| 1. |
- Obst, Matthias, 1974, et al.
(author)
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A Marine Biodiversity Observation Network for Genetic Monitoring of Hard-Bottom Communities (ARMS-MBON)
- 2020
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 7
-
Journal article (peer-reviewed)abstract
- Marine hard-bottom communities are undergoing severe change under the influence of multiple drivers, notably climate change, extraction of natural resources, pollution and eutrophication, habitat degradation, and invasive species. Monitoring marine biodiversity in such habitats is, however, challenging as it typically involves expensive, non-standardized, and often destructive sampling methods that limit its scalability. Differences in monitoring approaches furthermore hinders inter-comparison among monitoring programs. Here, we announce a Marine Biodiversity Observation Network (MBON) consisting of Autonomous Reef Monitoring Structures (ARMS) with the aim to assess the status and changes in benthic fauna with genomic-based methods, notably DNA metabarcoding, in combination with image-based identifications. This article presents the results of a 30-month pilot phase in which we established an operational and geographically expansive ARMS-MBON. The network currently consists of 20 observatories distributed across European coastal waters and the polar regions, in which 134 ARMS have been deployed to date. Sampling takes place annually, either as short-term deployments during the summer or as long-term deployments starting in spring. The pilot phase was used to establish a common set of standards for field sampling, genetic analysis, data management, and legal compliance, which are presented here. We also tested the potential of ARMS for combining genetic and image-based identification methods in comparative studies of benthic diversity, as well as for detecting non-indigenous species. Results show that ARMS are suitable for monitoring hard-bottom environments as they provide genetic data that can be continuously enriched, re-analyzed, and integrated with conventional data to document benthic community composition and detect non-indigenous species. Finally, we provide guidelines to expand the network and present a sustainability plan as part of the European Marine Biological Resource Centre (www.embrc.eu).
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| 2. |
- Norkko, J., et al.
(author)
-
A welcome can of worms? Hypoxia mitigation by an invasive species
- 2012
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In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 18:2, s. 422-434
-
Journal article (peer-reviewed)abstract
- Invasive species and bottom-water hypoxia both constitute major global threats to the diversity and integrity of marine ecosystems. These stressors may interact with unexpected consequences, as invasive species that require an initial environmental disturbance to become established can subsequently become important drivers of ecological change. There is recent evidence that improved bottom-water oxygen conditions in coastal areas of the northern Baltic Sea coincide with increased abundances of the invasive polychaetes Marenzelleria spp. Using a reactive-transport model, we demonstrate that the long-term bioirrigation activities of dense Marenzelleria populations have a major impact on sedimentary phosphorus dynamics. This may facilitate the switch from a seasonally hypoxic system back to a normoxic system by reducing the potential for sediment-induced eutrophication in the upper water column. In contrast to short-term laboratory experiments, our simulations, which cover a 10-year period, show that Marenzelleria has the potential to enhance long-term phosphorus retention in muddy sediments. Over time bioirrigation leads to a substantial increase in the iron-bound phosphorus content of sediments while reducing the concentration of labile organic carbon. As surface sediments are maintained oxic, iron oxyhydroxides are able to persist and age into more refractory forms. The model illustrates mechanisms through which Marenzelleria can act as a driver of ecological change, although hypoxic disturbance or natural population declines in native species may be needed for them to initially become established. Invasive species are generally considered to have a negative impact; however, we show here that one of the main recent invaders in the Baltic Sea may provide important ecosystem services. This may be of particular importance in low-diversity systems, where disturbances may dramatically alter ecosystem services due to low functional redundancy. Thus, an environmental problem in one region may be either exacerbated or alleviated by a single species from another region, with potentially ecosystem-wide consequences.
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| 3. |
- Kauppi, L., et al.
(author)
-
Seasonal variability in ecosystem functions : quantifying the contribution of invasive species to nutrient cycling in coastal ecosystems
- 2017
-
In: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 572, s. 193-207
-
Journal article (peer-reviewed)abstract
- Benthic ecosystems at temperate and high latitudes experience marked seasonal variation in the environmental factors affecting nutrient remineralization processes both directly and indirectly through their effects on the benthic communities. The invasive polychaete genus Marenzelleria represents new functionality in Baltic Sea sediments through its deep burrowing and extensive gallery formation, thus possibly greatly affecting benthic oxygen and nutrient fluxes. We assessed the seasonal contribution of Marenzelleria spp. to fluxes of solutes in monthly field measurements at 2 sites, 10 and 33 m deep, in the northern Baltic Proper over 1 yr. In general, the fluxes of inorganic nutrients and oxygen were higher during summer than during winter, and the seasonal variation was more pronounced at the deeper, more biologically active site. By using variation partitioning, we were able to demonstrate that Marenzelleria and other macrofauna could account for up to 92% of the variation in the fluxes depending on the site and season. Fauna was the most important in predicting the fluxes in spring when the sediment organic content and the abundance of juvenile Marenzelleria spp. were highest, while during e.g. winter, the influence of Marenzelleria spp., even though abundant, on solute fluxes was negligible. The results from this study have implications for management, and, importantly, for the modelling of nutrient budgets often based on values from studies conducted during the summer period only, thus possibly greatly miscalculating the annual nutrient fluxes.
