Articles | Volume 12, issue 16
19 Aug 2015
Research article | 19 Aug 2015
Macroalgae contribute to nested mosaics of pH variability in a subarctic fjord
D. Krause-Jensen et al.
No articles found.
Anna Escolano-Moltó, Susana Flecha, Raquel Vaquer-Sunyer, Marlene Wesselmann, Núria Marbà, and Iris Eline Hendriks
Revised manuscript under review for BGShort summary
Seagrasses are marine plants with the capacity to act as carbon sinks due to their high primary productivity, using carbon for growth. This capacity can play a key role in climate change mitigation. We compiled published and own data and show two Mediterranean seagrass species have different metabolic rates and the method used influences the rates of the measurements. Also the Eastern basin is more productive compared to the Western Mediterranean while most communities act as carbon sinks.
Nadia Burgoa, Francisco Machín, Ángeles Marrero-Díaz, Ángel Rodríguez-Santana, Antonio Martínez-Marrero, Javier Arístegui, and Carlos Manuel Duarte
Ocean Sci., 16, 483–511,Short summary
The main objective of the study is to analyze the export of carbon to the open ocean from the rich waters of the upwelling system of North Africa. South of the Canary Islands, permanent upwelling interacts with other physical processes impacting the main biogeochemical processes. Taking advantage of data from two cruises combined with the outputs of models, important conclusions from the differences observed between seasons are obtained, largely related to changes in the CVFZ in this area.
Celina Burkholz, Neus Garcias-Bonet, and Carlos M. Duarte
Biogeosciences, 17, 1717–1730,Short summary
Seagrass meadows store carbon in their biomass and sediments, but they have also been shown to be sources of carbon dioxide (CO2) and methane (CH4). We experimentally investigated the effect of warming and prolonged darkness on CO2 and CH4 fluxes in Red Sea seagrass (Halophila stipulacea) communities. Our results indicated that sublethal warming may lead to increased emissions of greenhouse gases from seagrass meadows which may contribute to further enhance global warming.
Kimberlee Baldry, Vincent Saderne, Daniel C. McCorkle, James H. Churchill, Susana Agusti, and Carlos M. Duarte
Biogeosciences, 17, 423–439,Short summary
The carbon cycling of coastal ecosystems over large spatial scales is not well measured relative to the open ocean. In this study we measure the carbonate system in the three habitats, to measure ecosystem-driven changes compared to offshore waters. We find (1) 70 % of seagrass meadows and mangrove forests show large ecosystem-driven changes, and (2) mangrove forests show strong and consistent trends over large scales, while seagrass meadows display more variability.
Miguel Agulles, Gabriel Jordà, Burt Jones, Susana Agustí, and Carlos M. Duarte
Ocean Sci., 16, 149–166,Short summary
The Red Sea holds one of the most diverse marine ecosystems in the world, although fragile and vulnerable to ocean warming. To better understand the long-term variability and trends of temperature in the whole water column, we produce a 3-D gridded temperature product (TEMPERSEA) for the period 1958–2017, based on a large number of in situ observations, covering the Red Sea and the Gulf of Aden.
Susana Agustí, Jeffrey W. Krause, Israel A. Marquez, Paul Wassmann, Svein Kristiansen, and Carlos M. Duarte
Biogeosciences, 17, 35–45,Short summary
We found that 24 % of the total diatoms community in the Arctic water column (450 m depth) was located below the photic layer. Healthy diatom communities in active spring–bloom stages remained in the photic layer. Dying diatom communities exported a large fraction of the biomass to the aphotic zone, fuelling carbon sequestration and benthic ecosystems in the Arctic. The results of the study conform to a conceptual model where diatoms grow during the bloom until silicic acid stocks are depleted.
Johnna M. Holding, Stiig Markager, Thomas Juul-Pedersen, Maria L. Paulsen, Eva F. Møller, Lorenz Meire, and Mikael K. Sejr
Biogeosciences, 16, 3777–3792,Short summary
Phytoplankton sustain important fisheries along the coast of Greenland. However, climate change is causing severe melting of the Greenland Ice Sheet, and continued melting has the potential to alter fjord ecosystems. We investigate how freshwater from the ice sheet is impacting the environment of one fjord in northeast Greenland, causing a low production of phytoplankton. This fjord may be a model for how some fjord ecosystems will be altered following increased melting and glacial retreat.
Daffne C. López-Sandoval, Katherine Rowe, Paloma Carillo-de-Albonoz, Carlos M. Duarte, and Susana Agustí
Biogeosciences, 16, 2983–2995,Short summary
We addressed how the intertwined effect of temperature and nutrients modulates the metabolic response of planktonic communities in the Red Sea, one of the warmest seas on earth. Our study unveiled that photosynthesis increases at a faster pace than respiration rates for this group of organisms formed by microalgae, bacteria, and drifting animals. This anomaly is likely due to the nature of the basin where the warmest waters are frequently enriched with nutrients, which favours microalgae growth.
Susann Rossbach, Vincent Saderne, Andrea Anton, and Carlos M. Duarte
Biogeosciences, 16, 2635–2650,Short summary
Giant clams including the species Tridacna maxima are unique among bivalves as they live in symbiosis with unicellular algae and generally function as net photoautotrophs. Light is therefore crucial for these species to thrive. We show that net calcification and photosynthetic rates of T. maxima are light dependent, with maximum rates at conditions comparable to 4 m water depth, reflected also in the depth-related distribution in the Red Sea with maximum abundances in shallow sunlit coral reefs.
Neus Garcias-Bonet, Raquel Vaquer-Sunyer, Carlos M. Duarte, and Núria Marbà
Biogeosciences, 16, 167–175,Short summary
We assess the impact of warming on nitrogen fixation in three key Mediterranean macrophytes by experimentally measuring sediment nitrogen fixation rates at current and projected seawater temperature by 2100 under a scenario of moderate greenhouse gas emissions. The temperature dependence of nitrogen fixation could potentially increase rates by 37 % by the end of the century, with important consequences for primary production in coastal ecosystems.
Neus Garcias-Bonet, Marco Fusi, Muhammad Ali, Dario R. Shaw, Pascal E. Saikaly, Daniele Daffonchio, and Carlos M. Duarte
Biogeosciences, 15, 7333–7346,Short summary
Nitrogen (N) loads are detrimental for coastal ecosystems. We measured the balance between N losses and gains in a Red Sea seagrass. The N loss was higher than N2 fixed, pointing out the importance of seagrasses in removing N from the system. N2 losses increased with temperature. Therefore, the forecasted warming could increase the N2 flux to the atmosphere, potentially impacting seagrass productivity and their capacity to mitigate climate change but also enhancing their potential N removal.
Ariane Arias-Ortiz, Pere Masqué, Jordi Garcia-Orellana, Oscar Serrano, Inés Mazarrasa, Núria Marbà, Catherine E. Lovelock, Paul S. Lavery, and Carlos M. Duarte
Biogeosciences, 15, 6791–6818,Short summary
Efforts to include tidal marsh, mangrove and seagrass ecosystems in existing carbon mitigation strategies are limited by a lack of estimates of carbon accumulation rates (CARs). We discuss the use of 210Pb dating to determine CARs in these habitats, which are often composed of heterogeneous sediments and affected by sedimentary processes. Results show that obtaining reliable geochronologies in these systems is ambitious, but estimates of mean 100-year CARs are mostly secure within 20 % error.
