Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community‐level responses

Biological communities are shaped by complex interactions between organisms and their environment as well as interactions with other species. Humans are rapidly changing the marine environment through increasing greenhouse gas emissions, resulting in ocean warming and acidification. The first response by animals to environmental change is predominantly through modification of their behaviour, which in turn affects species interactions and ecological processes. Yet, many climate change studies ignore animal behaviour. Furthermore, our current knowledge of how global change alters animal behaviour is mostly restricted to single species, life phases and stressors, leading to an incomplete view of how coinciding climate stressors can affect the ecological interactions that structure biological communities. Here, we first review studies on the effects of warming and acidification on the behaviour of marine animals. We demonstrate how pervasive the effects of global change are on a wide range of critical behaviours that determine the persistence of species and their success in ecological communities. We then evaluate several approaches to studying the ecological effects of warming and acidification, and identify knowledge gaps that need to be filled, to better understand how global change will affect marine populations and communities through altered animal behaviours. Our review provides a synthesis of the far‐reaching consequences that behavioural changes could have for marine ecosystems in a rapidly changing environment. Without considering the pervasive effects of climate change on animal behaviour we will limit our ability to forecast the impacts of ocean change and provide insights that can aid management strategies.     

Turning on the heat: ecological response to simulated warming in the sea

Significant warming has been observed in every ocean, yet our ability to predict the consequences of oceanic warming on marine biodiversity remains poor. Experiments have been severely limited because, until now, it has not been possible to manipulate seawater temperature in a consistent manner across a range of marine habitats. We constructed a "hot-plate" system to directly examine ecological responses to elevated seawater temperature in a subtidal marine system. The substratum available for colonisation and overlying seawater boundary layer were warmed for 36 days, which resulted in greater biomass of marine organisms and a doubling of space coverage by a dominant colonial ascidian. The "hot-plate" system will facilitate complex manipulations of temperature and multiple stressors in the field to provide valuable information on the response of individuals, populations and communities to environmental change in any aquatic habitat.     

Functional responses and scaling in predator-prey interactions of marine fishes: contemporary issues and emerging concepts

Predator-prey interactions are a primary structuring force vital to the resilience of marine communities and sustainability of the world's oceans. Human influences on marine ecosystems mediate changes in species interactions. This generality is evinced by the cascading effects of overharvesting top predators on the structure and function of marine ecosystems. It follows that ecological forecasting, ecosystem management, and marine spatial planning require a better understanding of food web relationships. Characterising and scaling predator-prey interactions for use in tactical and strategic tools (i.e. multi-species management and ecosystem models) are paramount in this effort. Here, we explore what issues are involved and must be considered to advance the use of predator-prey theory in the context of marine fisheries science. We address pertinent contemporary ecological issues including (1) the approaches and complexities of evaluating predator responses in marine systems; (2) the 'scaling up' of predator-prey interactions to the population, community, and ecosystem level; (3) the role of predator-prey theory in contemporary fisheries and ecosystem modelling approaches; and (4) directions for the future. Our intent is to point out needed research directions that will improve our understanding of predator-prey interactions in the context of the sustainable marine fisheries and ecosystem management.     

Ecological and evolutionary consequences of linked life-history stages in the sea

Naturalists and scientists have been captivated by the diversity of marine larval forms since they were discovered following the advent of the microscope. Because they often bear little resemblance to adults, larvae were identified initially as new life forms, classified into different groups based on the similarity of their body plans and given new names that are still with us today. The radically different body plans and lifestyles of marine larvae and adults have led most investigators historically to study the two phases of complex life cycles in isolation. More recently, important ecological insights have sprung from taking a holistic view of marine life cycles. Meanwhile, the evolutionary (phenotypic and genetic) links among life-history phases remain less appreciated. In this review, our objective is to evaluate the evolutionary links within marine life cycles, and explore their ecological and evolutionary consequences. We provide a brief overview of marine life histories, discuss the phenotypic and genetic links between the two phases of the life cycle and pose challenges to advance our understanding of the evolutionary constraints acting on marine life histories.     

