. This pattern agrees roughly with observed spawning seasonality, but with temporal discrepancy of about two months in the peaks of both series. Spatially, we obtained higher retention from 10 S to 20 S, whereas the observed maximum egg concentration was located between 6°S and 14°S. Among the three sets of simulations, the one taking into account larval vertical swimming behavior lead to the best match with the data.     

利用栖息地适宜指数分析秘鲁外海茎柔鱼渔场分布

根据2003—2007年秘鲁外海茎柔鱼渔获数据以及海洋环境数据[表温(SST),表温水平梯度、表层盐度(SSS)、海面高度(SSH)、叶绿素(Chl-a)浓度],利用主成分分析法确定各环境因子的权重,分别采用权重求和法和几何平均法进行栖息地适宜指数(HSI)建模分析,选择最优模型进行实证分析,结果表明,权重最高的环境因子为SST,最小的为Chl-a浓度。HSI值较高的海区一般位于200海里专属经济区外附近海域。经统计比较,用权重求和法计算所得HSI值好于几何平均法。利用2008年茎柔鱼生产数据进行实证分析,产量和作业次数随HSI值升高而增加,权重求和法的HSI模型可用于茎柔鱼渔场的实时动态预报。分析还显示,HSI分布情况与研究海域的的海洋环境密切相关,HSI不小于0.8的海区一般处在水团交汇处。