110. Experimental evidence of low pH negative effect on growth and calcification of Argopecten purpuratus (Lamarck, 1819)

Córdova, K. Z. L.1,2,3 ; Fernández, E.2; Flye-Sainte Marie, J.4; Graco, M. 2, 1; Aguirre, A.3

1 Ciencias del Mar, Universidad Peruana Cayetano Heredia
2 Área funcional de Oceanografía Química y Geológica, Instituto del Mar del Perú
3 Laboratorio de Ecofisiología Acuática, Instituto del Mar del Perú
4 LEMAR (UBO/CNRS/IRD), Université de Bretagne Occidentale
There is some evidence that the anthropogenic CO2 modifies the seawater, in particular the pH, increasing the ocean acidity. This change affect the carbonate system and in consequence the calcifying organisms such as scallops (Argopecten purpuratus). Along the Peruvian coast natural conditions of low pH (< 7,9) is a normal condition in the habitat of this species due to the coastal upwelling. In this context, an experiment was performed in order to test the effects of low pH on growth, calcification and dissolution in juvenile scallops (average size: 14 mm height). During one month, scallops were exposed to two different conditions: control with unmanipulated seawater presenting pH conditions similar to those found in situ (pHT mean = 7.8) and the treatment, in which seawater was injected with CO2 lowering the pH (pHT mean = 7.4). Under the control conditions, scallops exhibited a similar growth to those observed in the field (0.3 mm.d-1). Shell height and weight at the end of the experiment, growth and calcification rates were significantly lower in the low pH condition (p < 0.05). The weight of the soft tissues showed no significant difference between treatments. Dissolution rates were significantly higher in the treatment (p < 0.05). The results indicate that the low pH conditions affect the growth of the hard parts of the Peruvian scallop that might induce an increased susceptibility to predation and affect the aquaculture of this species. However, further studies are necessary during ontogeny and incorporate other stressors such as oxygen to better understand and predict responses of this species to environmental variability and global change.

Keywords: Argopecten purpuratus, pH, growth, calcification, dissolution.

Landscape changes on Deception Island’s coast after subglacial volcanic eruptions

M.C. Muniz1, R.M Anjos1, *, R.P. Cardoso1, L. H. Rosa2, R. Vieira1, H. Marotta1, K. Macario1, A. Ayres Neto1, C.D.N. Barboza1, A.S. Cid1, L.F. Rodrigues1

1LARA – Laboratório de Radioecologia, Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ, Brazil.

We have examined the radiocarbon ages, carbon and nitrogen isotopic compositions, and particle-size distributions in an ornithogenic soil profile from the Whalers Bay, Deception Island in Antarctica. In general, the textural characteristics of the sediment samples can be classified as muddy sand (very coarse silty very fine sand, poorly sorted). The δ13C values range from −24.8‰ to −23.0‰, showing that the predominant carbon source in Antarctic sediments is from terrestrial origin, such as mosses and lichens. The C/N ratio of the organic matter range of 5.2–8.6, consistent with the presence of penguin guano. The δ15N values range from 1.3‰ to 6.6‰, such that higher values (> 6) are observed in the topsoil and the layer of 27.5 ± 2.5 cm. However, the layers below them show a gradual decrease of δ15N. The chronology from bulk sediment samples indicate that the initial development of the organic matter began between 12500 and 11800 yr cal. BP. Additionally, the upper ground layers (between 2.5 ± 2.5 and 22.5 ± 2.5 cm depth) do not exhibit the age values monotonically increasing with depth. This behavior is only observed for layers below 27.5 ± 2.5cm depth, suggesting that the soil around this area can only be considered undisturbed below this sediment layer. Layers above this value are subjected to intense water erosion. Environment changes from the subglacial volcanic eruptions can be considered as an important factor not only for the understanding of its destruction power, but also about of the meltwater discharge effects on the autochthonous production imbalance and the erosion input from highest areas to the Antarctic coastal areas.

Bridging the OA Data Management Workflow Gap

Eugene F. Burger1, Kevin M. O’Brien2, Karl M. Smith2, Ansley Manke1, Roland Schweitzer3

1 NOAA/PMEL, Seattle, WA, 98112 USA
2 University Washington, Seattle, WA, 98112 USA
3 WeatherTop Consulting, Bryan, TX, 77801 USA

Effective use of data collected in support of Ocean Acidification research for analysis and synthesis product generation, it is desirable that the data are quality controlled, documented, and accessible by the applications scientists prefer to use. The processing requirements, along with increases in data volume now require a significant effort by OA scientists. Second level data processing and quality control is time-consuming, and reduces the resources available to scientists to perform their research. National data directives now require our scientific data to be documented, publically available and archived in two years or less, further adding to the scientists’ data management burden. Although procedures exist to submit data to archival centers, it is the data-workflow gap between initial data processing, known as level one processing, and data archival that has not been addressed for a significant amount of OA data.

