Cultivating seaweed and sinking its biomass to the deep ocean for carbon sequestration has gained serious attention in the scientific community and private sectors as a potential ocean-based climate solution. However, there are still large knowledge gaps that hinder our ability to make well-informed decisions about the carbon sequestration efficacy of this approach and its ecological effects and impacts. Developed with partner Monterey Bay Aquarium Research Institute, this new framework offers a globally applicable research framework intended to guide controlled field trials, observational, laboratory, and modeling efforts needed to estimate the effects of seaweed sinking programs at ‘climate-relevant’ scales (e.g., megatons or gigatons of carbon per year).

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在新的牡蛎礁石修复中采用丰富的海洋声景可促进牡蛎种群的增长及其生境建设

Soundscape Enrichment Enhances Recruitment and Habitat Building on New Oyster Reef Restorations

作者: Dominic McAfee, Brittany R. Williams, Lachlan McLeod, Andreas Reuter, Zak Wheaton and Sean D. Connell

期刊: Journal of Applied Ecology 

海洋声景为分散的幼虫寻找合适的栖息地提供了重要的引导信号。然而，栖息地的大量减少已经使海洋声景及其促进（自然种群）增长的功能退化。栖息地恢复工作可以为栖息地的再生提供合适的基质，比如建造礁石来促进牡蛎种群的增长和扩大栖息地，但这主要发生在声景被破坏以及其促进（自然种群）增长能力受限的地方。在新建的礁石上使用扬声器技术来优化海洋声景，也许能确保有足量的（自然种群）增长，为期望的栖息地建立一个恢复的轨迹。

在澳大利亚最大的两个牡蛎礁修复项目中，我们在四个地点和整个牡蛎种群增长季节的三个时间段部署了低成本的海洋扬声器，以测试丰富的声景是否能促进牡蛎种群的增长和其栖息地环境的形成。通过控制声景的播放与否，我们比较了在时空条件下牡蛎吸纳程度和定居数量，以及牡蛎栖息地的范围和在新建的巨大礁石形成的立体栖息地。在有或没有声景播放的情况下，我们比较了牡蛎在不同空间和时间的安置板上，在其栖息地覆盖面以及在新建的大石礁上的立体栖息地的种群增长率。

在两个珊瑚礁修复工程中部署的安置板上，声景播放使牡蛎种群增长显著增加，10个地点中的8个地点的牡蛎种群增长，平均（±1 SE）增加5.1±1.9倍（每平方米增加5281±1384个幼虫），并增加多达18倍。5个月后，牡蛎覆盖的表面范围与有扬声器组和没有扬声器组没有区别。然而，声景播放似乎会影响牡蛎的早期种群增长， 导致每块巨石上的大牡蛎明显增多，相对于非扬声器组的对照，形成的三维生境建设平均为4.3±1.2倍。

融合与应用。我们的结果表明，在新的修复点使用扬声器来丰富海洋声景，可以促进牡蛎的增群增长，让更多的大牡蛎在珊瑚礁修复顶部形成更多的立体栖息地。加速这些垂直栖息地的形成中提供的生态功能更是激发推动了修复工作的开展，扬声器技术在新的礁石恢复地点的早期应用可能有助于在理想的生境恢复轨迹上引导生态演替，减少持续干预的大量成本。

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（实习生熊坤编译）

Fig. 2 Two reef restoration sites in Gulf St. Vincent, South Australia (bottom left): the 20-ha Windara Reef (circle) composed of 159 boulder reefs (dotted rectangles), and the 3-ha Glenelg Reef (diamond) composed of 14 reefs. Stars denote sites for the speaker (black stars) and control (white stars) treatments. Diagram of the self-constructed, low-cost speakers (bottom right) used to enrich soundscapes.

Marine soundscapes provide important navigational cues to dispersing larvae in search of suitable habitat. Yet, widespread habitat loss has degraded marine soundscapes and their functional role in recruitment. Habitat restoration efforts can provide suitable substrate for habitat regeneration, such as constructing reefs to facilitate recruitment and habitat growth by oysters, but typically occur where soundscapes are degraded and recruitment is limited. Enhancing marine soundscapes on newly constructed reefs using speaker technology may ensure sufficient recruitment to establish a trajectory of recovery for the desired habitat.