Chemical defenses: from compounds to communities

Marine natural products play critical roles in the chemical defense of many marine organisms and in some cases can influence the community structure of entire ecosystems. Although many marine natural products have been studied for biomedical activity, yielding important information about their biochemical effects and mechanisms of action, much less is known about ecological functions. The way in which marine consumers perceive chemical defenses can influence their health and survival and determine whether some natural products persist through a food chain. This article focuses on selected marine natural products, including okadaic acid, brevetoxins, lyngbyatoxin A, caulerpenyne, bryostatins, and isocyano terpenes, and examines their biosynthesis (sometimes by symbiotic microorganisms), mechanisms of action, and biological and ecological activity. We selected these compounds because their impacts on marine organisms and communities are some of the best-studied among marine natural products. We discuss the effects of these compounds on consumer behavior and physiology, with an emphasis on neuroecology. In addition to mediating a variety of trophic interactions, these compounds may be responsible for community-scale ecological impacts of chemically defended organisms, such as shifts in benthic and pelagic community composition. Our examples include harmful algal blooms; the invasion of the Mediterranean by Caulerpa taxifolia; overgrowth of coral reefs by chemically rich macroalgae and cyanobacteria; and invertebrate chemical defenses, including the role of microbial symbionts in compound production.     

New insights into relationships between active and dormant organisms,phylogenetic diversity and ecosystem productivity

Marine microbes make up a key part of ocean food webs and drive ocean chemistry through a range of metabolic processes. A fundamental question in ecology is whether the diversity of organisms in a community shapes the ecological functions of that community. While there is substantial evidence to support a positive link between diversity and ecological productivity for macro‐organisms in terrestrial environments, this relationship has not previously been verified for marine microbial communities. One factor complicating the understanding of this relationship is that many marine microbes are dormant and are easily dispersed by ocean currents, making it difficult to ensure that the organisms found in a given environmental sample accurately reflect processes occurring in that environment. Another complication is that, due to microbes great range of genotypic and phenotypic variability, communities with distantly related species may have greater range of metabolic functions than communities have the same richness and evenness, but in which the species present are more closely related to each other. In this issue of Molecular Ecology, Galand et al. (2015) provide compelling evidence that the most metabolically active communities are those in which the nondormant portion of the microbial community has the highest phylogenetic diversity. They also illustrate that focusing on the active portion of the community allows for detection of temporal patterns in community structure that would not be otherwise evident. The authors’ point out that the presence of many dormant organisms that do not contribute to ecosystem functioning is a feature that makes microbial ecosystems fundamentally different from macro‐ecosystems and that this difference needs to be accounted for in microbial ecology theory.     

Spatially variable effects of copper on sessile invertebrates across a marina

Heavy metals often occur at elevated concentrations in bays and estuaries surrounded by urbanised areas and can cause substantial ecological changes to marine communities. The toxic effect of heavy metals can be modified by a several physico-chemical processes in the marine environment. These processes can vary greatly over small scales, so it is likely that the ecological effects of heavy metals on marine biota also vary substantially over similar spatial scales. We used a manipulative field experiment to assess the spatial variation in the effect of copper on sessile invertebrates within a marina and tested whether this variation was influenced by variation in localised water flow. Effects of copper were not consistent over relatively small spatial scales (i.e. metres) for all sessile invertebrate species. Three of the twenty sessile invertebrates from our experimental assemblages showed significant small scale variation in the effect of copper at the scale of metres. For these taxa, the effect of copper varied in magnitude and direction. We had predicted that the effect of copper would diminish with increased water flow, but this did not occur for any taxa. We suggest that variations in the presence of organic or inorganic compounds or in pH within the marina may provide alternative explanations for the spatially variable effects detected in this study. Our study's findings highlight the need for future field assessments of the complex physical, chemical and biological influences on the ecological effects of heavy metals, particularly at small spatial scales. Such studies are the key to improving our prediction about the effects of heavy metals on marine organisms and aid in better characterisation of the risk of heavy metals in the marine environment.     

