Microplastic interactions with North Atlantic mesopelagic fish

Abstract Microplastics in the marine environment are well documented, and interactions with marine biota have been described worldwide. However, interactions with vertically migrating fish are poorly understood. The diel vertical migration of mesopelagic fish represents one, if not the largest, vertical migration of biomass on the planet, and is thus an important link between the euphotic zone, transporting carbon and other nutrients to global deep sea communities. Knowledge of how mesopelagic fish interact and distribute plastic as a marine contaminant is required as these populations have been identified as a potential global industrial fishery for fishmeal production. Ingestion of microplastic by mesopelagic fish in the Northeast Atlantic was studied. Approximately 11% of the 761 fish examined had microplastics present in their digestive tracts. No clear difference in ingestion frequency was identified between species, location, migration behaviour, or time of capture. While ingesting microplastic may not negatively impact individual mesopelagic fish, the movement of mesopelagic fish from the euphotic zone to deeper waters could mediate transfer of microplastics to otherwise unexposed species and regions of the world's oceans.

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Metazoans, migrations, and the ocean's biological carbon pump

10.1101/2021.03.22.436489 ◽

2021 ◽

Author(s):

Jérôme Pinti ◽

Timothy DeVries ◽

Tommy Norin ◽

Camila Serra-Pompei ◽

Roland Proud ◽

...

Keyword(s):

Vertical Migration ◽

Diel Vertical Migration ◽

Euphotic Zone ◽

Mesopelagic Fish ◽

Carbon Export ◽

Carbon Pump ◽

Oceanic Carbon ◽

Unregulated Fishing ◽

Global Carbon ◽

Biological Carbon Pump

Diel vertical migration of fish and other metazoans actively transports organic carbon from the ocean surface to depth, contributing to the biological carbon pump. Here, we use a global vertical migration model to estimate global carbon fluxes and sequestration by fish and metazoans due to respiration, fecal pellets, and deadfalls. We estimate that fish and metazoans contribute 5.2 PgC/yr (2.1-8.8PgC/yr) to passive export out of the euphotic zone. Together with active transport, we estimate that fish are responsible for 20% (9-29%) of global carbon export, and 32% (18-43%) of oceanic carbon sequestration, with forage and deep-dwelling mesopelagic fish contributing the most. This essential ecosystem service could be at risk from unregulated fishing on the high seas.

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Why do the two most abundant copepods in the North Atlantic differ so markedly in their diel vertical migration behaviour?

Journal of Sea Research ◽

10.1016/s1385-1101(97)00030-0 ◽

1997 ◽

Vol 38 (1-2) ◽

pp. 85-92 ◽

Cited By ~ 9

Author(s):

G.C. Hays ◽

A.J. Warner ◽

P. Tranter

Keyword(s):

North Atlantic ◽

Vertical Migration ◽

Diel Vertical Migration ◽

The North ◽

Migration Behaviour ◽

The North Atlantic

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The Importance of Mesozooplankton Diel Vertical Migration for Sustaining a Mesopelagic Food Web

10.1101/642975 ◽

2019 ◽

Author(s):

Thomas B. Kelly ◽

Peter C. Davison ◽

Ralf Goericke ◽

Michael R. Landry ◽

Mark D. Ohman ◽

...

Keyword(s):

Active Transport ◽

Vertical Migration ◽

Diel Vertical Migration ◽

Deep Ocean ◽

Total Carbon ◽

Sensitivity Analyses ◽

Mesopelagic Fish ◽

Ecosystem Research ◽

Carbon Demand ◽

Gross Growth Efficiency

AbstractWe used extensive ecological and biogeochemical measurements obtained from quasi-Lagrangian experiments during two California Current Ecosystem Long-Term Ecosystem Research cruises to analyze carbon fluxes between the epipelagic and mesopelagic zones using a linear inverse ecosystem model (LIEM). Measurement constraints on the model include 14C primary productivity, dilution-based microzooplankton grazing rates, gut pigment-based mesozooplankton grazing rates (on multiple zooplankton size classes), 234Th:238U disequilibrium and sediment trap measured carbon export, and metabolic requirements of micronekton, zooplankton, and bacteria. A likelihood approach (Markov Chain Monte Carlo) was used to estimate the resulting flow uncertainties from a sample of potential flux networks. Results highlight the importance of mesozooplankton active transport (i.e., diel vertical migration) for supplying the carbon demand of mesopelagic organisms and sequestering carbon dioxide from the atmosphere. In nine water parcels ranging from a coastal bloom to offshore oligotrophic conditions, mesozooplankton active transport accounted for 18% - 84% (median: 42%) of the total carbon supply to the mesopelagic, with gravitational settling of POC (12% - 55%; median: 37%) and subduction (2% - 32%; median: 14%) providing the majority of the remainder. Vertically migrating zooplankton contributed to downward carbon flux through respiration and excretion at depth and via consumption loses to predatory zooplankton and mesopelagic fish (e.g. myctophids and gonostomatids). Sensitivity analyses showed that the results of the LIEM were robust to changes in nekton metabolic demands, rates of bacterial production, and mesozooplankton gross growth efficiency. This analysis suggests that prior estimates of zooplankton active transport based on conservative estimates of standard (rather than active) metabolism should be revisited.Contribution to the FieldUnderstanding the flows of carbon within the ocean is important for predicting how global climate will shift; yet even after decades of research, the magnitude with which the ocean sequesters carbon is highly uncertain. One reason behind this uncertainty is that a variety of mechanisms control the balance between carbon input and carbon output within the ocean. The topic of this work is to inspect the role of biological organisms in physically transferring organic carbon from the surface to the deep ocean. As opposed to other mechanisms—such as sinking particles, the biological transfer of carbon is difficult to measure directly and is often quite variable, leading to large uncertainties. Here we use an extensive set of in situ observations off the coast of southern California to model the flow of carbon through the ecosystem. The model determined that in our study area nearly half of the total transfer of carbon from the surface ocean to deep was carried out by zooplankton that swim up to the surface each night to feed. This finding has direct implications for global carbon budgets, which often underestimate this transfer of carbon.