We propose tools and processes that will streamline OA data processing and quality control. This vision suggests a solution that relies on a combination extending existing development and new development on tools that will allow users to span this data workflow gap; to streamline the processing, quality control, and archive submission of biogeochemical OA data and metadata. Workflow established by this software will reduce the data management burden for scientists while also creating data in interchangeable standards-based formats that promote easier use of the high-value data. Time savings gained by this streamlined data processing will also allow scientists to meet their obligations for data archival. This poster will present this vision and highlight the existing applications and tools, built for the SOCAT effort, which, if extended, can meet these OA data management requirements at a much-reduced development cost.

109. Marine Bioaccumulation Experiment Activities in Indonesia

Heny Suseno1, Wahyu Retno Prihatiningsih1

 

1 Marine Radioecology Research Group, PTKMR -National Nuclear Energy Agency, Indonesia

henis@batan.go.id

 

Background:

Marine radioecology research group have performed marine radioecology research such as: monitoring radionuclides in marine environment, biokinetic experiment for determine capability of marine biota to bioaccumulated 137Cs and heavy metal (using radiotracer) and risk assessment that used the ERICA tool. The background our research are surface ocean CO2 partial pressure (pCO2) is also expected to increase in proportion to the atmospheric CO2 increase due to the oceanic uptake of anthropogenic CO2. Increasing pCO2 in the surface ocean causes major shifts in seawater carbonate chemistry (aragonite saturation) and is likely to reduce pH. Such acidification of surface waters could affect marine organisms and in particular those having carbonate skeleton such as corals, coralline algae, foraminifera and coccolithophores for which calcification rates may decrease. In addition to these biological effects, new data areemerging on the disturbances of physiological process such as growth, development, metabolism, ionoregulation andacid-base balance under elevated temperature and pCO2. The increasing release of CO2 by human activities leads to ocean acidification and global warming. Both those consequences (i.e., increase in seawater pCO2 and temperature) may drastically affect the physiology of marine organisms.

Methods:

We are preparing to performed research influences of increasing of pCO2 in marine environment on the ability of bioaccumulation of contaminants by marine organism.  We also have submitted national research competition with thematic of radiotracer application to study decline of  calcinations process in coral due increasing pCO2 in surface seawater.

Findings:

On progress

Conclusions:

50. Ocean Acidification Effects on Productivity in a Coastal Antarctic Marine Microbial Community

Stacy L Deppeler (1)*, Karen Westwood (2,3), Imojen Pearce (2), Penelope Pascoe (2), Andrew T Davidson (2,3)

1 Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
2 Australian Antarctic Division, Channel Highway, Kingston, Tasmania 7050, Australia
3 Antarctic Climate and Ecosystems Cooperative Research Centre, Private Bag 80, Hobart, Tasmania 7001, Australia


Background
The Southern Ocean is responsible for ~40% of the ocean’s uptake of anthropogenic CO2. Marine microbes (phytoplankton, protozoa and bacteria) are the base of the Antarctic food chain and critical determinants of the fixation and fate of carbon in the oceans. Few studies on ocean acidification have been performed in Antarctic waters and while its effect on marine microbes in this region are critical to ecosystem function they are poorly understood.

Methods
Six 650 L minicosm tanks were used to expose a natural community of Antarctic marine microbes from near-shore waters off Davis Station, Antarctica, to different CO2 concentrations ranging from ambient (343 ppm) to 1641 ppm. Primary and bacterial productivity was measured through the uptake of radioisotope labelled 14C-bicarbonate and 14C-Leucine, respectively, and normalised to cell abundance.

Findings
Results showed that rates of gross primary production decreased markedly with increasing CO2 concentration mainly due to the lower cell growth in the high CO2 treatments. The maximum photosynthetic rate (Pmax) and cell-specific productivity were similar across all treatments, suggesting that the cellular photosynthetic performance was not diminished by increased CO2. No marked difference was observed in rates of bacterial production amongst CO2 treatments. However, cell-specific rates of production increased substantially, despite the decline in abundance over time in all treatments.

Conclusions
This research helps establish critical thresholds of pCO2 that change microbial productivity in Antarctic waters and aids prediction of the future effects of anthropogenic CO2 on the Antarctic ecosystem.