Using successional theory to measure marine ecosystem health

Marine ecosystems are diverse and complex, providing significant challenges to the development of generalizable metrics of ecosystem health. Of particular concern is the varied form of change caused by multiple human activities, which limits the capacity to generate a single measure to encapsulate the overall condition of the ecosystem. Here we consider how successional theory can help to simplify our understanding of marine community structure, especially when viewed in context of human disturbance. During succession, the emergent properties of communities change in predictable ways. As communities mature, there is an increase in total production and biomass, the mean size of organisms, the level of internal recycling of food and nutrients, and the mean trophic level. Using a set of multi-species trophic models, we explore the changes in community structure that are likely to occur during succession. These changes include increases in biomass within trophic levels due to decreased rates of energy and food loss through trophic and production inefficiencies, and potential shifts from top-down control early in succession to bottom-up later. Because human activities disproportionately favor early-successional species, we can gain insights by considering community degradation in the context of succession being played in reverse. Indicators of health based on ecological succession thus provide a mechanistic view to measure the impact of human activities (both positive and negative) on marine ecosystems.     

Marine protected areas: Theoretical background for design and operation

This review paper deals with the problem of the design and operation of marine reserves in the context of modern views on the hierarchical organization of marine ecosystems. The state of the art in the theoretical aspect of the establishment and development of marine protected areas (MPAs) is discussed. Despite the increasing number of publications on MPAs, which are mainly focused on social and economic issues, studies devoted to the ecological bases for the establishment and operation of marine reserves are still scarce. However, the low efficiency of the existing MPAs and their systems may be a result of the lack of an ecological background in MPA designs. Recent threats to the diversity of marine organisms are analyzed, and changes in the relative significance of anthropogenic factors affecting the marine biological diversity are assessed. The hierarchical nature of and the existence of characteristic spatial scales in the marine ecosystems are critical issues that must be taken into account together with scale-oriented analysis of the anthropogenic threats. On the basis of the scale-oriented concept of the marine ecosystems, new theoretical approaches to the design and operation of MPAs are formulated. In particular, theoretical bases for the estimation of the minimal size of marine reserves and a hierarchical approach to the design of MPA systems are proposed. Formal schemes of classification of sea bottom communities (The Marine Habitat Classification for Britain and Ireland and EUNIS) are discussed.     

Predicting ecological consequences of marine top predator declines

Recent studies document unprecedented declines in marine top predators that can initiate trophic cascades. Predicting the wider ecological consequences of these declines requires understanding how predators influence communities by inflicting mortality on prey and inducing behavioral modifications (risk effects). Both mechanisms are important in marine communities, and a sole focus on the effects of predator-inflicted mortality might severely underestimate the importance of predators. We outline direct and indirect consequences of marine predator declines and propose an integrated predictive framework that includes risk effects, which appear to be strongest for long-lived prey species and when resources are abundant. We conclude that marine predators should be managed for the maintenance of both density- and risk-driven ecological processes, and not demographic persistence alone.     

海洋微塑料污染的生态效应研究进展

海洋微塑料污染已成为全球性环境问题。微塑料粒径小,易与海洋生物发生相互作用,可通过多种途径进入海洋生物体内,并在其组织和器官中蓄积和转移,对机体产生毒害。微塑料可沿食物链进行传递,威胁海洋生态系统的健康与稳定。因此,海洋生物与微塑料的相互作用以及海洋微塑料污染的生态效应成为当前研究的热点。综述微塑料的生物附着、生物摄入、对海洋生物的毒性效应及其与化学污染物的复合毒性效应研究的基础上,提出未来微塑料生态效应研究应重点关注我国海洋环境中微塑料的污染现状及生物摄入状况、微塑料的生物效应及其毒理学机制研究、微塑料与其他污染物的复合效应、以及微塑料在海洋生态系统中的作用及其生物地球化学行为等。     

Marine macrophysiology: studying physiological variation across large spatial scales in marine systems

A new approach toward understanding marine ecosystems has emerged through the integration of ecological physiology and macroecology. This multidisciplinary approach, titled here marine macrophysiology, facilitates unique insight into the foundation of macro-scale ecological patterns, such as biogeographic distributions, via examination of functional attributes of marine organisms across large spatial scales. For example, these broad-scale physiological inquiries confer the ability to directly assess the abundant-center hypothesis (aka Brown's principle) which proposes that species have decreased performance toward their range edges. By extension, the marine macrophysiological perspective also stands to clarify our understanding of more complex macro-scale phenomena such as biological invasions, the design of marine protected areas, and species' responses to global climate change. In this article, we review recent marine macrophysiology research and offer insights into future directions for this emerging field.     

