基于机会成本法的海洋保护区生态保护补偿标准

建立海洋保护区已被公认为维持海洋生物多样性和防止海洋生态环境恶化的重要途径,而合理实施生态保护补偿是确保海洋保护区建设和管理成效、促进区域经济发展机会公平的关键手段。以土地、海域为载体,从机会成本补偿的角度出发,分别设置了机会成本补偿基数、区域调整系数、分区补偿系数和开发限度补偿系数,构建了海洋保护区生态保护补偿标准测算方法,并选取全国8个省(市)14个国家级海洋自然保护区开展了实证分析。结果表明:2015年案例区的机会成本补偿测算结果介于0.66×10~4—10.69×10~4元/km~2之间,河北昌黎黄金海岸国家级自然保护区和天津古海岸与湿地国家级自然保护区的补偿金额显著高于其他保护区,分别为10.69×10~4元/km~2和10.47×10~4元/km~2,相比之下,其余12个保护区的平均补偿金额为1.70×10~4元/km~2。     

消痰化瘀利窍中药组方对改善慢性间歇性低氧大鼠心肌纤维化的作用及其机制*

目的: 探讨转化生长因子-β(TGF-β)信号通路在消痰化瘀利窍中药组方(XC)对改善慢性间歇性低氧(CIH)大鼠心肌纤维化中的作用。方法: 40只SD 大鼠,随机分为常氧组(Normoxia)、常氧+中药干预组(TCMC)、慢性间歇性低氧模型组(CIH)、CIH +中药干预组(TCMC+CIH),每组10只。通过向舱内充入氮气,使舱内氧体积分数在90 s内从21%下降到9%,随后90 s再充氧气使舱内氧体积分数逐渐上升到21%为一循环建立CIH模型。CIH 与 TCMC+CIH 组大鼠置于CIH装置, Normoxia 和TCMC组大鼠置于正常氧舱。此外TCMC+CIH 与 TCMC 组大鼠于每日XC生药(24 g/kg)煎制灌胃,而 CIH 组与 Normoxia 组大鼠给予等体积生理盐水。造模结束后,天狼星红染色观察大鼠心肌间质内胶原沉积情况;Western blot 法检测大鼠心肌间质中 CollagenⅠ、Collagen Ⅲ、Fibronectin、TGF-β、p-Smad2、p-Smad3的蛋白表达水平。采用Q-PCR法检测基质金属蛋白酶2(MMP-2)和基质金属蛋白酶抑制因子 2 (TIMP-2) 的 mRNA表达水平。结果: 与正常组比较,CIH大鼠心肌组织出现明显胶原的沉积,CollagenⅠ、Collagen Ⅲ和Fibronectin蛋白表达明显增多(P均＜0.01),TGF-β、p-Smad2、p-Smad3蛋白表达水平也明显增高(P均＜0.01);CIH大鼠心肌组织TIMP-2 mRNA上调导致MMP-2 mRNA明显减少(P均＜0.01)。给予XC干预后,CIH大鼠心肌组织胶原沉积明显减少,CollagenⅠ、Collagen Ⅲ和Fibronectin蛋白表达明显降低(P＜0.05,P＜ 0.01,P＜0.05);CIH大鼠心肌组织中TGF-β、p-Smad2、p-Smad3蛋白表达水平明显降低(P＜0.01,P＜0.05,P＜ 0.01)。心肌组织中TIMP-2明显基因减少致MMP-2增多(P均＜0.05)。 结论: 消痰化瘀利窍中药组方可抑制CIH大鼠心肌纤维化的形成,进而改善CIH大鼠心肌功能。其机制与该中药组方下调TGF-β/ Smad2/3信号通路及下调TIMP-2mRNA有关。     

海洋酸化对微藻关键生理过程的调控机制及环境因素的影响

人类活动排放大量的CO₂通过海气界面进入海洋,打破原有海水碳酸盐平衡进而造成海洋酸化(OA)。OA会影响海水和海洋污染物的理化性质,进而对生活在海洋表层的浮游藻类生理过程产生显著调控作用。海洋微藻作为海洋中主要的初级生产者,其生理功能与过程的正常进行对于海洋生态系统具有重要作用。本文综述了OA对海洋微藻光合固碳、钙化过程、固氮作用3个关键生理过程的调控作用和具体机制,总结了OA条件下,环境因素(如太阳辐射、温度、营养元素)对微藻生理过程和生长的影响,以及OA通过改变典型海洋污染物(如有机污染物、重金属、微塑料)的环境行为而对微藻生理过程的调控作用。最后,结合研究现状,对未来需要开展的研究方向进行展望。本文为进一步了解OA对海洋生态系统的潜在影响提供了重要信息。     

