Bottom-up Control Research Articles

Belowground top-down and aboveground bottom-up effects structure multitrophic community relationships in a biodiverse forest

Ecosystem functioning and human well-being critically depend on numerous species interactions above- and belowground. However, unraveling the structure of multitrophic interaction webs at the ecosystem level is challenging for biodiverse ecosystems. Attempts to identify major relationships between trophic levels usually rely on simplified proxies, such as species diversity. Here, we propose to consider the full information on species composition across trophic levels, using Procrustes correlation and structural equation models. We show that species composition data of a highly diverse subtropical forest―with 5,716 taxa across 25 trophic groups― reveal strong interrelationships among plants, arthropods, and microorganisms, indicating complex multitrophic interactions. We found substantial support for top-down effects of microorganisms belowground, indicating important feedbacks of microbial symbionts, pathogens, and decomposers on plant communities. In contrast, aboveground pathways were characterized by bottom-up control of plants on arthropods, including many non-trophic links. Additional analyses based on diversity patterns revealed much weaker interrelationships. Our study suggests that multitrophic communities in our forest system are structured via top-down effects of belowground biota on plants, which in turn affect aboveground arthropod communities across trophic levels. Moreover, the study shows that the consequences of species loss will be more complex than indicated by studies based solely on diversity.

Ocean acidification as a driver of community simplification via the collapse of higher-order and rise of lower-order consumers

Increasing oceanic uptake of CO2 is predicted to drive ecological change as both a resource (i.e. CO2 enrichment on primary producers) and stressor (i.e. lower pH on consumers). We use the natural ecological complexity of a CO2 vent (i.e. a seagrass system) to assess the potential validity of conceptual models developed from laboratory and mesocosm research. Our observations suggest that the stressor-effect of CO2 enrichment combined with its resource-effect drives simplified food web structure of lower trophic diversity and shorter length. The transfer of CO2 enrichment from plants to herbivores through consumption (apparent resource-effect) was not compensated by predation, because carnivores failed to contain herbivore outbreaks. Instead, these higher-order consumers collapsed (apparent stressor-effect on carnivores) suggesting limited trophic propagation to predator populations. The dominance of primary producers and their lower-order consumers along with the loss of carnivores reflects the duality of intensifying ocean acidification acting both as resource-effect (i.e. bottom-up control) and stressor-effect (i.e. top-down control) to simplify community and trophic structure and function. This shifting balance between the propagation of resource enrichment and its consumption across trophic levels provides new insights into how the trophic dynamics might stabilize against or propagate future environmental change.

Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem.

The trophic flow of a species is considered a characteristic trait reflecting its trophic position and function in the ecosystem and its interaction with the environment. However, climate patterns are changing and we ignore how patterns of trophic flow are being affected. In the Humboldt Current ecosystem, arguably one of the most productive marine systems, El Niño-Southern Oscillation is the main source of interannual and longer-term variability. To assess the effect of this variability on trophic flow we built a 16-year series of mass-specific somatic production rate (P/B) of the Peruvian scallop (Argopecten purpuratus), a species belonging to a former tropical fauna that thrived in this cold ecosystem. A strong increase of the P/B ratio of this species was observed during nutrient-poor, warmer water conditions typical of El Niño, owing to the massive recruitment of fast-growing juvenile scallops. Trophic ecology theory predicts that when primary production is nutrient limited, the trophic flow of organisms occupying low trophic levels should be constrained (bottom-up control). For former tropical fauna thriving in cold, productive upwelling coastal zones, a short time of low food conditions but warm waters during El Niño could be sufficient to waken their ancestral biological features and display massive proliferations.

Quantifying keystone species complexes: Ecosystem-based conservation management in the King George Island (Antarctic Peninsula)

A keystone species complex (KSC) is a small set of interacting species that play an outstandingly important role in community organization. Two KSC indices are suggested and have been calculated in the coastal benthic/pelagic ecosystem of Fildes Bay, King George Island (Antarctica). These indices of keystoneness emerge after considering: (1) functional indices based on steady-state and dynamic quantitative trophic models (using bottom-up, mixed and top-down control flow mechanisms); (2) structural indices including bottom-up and top-down control mechanisms, (3) semi-quantitative (qualitative) keystone indices using loop analysis (under mixed control); and (4) topological key player indices based on the centrality of node sets in the network. The models constructed and analyzed describe the interactions of the most abundant species and functional groups inhabiting the coastal ecological systems of Fildes Bay. Although our results only represent the transient dynamics of these ecological systems, the KSC indices identified the following trophically connected common core of components: the functional groups of Seastars (top-predators), the herbivorous sea urchin species Sterechinus neumayeri and the Phytoplankton (primary producers). The KSC indices for Fildes Bay could facilitate the design and assessment of conservation monitoring, especially when the Antarctic ecosystems are being severely stressed by the direct effects of global warming and UV radiation. A more holistic view of conservation remains difficult because the traditional view is based principally on single species. This imposes an even greater challenge, for global changes accompany the network of interacting species, co-varying with the variables of the natural system.