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| 4. |
- Attard, K. M., et al.
(author)
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Seasonal metabolism and carbon export potential of a key coastal habitat : The perennial canopy-forming macroalga Fucus vesiculosus
- 2019
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In: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 64:1, s. 149-164
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Journal article (peer-reviewed)abstract
- The important role of macroalgal canopies in the oceanic carbon (C) cycle is increasingly being recognized, but direct assessments of community productivity remain scarce. We conducted a seasonal study on a sublittoral Baltic Sea canopy of the brown alga Fucus vesiculosus, a prominent species in temperate and Arctic waters. We investigated community production on hourly, daily, and seasonal timescales. Aquatic eddy covariance (AEC) oxygen flux measurements integrated similar to 40 m(2) of the seabed surface area and documented considerable oxygen production by the canopy year-round. High net oxygen production rates of up to 35 +/- 9 mmol m(-2) h(-1) were measured under peak irradiance of similar to 1200 mu mol photosynthetically active radiation (PAR) m(-2) s(-1) in summer. However, high rates > 15 mmol m(-2) h(-1) were also measured in late winter (March) under low light intensities < 250 mu mol PAR m(-2) s(-1) and water temperatures of similar to 1 degrees C. In some cases, hourly AEC fluxes documented an apparent release of oxygen by the canopy under dark conditions, which may be due to gas storage dynamics within internal air spaces of F. vesiculosus. Daily net ecosystem metabolism (NEM) was positive (net autotrophic) in all but one of the five measurement campaigns (December). A simple regression model predicted a net autotrophic canopy for two-thirds of the year, and annual canopy NEM amounted to 25 mol O-2 m(-2) yr(-1), approximately six-fold higher than net phytoplankton production. Canopy C export was similar to 0.3 kg C m(-2) yr(-1), comparable to canopy standing biomass in summer. Macroalgal canopies thus represent regions of intensified C assimilation and export in coastal waters.
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| 5. |
- Eriksson, Susanne P., 1964, et al.
(author)
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Episodic disturbance events modify predator-prey interactions in soft sediments
- 2005
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In: Estuarine Coastal and Shelf Science. - : Elsevier BV. - 0272-7714. ; 64:2-3, s. 289-294
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Journal article (peer-reviewed)abstract
- Physical disturbance events are common in shallow soft-sediment habitats and can have significant effects on predator-prey interactions. While several studies have reported on predator aggregations following disturbance events, few studies have investigated the mechanisms and interactive effects of predation and physical disturbance on prey survival in shallow soft-sediment habitats. In this study the interactive effects of sediment resuspension and predation by two contrasting epibenthic predator species were tested on the survival of the amphipod Corophium volutator in a laboratory experiment. The shrimp Crangon crangon and juvenile plaice Pleuronectes platessa were used as predators, both numerical dominants in shallow soft sediments on the Swedish west coast. In addition we quantified epibenthic predator aggregation in the field following small-scale disturbances. In the laboratory, synergistic negative effects of predation and non-lethal disturbance on Corophium survival were found with both predator species, and rapid aggregation of several mobile epibenthic predator species following disturbance was demonstrated in the field. Abundances of C. crangon, the numerically dominant predator in the field, were doubled in disturbed patches within 2 min following disturbance. Our study emphasises the importance of considering episodic small-scale disturbances when interpreting predation effects and trophic interactions in shallow soft-sediment systems. (c) 2005 Elsevier Ltd. All rights reserved.
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| 6. |
- Gladstone-Gallagher, Rebecca V., et al.
(author)
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Social-ecological connections across land, water, and sea demand a reprioritization of environmental management
- 2022
-
In: Elementa. - : University of California Press. - 2325-1026. ; 10:1
-
Journal article (peer-reviewed)abstract
- Despite many sectors of society striving for sustainability in environmental management, humans often fail to identify and act on the connections and processes responsible for social–ecological tipping points. Part of the problem is the fracturing of environmental management and social–ecological research into ecosystem domains (land, freshwater, and sea), each with different scales and resolution of data acquisition and distinct management approaches. We present a perspective on the social–ecological connections across ecosystem domains that emphasize the need for management reprioritization to effectively connect these domains. We identify critical nexus points related to the drivers of tipping points, scales of governance, and the spatial and temporal dimensions of social–ecological processes. We combine real-world examples and a simple dynamic model to illustrate the implications of slow management responses to environmental impacts that traverse ecosystem domains. We end with guidance on management and research opportunities that arise from this cross-domain lens to foster greater opportunity to achieve environmental and sustainability goals.
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| 7. |
- Jansson, A., et al.