植物与植食性昆虫化学互作研究进展

植物与植食性昆虫之间存在着复杂的化学相互作用。一方面,当遭受植食性昆虫为害时,植物能识别植食性昆虫相关分子模式,触发早期信号事件和激素信号转导途径,并由此引起转录组与代谢组重组、直接和间接防御化合物含量升高,最后提高对植食性昆虫的抗性。另一方面,植食性昆虫也能识别植物的防御反应,并能通过分泌效应子、选贮、解毒以及降低敏感性等反防御措施抑制或适应植物的化学防御。深入剖析植物与植食性昆虫的化学互作,不仅可在理论上丰富对昆虫与植物互作关系的理解,而且可在实践上为作物害虫防控新技术的开发提供重要的理论与技术指导。     

全球中华鲎资源保护现状及对策建议

鲎是古老的海洋节肢动物。中华鲎(Tachypleus tridentatus)是世界现存4种鲎中体型最大的一种, 是河口生态系统的标志物种, 同时其血液被用于生产医用检验试剂――鲎试剂。中华鲎的自然地理分布范围相当狭窄, 仅局限于日本濑户内海向南延伸至印度尼西亚爪哇岛北岸以北的太平洋西岸海域, 其中在中国东岸和日本南部海域的历史产量较高。自20世纪50年代以来中华鲎种群数量出现了显著减少, 2019年中华鲎在IUCN红色名录中的濒危等级正式更新为濒危(EN), 明确了中华鲎资源呈现全球性衰退的状态, 究其原因可归纳为鲎生境破坏和过度捕捞两个方面。在开展鲎资源保护的实践工作中, 作者深刻反思当前鲎资源保护在海洋保护区划定、增殖放流及科普和野生动物保护法宣传中存在的问题并提出相应建议, 包括加快完善种群基线数据, 制定标准化种群和生境基线监测指南, 构建科学放流体系等, 以期推进全球范围内的中华鲎资源保护与科学管理。     

Reconstructing marine plankton food web interactions using DNA metabarcoding

Knowledge of zooplankton in situ diet is critical for accurate assessment of marine ecosystem function and structure, but due to methodological constraints, there is still a limited understanding of ecological networks in marine ecosystems. Here, we used DNA‐metabarcoding to study trophic interactions, with the aim to unveil the natural diet of zooplankton species under temporal variation of food resources. Several target consumers, including copepods and cladocerans, were investigated by sequencing 16S rRNA and 18S rRNA genes to identify prokaryote and eukaryote potential prey present in their guts. During the spring phytoplankton bloom, we found a dominance of diatom and dinoflagellate trophic links to copepods. During the summer period, zooplankton including cladocerans showed a more diverse diet dominated by cyanobacteria and heterotrophic prey. Our study suggests that copepods present trophic plasticity, changing their natural diet over seasons, and adapting their feeding strategies to the available prey spectrum, with some species being more selective. We did not find a large overlap of prey consumed by copepods and cladocerans, based on prey diversity found in their guts, suggesting that they occupy different roles in the trophic web. This study represents the first molecular approach to investigate several zooplankton–prey associations under seasonal variation, and highlights how, unlike other techniques, the diversity coverage is high when using DNA, allowing the possibility to detect a wide range of trophic interactions in plankton communities.     