Diverse responses of species to landscape fragmentation in a simple food chain.

Habitat destruction, characterized by habitat loss and fragmentation, is a key driver of species extinction in spatial extended communities. Recently, there has been some progress in the theory of spatial food webs, however to date practically little is known about how habitat configurational fragmentation influences multi-trophic food web dynamics. To explore how habitat fragmentation affects species persistence in food webs, we introduce a modelling framework that describes the site occupancy of species in a tri-trophic system. We assume that species dispersal range increases with trophic level, exploiting pair-approximation techniques to describe the effect of habitat clustering. In accordance with the trophic rank hypothesis, both habitat loss and fragmentation generally cause species extinction, with stronger effects occurring at higher trophic levels. However, species display diverse responses (negative, neutral or positive) to habitat loss and fragmentation separately, depending on their dispersal range and trophic position. Counter-intuitively, prey species may benefit from habitat loss due to a release in top-down control. Similarly, habitat fragmentation has almost no influence on the site occupancy of the intermediate consumer in the tri-trophic system, though it decreases those of both basal species and top predator. Consequently, species' responses to habitat destruction vary as other species become extinct. Our results reiterate the importance of the interplay between bottom-up and top-down control in trophically linked communities, and highlight the complex responses occurring in even a simple food chain.

Factors dominating bacterioplankton abundance and production in the Nordic seas and the Chukchi Sea in summer 2012

Abundance and production of bacterioplankton were measured in the Nordic seas and Chukchi Sea during the 5th Chinese Arctic Research Expedition in summer 2012. The results showed that average bacterial abundances ranged from 3.31×1011 cells/m3 to 2.25×1011 cells/m3, and average bacterial productions (calculated by carbon) were 0.46 mg/(m3·d) and 0.54 mg/(m3·d) in the Nordic seas and Chukchi Sea, respectively. T-test result showed that bacterial abundances were significantly different between the Nordic seas and Chukchi Sea, however, no significant difference was observed regarding bacterial productions. Based on the slope of lg bacterial biomass versus lg bacterial production, bacterial communities in the Nordic seas and Chukchi Sea were moderately dominated by bottom-up control. Both Pearson correlation analysis and multivariable linear regression indicated that temperature had significant positive correlation with bacterial abundance in the Chukchi Sea, while no correlations with productions in both areas. Meanwhile, Chl a had positive correlations with both bacterial abundance and production in these two regions. As the temperature and Chl a keep changing in the future, we suggest that both bacterial abundance and production been hanced in the Chukchi Sea but weaken in the Nordic seas, though the enhancement will not be dramatic as a result of higher pressure of predation and viral lysis.

Temperature regulation of marine heterotrophic prokaryotes increases latitudinally as a breach between bottom-up and top-down controls.

Planktonic heterotrophic prokaryotes make up the largest living biomass and process most organic matter in the ocean. Determining when and where the biomass and activity of heterotrophic prokaryotes are controlled by resource availability (bottom-up), predation and viral lysis (top-down) or temperature will help in future carbon cycling predictions. We conducted an extensive survey across subtropical and tropical waters of the Atlantic, Indian and Pacific Oceans during the Malaspina 2010 Global Circumnavigation Expedition and assessed indices for these three types of controls at 109 stations (mostly from the surface to 4,000m depth). Temperature control was approached by the apparent activation energy in eV (ranging from 0.46 to 3.41), bottom-up control by the slope of the log-log relationship between biomass and production rate (ranging from -0.12 to 1.09) and top-down control by an index that considers the relative abundances of heterotrophic nanoflagellates and viruses (ranging from 0.82 to 4.83). We conclude that temperature becomes dominant (i.e. activation energy >1.5eV) within a narrow window of intermediate values of bottom-up (0.3-0.6) and top-down 0.8-1.2) controls. A pervasive latitudinal pattern of decreasing temperature regulation towards the Equator, regardless of the oceanic basin, suggests that the impact of global warming on marine microbes and their biogeochemical function will be more intense at higher latitudes. Our analysis predicts that 1°C ocean warming will result in increased biomass of heterotrophic prokaryoplankton only in waters with <26°C of mean annual surface temperature.