生态化学计量学在水生态系统中的研究与应用

生态化学计量学主要是研究碳、氮、磷等元素在各种生态过程中平衡的一门科学,其核心问题是揭示生物体元素组成的差异对生态功能的影响。由于生态化学计量学研究可以把生态实体的各个层次在元素水平上统一起来,因此生态化学计量学已成为许多生态系统的新兴研究工具。目前,生态化学计量学的研究与应用已深入到生态学的各个层次(分子、细胞、个体、种群、群落、生态系统及区域等不同尺度)。该文围绕生态化学计量学的两个重要组成理论,并结合笔者近年来的研究,归纳总结了生态化学计量学在水生态系统中的研究与应用及未来研究重点,希望有助于推动我国生态化学计量学在水生态系统中的应用研究。     

单细胞稳定同位素标记技术在固氮微生物中的应用研究

生物固氮是指固氮微生物将大气中氮气还原为生物可利用氨的过程,是环境中新氮的主要来源,调控初级生产力并影响氮储库的收支平衡。由于环境中大部分固氮微生物不可纯培养,不依赖培养且具有高空间分辨率水平的单细胞技术,成为研究固氮微生物的有力手段。~(15)N_2稳定同位素标记技术,以微生物对~(15)N的同化量或速率为依据,是表征微生物固氮活性的最直接手段。本文对~(15)N_2稳定同位素标记结合两种单细胞技术,即纳米二次离子质谱(Nano SIMS)和单细胞拉曼光谱,用于固氮微生物研究的最新进展进行了综述,内容包括揭示环境中高活性固氮微生物、空间分布、与其他生物的共生关系、细胞生理状态等,并进一步对近期发展的基于单细胞拉曼光谱的固氮微生物研究进行了展望。     

水圈微生物：推动地球重要元素循环的隐形巨人

正生活在水圈环境中的微生物数量巨大、遗传与代谢方式极为多样,它们驱动着地球上重要元素的循环。水圈微生物研究已经成为生命科学与地球科学的研究热点。国家自然科学基金委员会于2017年启动了"水圈微生物驱动地球元素循环的机制"重大研究计划(简称"水圈微生物"计划)。"水圈微生物"计划拟选择典型水圈生境,通过多学科交叉研究,借助新技术、新方法,揭示水圈微生物在物种、群落和生态水平驱动碳氮硫循环的机制及其环境响应,     

Bacterial primary colonization and early succession on surfaces in marine waters as determined by amplified rRNA gene restriction analysis and sequence analysis of 16S rRNA genes

The nearly universal colonization of surfaces in marine waters by bacteria and the formation of biofilms and biofouling communities have important implications for ecological function and industrial processes. However, the dynamics of surface attachment and colonization in situ, particularly during the early stages of biofilm establishment, are not well understood. Experimental surfaces that differed in their degrees of hydrophilicity or hydrophobicity were incubated in a salt marsh estuary tidal creek for 24 or 72 h. The organisms colonizing these surfaces were examined by using a cultivation-independent approach, amplified ribosomal DNA restriction analysis. The goals of this study were to assess the diversity of bacterial colonists involved in early succession on a variety of surfaces and to determine the phylogenetic affiliations of the most common early colonists. Substantial differences in the representation of different cloned ribosomal DNA sequences were found when the 24- and 72-h incubations were compared, indicating that some new organisms were recruited and some other organisms were lost. Phylogenetic analyses of the most common sequences recovered showed that the colonists were related to organisms known to inhabit surfaces or particles in marine systems. A total of 22 of the 26 clones sequenced were affiliated with the Roseobacter subgroup of the alpha subdivision of the division Proteobacteria (alpha-Proteobacteria), and most of these clones were recovered at a high frequency from all surfaces after 24 or 72 h of incubation. Two clones were affiliated with the Alteromonas group of the gamma-Proteobacteria and appeared to be involved only in the very early stages of colonization (within the first 24 h). A comparison of the colonization patterns on the test surfaces indicated that the early bacterial community succession rate and/or direction may be influenced by surface physicochemical properties. However, organisms belonging to the Roseobacter subgroup are ubiquitous and rapid colonizers of surfaces in coastal environments.