Reductions in the dietary niche of southern sea otters (Enhydra lutris nereis) from the Holocene to the Anthropocene

The sea otter (Enhydra lutris) is a marine mammal hunted to near extinction during the 1800s. Despite their well‐known modern importance as a keystone species, we know little about historical sea otter ecology. Here, we characterize the ecological niche of ancient southern sea otters (E. lutris nereis) using δ¹³C analysis and δ¹⁵N analysis of bones recovered from archaeological sites spanning ~7,000 to 350 years before present (N = 112 individuals) at five regions along the coast of California. These data are compared with previously published data on modern animals (N = 165) and potential modern prey items. In addition, we analyze the δ¹⁵N of individual amino acids for 23 individuals to test for differences in sea otter trophic ecology through time. After correcting for tissue‐specific and temporal isotopic effects, we employ nonparametric statistics and Bayesian niche models to quantify differences among ancient and modern animals. We find ancient otters occupied a larger isotopic niche than nearly all modern localities; likely reflecting broader habitat and prey use in prefur trade populations. In addition, ancient sea otters at the most southerly sites occupied an isotopic niche that was more than twice as large as ancient otters from northerly regions. This likely reflects greater invertebrate prey diversity in southern California relative to northern California. Thus, we suggest the potential dietary niche of sea otters in southern California could be larger than in central and northern California. At two sites, Año Nuevo and Monterey Bay, ancient otters had significantly higher δ¹⁵N values than modern populations. Amino acid δ¹⁵N data indicated this resulted from shifting baseline isotope values, rather than a change in sea otter trophic ecology. Our results help in better understanding the contemporary ecological role of sea otters and exemplify the strength of combing zooarchaeological and biological information to provide baseline data for conservation efforts.     

Ringed seal (Pusa hispida) seasonal movements,diving, and haul‐out behavior in the Beaufort,Chukchi, and Bering Seas (2011–2017)

Continued Arctic warming and sea‐ice loss will have important implications for the conservation of ringed seals, a highly ice‐dependent species. A better understanding of their spatial ecology will help characterize emerging ecological trends and inform management decisions. We deployed satellite transmitters on ringed seals in the summers of 2011, 2014, and 2016 near Utqia?vik (formerly Barrow), Alaska, to monitor their movements, diving, and haul‐out behavior. We present analyses of tracking and dive data provided by 17 seals that were tracked until at least January of the following year. Seals mostly ranged north of Utqia?vik in the Beaufort and Chukchi Seas during summer before moving into the southern Chukchi and Bering Seas during winter. In all seasons, ringed seals occupied a diversity of habitats and spatial distributions, from near shore and localized, to far offshore and wide‐ranging in drifting sea ice. Continental shelf waters were occupied for >96% of tracking days, during which repetitive diving (suggestive of foraging) primarily to the seafloor was the most frequent activity. From mid‐summer to early fall, 12 seals made ~1‐week forays off‐shelf to the deep Arctic Basin, most reaching the retreating pack‐ice, where they spent most of their time hauled out. Diel activity patterns suggested greater allocation of foraging efforts to midday hours. Haul‐out patterns were complementary, occurring mostly at night until April‐May when midday hours were preferred. Ringed seals captured in 2011—concurrent with an unusual mortality event that affected all ice‐seal species—differed morphologically and behaviorally from seals captured in other years. Speculations about the physiology of molting and its role in energetics, habitat use, and behavior are discussed; along with possible evidence of purported ringed seal ecotypes.     

Heat stress responses and population genetics of the kelp Laminaria digitata (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations

To understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp Laminaria digitata in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold‐temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural L. digitata populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common‐garden heat stress experiment applying 15°C to 23°C over eight days. We assessed growth, photosynthetic quantum yield, carbon and nitrogen storage, and xanthophyll pigment contents as response traits. Population connectivity and genetic diversity were analyzed with microsatellite markers. Results from the heat stress experiment suggest that the upper temperature limit of L. digitata is nearly identical across its distribution range, but subtle differences in growth and stress responses were revealed for three populations from the species’ ecological range margins. Two populations at the species’ warm distribution limit showed higher temperature tolerance compared to other populations in growth at 19°C and recovery from 21°C (Quiberon, France), and photosynthetic quantum yield and xanthophyll pigment responses at 23°C (Helgoland, Germany). In L. digitata from the northernmost population (Spitsbergen, Norway), quantum yield indicated the highest heat sensitivity. Microsatellite genotyping revealed all sampled populations to be genetically distinct, with a strong hierarchical structure between southern and northern clades. Genetic diversity was lowest in the isolated population of the North Sea island of Helgoland and highest in Roscoff in the English Channel. All together, these results support the hypothesis of moderate local differentiation across L. digitata's European distribution, whereas effects are likely too weak to ameliorate the species’ capacity to withstand ocean warming and marine heatwaves at the southern range edge.