(author)
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Growth and survival in a changing environment: Combined effects of moderate hypoxia and low pH on juvenile bivalve Macoma balthica
- 2015
-
In: Journal of Sea Research. - : Elsevier BV. - 1385-1101. ; 102, s. 41-47
-
Journal article (peer-reviewed)abstract
- Baltic Sea species live in a complex, variable environment characterized by highly fluctuating hydrology, including large seasonal and diel pH variations. For decades, oxygen deficiency caused by anthropogenic eutrophication has affected the Baltic Sea, and large areas of the seafloor are permanently hypoxic resulting in severely degraded benthic communities. Species living in this system are thus potentially tolerant and adapted to this fluctuating environment, but also vulnerable as illustrated by high mortality of benthic species as a result of hypoxia. In the future, the frequency and extent of regularly co-occurring low oxygen and low pH levels will likely increase with on-going climate change. A key species in the Baltic Sea soft-bottom communities, the bivalve Macoma balthica (L.), experiences such conditions throughout its life-cycle, and therefore serves as a good model organism for studying the combined effects of oxygen and pH conditions. To study the response of M. balthica to multiple changes occurring in the benthic environment, we conducted an experiment to investigate the survival and shell growth of newly settled juveniles simultaneously exposed to two pH levels (7.85 and 7.35) and two oxygen levels (8.5 and 3.0 mg/l) for 29 days in a fully factorial design. Survival was high in all treatments (>60%), but significantly higher in the two low oxygen treatments (>70%). Although positive growth was observed in all treatments, pH and oxygen as well as their interaction significantly affected relative growth. The highest growth was observed in the "low O-2/high pH" treatment, which was 2.4 times higher than in both treatments with high oxygen. Although the mechanism for these differences remains unknown, hypoxia-induced metabolic depression likely plays a role. Our results highlight the need to know more about the occurrence and performance of benthic species regularly exposed to changing conditions, and of the range and conditions encountered in situ. With the predicted future negative changes in oxygen availability as well as pH, the adaptive responses of benthic species to multiple stressors will be critical in understanding ecosystem dynamics in the face of change. (C) 2015 Elsevier B.V. All rights reserved.
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| 8. |
- Josefson, A. B., et al.
(author)
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Burial and decomposition of plant pigments in surface sediments of the Baltic Sea: role of oxygen and benthic fauna
- 2012
-
In: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 455, s. 33-49
-
Journal article (peer-reviewed)abstract
- Degradation and burial of organic matter in sediments are important processes for oxygen dynamics and thus for the outcome of eutrophication. To assess the influences of bottom-water oxygen and macroinvertebrate fauna function on these processes, we investigated distributions of phytopigments as markers of phytoplankton detritus in surface sediments across the Baltic Sea. We compared pigment concentrations among sites with different oxygen levels and different values of a bioturbation potential index combining abundance, individual size and species-specific rankings of mobility and sediment reworking (BPI). BPI was positively influenced by oxygen availability, with a threshold at 45 to 90 mu mol l(-1), below which it decreased rapidly to zero in anoxic sediments. There was significant co-variation between pigments and both oxygen and BPI after accounting for differences in pigment concentrations with sediment depth and among different sub-areas, which were largely attributed to different inputs of phytoplankton. Negative correlations between pigments and both BPI and oxygen in communities dominated by Macoma balthica and Scoloplos armiger, and between pigments and BPI in the upper sediment layers inhabited by Monoporeia affinis and Pontoporeia femorata, suggested increased degradation with increasing bioturbation. Positive correlations between pigments and BPI in communities dominated by Marenzelleria spp. suggested mainly burial, which also was supported by positive correlations between Marenzelleria abundance and both sediment water content and the freshness of buried organic material. It is hypothesised that a shift from sensitive resident species like Monoporeia or Scoloplos to the more hypoxia-tolerant Marenzelleria will slow down overall degradation rates, counteracting hypoxia formation in the bottom water. ELEOESCHGER D, 1991, MARINE ECOLOGY-PROGRESS SERIES, V70, P83
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| 9. |
- Kauppi, L., et al.
(author)
-
Increasing densities of an invasive polychaete enhance bioturbation with variable effects on solute fluxes
- 2018
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
-
Journal article (peer-reviewed)abstract
- Bioturbation is a key process affecting nutrient cycling in soft sediments. The invasive polychaete genus Marenzelleria spp. has established successfully throughout the Baltic Sea increasing species and functional diversity with possible density-dependent effects on bioturbation and associated solute fluxes. We tested the effects of increasing density of M. arctia, M. viridis and M. neglecta on bioturbation and solute fluxes in a laboratory experiment. Benthic communities in intact sediment cores were manipulated by adding increasing numbers of Marenzelleria spp. The results showed that Marenzelleria spp. in general enhanced all bioturbation metrics, but the effects on solute fluxes varied depending on the solute, on the density and species identity of Marenzelleria, and on the species and functional composition of the surrounding community. M. viridis and M. neglecta were more important in predicting variation in phosphate and silicate fluxes, whereas M. arctia had a larger effect on nitrogen cycling. The complex direct and indirect pathways indicate the importance of considering the whole community and not just species in isolation in the experimental studies. Including these interactions provides a way forward regarding our understanding of the complex ecosystem effects of invasive species.