The network model of delirium

The coordinated function of brain networks underlies consciousness, attention and reality testing, all of which are impaired in delirium. The default-mode network, salience network, frontoparietal control network and dorsal attention network are brain networks with integral roles in the maintenance and modulation of the aforementioned functions. Multiple lines of evidence point to their dysfunction in delirium. The convergence of neurotransmitter changes, neuroendocrine and inflammatory stressors on brain networks disrupts bottom-up and top-down attentional control. Neuroimaging and neuroanatomy correlates are potentially consistent with this hypothesis. Overall, this model appears to have significant utility in connecting the seemingly disparate precipitants of delirium while accounting for the clinical manifestations of the syndrome.

Plant-mediated resource partitioning by coexisting parasitoids.

Although it has been frequently suggested that resource partitioning of speciescoexisting at the same trophic level can be mediated by interactions with species at non-adjacent trophic levels, empirical evidence supporting this claim is scarce. Here we demonstrate that plants may mediate resource partitioning for two parasitoids that share the same herbivorous host. The tephritid fly Tephritis femoralis is the primary pre-dispersal seed predator of two Asteraceae species, Saussurea nigrescens and Anaphalis flavescens, both of which dominate the plant community in the alpine meadows of the Tibetan Plateau. Field surveys and molecular barcoding analyses showed that the identity of the fly's main predator depended on the plant in which the fly developed. Tephritid flies that developed in S.nigrescens were preyed upon mainly by the parasitoid wasp Pteromalus albipennis, while the parasitoid Mesopolobus sp. was the main predator of flies that developed in A.flavescens. Microcosm experiments revealed that P.albipennis could not exploit the host flies within the capitula of A.flavescens due to food limitation (capitula are too small), while Mesopolobus sp. could not exploit the host flies within the capitula of S.nigrescens due to its inability to reach the host with its ovipositor (capitula are too large). Such bottom-up control of plant species traits may facilitate the coexistence of parasitoid wasps sharing a common host in this system. We suggest that interactions between non-adjacent trophic levels may potentially promote species coexistence and diversity in biological communities.

Complementarity As Generative Principle: A Thought Pattern for Aesthetic Appreciations and Cognitive Appraisals in General.

In experimental aesthetics the relationship between the arts and cognitive neuroscience has gained particular interest in recent years. But has cognitive neuroscience indeed something to offer when studying the arts? Here we present a theoretical frame within which the concept of complementarity as a generative or creative principle is proposed; neurocognitive processes are characterized by the duality of complementary activities like bottom-up and top-down control, or logistical functions like temporal control and content functions like perceptions in the neural machinery. On that basis a thought pattern is suggested for aesthetic appreciations and cognitive appraisals in general. This thought pattern is deeply rooted in the history of philosophy and art theory since antiquity; and complementarity also characterizes neural operations as basis for cognitive processes. We then discuss some challenges one is confronted with in experimental aesthetics; in our opinion, one serious problem is the lack of a taxonomy of functions in psychology and neuroscience which is generally accepted. This deficit makes it next to impossible to develop acceptable models which are similar to what has to be modeled. Another problem is the severe language bias in this field of research as knowledge gained in many languages over the ages remains inaccessible to most scientists. Thus, an inspection of research results or theoretical concepts is necessarily too narrow. In spite of these limitations we provide a selective summary of some results and viewpoints with a focus on visual art and its appreciation. It is described how questions of art and aesthetic appreciations using behavioral methods and in particular brain-imaging techniques are analyzed and evaluated focusing on such issues like the representation of artwork or affective experiences. Finally, we emphasize complementarity as a generative principle on a practical level when artists and scientists work directly together which can lead to new insights and broader perspectives on both sides.