Jeffrey W. Krause, Carlos M. Duarte, Israel A. Marquez, Philipp Assmy, Mar Fernández-Méndez, Ingrid Wiedmann, Paul Wassmann, Svein Kristiansen, and Susana Agustí
Biogeosciences, 15, 6503–6517,Short summary
Diatoms can dominate the Arctic Ocean spring bloom, the key annual event for regional food webs. Diatom growth requires silicon and this nutrient has been declining in the European Arctic. This study communicates an unprecedented combination of silicon-cycling measurements around Svalbard during the spring and shows that dissolved silicon can limit diatom production. These results suggest an important coupling of silicon and carbon cycling during the spring bloom in the European Arctic.
Mallory A. Sea, Neus Garcias-Bonet, Vincent Saderne, and Carlos M. Duarte
Biogeosciences, 15, 5365–5375,Short summary
Mangroves are capable of storing carbon in their roots, leaves, and in the sediment; however they can also emit carbon as greenhouse gases (GHG) to the atmosphere. In this study, we collected sediment cores and calculated GHG flux rates from mangrove forests along the Red Sea coastline. Using flux rates reported in this study, we determined that Red Sea mangroves are net carbon sinks, storing more carbon than they emit. This study provides rationale to conserve and expand Red Sea mangroves.
Aisling Fontanini, Alexandra Steckbauer, Sam Dupont, and Carlos M. Duarte
Biogeosciences, 15, 3717–3729,Short summary
Invertebrate species of the Gullmar Fjord (Sweden) were exposed to four different treatments (high/low oxygen and low/high CO2) and respiration measured. Respiration responses of species of contrasting habitats and life-history strategies to single and multiple stressors was evaluated. Results show that the responses of the respiration were highly species specific as we observed both synergetic as well as antagonistic responses, and neither phylum nor habitat explained trends in respiration.
Francesca Iuculano, Carlos Maria Duarte, Núria Marbà, and Susana Agustí
Biogeosciences, 14, 5069–5075,
Carlos M. Duarte
Biogeosciences, 14, 301–310,Short summary
Vegetated coastal habitats (mangroves, seagrass meadows, salt marshes and macroalgal beds) are key contributors to the marine carbon budget, but remain hidden in the representation of the coastal carbon budget. While they have been acknowledged to play an important role in carbon burial, this is small compared to the export flow, which may lead to carbon sequestration beyond these habitats. The carbon fluxes supported by vegetated coastal habitats are globally relevant.
Oscar Serrano, Paul S. Lavery, Carlos M. Duarte, Gary A. Kendrick, Antoni Calafat, Paul H. York, Andy Steven, and Peter I. Macreadie
Biogeosciences, 13, 4915–4926,Short summary
We explored the relationship between organic carbon and mud (i.e. silt and clay) contents in seagrass ecosystems to address whether mud can be used to predict soil C content, thereby enabling robust scaling up exercises at a low cost as part of blue carbon stock assessments. We show that mud is not a universal proxy for blue carbon content in seagrass ecosystems, but it can be used to estimate soil Corg content when low biomass seagrass species (i.e. Zostera, Halodule and Halophila) are present.
Oscar Serrano, Aurora M. Ricart, Paul S. Lavery, Miguel Angel Mateo, Ariane Arias-Ortiz, Pere Masque, Mohammad Rozaimi, Andy Steven, and Carlos M. Duarte
Biogeosciences, 13, 4581–4594,Short summary
The recent focus on carbon (C) trading has intensified interest in "Blue Carbon" – C sequestered by coastal vegetation. However, the factors influencing C storage are poorly understood. The patterns found in this study support that C storage in Posidonia seagrass soils is influenced by interactions of biological, chemical and physical factors within the meadow. We conclude that there is a need to improve global estimates accounting for biogeochemical factors driving variability within habitats.
T. Erin Cox, Frédéric Gazeau, Samir Alliouane, Iris E. Hendriks, Paul Mahacek, Arnaud Le Fur, and Jean-Pierre Gattuso
Biogeosciences, 13, 2179–2194,Short summary
The ocean absorbs atmospheric carbon dioxide (CO2) which increases the concentrations of CO2 and decreases pH in a process called ocean acidification. Because seagrass rely on carbon for photosynthesis they are expected to benefit under future ocean acidification. We manipulated pH in a Posidonia oceanica seagrass meadow. Seagrass traits, photosynthesis, and growth were not affected. Any benefit from ocean acidification over the next century on Posidonia physiology and growth may be minimal.
J. Sievers, L. L. Sørensen, T. Papakyriakou, B. Else, M. K. Sejr, D. Haubjerg Søgaard, D. Barber, and S. Rysgaard
The Cryosphere, 9, 1701–1713,
I. Mazarrasa, N. Marbà, C. E. Lovelock, O. Serrano, P. S. Lavery, J. W. Fourqurean, H. Kennedy, M. A. Mateo, D. Krause-Jensen, A. D. L. Steven, and C. M. Duarte
Biogeosciences, 12, 4993–5003,Short summary
There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the organic fraction and ignored the inorganic carbon pool. This study offers the first global assessment of PIC stocks and accumulation rates in seagrass sediments, identifying these ecosystems as important contributors to carbonate dynamics in coastal areas.
L. Meire, D. H. Søgaard, J. Mortensen, F. J. R. Meysman, K. Soetaert, K. E. Arendt, T. Juul-Pedersen, M. E. Blicher, and S. Rysgaard
Biogeosciences, 12, 2347–2363,Short summary
The Greenland Ice Sheet releases large amounts of freshwater, which strongly influences the biogeochemistry of the adjacent fjord systems and continental shelves. Here we present seasonal observations of the carbonate system in the surface waters of a west Greenland tidewater outlet glacier fjord. Our data reveal a permanent undersaturation of CO2 in the surface layer of the entire fjord and adjacent shelf, creating a high annual uptake of 65gCm-2yr-1.
L. S. García-Corral, E. Barber, A. Regaudie-de-Gioux, S. Sal, J. M. Holding, S. Agustí, N. Navarro, P. Serret, P. Mozetič, and C. M. Duarte
Biogeosciences, 11, 4529–4540,
J.-P. Gattuso, W. Kirkwood, J. P. Barry, E. Cox, F. Gazeau, L. Hansson, I. Hendriks, D.I. Kline, P. Mahacek, S. Martin, P. McElhany, E. T. Peltzer, J. Reeve, D. Roberts, V. Saderne, K. Tait, S. Widdicombe, and P. G. Brewer