Across two of the largest oyster reef restorations in Australia, we deployed low-cost marine speakers at four sites and at three times throughout the recruitment season to test whether soundscape enrichment could boost recruitment and habitat formation by oysters. In the presence and absence of soundscape playback, we compared oyster recruitment rates to settlement panels across space and time, and oyster habitat cover and three-dimensional habitat building on newly constructed boulder reefs.

On the settlement panels deployed across the two reef restorations, soundscape playback significantly increased oyster recruitment at 8 of the 10 sites by an average (±1 SE) 5.1 ± 1.9 times (5281 ± 1384 more larvae per m²), and by as much as 18 times.

On boulders atop newly constructed reefs, where the restoration goal is for oysters to form three-dimensional habitat, the surface area covered by oysters after 5 months did not differ between speaker and control treatments. However, soundscape playback appeared to influence the earlier recruitment of oysters, resulting in significantly more large oysters per boulder that formed significantly more three-dimensional habitat building by an average 4.3 ± 1.2 times relative to nonspeaker controls.

Synthesis and applications. Our results show that using speakers to enrich marine soundscapes at new restoration sites can boost oyster recruitment, resulting in more larger oysters that form more three-dimensional habitat atop reef restorations. In accelerating the formation of these vertical growth forms, which provide the ecological functions that motivate restoration efforts, the early application of speaker technology on new reef restorations may help steer ecological succession on a trajectory of desired habitat recovery, potentially reducing the substantial cost of ongoing intervention.

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旗舰级海洋巨型食草动物的增长对海草生态系统多功能性的影响

Seagrass Ecosystem Multifunctionality

Under the Rise of a Flagship Marine Megaherbivore

作者: Marjolijn J. A. Christianen, Fee O. H. Smulders, Jan Arie Vonk, Leontine E. Becking, Tjeerd J. Bouma, Sabine M. Engel, Rebecca K. James, Mabel I. Nava, Jaco C. de Smit, Jurjan P. van der Zee, Per J. Palsbøll and Elisabeth S. Bakker

期刊: Global Change Biology 

大型食草动物（巨型食草动物）对生态系统功能有深远的影响。然而，对于大型食草动物种群变化如何影响生态系统多功能性仍然知之甚少。全面理解其对生态系统多功能性的总体影响需要采取一种综合性生态系统方法，尤其是在海洋系统中找到这样一种方法则更具挑战性。我们在一个热带加勒比海海草生态系统中用实验模拟了不同放牧强度并评估了其对于生态系统功能及其多功能性的影响。我们选择了一种重要的海洋巨型食草动物绿海龟作为实验模型，其在生态环境中的角色在众多觅食区中日渐凸显，这些觅食区的种群数量经历了过去几个世纪的大量减少后正通过保育工作逐渐得以恢复，与此同时历史记载的过度放牧事件也有所增加。为了量化这些影响，我们采用了一种新的海草生态系统多功能综合指数，该指数基于反映生态系统服务中的多种公认的海草生态系统功能度量。结果表明，中龟放牧产生的养分循环速率和碳储量最高，而在没有海龟放牧的情况下，沉积物的稳定性、分解率、表层动物的丰富度和鱼类生物量是最高的。相反，密集放牧对生态系统功能产生了不同程度的巨大影响和多功能性的崩溃。这些结果表明，（i）大型食草动物回归会对沿海生态系统功能和多功能性产生巨大影响，（ii）保育工作偏重于巨型食草动物，但忽视捕食者或栖息地等关键驱动因素，可能会导致过度放牧引起的多功能丧失，（iii）多功能指数作为评估生态系统性能的定量工具，显示出了巨大的潜力。巨型食草动物丰度的显著和迅速变化（通过灭绝和保护）导致生态系统功能的不平衡，并大大改变甚至损害生态系统服务，从而有助于抵消全球变化的影响。迫切需要在环境管理中采用综合生态系统方法，以保护和增强生态系统的多功能性。