Physiographic factors underlie rates of biomass production during succession in Great Lakes forest landscapes

Biomass production in living trees is the basis of numerous forest ecosystem functions and services. However, rates of and controls on biomass production vary widely across temperate forests, particularly over successional timescales of decades and centuries. Biomass production in temperate forests is most often interpreted within the context of biotic or top-down controls, such as species composition or disturbance. However, there is need to investigate how bottom-up physiographic factors, such as landform attributes, drainage, and soil properties mediate biomass production. In order to investigate patterns, controls, and potentials for biomass production across spatial levels ranging from individual ecosystems, to landscapes, to entire regions, we synthesized long-term forest inventory datasets from the United States Great Lakes region, placed them in the context of a hierarchical ecological unit classification, and tested the influence of physiographic factors on biomass production rates and temporal trajectories across ecological levels. Key findings include: 1) At nearly all ecological levels, physiographic controls (e.g., soil texture, drainage class, water table depth) on soil moisture status are significant predictors of variation in biomass production rates, with mesic sites accumulating biomass more rapidly than xeric sites, which, in turn accumulate biomass more rapidly than hydric sites. 2) Aboveground live biomass can apparently continue to accumulate through 2–3 centuries of succession, exceeding 300–400Mgha−1 on mesic sites throughout the region. 3) Stand age distributions indicate that hydric sites are harvested least often, while the high production rates of mesic sites suggest they are most appropriate for frequent harvesting. 4) Median, 1st-quartile, and 3rd-quartile growth rates of individual ecosystems, landscapes, and ecoregional subsections and sections reveal ecological units in which forests may vary in their potential for increases or decreases in biomass production, e.g., due to management interventions, climate change, or disturbances. Specifically, some units have tightly constrained distributions, suggesting little capacity for change in production rates relative to observed medians, while other units have wide variation in biomass production rates, indicating the potential for relatively large increases or decreases in production. Altogether, the results of this analysis show that physiography exerts widespread, bottom-up controls on biomass production across the region of study, and can be used in spatially explicit frameworks to understand ecosystem functioning and inform scientific forest management.

Bottom-up and top-down control of the Benguela ecosystem's seabirds

Abstract Ten of the 15 seabird species that breed in the Benguela upwelling ecosystem, including six species that are endemic to it, are now classified as threatened or near-threatened in terms of Red List criteria. Both bottom-up (operating from lower in the food chain) and top-down (operating from higher in the food chain, or outside it) processes have influenced the seabirds. Historical harvests of eggs and guano caused a large decrease in numbers of African penguins Spheniscus demersus and altered their breeding habitat. More recently, food scarcity reduced the populations of several species that compete with fisheries for prey and was largely responsible for the recent collapse of penguins in South Africa. Predation, oiling and disturbance also have adversely affected seabirds and their relative impact may increase as species populations and sizes of colonies decrease. Co-ordinated management of the different factors diminishing populations will be necessary if the conservation status of seabirds in the Benguela ecosystem is to be improved.

Robustness of metacommunities with omnivory to habitat destruction: disentangling patch fragmentation from patch loss.

Habitat destruction, characterized by patch loss and fragmentation, is a major driving force of species extinction, and understanding its mechanisms has become a central issue in biodiversity conservation. Numerous studies have explored the effect of patch loss on food web dynamics, but ignored the critical role of patch fragmentation. Here we develop an extended patch-dynamic model for a tri-trophic omnivory system with trophic-dependent dispersal in fragmented landscapes. We found that species display different vulnerabilities to both patch loss and fragmentation, depending on their dispersal range and trophic position. The resulting trophic structure varies depending on the degree of habitat loss and fragmentation, due to a tradeoff between bottom-up control on omnivores (dominated by patch loss) and dispersal limitation on intermediate consumers (dominated by patch fragmentation). Overall, we find that omnivory increases system robustness to habitat destruction relative to a simple food chain.

Bottom-Up Effects on Biomass Versus Top-Down Effects on Identity: A Multiple-Lake Fish Community Manipulation Experiment

The extent to which ecosystems are regulated by top-down relative to bottom-up control has been a dominant paradigm in ecology for many decades. For lakes, it has been shown that predation by fish is an important determinant of variation in zooplankton and phytoplankton community characteristics. Effects of fish are expected to not only be a function of total fish biomass, but also of functional composition of the fish community. Previous research on the importance of trophic cascades in lakes has largely focused on the role of zooplanktivorous and piscivorous fish. We conducted a large-scale multiple-lake fish community manipulation experiment to test for the effect of differences in fish functional community composition on the trophic structure of lakes. We examine the effect of top-down and bottom-up factors on phytoplankton and zooplankton biomass as well as on their community composition. We put our data in a broader perspective by comparing our results to data of a survey that also included ponds with low fish densities as well as ponds with very high densities of fish. Our results indicate that the overall food web structure under relative high fish densities is primarily structured by bottom-up factors, whereas community characteristics seem to be primarily regulated by top-down factors. Our results suggest a subtle interplay between bottom-up and top-down factors, in which bottom-up factors dominate in determining quantities while top-down effects are important in determining identities of the communities.