Biogeosciences, 11, 4057–4075,
I. E. Hendriks, Y. S. Olsen, L. Ramajo, L. Basso, A. Steckbauer, T. S. Moore, J. Howard, and C. M. Duarte
Biogeosciences, 11, 333–346,
S. Lasternas, M. Piedeleu, P. Sangrà, C. M. Duarte, and S. Agustí
Biogeosciences, 10, 2129–2143,
R. Vaquer-Sunyer, C. M. Duarte, J. Holding, A. Regaudie-de-Gioux, L. S. García-Corral, M. Reigstad, and P. Wassmann
Biogeosciences, 10, 1451–1469,
M. Alcaraz, R. Almeda, E. Saiz, A. Calbet, C. M. Duarte, S. Agustí, R. Santiago, and A. Alonso
Biogeosciences, 10, 689–697,
E. A. A. Versteegh, M. E. Blicher, J. Mortensen, S. Rysgaard, T. D. Als, and A. D. Wanamaker Jr.
Biogeosciences, 9, 5231–5241,
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Ricardo González-Gil, Neil S. Banas, Eileen Bresnan, and Michael R. Heath
Biogeosciences, 19, 2417–2426,Short summary
In oceanic waters, the accumulation of phytoplankton biomass in winter, when light still limits growth, is attributed to a decrease in grazing as the mixed layer deepens. However, in coastal areas, it is not clear whether winter biomass can accumulate without this deepening. Using 21 years of weekly data, we found that in the Scottish coastal North Sea, the seasonal increase in light availability triggers the accumulation of phytoplankton biomass in winter, when light limitation is strongest.
Birgit Koehler, Mårten Erlandsson, Martin Karlsson, and Lena Bergström
Biogeosciences, 19, 2295–2312,Short summary
Understanding species richness patterns remains a challenge for biodiversity management. We estimated fish species richness over a coastal salinity gradient (3–32) with a method that allowed comparing data from various sources. Species richness was 3-fold higher at high vs. low salinity, and salinity influenced species’ habitat preference, mobility and feeding type. If climate change causes upper-layer freshening of the Baltic Sea, further shifts along the identified patterns may be expected.
Uri Obolski, Thomas Wichard, Alvaro Israel, Alexander Golberg, and Alexander Liberzon
Biogeosciences, 19, 2263–2271,Short summary
The algal genus Ulva plays a major role in coastal ecosystems worldwide and is a promising prospect as an seagriculture crop. A substantial hindrance to cultivating Ulva arises from sudden sporulation, leading to biomass loss. This process is not yet well understood. Here, we characterize the dynamics of Ulva growth, considering the potential impact of sporulation inhibitors, using a mathematical model. Our findings are an essential step towards understanding the dynamics of Ulva growth.
Emanuela Fanelli, Samuele Menicucci, Sara Malavolti, Andrea De Felice, and Iole Leonori
Biogeosciences, 19, 1833–1851,Short summary
Zooplankton play a key role in marine ecosystems, forming the base of the marine food web and a link between primary producers and higher-order consumers, such as fish. This aspect is crucial in the Adriatic basin, one of the most productive and overexploited areas of the Mediterranean Sea. A better understanding of community and food web structure and their response to water mass changes is essential under a global warming scenario, as zooplankton are sensitive to climate change.
Masaya Yoshikai, Takashi Nakamura, Rempei Suwa, Sahadev Sharma, Rene Rollon, Jun Yasuoka, Ryohei Egawa, and Kazuo Nadaoka
Biogeosciences, 19, 1813–1832,Short summary
This study presents a new individual-based vegetation model to investigate salinity control on mangrove productivity. The model incorporates plant hydraulics and tree competition and predicts unique and complex patterns of mangrove forest structures that vary across soil salinity gradients. The presented model does not hold an empirical expression of salinity influence on productivity and thus may provide a better understanding of mangrove forest dynamics in future climate change.
Coulson A. Lantz, William Leggat, Jessica L. Bergman, Alexander Fordyce, Charlotte Page, Thomas Mesaglio, and Tracy D. Ainsworth
Biogeosciences, 19, 891–906,Short summary
Coral bleaching events continue to drive the degradation of coral reefs worldwide. In this study we measured rates of daytime coral reef community calcification and photosynthesis during a reef-wide bleaching event. Despite a measured decline in coral health across several taxa, there was no change in overall daytime community calcification and photosynthesis. These findings highlight potential limitations of these community-level metrics to reflect actual changes in coral health.
Hyewon Heather Kim, Jeff S. Bowman, Ya-Wei Luo, Hugh W. Ducklow, Oscar M. Schofield, Deborah K. Steinberg, and Scott C. Doney
Biogeosciences, 19, 117–136,Short summary
Heterotrophic marine bacteria are tiny organisms responsible for taking up organic matter in the ocean. Using a modeling approach, this study shows that characteristics (taxonomy and physiology) of bacteria are associated with a subset of ecological processes in the coastal West Antarctic Peninsula region, a system susceptible to global climate change. This study also suggests that bacteria will become more active, in particular large-sized cells, in response to changing climates in the region.
Raúl Tapia, Sze Ling Ho, Hui-Yu Wang, Jeroen Groeneveld, and Mahyar Mohtadi
Revised manuscript accepted for BGShort summary
We report census counts of planktic foraminifera in depth-stratified plankton net samples off Indonesia. Our results show that the vertical distribution of foraminifera species routinely used in paleoceanographic reconstructions varies in hydrographically distinct regions, likely in response to food availability. Consequently, the thermal gradient based on mixed layer and thermocline dwellers also differs for these regions, suggesting potential implications for paleoceanographic reconstructions.
Alice E. Webb, Didier M. de Bakker, Karline Soetaert, Tamara da Costa, Steven M. A. C. van Heuven, Fleur C. van Duyl, Gert-Jan Reichart, and Lennart J. de Nooijer
Biogeosciences, 18, 6501–6516,Short summary
The biogeochemical behaviour of shallow reef communities is quantified to better understand the impact of habitat degradation and species composition shifts on reef functioning. The reef communities investigated barely support reef functions that are usually ascribed to conventional coral reefs, and the overall biogeochemical behaviour is found to be similar regardless of substrate type. This suggests a decrease in functional diversity which may therefore limit services provided by this reef.
Emmanuel Devred, Andrea Hilborn, and Cornelia Elizabeth den Heyer
Biogeosciences, 18, 6115–6132,Short summary
A theoretical model of grey seal seasonal abundance on Sable Island (SI) coupled with chlorophyll-a concentration [chl-a] measured by satellite revealed the impact of seal nitrogen fertilization on the surrounding waters of SI, Canada. The increase in seals from about 100 000 in 2003 to about 360 000 in 2018 during the breeding season is consistent with an increase in [chl-a] leeward of SI. The increase in seal abundance explains 8 % of the [chl-a] increase.
Julie Meilland, Michael Siccha, Maike Kaffenberger, Jelle Bijma, and Michal Kucera
Biogeosciences, 18, 5789–5809,Short summary
Planktonic foraminifera population dynamics has long been assumed to be controlled by synchronous reproduction and ontogenetic vertical migration (OVM). Due to contradictory observations, this concept became controversial. We here test it in the Atlantic ocean for four species of foraminifera representing the main clades. Our observations support the existence of synchronised reproduction and OVM but show that more than half of the population does not follow the canonical trajectory.