40. The impact of high pCO2, both static and fluctuating, on whole-organism thermal tolerance

Robert P. Ellis (1)*, Mauricio A. Urbina (1,2), Cameron Hird (1), Ceri Lewis (1)

1 Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
2 Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile

Background
Organisms’ thermal tolerance has traditionally been used as a predictor of the effect of climate change on species distributions. However, CO2-driven climate change is occurring alongside a parallel increase in seawater pCO2 which is driving ocean acidification. In many coastal regions these changes in pCO2 are not occurring as stable linear decreases over time, but manifest as highly dynamic, fluctuating conditions over a range of temporal and spatial scales. It is not yet fully understood how increases in pCO2, and hence OA, influence an organisms thermal tolerance, and therefore accurately projecting shifts in species distribution due to climate change remains challenging. Consequently, understanding how any complex fluctuations in pCO2 influence thermal tolerance of marine organisms is key for accurately predicting the impact of climate change on future species distributions.

Methods
We exposed the harbour ragworm, Hediste diversicolor, to one of four pCO2 regimes for 14 days prior to monitoring metabolic rate and upper and lower thermal tolerance (CTmax and CTmin). Treatments were chosen to represent ambient (400 µatm static), 2100 RCP 8.5 (950 µatm static) and 2300 A2 (1900 µatm static) emissions scenarios. Furthermore a fluctuating treatment (cycling between 400 µatm and 1900 µatm representing a semidiurnal tidal cycle) was included.

Findings
These experiments show that both metabolic rate and organismal thermal tolerance were significantly affected by seawater pCO2, and moreover the pCO2 regime (static or fluctuating) affected the magnitude of worms’ responses to high CO2 perturbations.

Conclusions
Understanding the impact of pCO2 on thermal tolerance is a key component for accurately projecting/modelling shifts in species distribution in a changing ocean. Moreover for an accurate representation of this effect we have shown that incorporating measures of fluctuating pCO2 regimes over different temporal or spatial scales is vital.

51. Distribution of Pelagic Biogenic Carbonates in the Southern Ocean south of Australia: a Baseline for Ocean Acidification Impact Assessment

Abraham Passmore (1), Thomas W. Trull (1)*, Diana M. Davies (1), Tim Smit (1)

1. Antarctic Climate and Ecosystems CRC, CSIRO Oceans and Atmosphere, and University of Tasmania Institute of Marine and Antarctic Studies, Hobart, Tasmania, 7001, Australia

The Southern Ocean provides a vital service by absorbing about one sixth of humankind’s annual emissions of CO2. This comes with a cost – an increase in ocean acidity that is expected to have negative impacts on ocean ecosystems. The reduced ability of phytoplankton and zooplankton to precipitate carbonate shells is a clearly identified risk. The impact depends on the significance of these organisms in Southern Ocean ecosystems, but there is very little information on their abundance or distribution. To quantify their presence, we used coulometric measurement of particulate inorganic carbonate (PIC) on particles filtered from surface seawater into two size fractions: 50-200 um to represent foraminifera (the most important biogenic carbonate forming zooplankton) and 1-50 um to represent coccolithophores (the most important biogenic carbonate forming phytoplankton). Ancillary measurements of biogenic silica (bSi) and particulate organic carbon (POC) provided context as estimates of the abundance of diatoms (the most abundant phytoplankton in polar waters), and total microbial biomass, respectively. Results along 9 transects from Australia to Antarctica in 2008-2015 showed low levels of all biogenic carbonate fractions compared to northern hemisphere polar waters. Levels were also ~5-fold lower than suggested by MODIS Aqua satellite remote sensing images. Coccolithophores exceeded the biomass of diatoms in Subantarctic waters, but their abundance decreased more than 10-fold southwards into Antarctic waters where diatoms dominated. Foram PIC contents were much lower, ~1/10 of coccolithophore levels, and also decreased southward. These decreases parallel the southward decrease in the saturation state of calcium carbonate in seawater, consistent with the theory that decreasing saturation restricts abundance and thus that advancing acidification will impact distributions. But other controls are also likely, and responses are likely to differ among different species. Expanded and more detailed surveys are required to better determine probable impacts.