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| 10. |
- Kauppi, L., et al.
(author)
-
Seasonal population dynamics of the invasive polychaete genus Marenzelleria spp. in contrasting soft-sediment habitats
- 2018
-
In: Journal of Sea Research. - : Elsevier BV. - 1385-1101 .- 1873-1414. ; 131, s. 46-60
-
Journal article (peer-reviewed)abstract
- Three species of the invasive polychaete genus Marenzelleria are among the dominant benthic taxa in many, especially deeper, areas in the Baltic Sea. The population dynamics of the polychaetes in the Baltic are, however, still largely unknown. We conducted monthly samplings of the benthic communities and environmental parameters at five sites with differing depths and sediment characteristics in the northern Baltic Sea (59 degrees 50.896', 23 degrees 15.092') to study the population dynamics, productivity and growth of Marenzelleria spp. from April 2013 to June 2014. The species of Marenzelleria occurring at the study sites were identified by genetic analyses. At the deepest site (33 m) only M. arctia was present, while all three species were found at the shallower, muddy sites (up to 20 m depth). At the shallow (6 m) sandy site only M. viridis and M. neglecta occurred. The sites differed in the seasonal dynamics of the Marenzelleria spp. population, reflecting the different species identities. The muddy sites up to 20 m depth showed clear seasonal dynamics, with the population practically disappearing by winter, whereas more stable populations occurred at the deepest site and at the sandy site. The highest density, biomass and production were observed at the 20 m deep, organic-rich muddy site where all three species recruited. The seasonally very high densities are likely to have important consequences for organic matter processing, and species interactions at these sites. The observed high productivity of the populations has possibly facilitated their establishment, and considerably increased secondary production in especially the deeper areas.
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| 11. |
- Norkko, J., et al.
(author)
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Conditional responses to increasing scales of disturbance, and potential implications for threshold dynamics in soft-sediment communities
- 2010
-
In: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 413, s. 253-266
-
Journal article (peer-reviewed)abstract
- Disturbance-recovery experiments conducted across environmental gradients can reveal the relative importance of processes, feedbacks and threshold conditions that sustain ecosystem functioning and resilience. In the present paper we argue that threshold responses to disturbance (e.g. marked non-linear shifts in abundance of important species) are scale-, context- and species-dependent. In order to test the context- dependency in recovery dynamics of soft-sediment benthic communities, we conducted a large-scale sublittoral experiment investigating patterns in recovery of 2 functionally different groups of deposit feeders (surface vs. subsurface deposit feeders; Hydrobiidae vs. Oligochaeta) with increasing spatial scales of hypoxic disturbance in the Baltic Sea. Plots (1, 4 and 16 m(2)) were defaunated at 4 sandy sites (5 m depth) that varied in exposure to wind-waves, and subsequent recovery of macrofaunal abundances was monitored over 15 mo, focusing on post-larval recolonisation. Recovery patterns were site-specific, depended on the scale of disturbance, and indicated a shift in the relative importance of smaller-scale biological factors to broader-scale physical factors, i.e. waves, currents and sediment transport, when moving from sheltered to more exposed sites. We found group-specific responses, related to mode of living (epifaunal/infaunal) and dispersal potential. In addition, Hydrobiidae exhibited opportunistic population increases in response to disturbance, likely due to increased food availability. The results highlight the importance of interactions between environmental factors, and understanding natural-history characteristics and relative mobility of different taxa, when assessing both the resilience and the recovery of benthic communities.
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| 12. |
- Rodil, Iván F., et al.
(author)
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Estimating Respiration Rates and Secondary Production of Macrobenthic Communities Across Coastal Habitats with Contrasting Structural Biodiversity
- 2020
-
In: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 23:3, s. 630-647
-
Journal article (peer-reviewed)abstract
- A central goal of benthic ecology is to describe the pathways and quantities of energy and material flow in seafloor communities over different spatial and temporal scales. We examined the relative macrobenthic contribution to the seafloor metabolism by estimating respiration and secondary production based on seasonal measurements of macrofauna biomass across key coastal habitats of the Baltic Sea archipelago. Then, we compared the macrofauna estimates with estimates of overall seafloor gross primary production and respiration obtained from the same habitats using the aquatic eddy covariance technique. Estimates of macrobenthic respiration rates suggest habitat-specific macrofauna contribution (%) to the overall seafloor respiration ranked as follows: blue mussel reef (44.5) > seagrass meadow (25.6) > mixed meadow (24.1) > bare sand (17.8) > Fucus-bed (11.1). In terms of secondary production (g C m(-2) y(-1)), our estimates suggest ranking of habitat value as follows: blue mussel reef (493.4) > seagrass meadow (278.5) > Fucus-bed (102.2) > mixed meadow (94.2) > bare sand (52.1). Our results suggest that approximately 12 and 10% of the overall soft-sediment metabolism translated into macrofauna respiration and secondary production, respectively. The hard-bottoms exemplified two end-points of the coastal metabolism, with the Fucus-bed as a high producer and active exporter of organic C (that is, net autotrophy), and the mussel reef as a high consumer and active recycler of organic C (that is, net heterotrophy). Using a combination of metrics of ecosystem functioning, such as respiration rates and secondary production, in combination with direct habitat-scale measurements of O-2 fluxes, our study provides a quantitative assessment of the role of macrofauna for ecosystem functioning across heterogeneous coastal seascapes.