Federica Maggioni, Mireille Pujo-Pay, Jérome Aucan, Carlo Cerrano, Barbara Calcinai, Claude Payri, Francesca Benzoni, Yves Letourneur, and Riccardo Rodolfo-Metalpa
Biogeosciences, 18, 5117–5140,Short summary
Based on current experimental evidence, climate change will affect up to 90 % of coral reefs worldwide. The originality of this study arises from our recent discovery of an exceptional study site where environmental conditions (temperature, pH, and oxygen) are even worse than those forecasted for the future. While these conditions are generally recognized as unfavorable for marine life, we found a rich and abundant coral reef thriving under such extreme environmental conditions.
Nisan Sariaslan and Martin R. Langer
Biogeosciences, 18, 4073–4090,Short summary
Analyses of foraminiferal assemblages from the Mamanguape mangrove estuary (northern Brazil) revealed highly diverse, species-rich, and structurally complex biotas. The atypical fauna resembles shallow-water offshore assemblages and are interpreted to be the result of highly saline ocean waters penetrating deep into the estuary. The findings contrast with previous studies, have implications for the fossil record, and provide novel perspectives for reconstructing mangrove environments.
Jutta E. Wollenburg, Jelle Bijma, Charlotte Cremer, Ulf Bickmeyer, and Zora Mila Colomba Zittier
Biogeosciences, 18, 3903–3915,Short summary
Cultured at in situ high-pressure conditions Cibicides and Cibicidoides taxa develop lasting ectoplasmic structures that cannot be retracted or resorbed. An ectoplasmic envelope surrounds their test and may protect the shell, e.g. versus carbonate aggressive bottom water conditions. Ectoplasmic roots likely anchor the specimens in areas of strong bottom water currents, trees enable them to elevate themselves above ground, and twigs stabilize and guide the retractable pseudopodial network.
Biogeosciences, 18, 3631–3635,Short summary
The Indian Ocean Rim hosts many of the underdeveloped and emerging economies that depend on ocean resources for the livelihood of millions. Operational ocean information services cater to the requirements of resource managers and end-users to efficiently harness resources, mitigate threats and ensure safety. This paper outlines existing tools and explores the ongoing research that has the potential to convert the findings into operational services in the near- to midterm.
Finn Mielck, Rune Michaelis, H. Christian Hass, Sarah Hertel, Caroline Ganal, and Werner Armonies
Biogeosciences, 18, 3565–3577,Short summary
Marine sand mining is becoming more and more important to nourish fragile coastlines that face global change. We investigated the largest sand extraction site in the German Bight. The study reveals that after more than 35 years of mining, the excavation pits are still detectable on the seafloor while the sediment composition has largely changed. The organic communities living in and on the seafloor were strongly decimated, and no recovery is observable towards previous conditions.
France Van Wambeke, Elvira Pulido, Philippe Catala, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Barbara Marie, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, and Christian Tamburini
Biogeosciences, 18, 2301–2323,Short summary
Michaelis–Menten kinetics were determined for alkaline phosphatase, aminopeptidase and β-glucosidase in the Mediterranean Sea. Although the ectoenzymatic-hydrolysis contribution to heterotrophic prokaryotic needs was high in terms of N, it was low in terms of C. This study points out the biases in interpretation of the relative differences in activities among the three tested enzymes in regard to the choice of added concentrations of fluorogenic substrates.
Oscar E. Romero, Simon Ramondenc, and Gerhard Fischer
Biogeosciences, 18, 1873–1891,Short summary
Upwelling intensity along NW Africa varies on the interannual to decadal timescale. Understanding its changes is key for the prediction of future changes of CO2 sequestration in the northeastern Atlantic. Based on a multiyear (1988–2009) sediment trap experiment at the site CBmeso, fluxes and the species composition of the diatom assemblage are presented. Our data help in establishing the scientific basis for forecasting and modeling future states of this ecosystem and its decadal changes.
Katharine T. Bigham, Ashley A. Rowden, Daniel Leduc, and David A. Bowden
Biogeosciences, 18, 1893–1908,Short summary
Turbidity flows – underwater avalanches – are large-scale physical disturbances believed to have profound impacts on productivity and diversity of benthic communities in the deep sea. We reviewed published studies and found that current evidence for changes in productivity is ambiguous at best, but the influence on regional and local diversity is clearer. We suggest study design criteria that may lead to a better understanding of large-scale disturbance effects on deep-sea benthos.
Phillip Williamson, Hans-Otto Pörtner, Steve Widdicombe, and Jean-Pierre Gattuso
Biogeosciences, 18, 1787–1792,Short summary
The reliability of ocean acidification research was challenged in early 2020 when a high-profile paper failed to corroborate previously observed impacts of high CO2 on the behaviour of coral reef fish. We now know the reason why: the
replicatedstudies differed in many ways. Open-minded and collaborative assessment of all research results, both negative and positive, remains the best way to develop process-based understanding of the impacts of ocean acidification on marine organisms.
Michael Lintner, Bianca Lintner, Wolfgang Wanek, Nina Keul, and Petra Heinz
Biogeosciences, 18, 1395–1406,Short summary
Foraminifera are unicellular marine organisms that play an important role in the marine element cycle. Changes of environmental parameters such as salinity or temperature have a significant impact on the faunal assemblages. Our experiments show that changes in salinity immediately influence the foraminiferal activity. Also the light regime has a significant impact on carbon or nitrogen processing in foraminifera which contain no kleptoplasts.
Michele Casini, Martin Hansson, Alessandro Orio, and Karin Limburg
Biogeosciences, 18, 1321–1331,Short summary
In the past 20 years the condition of the eastern Baltic cod has dropped, with large implications for the fishery. Our results show that simultaneously the cod population has moved deeper while low-oxygenated waters detrimental for cod growth have become shallower. Cod have thus dwelled more in detrimental waters, explaining the drop in its condition. This study, using long-term fish and hydrological monitoring data, evidences the impact of deoxygenation on fish biology and fishing.
Elizabeth D. LaBone, Kenneth A. Rose, Dubravko Justic, Haosheng Huang, and Lixia Wang
Biogeosciences, 18, 487–507,Short summary
The hypoxic zone is an area of low dissolved oxygen (DO) in the Gulf of Mexico. Fish can be killed by exposure to hypoxia and can be negatively impacted by exposure to low, nonlethal DO concentrations (sublethal DO). We found that high sublethal area resulted in higher exposure and DO variability had a small effect on exposure. There was a large variation in exposure among individuals, which when combined with spatial variability of DO, can result in an underestimation of exposure when averaged.
Svenja Reents, Peter Mueller, Hao Tang, Kai Jensen, and Stefanie Nolte
Biogeosciences, 18, 403–411,Short summary
By conducting a flooding experiment with two genotypes of the salt-marsh grass Elymus athericus, we show considerable differences in biomass response to flooding within the same species. As biomass production plays a major role in sedimentation processes and thereby salt-marsh accretion, we emphasise the importance of taking intraspecific differences into account when evaluating ecosystem resilience to accelerated sea level rise.
Cara Nissen and Meike Vogt
Biogeosciences, 18, 251–283,Short summary
Using a regional Southern Ocean ecosystem model, we find that the relative importance of Phaeocystis and diatoms at high latitudes is controlled by iron and temperature variability, with light levels controlling the seasonal succession in coastal areas. Yet, biomass losses via aggregation and grazing matter as well. We show that the seasonal succession of Phaeocystis and diatoms impacts the seasonality of carbon export fluxes with ramifications for nutrient cycling and food web dynamics.