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（实习生吕晴编译）

Fig. 3 (a) The number of publications on seagrass and green turtle grazing in peer-reviewed journals is accelerating over time (Web of Science, Scopus, Google Scholar 1960–2022, Supplementary information text S1) mirroring the recovery of green turtle populations. Arrow 1: (McRoy & Helfferich, 1977; Thayer et al., 1977); arrow 2: (Jackson, 1997), arrow 3: (Chaloupka et al., 2008; Mazaris et al., 2017; Weber et al., 2014). (b) A selection of sites illustrates that all three different grazing scenarios for green turtles occur in coastal (sub-)tropical seagrass ecosystems around the world, in all three ocean basins where green turtles are found. Green dots: global seagrass distribution (UNEP-WCMC & Short, 2021), blue: distribution of the green turtle, Chelonia mydas, (Kot et al., 2022). (Scenario 1) (Gaubert-Boussarie et al., 2021; Jackson, 1997; Jones et al., 2018; van der Laan & Wolff, 2006; Vonk et al., 2008); (Scenario 2) (Ballorain et al., 2010; Christianen et al., 2019; Gulick et al., 2020; Molina Hernández & van Tussenbroek, 2014; Rodriguez & Heck, 2020; Scott et al., 2020); (Scenario 3) (Christianen et al., 2014; Fourqurean et al., 2019; Gangal et al., 2021).

Large grazers (megaherbivores) have a profound impact on ecosystem functioning. However, how ecosystem multifunctionality is affected by changes in megaherbivore populations remains poorly understood. Understanding the total impact on ecosystem multifunctionality requires an integrative ecosystem approach, which is especially challenging to obtain in marine systems. We assessed the effects of experimentally simulated grazing intensity scenarios on ecosystem functions and multifunctionality in a tropical Caribbean seagrass ecosystem. As a model, we selected a key marine megaherbivore, the green turtle, whose ecological role is rapidly unfolding in numerous foraging areas where populations are recovering through conservation after centuries of decline, with an increase in recorded overgrazing episodes. To quantify the effects, we employed a novel integrated index of seagrass ecosystem multifunctionality based upon multiple, well-recognized measures of seagrass ecosystem functions that reflect ecosystem services. Experiments revealed that intermediate turtle grazing resulted in the highest rates of nutrient cycling and carbon storage, while sediment stabilization, decomposition rates, epifauna richness, and fish biomass are highest in the absence of turtle grazing. In contrast, intense grazing resulted in disproportionally large effects on ecosystem functions and a collapse of multifunctionality. These results imply that (i) the return of a megaherbivore can exert strong effects on coastal ecosystem functions and multifunctionality, (ii) conservation efforts that are skewed toward megaherbivores, but ignore their key drivers like predators or habitat, will likely result in overgrazing-induced loss of multifunctionality, and (iii) the multifunctionality index shows great potential as a quantitative tool to assess ecosystem performance. Considerable and rapid alterations in megaherbivore abundance (both through extinction and conservation) cause an imbalance in ecosystem functioning and substantially alter or even compromise ecosystem services that help to negate global change effects. An integrative ecosystem approach in environmental management is urgently required to protect and enhance ecosystem multifunctionality.

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印度尼西亚海区帝汶海峡海流的潜标观测结果

Moored Observations of the

Timor Passage Currents in the Indonesian Seas

作者：Jing Wang, Zhengbei Zhang, Xiang Li, Zheng Wang, Yao Li, Jiajia Hao, Xia Zhao, Corry Corvianawatie, Dewi Surinati, Dongliang Yuan and Tengfei Xu