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| 13. |
- Thakur, Roseline C., et al.
(author)
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An evaluation of new particle formation events in Helsinki during a Baltic Sea cyanobacterial summer bloom
- 2022
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In: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:9, s. 6365-6391
-
Journal article (peer-reviewed)abstract
- Several studies have investigated new particle formation (NPF) events from various sites ranging from pristine locations, including forest sites, to urban areas. However, there is still a dearth of studies investigating NPF processes and subsequent aerosol growth in coastal yet semi-urban sites, where the tropospheric layer is a concoction of biogenic and anthropogenic gases and particles. The investigation of factors leading to NPF becomes extremely complex due to the highly dynamic meteorological conditions at the coastline especially when combined with both continental and oceanic weather conditions. Herein, we engage in a comprehensive study of particle number size distributions and aerosol-forming precursor vapors at the coastal semi-urban site in Helsinki, Finland. The measurement period, 25 June-18 August 2019, was timed with the recurring cyanobacterial summer bloom in the Baltic Sea region and coastal regions of Finland. Our study recorded several regional/local NPF and aerosol burst events during this period. Although the overall anthropogenic influence on sulfuric acid (SA) concentrations was low during the measurement period, we observed that the regional or local NPF events, characterized by SA concentrations on the order of 10(7) molec. cm(-3), occurred mostly when the air mass traveled over the land areas. Interestingly, when the air mass traveled over the Baltic Sea, an area enriched with algae and cyanobacterial blooms, high iodic acid (IA) concentration coincided with an aerosol burst or a spike event at the measurement site. Further, SA-rich bursts were seen when the air mass traveled over the Gulf of Bothnia, enriched with cyanobacterial blooms. The two most important factors affecting aerosol precursor vapor concentrations, and thus the aerosol formation, were speculated to be (1) the type of phytoplankton species and intensity of bloom present in the coastal regions of Finland and the Baltic Sea and (2) the wind direction. During the events, most of the growth of sub-3 nm particles was probably due to SA, rather than IA or methane sulfonic acid (MSA); however much of the particle growth remained unexplained indicative of the strong role of organics in the growth of particles, especially in the 3-7 nm particle size range. Further studies are needed to explore the role of organics in NPF events and the potential influence of cyanobacterial blooms in coastal locations.
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| 14. |
- Thrush, S. F., et al.
(author)
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beta-Diversity and Species Accumulation in Antarctic Coastal Benthos: Influence of Habitat, Distance and Productivity on Ecological Connectivity
- 2010
-
In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 5:7
-
Journal article (peer-reviewed)abstract
- High Antarctic coastal marine environments are comparatively pristine with strong environmental gradients, which make them important places to investigate biodiversity relationships. Defining how different environmental features contribute to shifts in beta-diversity is especially important as these shifts reflect both spatio-temporal variations in species richness and the degree of ecological separation between local and regional species pools. We used complementary techniques (species accumulation models, multivariate variance partitioning and generalized linear models) to assess how the roles of productivity, bio-physical habitat heterogeneity and connectivity change with spatial scales from metres to 100's of km. Our results demonstrated that the relative importance of specific processes influencing species accumulation and beta-diversity changed with increasing spatial scale, and that patterns were never driven by only one factor. Bio-physical habitat heterogeneity had a strong influence on beta-diversity at scales <290 km, while the effects of productivity were low and significant only at scales >40 km. Our analysis supports the emphasis on the analysis of diversity relationships across multiple spatial scales and highlights the unequal connectivity of individual sites to the regional species pool. This has important implications for resilience to habitat loss and community homogenisation, especially for Antarctic benthic communities where rates of recovery from disturbance are slow, there is a high ratio of poor-dispersing and brooding species, and high biogenic habitat heterogeneity and spatio-temporal variability in primary production make the system vulnerable to disturbance. Consequently, large areas need to be included within marine protected areas for effective management and conservation of these special ecosystems in the face of increasing anthropogenic disturbance.
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| 15. |
- Valanko, S., et al.