Jiangtao Li, Lingyuan Gu, Shijie Bai, Jie Wang, Lei Su, Bingbing Wei, Li Zhang, and Jiasong Fang
Biogeosciences, 18, 113–133,Short summary
Few studies have focused on the particle-attached (PA) and free-living (FL) microbes of the deep ocean. Here we determined PA and FL microbial communities along depth profiles of the SCS. PA and FL fractions accommodated divergent microbial compositions, and most of them are potentially generalists with PA and FL dual lifestyles. A potential vertical connectivity between surface-specific microbes and those in the deep ocean was indicated, likely through microbial attachment to sinking particles.
Saskia Brix, Karen J. Osborn, Stefanie Kaiser, Sarit B. Truskey, Sarah M. Schnurr, Nils Brenke, Marina Malyutina, and Pedro Martinez Arbizu
Biogeosciences, 17, 6163–6184,Short summary
The Clarion–Clipperton Fracture Zone (CCZ) located in the Pacific is commercially the most important area of proposed manganese nodule mining. Extraction of this will influence the life and distribution of small deep-sea invertebrates like peracarid crustaceans, of which >90 % are undescribed species new to science. We are doing a species delimitation approach as baseline for an ecological interpretation of species distribution and discuss the results in light of future deep-sea conservation.
Amal Jayakumar and Bess B. Ward
Biogeosciences, 17, 5953–5966,Short summary
Diversity and community composition of nitrogen-fixing microbes in the three main oxygen minimum zones of the world ocean were investigated using nifH clone libraries. Representatives of three main clusters of nifH genes were detected. Sequences were most diverse in the surface waters. The most abundant OTUs were affiliated with Alpha- and Gammaproteobacteria. The sequences were biogeographically distinct and the dominance of a few OTUs was commonly observed in OMZs in this (and other) studies.
Guillermo Feliú, Marc Pagano, Pamela Hidalgo, and François Carlotti
Biogeosciences, 17, 5417–5441,Short summary
The impact of Saharan dust deposition events on the Mediterranean Sea ecosystem was studied during a basin-scale survey (PEACETIME cruise, May–June 2017). Short-term responses of the zooplankton community were observed after episodic dust deposition events, highlighting the impact of these events on productivity up to the zooplankton level in the poorly fertilized pelagic ecosystems of the southern Mediterranean Sea.
Douglas Lessa, Raphaël Morard, Lukas Jonkers, Igor M. Venancio, Runa Reuter, Adrian Baumeister, Ana Luiza Albuquerque, and Michal Kucera
Biogeosciences, 17, 4313–4342,Short summary
We observed that living planktonic foraminifera had distinct vertically distributed communities across the Subtropical South Atlantic. In addition, a hierarchic alternation of environmental parameters was measured to control the distribution of planktonic foraminifer's species depending on the water depth. This implies that not only temperature but also productivity and subsurface processes are signed in fossil assemblages, which could be used to perform paleoceanographic reconstructions.
Karl M. Attard and Ronnie N. Glud
Biogeosciences, 17, 4343–4353,Short summary
Light-use efficiency defines the ability of primary producers to convert sunlight energy to primary production. This report provides a framework to compute hourly and daily light-use efficiency using underwater eddy covariance, a recent technological development that produces habitat-scale rates of primary production for many different habitat types. The approach, tested on measured flux data, provides a useful means to compare habitat productivity across time and space.
Stacy Deppeler, Kai G. Schulz, Alyce Hancock, Penelope Pascoe, John McKinlay, and Andrew Davidson
Biogeosciences, 17, 4153–4171,Short summary
Our study showed how ocean acidification can exert both direct and indirect influences on the interactions among trophic levels within the microbial loop. Microbial grazer abundance was reduced at CO2 concentrations at and above 634 µatm, while microbial communities increased in abundance, likely due to a reduction in being grazed. Such changes in predator–prey interactions with ocean acidification could have significant effects on the food web and biogeochemistry in the Southern Ocean.
Mirjana Najdek, Marino Korlević, Paolo Paliaga, Marsej Markovski, Ingrid Ivančić, Ljiljana Iveša, Igor Felja, and Gerhard J. Herndl
Biogeosciences, 17, 3299–3315,Short summary
The response of Cymodocea nodosa to environmental changes was reported during a 15-month period. The meadow decline was triggered in spring by the simultaneous reduction of available light in the water column and the creation of anoxic conditions in the rooted area. This disturbance was critical for the plant since it took place during its recruitment phase when metabolic needs are maximal and stored reserves minimal. The loss of such habitat-forming seagrass is a major environmental concern.
Timm Schoening, Autun Purser, Daniel Langenkämper, Inken Suck, James Taylor, Daphne Cuvelier, Lidia Lins, Erik Simon-Lledó, Yann Marcon, Daniel O. B. Jones, Tim Nattkemper, Kevin Köser, Martin Zurowietz, Jens Greinert, and Jose Gomes-Pereira
Biogeosciences, 17, 3115–3133,Short summary
Seafloor imaging is widely used in marine science and industry to explore and monitor areas of interest. The selection of the most appropriate imaging gear and deployment strategy depends on the target application. This paper compares imaging platforms like autonomous vehicles or towed camera frames and different deployment strategies of those in assessing the megafauna abundance of polymetallic-nodule fields. The deep-sea mining industry needs that information for robust impact monitoring.
Tatsuro Tanioka and Katsumi Matsumoto
Biogeosciences, 17, 2939–2954,Short summary
We conducted an extensive literature survey (meta-analysis) on how the C : N : P ratio varies with change in key environmental drivers. We found that the expected reduction in nutrients and warming under the future climate change scenario is likely to result in increased C : P and C : N of marine phytoplankton. Further, our findings highlight the greater stoichiometric plasticity of eukaryotes over prokaryotes, which provide us insights on how to understand and model plankton.
Vanessa Joglar, Antero Prieto, Esther Barber-Lluch, Marta Hernández-Ruiz, Emilio Fernández, and Eva Teira
Biogeosciences, 17, 2807–2823,Short summary
Coastal marine ecosystems are among the most ecologically and economically productive areas providing a large fraction of ecosystem goods and services to human populations, and B vitamins have long been considered important growth factors for phytoplankton. Our findings indicate that the responses of microbial plankton to B-vitamin supply are mainly driven by the bacterial community composition and that microbial plankton in this area seems to be well adapted to cope with B-vitamin shortage.
Tasnim Patel, Henri Robert, Cedric D'Udekem D'Acoz, Koen Martens, Ilse De Mesel, Steven Degraer, and Isa Schön
Biogeosciences, 17, 2731–2744,Short summary
Exploitation of deep-sea resources in one of the largest ecosystems on the planet has rendered research of its biodiversity more urgent than ever before. We investigated the known habitats and connectivity of deep-sea scavenging amphipods and obtained important knowledge about several species. We also demonstrated that a long-term disturbance experiment has possibly reduced amphipod biodiversity. These data and further sampling expeditions are instrumental for formulating sustainable policies.