13. Response of the photosynthetic rate of macrophytes to increased CO2 concentrations in a brackish-water ecosystem

Pajusalu Liina*, Martin Georg, Põllumäe Arno, and Paalme Tiina

Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Estonia

The future increasing CO2 concentrations together with eutrophication and the predicted warming of seawater will create multiple threats to the coastal ecosystems of the Baltic Sea. Macrophytes are important structural component in the shallow coastal Baltic Sea ecosystems. However, their response to acidification and climate change is not well understood. The aim of the current study was to assess whether partial pressure of carbon dioxide (pCO2) and different environmental factors exerted interactive effects on the photosynthesis of key macrophyte species. The second objective examines the short-term variability of carbonate chemistry in shallow-water macroalgal habitats. The field experiments were conducted in Kõiguste Bay (northern part of Gulf of Riga, the Baltic Sea) during vegetation seasons of 2011-2014. Separate mesocosms were maintained at different pCO2 levels: ~2000, ~1000 and ~200 µatm. We measured the short-term photosynthetic responses of four macroalgal species: Fucus vesiculosus, Furcellaria lumbricalis, Ulva intestinalis, Cladophora glomerata and seagrass: Zostera marina. Our results show that increased CO2 levels may enhance the photosynthetic rate of macrophyte species and suggest that predicted marine acidification of the Baltic Sea could have implications for interspecific competition and structure of benthic communities in a future high CO2 world. Daily pH fluctuations may be larger than 1 unit in a shallow-water macrophyte meadow in summer conditions. These daily pH changes may be of a larger magnitude than the scenario modeling suggests for the surface–water pH decrease in the Baltic Sea by 2100.

12. Living in the boundary layer of kelp blades: refuge from ocean acidification or training for harsh conditions?

Fanny Noisette (1), Catriona Hurd (1)*

1 Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, 7004 TAS Hobart, Australia

Background
Seaweeds are able to modify the chemical environment at their surface, in a micro-zone called the diffusive boundary layer (DBL) via their metabolic processes controlled by light intensity. Depending the thickness of the DBL, sessile invertebrates such as calcifying bryozoans or tube-forming polychaetes living at the surface of the blades can be affected by the chemical variations occurring in this layer. In the context of ocean acidification, these microhabitats might be considered as a refuge from lower pH during light as photosynthesis temporarily raises the pH to values higher than the mainstream seawater.

Methods
The thickness and the characteristics of the DBL were assessed at current day pH 8.1 and that predicted for the end of the century, pH 7.7, and seawater flows (slow: 0.5 and fast: 10 cm s-1) on blades of the kelp Ecklonia radiata. Oxygen and pH profiles from the blade surface to the mainstream seawater were measured with microsensors in both bare blades and blades colonized by the bryozoan Membranipora membranacea.

Findings
As predicted, the DBL was thicker in slow than in fast flow. We also assumed that the DBL would thinner on blades colonized by bryozoans whereas actually, their presence increased the DBL by creating their own one in addition to the kelp one. The oxygen concentrations and pH levels in the DBL were affected by the presence of bryozoans and the mainstream pH in different ways depending the flow.

Conclusions
These results show that living in the DBL of the kelps can constitute a refuge from ocean acidification or a training for harsh conditions for calcifying organisms living there, particularly in slow flow conditions.

11. Krill (Euphausia pacifica) Development in the Laboratory is Impaired at Currently Observed pCO2 Levels

Anna K. McLaskey (1)*, Julie E. Keister (1), Paul McElhany (2), M. Brady Olson (3), D. Shallin Busch (4), Mike Maher (2), Amanda K. Winans (1)

1 University of Washington, School of Oceanography, Seattle, WA, 98105, USA
2 NOAA Northwest Fisheries Science Center, Seattle, WA, 98112, USA
3 Western Washington University, Shannon Point Marine Center, Anacortes, WA, 98221, USA
4 NOAA Northwest Fisheries Science Center and Ocean Acidification Program, Seattle, WA, 98112, USA

Background
Euphausiids are a critically important component of marine ecosystems around the world, but ocean acidification (OA) work on euphausiids is limited. Research to date has shown that hatching of Euphausia superba eggs and survival of Nyctiphanes couchii sub-adults are reduced at elevated pCO2 levels. Euphausia pacifica is a dominant and trophically important zooplankton species throughout the North Pacific and the California Current Ecosystem, where naturally low pH conditions occur. The areal and temporal extents of these low pH conditions are expected to increase under OA.

Methods
We sampled the vertical distribution of E. pacifica eggs and larvae with simultaneous carbonate chemistry measurements to characterize their exposure in Puget Sound, WA, a large estuary connected to the California Current. We also collected adult females and spawned them under a wide range of pCO2 conditions in the laboratory, tracking hatching success, larval development and survival. Our laboratory experiments were designed to cover the broad range of pH conditions that E. pacifica currently experiences in Puget Sound (pH 8.0, 7.7, 7.4) and may experience in the future (pH 7.3, 7.2).

Findings
In Puget Sound, WA, E. pacifica larval stages, particularly the nauplius 2 and metanauplius stages, are found throughout the water column (20-180m), where they are exposed to pH 7.8-7.5. In the laboratory, E. pacifica hatching is robust to a range of pH levels, but larval development and survival are reduced at lower pH; survival from three days post hatch to the calyptopis 2 stage was reduced by an average of 20% at pH 7.69 compared to pH 7.96.

Conclusions
This study indicates that E. pacifica may be living near the limits of its pH tolerance and continued OA could push these organisms past their threshold, with negative consequences for their populations and higher trophic levels.

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