(author)
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Rates of post-larval bedload dispersal in a non-tidal soft-sediment system
- 2010
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In: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 416, s. 145-163
-
Journal article (peer-reviewed)abstract
- Quantifying rates of dispersal and understanding patterns of colonization are key for predicting disturbance-recovery dynamics. For soft-sediment benthic communities recruitment is not restricted to one single event, but can be highly variable on several spatial and temporal scales. To investigate the temporal persistence of post-larval bedload transport in a non-tidal system, field experiments were conducted at 4 sites (5 m depth) across a wind-wave exposure gradient over 2 summers. Results indicate that bedload dispersal is temporally variable and dependent on an interaction between species-specific characteristics (including seasonal peaks in reproduction), site-specific hydrographic conditions, grain size characteristics and transport of sediments and drift algae. Dispersal of more passive taxa (Ostracoda, juvenile gastropods, Macoma balthica) was found to be associated with higher rates of sediment and algal transport, while more active species (Hydrobia ulvae and Potamopyrgus antipodarum) dispersed relatively more at sheltered sites. At higher rates of sediment transport, there was an increase in the proportion of larger M. balthica individuals dispersing, in contrast to Hydrobiidae, which had an increased proportion of smaller individuals. Our study suggests that frequent post-larval dispersal plays a central role in the population dynamics of many benthic invertebrates, in non-tidal systems. While the distribution of species is heavily influenced by peaked larval recruitment over large spatial scales, the net result of continuous small-scale dispersal events is clearly important and may contribute to the resilience of benthic communities.
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| 16. |
- Andersen, JH, et al.
(author)
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Getting the measure of eutrophication in the Baltic Sea: towards improved assessment principles and methods
- 2011
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In: Biogeochemistry. - 0168-2563. ; 106:2, s. 137-156
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Journal article (peer-reviewed)abstract
- The eutrophication status of the entire Baltic Sea is classified using a multi-metric indicator-based assessment tool. A total of 189 areas are assessed using indicators where information on reference conditions (RefCon), and acceptable deviation (AcDev) from reference condition could be combined with national monitoring data from the period 2001–2006. Most areas (176) are classified as ‘affected by eutrophication’ and only two open water areas and 11 coastal areas are classified as ‘unaffected by eutrophication’. The classification is made by application of the recently developed HELCOM Eutrophication Assessment Tool (HEAT), which is described in this paper. The use of harmonized assessment principles and the HEAT tool allows for direct comparisons between different parts of the Baltic Sea despite variations in monitoring activities. The impaired status of 176 areas is directly related to nutrient enrichment and elevated loads from upstream catchments. Baltic Sea States have implemented nutrient management strategies since years which have reduced nutrient inputs. However, eutrophication is still a major problem for large parts of the Baltic Sea. The 2007 Baltic Sea Action Plan is projected to further reduce nutrient inputs aiming for a Baltic Sea unaffected by eutrophication by 2021.
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| 17. |
- Broman, Elias, 1985-, et al.
(author)
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Biotic interactions between benthic infauna and aerobic methanotrophs mediate methane fluxes from coastal sediments
- 2024
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In: The ISME journal. - 1751-7370 .- 1751-7362. ; 18:1
-
Journal article (peer-reviewed)abstract
- Coastal ecosystems dominate oceanic methane (CH4) emissions. However, there is limited knowledge about how biotic interactions between infauna and aerobic methanotrophs (i.e. CH4 oxidizing bacteria) drive the spatial-temporal dynamics of these emissions. Here, we investigated the role of meio- and macrofauna in mediating CH4 sediment-water fluxes and aerobic methanotrophic activity that can oxidize significant portions of CH4. We show that macrofauna increases CH4 fluxes by enhancing vertical solute transport through bioturbation, but this effect is somewhat offset by high meiofauna abundance. The increase in CH4 flux reduces CH4 pore-water availability, resulting in lower abundance and activity of aerobic methanotrophs, an effect that counterbalances the potential stimulation of these bacteria by higher oxygen flux to the sediment via bioturbation. These findings indicate that a larger than previously thought portion of CH4 emissions from coastal ecosystems is due to faunal activity and multiple complex interactions with methanotrophs.
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| 18. |
- Broman, Elias, et al.
(author)
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High throughput shotgun sequencing of eRNA reveals taxonomic and derived functional shifts across a benthic productivity gradient
- 2021
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In: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 30:13, s. 3023-39
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Journal article (peer-reviewed)abstract
- © 2020 The Authors. Molecular Ecology published by John Wiley & Sons Ltd Benthic macrofauna is regularly used in monitoring programmes, however the vast majority of benthic eukaryotic biodiversity lies mostly in microscopic organisms, such as meiofauna (invertebrates<1mm) and protists, that rapidly responds to environmental change. These communities have traditionally been hard to sample and handle in the laboratory, but DNA sequencing has made such work less time consuming. While DNA sequencing captures both alive and dead organisms, environmental RNA (eRNA) better targets living organisms or organisms of recent origin in the environment. Here, we assessed the biodiversity of three known bioindicator microeukaryote groups (nematodes, foraminifera, and ciliates) in sediment samples collected at seven coastal sites along an organic carbon (OC) gradient. We aimed to investigate if eRNA shotgun sequencing can be used to simultaneously detect differences in (i) biodiversity of multiple microeukaryotic communities; and (ii) functional feeding traits of nematodes. Results showed that biodiversity was lower for nematodes and foraminifera in high OC (6.2%–6.9%), when compared to low OC sediments (1.2%–2.8%). Dissimilarity in community composition increased for all three groups between Low OC and High OC, as well as the classified feeding type of nematode genera (with more nonselective deposit feeders in high OC sediment). High relative abundant genera included nematode Sabatieria and foraminifera Elphidium in high OC, and Cryptocaryon-like ciliates in low OC sediments. Considering that future sequencing technologies are likely to decrease in cost, the use of eRNA shotgun sequencing to assess biodiversity of benthic microeukaryotes could be a powerful tool in recurring monitoring programmes.