Daphne Cuvelier, Pedro A. Ribeiro, Sofia P. Ramalho, Daniel Kersken, Pedro Martinez Arbizu, and Ana Colaço
Biogeosciences, 17, 2657–2680,Short summary
Polymetallic nodule mining will remove hard substrata from the abyssal deep-sea floor. The only neighbouring ecosystems featuring hard substratum are seamounts, and their inhabiting fauna could aid in recovery post-mining. Nevertheless, first observations of seamount megafauna were very different from nodule-associated megafauna and showed little overlap. The possible uniqueness of these ecosystems implies that they should be included in management plans for the conservation of biodiversity.
Karen F. Wishner, Brad Seibel, and Dawn Outram
Biogeosciences, 17, 2315–2339,Short summary
Increasing deoxygenation and oxygen minimum zone expansion are consequences of global warming. Copepod species had different vertical distribution strategies and physiologies associated with oxygen profile variability (0–1000 m). Species (1) changed vertical distributions and maximum abundance depth, (2) shifted diapause depth, (3) changed diel vertical migration depths, or (4) changed epipelagic depth range in the aerobic mixed layer. Present-day variability helps predict future scenarios.
Magdalini Christodoulou, Timothy O'Hara, Andrew F. Hugall, Sahar Khodami, Clara F. Rodrigues, Ana Hilario, Annemiek Vink, and Pedro Martinez Arbizu
Biogeosciences, 17, 1845–1876,Short summary
Unexpectedly high diversity was revealed in areas licenced for polymetallic nodule mining exploration in the Pacific Ocean. For the first time, a comprehensive reference library including 287 novel ophiuroid sequences allocated to 43 species was produced. Differences in food availability along the nodule province of CCZ were reflected in the biodiversity patterns observed. The APEI3's dissimilarity with the exploration contract areas questions its ability to serve as a biodiversity reservoir.
Julie Meilland, Hélène Howa, Vivien Hulot, Isaline Demangel, Joëlle Salaün, and Thierry Garlan
Biogeosciences, 17, 1437–1450,Short summary
This study reports on planktonic foraminifera (PF) diversity and distribution in the Barents Sea. The species Globigerinita uvula and Turborotalita quinqueloba dominate the water column while surface sediments are dominated by Neogloboquadrina pachyderma. We hypothesize the unusual dominance of G. uvula in the water to be a seasonal signal or a result of climate forcing. Size-normalized-protein concentrations of PF show a northward decrease, suggesting biomass to vary with the environment.
Julien Richirt, Bettina Riedel, Aurélia Mouret, Magali Schweizer, Dewi Langlet, Dorina Seitaj, Filip J. R. Meysman, Caroline P. Slomp, and Frans J. Jorissen
Biogeosciences, 17, 1415–1435,Short summary
The paper presents the response of benthic foraminiferal communities to seasonal absence of oxygen coupled with the presence of hydrogen sulfide, considered very harmful for several living organisms. Our results suggest that the foraminiferal community mainly responds as a function of the duration of the adverse conditions. This knowledge is especially useful to better understand the ecology of benthic foraminifera but also in the context of palaeoceanographic interpretations.
Xiangqi Yi, Fei-Xue Fu, David A. Hutchins, and Kunshan Gao
Biogeosciences, 17, 1169–1180,Short summary
Combined effects of warming and light intensity were estimated in N2-fixing cyanobacterium Trichodesmium. Its physiological responses to warming were significantly modulated by light, with growth peaking at 27 °C under the light-saturating condition but being non-responsive across the range of 23–31 °C under the light-limiting condition. Light shortage also weakened the acclimation ability of Trichodesmium to warming, making light-limited Trichodesmium more sensitive to acute temperature change.
Jan Goleń, Jarosław Tyszka, Ulf Bickmeyer, and Jelle Bijma
Biogeosciences, 17, 995–1011,Short summary
We studied the organisation and dynamics of actin in foraminifera. Actin is one of the key structural proteins in most lifeforms. Our investigations show that in foraminifera it forms small granules, around 1 µm in diameter, that display rapid movement. This granularity is unusual in comparison to other organisms. We suppose that these granules are most likely involved in the formation of all types of pseudopods responsible for movement, food capturing, biomineralisation, and other functions.
Paulo Bonifácio, Pedro Martínez Arbizu, and Lénaïck Menot
Biogeosciences, 17, 865–886,Short summary
The patterns observed in the composition of polychaete assemblages were attributed to variations in food supply at the regional scale and nodule density at the local scale. The high levels of species replacement were mainly driven by rare species, leading to regional species pool estimates between 498 and 240 000 species. The high proportion of singletons seems reflect an under-sampling bias that is currently preventing the assessment of potential biodiversity loss due to nodule mining.
Stephanie Dutkiewicz, Pedro Cermeno, Oliver Jahn, Michael J. Follows, Anna E. Hickman, Darcy A. A. Taniguchi, and Ben A. Ward
Biogeosciences, 17, 609–634,Short summary
Phytoplankton are an essential component of the marine food web and earth's carbon cycle. We use observations, ecological theory and a unique trait-based ecosystem model to explain controls on patterns of marine phytoplankton biodiversity. We find that different dimensions of diversity (size classes, biogeochemical functional groups, thermal norms) are controlled by a disparate combination of mechanisms. This may explain why previous studies of phytoplankton diversity had conflicting results.
Emily White, Clara J. M. Hoppe, and Björn Rost
Biogeosciences, 17, 635–647,Short summary
The Arctic picoeukaryote Micromonas pusilla was acclimated to two pCO2 levels under a constant and a dynamic light, simulating more realistic light fields. M. pusilla was able to benefit from ocean acidification with an increase in growth rate, irrespective of the light regime. In dynamic light M. pusilla optimised its photophysiology for effective light usage during both low- and high-light periods. This highlights M. pusilla is likely to cope well with future conditions in the Arctic Ocean.
Oscar E. Romero, Karl-Heinz Baumann, Karin A. F. Zonneveld, Barbara Donner, Jens Hefter, Bambaye Hamady, Vera Pospelova, and Gerhard Fischer
Biogeosciences, 17, 187–214,Short summary
Monitoring of the multiannual evolution of populations representing different trophic levels allows for obtaining insights into the impact of climate variability in marine coastal upwelling ecosystems. By using a multiyear, continuous (1,900 d) sediment trap record, we assess the dynamics and fluxes of calcareous, organic and siliceous microorganisms off Mauritania (NW Africa). The experiment allowed for the recognition of a general sequence of seasonal variations of the main populations.
Ulrike Hanz, Claudia Wienberg, Dierk Hebbeln, Gerard Duineveld, Marc Lavaleye, Katriina Juva, Wolf-Christian Dullo, André Freiwald, Leonardo Tamborrino, Gert-Jan Reichart, Sascha Flögel, and Furu Mienis
Biogeosciences, 16, 4337–4356,Short summary
Along the Namibian and Angolan margins, low oxygen conditions do not meet environmental ranges for cold–water corals and hence are expected to be unsuitable habitats. Environmental conditions show that tidal movements deliver water with more oxygen and high–quality organic matter, suggesting that corals compensate unfavorable conditions with availability of food. With the expected expansion of oxygen minimum zones in the future, this study provides an example how ecosystems cope with extremes.