In search of oculomotor capture during film viewing: Implications for the balance of top-down and bottom-up control in the saccadic system

In the laboratory, the abrupt onset of a visual distractor can generate an involuntary orienting response: this robust oculomotor capture effect has been reported in a large number of studies (e.g. Ludwig & Gilchrist, 2002; Theeuwes, Kramer, Hahn, & Irwin, 1998) suggesting it may be a ubiquitous part of more natural visual behaviour. However the visual stimuli used in these experiments have tended to be static and had none of the complexity, and dynamism of more natural visual environments. In addition, the primary task in the laboratory (typically visual search) can be tedious for the participants with participant’s losing interest and becoming stimulus driven and more easily distracted. Both of these factors may have led to an overestimation of the extent to which oculomotor capture occurs and the importance of this phenomena in everyday visual behaviour. To address this issue, in the current series of studies we presented abrupt and highly salient visual distractors away from fixation while participants watched a film. No evidence of oculomotor capture was found. However, the distractor does effect fixation duration: we find an increase in fixation duration analogous to the remote distractor effect (Walker, Deubel, Schneider, & Findlay, 1997). These results suggest that during dynamic scene perception, the oculomotor system may be under far more top-down control than traditional laboratory based-tasks have previously suggested.

Bottom-up and top-down controls on coral reef sponges: disentangling within-habitat and between-habitat processes.

Polarized debates about top-down vs. bottom-up control have given way to more nuanced understanding of control by both resources and consumers in many systems, but coral reef sponges have recently been asserted to differ from other groups in being controlled exclusively top-down. This assertion has been countered by reports of exclusively bottom-up control, with both conclusions based on studies of the same species. Accelerating deterioration of coral reefs motivates knowing the contexts in which either consumers or nutrients or both control key ecosystem role players like sponges. Accordingly, genotype- and size-controlled individuals of 12 common Caribbean reef sponge species were transplanted, in the field, into five circumstances differing in predators, competitors, and the picoplankton consumed by sponges. Growth and survival of the experimental transplants for periods of 1-9yr revealed context-dependent control of sponges. Primary control of growth was bottom-up, with more picoplankton resulting in consistent and sustained higher growth rates for all 12 of these ecologically and phylogenetically diverse species. Top-down control was not detected within-habitat, on the coral reef. However, between-habitat control was by predation and competition, with reef sponges excluded from adjacent seagrass meadows by spongivorous starfish, and excluded from mangrove prop roots by faster-growing mangrove sponges. These results highlight the strong importance of experimental design details that consider behavior idiosyncrasies, sufficiently long time scales, and appropriate division of species into categories. Diametrically opposite results from studies of the same species also illustrate the inherently greater difficulty of detecting bottom-up processes and the importance of distinguishing within-habitat vs. between-habitat patterns and processes.

Consumer species richness and nutrients interact in determining producer diversity

While it is crucial to understand the factors that determine the biodiversity of primary producer communities, the relative importance of bottom-up and top-down control factors is still poorly understood. Using freshwater benthic algal communities in the laboratory as a model system, we find an unimodal relationship between nutrient availability and producer diversity, and that increasing number of consumer species increases producer diversity, but overall grazing decreases algal biodiversity. Interestingly, these two factors interact strongly in determining producer diversity, as an increase in nutrient supply diminishes the positive effect of consumer species richness on producer biodiversity. This novel and thus-far overlooked interaction of bottom-up and top-down control mechanisms of biodiversity may have a pronounced impact on ecosystem functioning and thus have repercussions for the fields of biodiversity conservation and restoration.

Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Términos Lagoon, Mexico) under 2009–2010 El Niño Modoki drought conditions

Abstract. The 2009–2010 period was marked by an episode of intense drought known as the El Niño Modoki event. Sampling of the Términos Lagoon (Mexico) was carried out in November 2009 in order to understand the influence of these particular environmental conditions on organic matter fluxes within the lagoon's pelagic ecosystem and, more specifically, on the relationship between phyto- and bacterioplankton communities. The measurements presented here concern biogeochemical parameters (nutrients, dissolved and particulate organic matter [POM], and dissolved polycyclic aromatic hydrocarbons [PAHs]), phytoplankton (biomass and photosynthesis), and bacteria (diversity and abundance, including PAH degradation bacteria and ectoenzymatic activities). During the studied period, the water column of the Términos Lagoon functioned globally as a sink and, more precisely, as a nitrogen assimilator. This was due to the high production of particulate and dissolved organic matter (DOM), even though exportation of autochthonous matter to the Gulf of Mexico was weak. We found that bottom-up control accounted for a large portion of the variability of phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and free-living prokaryote distribution in the lagoon. In the eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen near the Puerto Real coastal inlet and areas enriched in phosphate (PO4) near the Candelaria estuary. Such a decoupling limited the potential for primary production, resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) near the river mouths. In the western part of the lagoon, maximal phytoplankton development resulted from bacterial activity transforming particulate organic phosphorus (PP) and dissolved organic phosphorus (DOP) to available PO4 and the coupling between Palizada River inputs of nitrate (NO3) and PP. The Chumpan River contributed only marginally to PO4 inputs due to its very low contribution to overall river inputs. The highest dissolved total PAH concentrations were measured in the El Carmen Inlet, suggesting that the anthropogenic pollution of the zone is probably related to the oil-platform exploitation activities in the shallow waters of the southern of the Gulf of Mexico. We also found that a complex array of biogeochemical and phytoplanktonic parameters were the driving force behind the geographical distribution of bacterial community structure and activities. Finally, we showed that nutrients brought by the Palizada River supported an abundant bacterial community of PAH degraders, which are of significance in this important oil-production zone.

The combined effects of biotic and abiotic stress on species richness and connectance

Food web structure and species richness are both subject to biotic (e.g. predation pressure and resource limitation) and abiotic stress (e.g. environmental change). We investigated the combined effects of both types of stress on richness and connectance, and on their relationship, in a predator-prey system. To this end, we developed a mathematical two trophic level food-web model to investigate the effects of biotic and abiotic stress on food web connectance and species richness. We found negative effects of top-down and bottom-up control on prey and predator richness, respectively. Effects of top-down and bottom-up control were stronger when initial connectance was high and low, respectively. Bottom-up control could either aggravate or buffer negative effects of top-down control. Abiotic stress affecting predator richness had positive indirect effects on prey richness, but only when initial connectance was low. However, no indirect effects on predator richness were observed following direct effects on prey richness. Top-down and bottom-up control selected for weakly connected prey and highly connected predators, thereby decreasing and increasing connectance, respectively. Our simulations suggest a broad range of negative and positive richness-connectance relationships, thereby revisiting the often found negative relationship between richness and connectance in food webs. Our results suggest that (1) initial food-web connectance strongly influences the effects of biotic stress on richness and the occurrence of indirect effects on richness; and (2) the shape of the richness-connectance relationship depends on the type of biotic stress.

Animal pee in the sea: consumer-mediated nutrient dynamics in the world's changing oceans.

Humans have drastically altered the abundance of animals in marine ecosystems via exploitation. Reduced abundance can destabilize food webs, leading to cascading indirect effects that dramatically reorganize community structure and shift ecosystem function. However, the additional implications of these top-down changes for biogeochemical cycles via consumer-mediated nutrient dynamics (CND) are often overlooked in marine systems, particularly in coastal areas. Here, we review research that underscores the importance of this bottom-up control at local, regional, and global scales in coastal marine ecosystems, and the potential implications of anthropogenic change to fundamentally alter these processes. We focus attention on the two primary ways consumers affect nutrient dynamics, with emphasis on implications for the nutrient capacity of ecosystems: (1) the storage and retention of nutrients in biomass, and (2) the supply of nutrients via excretion and egestion. Nutrient storage in consumer biomass may be especially important in many marine ecosystems because consumers, as opposed to producers, often dominate organismal biomass. As for nutrient supply, we emphasize how consumers enhance primary production through both press and pulse dynamics. Looking forward, we explore the importance of CDN for improving theory (e.g., ecological stoichiometry, metabolic theory, and biodiversity-ecosystem function relationships), all in the context of global environmental change. Increasing research focus on CND will likely transform our perspectives on how consumers affect the functioning of marine ecosystems.