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| 19. |
- Broman, Elias, et al.
(author)
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Low Abundance of Methanotrophs in Sediments of Shallow Boreal Coastal Zones With High Water Methane Concentrations
- 2020
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In: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 11
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Journal article (peer-reviewed)abstract
- Coastal zones are transitional areas between land and sea where large amounts of organic and inorganic carbon compounds are recycled by microbes. Especially shallow zones near land have been shown to be the main source for oceanic methane (CH4) emissions. Water depth has been predicted as the best explanatory variable, which is related to CH4 ebullition, but exactly how sediment methanotrophs mediates these emissions along water depth is unknown. Here, we investigated the relative abundance and RNA transcripts attributed to methane oxidation proteins of aerobic methanotrophs in the sediment of shallow coastal zones with high CH4 concentrations within a depth gradient from 10–45 m. Field sampling consisted of collecting sediment (top 0–2 cm layer) from eight stations along this depth gradient in the coastal Baltic Sea. The relative abundance and RNA transcripts attributed to the CH4 oxidizing protein (pMMO; particulate methane monooxygenase) of the dominant methanotroph Methylococcales was significantly higher in deeper costal offshore areas (36–45 m water depth) compared to adjacent shallow zones (10–28 m). This was in accordance with the shallow zones having higher CH4 concentrations in the surface water, as well as more CH4 seeps from the sediment. Furthermore, our findings indicate that the low prevalence of Methylococcales and RNA transcripts attributed to pMMO was restrained to the euphotic zone (indicated by Photosynthetically active radiation (PAR) data, photosynthesis proteins, and 18S rRNA data of benthic diatoms). This was also indicated by a positive relationship between water depth and the relative abundance of Methylococcales and pMMO. How these processes are affected by light availability requires further studies. CH4 ebullition potentially bypasses aerobic methanotrophs in shallow coastal areas, reducing CH4 availability and limiting their growth. Such mechanism could help explain their reduced relative abundance and related RNA transcripts for pMMO. These findings can partly explain the difference in CH4 concentrations between shallow and deep coastal areas, and the relationship between CH4 concentrations and water depth.
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| 20. |
- Broman, Elias, 1985-, et al.
(author)
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No evidence of light inhibition on aerobic methanotrophs in coastal sediments using eDNA and eRNA
- 2023
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In: Environmental DNA. - 2637-4943. ; 5:4, s. 766-781
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Journal article (peer-reviewed)abstract
- It is estimated that up to half of global methane (CH4) emissions are derived from microbial processes in aquatic ecosystems. However, it is not fully understood which factors explain the spatial and temporal variability of these emissions. For example, light has previously been shown to both inhibit and stimulate aerobic methane-oxidizing bacteria (i.e., methanotrophs) in the water column. These contrasting results indicate that the mechanisms that light has on CH4 oxidation are not yet clearly known, even less so for benthic aerobic methanotrophs. Here, we tested whether light reaching the seafloor can inhibit methanotrophic activity on the sediment surface. We sampled and distributed over 40 intact sediment cores from two coastal sites (illuminated 10 m, and a dark site at 33 m water depth) into 0, 50, and 100 PAR light treatments. After 10 days, we found no difference between treatments for each site in pore-water CH4 concentrations, relative abundance of aerobic methanotrophs, or the number of RNA transcripts related to methane oxidation. Our results suggest that light attenuation in coastal waters does not significantly affect aerobic methanotrophs in coastal sediments.
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| 21. |
- Carstensen, Jacob, et al.
(author)
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Factors regulating the coastal nutrient filter in the Baltic Sea
- 2020
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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 49:6, s. 1194-1210
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Journal article (peer-reviewed)abstract
- The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
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| 22. |
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| 23. |
- Cummings, Vonda J., et al.