Alexia Dubuc, Ronald Baker, Cyril Marchand, Nathan J. Waltham, and Marcus Sheaves
Biogeosciences, 16, 3959–3976,Short summary
Little is known about how hypoxia influences mangrove fish assemblages. In situ video observations reveal species-specific avoidance strategies in response to developing hypoxia in a mangrove forest. Taxa commonly using mangroves could withstand hypoxia, while others usually associated with reef habitats were not recorded below 70 % saturation. These results suggest that hypoxia is an important factor shaping mangrove fish assemblages and could explain the low species richness usually observed.
AMAP: AMAP Assessment 2013: Arctic Ocean Acidification, Arctic Monitoring and Assessment Programme (AMAP), Oslo, Norway, viii + 99 pp., ISBN – 978-82-7971-082-0, 2013.
Arendt, K. E., Juul-Pedersen, T., Mortensen, J., Blicher, M. E., and Rysgaard, S: A 5-year study of seasonal patterns in mesozooplankton community structure in a sub-Arctic fjord reveals dominance of Microsetella norvegica (Crustacea, Copepoda), J. Plank. Res., 35, 105–120, 2013.
Arrigo, K. R., van Dijken, G., and Pabi, S.: Impact of a shrinking Arctic ice cover on marine primary production, Geophys. Res. Lett., 35, 1–6, 2008.
Attard, K. M., Glud, R. N., McGinnis, D. F., and Rysgaard, S.: Seasonal rates of benthic primary production in a Greenland fjord measured by aquatic eddy correlationLimnol, Oceanography, 59, 1555–1569, 2014.
Björk, M., Axelsson, L., and Beer, S.: Why is Ulva intestinalis the only macroalga inhabiting isolated rock pools along the Swedish Atlantic coast? Mar. Ecol. Prog. Ser., 284, 109–116, 2004.
Blicher, M. E. and Sejr, M. K.: Abundance, oxygen consumption and carbon demand of brittle stars in Young Sound and the NE Greenland shelf, Mar. Ecol. Prog. Ser., 422, 139–144, 2011.
Blicher, M. E., Sejr, M. K., and Rysgaard, S.: High carbon demand of dominant macrozoobenthic species indicates their central role in ecosystem carbon flow in a sub-Arctic fjord, Mar. Ecol. Ser., 383, 127–140, 2009.
Blicher, M. E., Rysgaard, S., and Sejr, M. K.: Growth and production of sea urchin Strongylocentrotus droebachiensis in a high-Arctic fjord, and growth along a climatic gradient (64 to 77 ° N), Mar. Ecol.-Prog. Ser., 341, 89–102, 2007.
Blicher, M. E., Sejr, M. K., and Høgslund, S.: Population structure of Mytilus edulis in the intertidal zone in a sub-Arctic fjord, SW Greenland, Mar. Ecol. Prog. Ser., 487, 89–100, 2013.
Connell, S. and Russell, B. D.: The direct effects of increasing CO2 and temperature on non-calcifying organisms: increasing the potential for phase shifts in kelp forests, Proc. R. Soc. B, 277, 1409–1415, 2010.
Cornwall, C. E., Hepburn, C. D., McGraw, C. M., Currie, K. I., Pilditch, C. A., Hunter, K. A., Boyd, P. W., and Hurd, C. L.: Diurnal fluctuations in seawater pH influence the response of a calcifying macroalga to ocean acidification, Proc. R. Soc. B, 280, 20132201, https://doi.org/10.1098/rspb.2013.2201, 2013a.
Cornwall, C. E., Hepburn, C. D., Pilditch, C. A., and Hurd, C. L.: Concentration boundary layers around complex assemblages of macroalgae: Implications for the effects of ocean acidification on understorey coralline algae, Limnol. Oceanogr., 58, 121–130, 2013b.
De Beer, D. and Larkum, A. W. D.: Photosynthesis and calcification in the calcifying algae Halimeda discoidea studied with microsensors, Plant Cell Environ., 24, 1209–1217, 2001.
Delille, B., Delille, D., Fiala, M., Prevost, C., and Frankignoulle, M.: Seasonal changes of pCO2 over a subantarctic Macrocystis kelp bed, Polar Biol., 23, 706–716, 2000.
Delille, B., Borges, A. V., and Delille, D.: Influence of giant kelp beds (Macrocystis pyrifera) on diel cycles of pCO2 and DIC in the Sub-Antarctic coastal area, Estuar. Coast Shelf Sci., 81, 114–122., 2009.
Dickson, A. G. and Millero, F. J.: A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep-Sea Res., 34, 1733–1743, 1987.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to best practices for ocean CO2 measurements, PICES Special Publication, 191 pp., 2007.
Duarte, C., Hendriks, I., Moore, T., Olsen, Y., Steckbauer, A., Ramajo, L., Carstensen, J., Trotter, J., and McCulloch, M.: Is Ocean Acidification an Open-Ocean Syndrome? Understanding Anthropogenic Impacts on Seawater pH, Estuar. Coast., 36, 221–236, 2013.
Fabry, V. J., McClintock, J. B., Mathis, J. T., and Grebmeier, J. M.: Ocean Acidification at High Latitudes: The Bellweather, Oceanography, 22, 160–171, 2009.
Frieder, C. A., Nam, S. H., Martz, T. R., and Levin, L. A.: High temporal and spatial variability of dissolved oxygen and pH in a nearshore California kelp forest, Biogeosciences, 9, 3917–3930, https://doi.org/10.5194/bg-9-3917-2012, 2012.
Frieder, C. A., Gonzales, J. P., Bockmon, E. E., Navarro, M. O., and Levini, L. A.: Can variable pH and low oxygen moderate ocean acidification outcomes for mussel larvae?, Glob. Change Biol., 20, 754–764, 2014.
Glud, R. N., Berg, P., Hume, A., Batty, P., Blicher, M. E., Lennert, K., and Rysgaard, S.: Benthic O2 exchange across hard-bottom substrates quantified by eddy correlation in a sub-Arctic fjord, Mar. Ecol.-Prog. Ser., 417, 1–12, 2010.
Helm, V., Humbert, A., and Miller, H.: Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2, Cryosphat, 8, 1539–1559, 2014.
Hendriks, I. E., Olsen, Y. S., Ramajo, L., Basso, L., Steckbauer, A., Moore, T. S., Howard, J., and Duarte, C. M.: Photosynthetic activity buffers ocean acidification in seagrass meadows, Biogeosciences, 11, 333–346, https://doi.org/10.5194/bg-11-333-2014, 2014.
Hofmann, G. E., Smith, J. E., Johnson, K. S., Send, U., Levin, L. A., Micheli, F., Paytan, A., Price, N. N., Peterson, B., Takeshita, Y., Matson, P. G., Crook, E. D., Kroeker, K. J.., Gambi, M. C., Rivest, E. B., Frieder, C. A., Yu, P. C., and Martz, T. R.: High-Frequency Dynamics of Ocean pH: A Multi-Ecosystem Comparison, PLoS ONE, 6, e28983, https://doi.org/10.1371/journal.pone.0028983, 2011.
Høgslund, S., Sejr, M. S., Wiktor, J. Jr., Blicher, M. E., and Wegeberg, S.: Intertidal community composition along rocky shores in Southwest Greenland: a quantitative approach, Polar Biol., 37, 1549–1561, 2014.