期刊：Journal of Geophysical Research: Oceans 

本文基于2017年9月至2019年12月布放在帝汶海峡中心的潜标测量结果，对帝汶海峡海流的结构和变率进行研究。观测发现，年平均海流向西流入印度洋上层1400米，最大核心流速约在50米处。据估算，通过帝汶海峡进入印度洋的上层1400米的海流平均流量为−9.9 ± 1.0 Sv (1 Sv = 106立方米/秒)，其中大部分流量集中在上层480米（-8.9Sv）。这一数值与1890米以上海流的努沙登加拉层结及输运的国际联合观测计划（INSTANT）估算值-7.5Sv显现出明显差异。2019年发生正位相印度洋偶极子事件期间，上层480米的流量仅略大于2018年正常年份的流量。帝汶海峡沿线流速的变率主要由上层150米海流的年循环和更低层海流的半年循环主导。上层海流的年循环主要受局部季风强迫驱动。在200米以下观测到的向下能量传播主要受来自印度洋的远程开尔文波驱动。帝汶海峡的流量变率由半年循环主导，该循环与赤道印度洋的半年环流有关，在年循环中上层和下层的流量基本相互抵消。

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（实习生江薇编译）

Fig. 4 The subsurface mooring configuration in the Timor Passage (a) and data coverage during the mooring period (b).

The structure and variability of the currents in the Timor Passage are studied based on the measurements from a subsurface mooring deployed in the center of the passage from September 2017 to December 2019. The annual mean currents are found to flow westward into the Indian Ocean in the upper 1,400 m, with a maximum velocity core at ∼50 m. The mean volume transport through the Timor Passage into the Indian Ocean is estimated to be −9.9 ± 1.0 Sv (1 Sv=10⁶m³s⁻¹) in the upper 1,400 m with much of this transport concentrated in the upper 480 m (−8.9 Sv). This value contrasts with the estimate of −7.5 Sv above 1,890 m based on INSTANT measurements. The transport during the 2019 positive Indian Ocean Dipole event was only slightly larger than that during the 2018 normal year in the upper 480 m. The variability in the along-strait velocity in the Timor Passage is dominated by an annual cycle in the upper 150 m and a semiannual cycle in the lower layer. The annual cycle in the upper layer is mainly driven by local monsoonal forcing. Downward energy propagation is observed below 200 m, which is shown to be mainly driven by remote Kelvin waves from the Indian Ocean. The transport variability through the Timor Passage is dominated by a semiannual cycle, associated with the semiannual circulation over the equatorial Indian Ocean, with the transport in the upper and lower layers largely canceling each other in the annual cycle.

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细胞特异性测量显示北太平洋

亚热带环流中颗粒附着型非蓝藻重氮营养菌有固氮作用

Cell-specific Measurements Show Nitrogen Fixation

by Particle-attached Putative Non-cyanobacterial Diazotrophs

in the North Pacific Subtropical Gyre

作者：Katie J. Harding, Kendra A. Turk-Kubo, Esther Wing Kwan Mak, Peter K. Weber, Xavier Mayali and Jonathan P. Zehr

期刊：Nature Communications

生物固氮是低营养表层海洋水体的一个重要的主要氮源。固氮蓝藻（即重氮营养蓝细菌）被认为是在这一过程中发挥了主要作用。尽管也有理论认为非蓝藻重氮营养菌也是含氧表层水体的重要氮来源，但这一论断尚未被证实。在该项研究中，我们同时使用15-N₂同位素和13C-碳酸氢盐同位素标记的培植，结合纳米二次离子质谱分析，以颗粒附着度高和适宜细胞生存为标准，从北太平洋亚热带环流样本中筛选出数万个相关地区。这些双同位素培养使我们可以分辨非蓝藻类固氮微生物和蓝藻类固氮微生物，测量推定的细胞特定固氮速率。通过这种方法，我们发现在含氧海表海域中，推定的非蓝藻重氮营养菌有固氮作用，在采样的七个地点中，有两个地点与富含有机物的颗粒（尺寸小于210微米的部分）有关。固氮作用发生时，我们所分析的颗粒中，至少含一个活跃的推定非蓝藻重氮营养菌的比例高达4.1%。假定的非蓝藻重氮营养菌的固氮速率 (0.76 ± 1.60 fmol N cell⁻¹ d⁻¹)表明，这些生物能够在含氧的地表水中固氮，或至少附着在颗粒上时能够固氮，这或有助于海洋固氮。