(author)
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Linking Ross Sea Coastal Benthic Communities to Environmental Conditions : Documenting Baselines in a Spatially Variable and Changing World
- 2018
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 5
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Journal article (peer-reviewed)abstract
- Understanding the functionality of marine benthic ecosystems, and how they are influenced by their physical environment, is fundamental to realistically predicting effects of future environmental change. The Antarctic faces multiple environmental pressures associated with greenhouse gas emissions, emphasizing the need for baseline information on biodiversity and the bio-physical processes that influence biodiversity. We describe a survey of shallow water benthic communities at eight Ross Sea locations with a range of environmental characteristics. Our analyses link coastal benthic community composition to seafloor habitat and sedimentary parameters and broader scale features, at locations encompassing considerable spatial extent and variation in environmental characteristics (e.g., seafloor habitat, sea ice conditions, hydrodynamic regime, light). Our aims were to: (i) document existing benthic communities, habitats and environmental conditions against which to assess future change, (ii) investigate the relationships between environmental and habitat characteristics and benthic community structure and function, and (iii) determine whether these relationships were dependent on spatial extent. A very high percentage (>95%) of the between-location variability in macro- or epifaunal community composition was explainable using multi-scale environmental variables. The explanatory power varied depending on the scale of influence of the environmental variables measured (fine and medium-scale habitat, broad scale), and with community type. However, the inclusion of parameters at all scales produced the most powerful model for both communities. Ice duration, ice thickness and snow cover were important broad scale variables identified that directly relate to climate change. Even when using only habitat-scale variables, extending the spatial scale of the study from three locations covering 32 km to eight locations covering ~340 km increased the degree of explanatory power from 18–32 to 64–78%. The increase in explanatory power with spatial extent lends weight to the possibility of using an indirect “space for time” substitution approach for future predictions of the effects of change on these coastal marine ecosystems. Given the multiple and interacting drivers of change in Antarctic coastal ecosystems a multidisciplinary, long term, repeated observation approach will be vital to both improve and test predictions of how coastal communities will respond to environmental change.
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| 24. |
- Gibbs, M., et al.
(author)
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Benthic nutrient fluxes along an estuarine gradient: influence of the pinnid bivalve Atrina zelandica in summer
- 2005
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In: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 288, s. 151-164
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Journal article (peer-reviewed)abstract
- Benthic nutrient fluxes (BNF) can supply 30 to 100% of the nutrient requirements of benthic and pelagic algae in an estuary, and can, thus, potentially sustain benthic and pelagic primary production within the estuarine food web. While BNF can be influenced by microbial processes, epibenthic suspension-feeding bivalves have the potential to alter fluxes by their influence on the community composition of surrounding macrofauna and benthic boundary conditions, and their feeding activities. In Mahurangi Harbour, New Zealand, the large suspension feeding pinnid Atrina zelandica (hereafter referred to as Atrina) occupies large areas of the harbour floor. Consequently, Atrina have the potential to substantially influence the BNF and, thus, primary production, and the food supply to the filter feeding community within the harbour, including the rack-farmed Pacific oyster aquaculture industry. Mahurangi Harbour is almost always isohaline, but exhibits a strong gradient in suspended sediment concentration, which declines from head to mouth. As Atrina increase their rate of pseudofaeces production with increases in suspended sediment concentration, we conducted in situ light and dark paired benthic chamber experiments with and without Atrina at 4 stations along this turbidity gradient, to determine their effect on BNF. Our results showed substantially greater BNF from Atrina beds than bare sediments. We also found greater net BNF (difference between Atrina beds and bare sediment) in the less turbid water under dark conditions, but enhanced water column nutrient supply in the more turbid water in light, due to Atrina excretion of ammoniacal nitrogen (NH4-N). On an areal basis, we estimate that BNF from Atrina beds may account for up to 80% of the nutrient supply for pelagic primary production and, thus, they are of major importance to the sustainability of aquaculture in this harbour.
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| 25. |
- Graco-Roza, Caio, et al.
(author)
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Distance decay 2.0 – A global synthesis of taxonomic and functional turnover in ecological communities
- 2022
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In: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 31:7, s. 1399-1421
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Journal article (peer-reviewed)abstract
- Aim: Understanding the variation in community composition and species abundances (i.e., beta-diversity) is at the heart of community ecology. A common approach to examine beta-diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 148 datasets comprising different types of organisms and environments.Location: Global.Time period: 1990 to present.Major taxa studied: From diatoms to mammals.Method: We measured the strength of the decay using ranked Mantel tests (Mantel r) and the rate of distance decay as the slope of an exponential fit using generalized linear models. We used null models to test whether functional similarity decays faster or slower than expected given the taxonomic decay along the spatial and environmental distance. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm and organismal features.Results: Taxonomic distance decay was stronger than functional distance decay along both spatial and environmental distance. Functional distance decay was random given the taxonomic distance decay. The rate of taxonomic and functional spatial distance decay was fastest in the datasets from mid-latitudes. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distance but a higher rate of decay along environmental distance. Marine ecosystems had the slowest rate of decay along environmental distances.Main conclusions: In general, taxonomic distance decay is a useful tool for biogeographical research because it reflects dispersal-related factors in addition to species responses to climatic and environmental variables. Moreover, functional distance decay might be a cost-effective option for investigating community changes in heterogeneous environments.
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