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Diel Vertical migration of marine organisms and the biological carbon pump

10.5194/egusphere-egu21-198 ◽

2021 ◽

Author(s):

Jerome Pinti ◽

Tim DeVries ◽

Tommy Norin ◽

Camila Serra-Pompei ◽

Roland Proud ◽

...

Keyword(s):

Carbon Sequestration ◽

Food Web ◽

Vertical Migration ◽

Diel Vertical Migration ◽

Marine Organisms ◽

Trophic Levels ◽

Mesopelagic Fish ◽

Pelagic Food Web ◽

Carbon Pump ◽

Biological Carbon Pump

Diel Vertical Migration (DVM) is a key feature of pelagic and mesopelagic ecosystems, mainly driven by predator-prey interactions along a time-varying vertical gradient of light. Marine organisms including meso-zooplankton and fish typically hide from visual predators at depth during daytime and migrate up at dusk to feed in productive near-surface waters during nighttime. Specific migration patterns, however, vary tremendously, for instance in terms of residency depth during day and night. In addition to environmental parameters such as light intensity and oxygen concentration, the migration pattern of each organism is intrinsically linked to the patterns of its conspecifics, its prey, and its predators through feedbacks that are hard to understand&#8212;but important to consider.DVM not only affects trophic interactions, but also the biogeochemistry of the world&#8217;s oceans.&#160; Organisms preying at the surface and actively migrating vertically transport carbon to depth, contributing to the biological carbon pump, and directly connecting surface production with mesopelagic and demersal ecosystems.Here, we present a method based on a game-theoretic trait-based mechanistic model that enables the optimal DVM patterns for all organisms in a food-web to be computed simultaneously. The results are used to investigate the contributions of the different food-web pathways to the active component of the biological carbon pump. We apply the method to a modern pelagic food-web (comprised of meso- and macro-zooplankton, forage fish, mesopelagic fish, large pelagic fish and gelatinous organisms), shedding light on the direct effects that different trophic levels can have on the DVM behaviours of each other. The model is run on a global scale to assess the carbon export mediated by different functional groups, through fecal pellet production, carcasses sinking and respiration.Finally, the model output is coupled to an ocean inverse circulation model to assess the carbon sequestration potential of the different export pathways. Results indicate that the carbon sequestration mediated by fish is much more important than presently recognised in global assessments of the biological carbon pump. The work we present relates to contemporary ecosystems, but we also explain how it can be adapted to fit any pelagic food-web structure to assess the contribution of the active biological pump to the global carbon cycle in past ecosystems.

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Changes in Light Intensity and Diel Vertical Migration: a Comparison of Marine and Freshwater Environments

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400015162 ◽

1995 ◽

Vol 75 (1) ◽

pp. 15-25 ◽

Cited By ~ 76

Author(s):

J. Ringelberg

Keyword(s):

Light Intensity ◽

Marine Environment ◽

Vertical Migration ◽

Diel Vertical Migration ◽

Response Mechanism ◽

Causal Factors ◽

Stimulus Response ◽

Vertical Distributions ◽

Using Data ◽

Freshwater Environments

Proximate aspects of diel vertical migration in the freshwater and marine environment are compared using data from the literature. Examples of migrations in both environments are presented, from which it is concluded that relative changes in light intensity before sunrise and after sunset are primary causes of migrations. Experiments have shown that photoreactive behaviour is enhanced in the presence of predators but inhibited by shortage of food. These factors are called secondary causal factors. A hierarchy of causal factors is proposed. In lakes fish exudates suffice but in marine biotopes like bays, it is possible that fish have to be actually present for enhancement to take effect. To what extent the presented stimulus-response mechanism holds for mesopelagic animals in oceans is discussed on the basis of vertical distributions of euphausiids.

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