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（实习生申澳编译）

Fig. 5 Map inset shows stations (S) sampled across the North Pacific Subtropical Gyre. Bar chart shows community N₂ fixation rates averages under natural-light (yellow) and all-dark (dark grey) conditions derived from biological triplicates. Individual N₂ fixation rates values are shown as black circles for each station and light treatment. Error bars are the standard deviations of the averages (n = 3). The limit of detection (LOD) for the N₂ fixation rates are shown with an X. Stations where the X is above the average are below the LOD but above the minimum quantifiable rate (MQR), all-dark values at S17 and S20 were below LOD and MQR (red), no data were available for S23 all-dark incubation. The lower pie charts show the relative proportion of cyanobacterial (green) and NCD (light grey) nifH sequences at each station. Source data are provided as a Source Data file.

Biological nitrogen fixation is a major important source of nitrogen for low-nutrient surface oceanic waters. Nitrogen-fixing (diazotrophic) cyanobacteria are believed to be the primary contributors to this process, but the contribution of non-cyanobacterial diazotrophic organisms in oxygenated surface water, while hypothesized to be important, has yet to be demonstrated. In this study, we used simultaneous ¹⁵N-dinitrogen and ¹³C-bicarbonate incubations combined with nanoscale secondary ion mass spectrometry analysis to screen tens of thousands of mostly particle-associated, cell-like regions of interest collected from the North Pacific Subtropical Gyre. These dual isotope incubations allow us to distinguish between non-cyanobacterial and cyanobacterial nitrogen-fixing microorganisms and to measure putative cell-specific nitrogen fixation rates. With this approach, we detect nitrogen fixation by putative non-cyanobacterial diazotrophs in the oxygenated surface ocean, which are associated with organic-rich particles (<210 µm size fraction) at two out of seven locations sampled. When present, up to 4.1% of the analyzed particles contain at least one active putative non-cyanobacterial diazotroph. The putative non-cyanobacterial diazotroph nitrogen fixation rates (0.76 ± 1.60 fmol N cell⁻¹ d⁻¹) suggest that these organisms are capable of fixing dinitrogen in oxygenated surface water, at least when attached to particles, and may contribute to oceanic nitrogen fixation.

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海平面上升可能加速岩石海岸悬崖的退缩速度

Sea-level Rise Will Likely Accelerate Rock Coast Cliff Retreat Rates

作者：Jennifer R. Shadrick, Dylan H. Rood, Martin D. Hurst, Matthew D. Piggott, Bethany G. Hebditch, Alexander J. Seal and Klaus M. Wilcken

期刊：Nature Communications

沿海地区对人为气候变化的应对对这些地区的基础设施和居民都至关重要。尽管岩石海岸在全球范围内无处不在，岩石海岸的稳定性在很大程度上是被忽视的。迄今为止，预想中由于海平面上升所导致的悬崖侵蚀加速都还未经过实际数据的检验。我们根据地形学和宇宙学放射性核素数据优化了一个海岸演化模型，以量化过去8000年的悬崖退缩率，并预测下个世纪的退缩率。我们发现，根据目前对海平面上升的预测，到2100年，悬崖退缩的速度将增加一个数量级：这一增长远远超过先前的预测。这项研究挑战了传统的沿海管理实践，揭示了即使是历史上稳定的岩石海岸也对海平面上升高度敏感，应该纳入未来的全球气候变化应对计划中。

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（实习生齐千萌编译）

Fig. 6 a Measured ¹⁰Be concentrations at Bideford with distance from the cliff base (1σ). b Measured ¹⁰Be and ²⁶Al concentrations at Scalby with distance from the cliff base (1σ). A shielded cliff sample was used to correct for any inherited CRNs present in the exposed platform rock samples to ensure that concentrations of ¹⁰Be and ²⁶Al solely reflect the exposure time due to cliff retreat (Methods). c Inheritance-corrected ¹⁰Be and ²⁶Al concentrations for Scalby. Slope of regression line = 6.70 ± 0.49 (1σ), and is comparable to the production rate ratio in quartz of ~6.75 ± 0.50 (1σ)⁴⁹. Intercept = 795 ± 3301 ²⁶Al atoms g−1 (1σ). Concentration are corrected for chemistry background using process blank samples and inherited CRN concentrations using shielded cliff samples (at distance 0 m) with errors propagated in quadrature.