Hurd, C. L. and Pilditch C. A.: Flow-induced morphological variations affect diffusion boundary-layer thickness of Macrocystis pyrifera (Heterokontophyta, Laminariales), J. Phycol., 47, 341-351, 2011.
Hurd, C. L., Cornwall, C. E., Currie, K., Hepburn, C. D., McGraw, C. M., Hunter, K. A., and Boyd P. W.: Metabolically-induced pH fluctuations by some coastal calcifiers exceed projected 22nd century ocean acidification: a mechanism for differential susceptibility?, Glob. Change Biol., 17, 3254–3262, 2011.
Jueterbock, A., Tyberghein, L.,Verbruggen, H., Coyer, J. A., Olsen, J. L., and Hoarau, G.: Climate change impact on seaweed meadow distribution in the North Atlantic rocky intertidal, Ecol. Evol., 3, 1356–1373, 2013.
Krause-Jensen, D. and Duarte, C. M. Expansion of vegetated coastal ecosystems in the future Arctic, Front. Mar. Sci., 1, 77, https://doi.org/10.3389/fmars.2014.00077, 2014.
Krause-Jensen, D., Marbà, N., Olesen, B., Sejr, M. K., Christensen, P. B., Rodrigues, J., Renaud, P. E., Balsby, T. J. S., and Rysgaard, S.: Seasonal sea ice cover as principal driver of spatial and temporal variation in depth extension and annual production of kelp in Greenland, Glob. Change Biol., 18, 2981–2994, 2012.
Krause-Jensen, D., Duarte, C. M., Hendriks, I. E., Meire, L., Blicher, M. E., Marbà, N., and Sejr, M. K.: Nested scales of pH variability in sub-Arctic Kobbefjord, SW Greenland, DIGI-TAL.CSIC, available at: http://hdl.handle.net/10261/112946, last access: 27 March 2015.
Kroeker K. J., Kordas, R. L., Crim, R., Hendriks, I. E., Ramajos, L., Singh, G. S., Duarte, C. M., and Gattuso, J.-P.: Impacts of ocean acidification on marine organisms: quantifying sensitivities and interaction with warming, Glob. Change Biol., 19, 1884–1896, 2013.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.: Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897–907, 1973.
Meire, L., Søgaard, D. H., Mortensen, J., Meysman, F. J. R., Soetaert, K., Arendt, K. E., Juul-Pedersen, T., Blicher, M. E., and Rysgaard, S.: Glacial meltwater and primary production are drivers of strong CO2 uptake in fjord and coastal waters adjacent to the Greenland Ice Sheet, Biogeosciences, 12, 2347–2363, https://doi.org/10.5194/bg-12-2347-2015, 2015.
Mercado J. M. and Gordillo F. J.: Inorganic carbon acquisition in algal communities: are the laboratory data relevant to the natural ecosystems?, Photosynth. Res., 109, 257–267, 2011.
Middelboe, A. L. and Hansen, P. J.: Direct effects of pH and inorganic carbon on macroalgal photosynthesis and growth, Mar. Biol. Res., 3, 134–144, 2007.
Olesen, B., Krause-Jensen, D., Marbà, N., and Christensen, P. B.: Eelgrass (Zostera marina L.) meadows in subarctic Greenland: Dense meadows with slow biomass turnover, Mar. Ecol. Prog. Ser., 518, 107–121, 2015.
Olischläger M., Bartsch, I., Gutow, L., and Wiencke, C.: Effects of ocean acidification on different life-cycle stages of the kelp Laminaria hyperborea (Phaeophyceae), Bot. Mar., 55, 511–525, 2012.
Parsons, T. R., Maita, Y., and Lalli, C. M.: A Manual of Chemical and Biological Methods for Seawater Analysis, Pergamon Press, 173 pp., 1984.
Pierrot, D. E. L. and Wallace, D. W. R.: MS Excel Program Developed for CO2 System Calculations. ORNL/CDIAC-105a. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee, 2006.
Popova, E. E., A. Yool, A. C. Coward, F. Dupont, C. Deal, S. Elliott, E. Hunke, M. Jin, M. Steele, and J. Zhang: What controls primary production in the Arctic Ocean? Results from an intercomparison of five general circulation models with biogeochemistry, J. Geophys. Res., 117, C00D12, https://doi.org/10.1029/2011JC007112, 2012.
Richter, A., Rysgaard, S., Dietrich, R., Mortensen, J., and Petersen, D.: Coastal tides in West Greenland derived from tide gauge records, Ocean Dyn., 61, 39–49, 2011.
Riera, P., Escaravage, C., and Leroux, C.: Trophic ecology of the rocky shore community associated with the Ascophyllum nodosum zone (Roscoff, France): a δ13C vs. δ15N investigation, Estuar. Coast Shelf Sci., 81, 143–148, 2009.
Sejr, M. K., Sand, M. K., Jensen, K. T., Petersen, J. K., Christensen, P. B., and Rysgaard, S.: Growth and production of Hiatella arctica (Bivalvia) in a high-Arctic fjord (Young Sound, Norhteast Greenland), Mar. Ecol. Prog. Ser., 244, 163–169, 2002.
Sejr, M. K., Krause-Jensen, D., Rysgaard, S., Sørensen, L. L., Christensen, P. B., and Glud, R. N.: Air-sea flux of CO2 in arctic coastal waters influenced by glacial melt water and sea ice, Tellus B, 63, 815–822, 10.1111/j.1600-0889.2011.00540.x, 2011.
Sejr, M. K., Krause-Jensen, D., Dalsgaard, T., Ruiz-Halpern, S., Duarte, C. M., Middelboe, M., Glud, R. N., Bendtsen, J., and Rysgaard, S.: Seasonal dynamics of autotrophic and heterotrophic plankton metabolism and pCO2 in a subarctic Greenland fjord, Limnol. Oceanogr., 59, 1764–1778, 2014.
Slagstad, D., Ellingsen, I. H., and Wassmann, P: Evaluating primary and secondary production in an Arctic Ocean void of summer sea ice: an experimental simulation approach, Prog. Oceanogr., 90, 117–131, 2011.
Takahashi, T., Olafsson, J., Goddard, J. G., Chipman, D. W., and Sutherland, S. C.: Seasonal variation of CO2 and nutrients in the high-latitude surface oceans: A comparative study, Global Biogeochem. Cy., 7, 843–878, 1993.
Thomsen, J., Casties, I., Pansch, C., Körtzinger, A., and Melzner, F.: Food availability outweighs ocean acidification effects in juvenile Mytilus edulis: laboratory and field experiments, Glob. Change Biol., 19, 1017–1027, 2013.
The Arctic Ocean is considered the most vulnerable ecosystem to ocean acidification (OA), but very little information is available on natural variability of pH in the Arctic coastal zone. We report pH variability at various scales in a Greenland fjord. Variability ranged up to 0.2-0.3 pH units horizontally and vertically in the fjord, between seasons and on diel basis in kelp forests and was extreme in tidal pools. Overall, primary producers played a fundamental role in producing mosaics of pH.
The Arctic Ocean is considered the most vulnerable ecosystem to ocean acidification (OA), but...