Coastal response to anthropogenic climate change is of central importance to the infrastructure and inhabitants in these areas. Despite being globally ubiquitous, the stability of rock coasts has been largely neglected, and the expected acceleration of cliff erosion following sea-level rise has not been tested with empirical data, until now. We have optimised a coastal evolution model to topographic and cosmogenic radionuclide data to quantify cliff retreat rates for the past 8000 years and forecast rates for the next century. Here we show that rates of cliff retreat will increase by up to an order of magnitude by 2100 according to current predictions of sea-level rise: an increase much greater than previously predicted. This study challenges conventional coastal management practices by revealing that even historically stable rock coasts are highly sensitive to sea-level rise and should be included in future planning for global climate change response.

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声明：本版块为尝试性栏目，旨在传播分享最新科研动态。中文翻译仅供参考，中英文若有不符之处，请以英文为准。如有不妥之处，请联系 [email protected] 进行订正或要求撤稿。

Disclaimer: This column is a new trial to share cutting-edge research with wider academic community. The Chinese is not an official translation, while the English is invoked from original publication. If there is anything inappropriate, please contact [email protected] to correct us or request for a retraction.

各类会议资源

Events, Webinars and Conferences

网络研讨会：2022年海岸带及河口地区峰会 将于 2022年12月4至8日 线上举行

Webinar: 2022 Coastal & Estuarine Summit. 4-8 December, online 

网络研讨会：建设具有气候适应性的渔业的新工具箱 将于 2022年12月8日 线上举行

Webinar: A new toolkit for building climate-resilient fisheries. 8 December, online

气候变率与可预报性研究(CLIVAR)/政府间海洋学委员会-全球海洋观测系统(IOC-GOOS)印度洋区域专家组第19次会议（IORP-19）暨2023年国际印度洋科学会议（IIOSC2023）将于 2023年2月6至9日 在澳大利亚珀斯举行

IORP-19 and 2023 International Indian Ocean Science Conference (IIOSC2023), 6-9 February 2023, Perth, Australia

“我们的海洋”青年领袖峰会 将于 2023年2月27日至3月1日 在巴拿马举行

Our Ocean Youth Leadership Summit, 27 February-1 March 2023, Panama

联合国教科文组织政府间海洋学委员会西太平洋分委会第十四届大会（WESTPAC-XIV） 将于 2023年4月4至7日 在印度尼西亚雅加达举行

Fourteenth Intergovernmental Session of the IOC Sub-Commission for the Western Pacific (WESTPAC-XIV), 4-7 April 2023, Jakarta, Indonesia

全球赤潮生态学与海洋学2023年研讨会 将于 2023年5月8至12日 在留尼汪举行

Symposium: GeoHab 2023, 8-12 May 2023, La Réunion

世界气候研究计划（WCRP）开放科学大会 将于 2023年10月23至27日 在 卢旺达基加利举行

World Climate Research Programme Open Science Conference, 23-27 October 2023, Kigali, Rwanda

发展机会

Jobs and Opportunities

• 联合国教科文组织政府间海洋学委员会西太平洋分委会召集第二次黑潮及邻近区域合作研究(CSK-2)倡议，请于 2023年1月20日 前提交
• IOC Sub-Commission for the Western Pacific (WESTPAC) Call for Initiatives for the 2nd Cooperative Study of the Kuroshio and Adjacent Regions (CSK-2), submit by 20 January 2023

• 第04/2022号海洋十年行动征集
• Call for Decade Actions No. 04/2022

• 海洋愿景（Ocean Visions）招募海洋生态系统再生方向自然/物理学研究人员，请于 12月5日 前申请
• Natural/physical scientist: Marine ecosystem regeneration, Ocean Visions. Apply by 5 December 

• 南非国际海洋研究所招募项目经理，工作地点位于开普敦，请于 12月15日 前申请
• Programme Manager: International Ocean Institute, Cape Town, South Africa. Apply by 15 December

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