Training course: Sistemas de carbonatos – documentación de conjuntos de datos, su análisis y visualización geográfica, en el marco del Objetivo de Desarrollo Sostenible 14.3 para minimizar los impactos de acidificación de los océanos (in Spanish)

Summary

El curso proporcionará las herramientas necesarias para evaluar la calidad de los datos QA/QC que permitan seleccionar sólo aquellos que cumplan con la calidad requerida para el indicador ODS 14.3.1. Aplicar las mejores prácticas para estandarizar y organizar los datos de acuerdo a la metodología 14.3.1. Identificar cuales son las herramientas de análisis más apropiadas y utilizarlas adecuadamente. Por último los participantes aprenderán a visualizar los resultados de los análisis de manera que sean entendibles para públicos no especializados, incrementando las capacidades en los países para reportar el indicador.
Continue reading ‘Training course: Sistemas de carbonatos – documentación de conjuntos de datos, su análisis y visualización geográfica, en el marco del Objetivo de Desarrollo Sostenible 14.3 para minimizar los impactos de acidificación de los océanos (in Spanish)’

Coral skeleton crystals record ocean acidification

Stylophora subseriata. Credit: Ratha Grimes

The acidification of the oceans is recorded in the crystals of coral skeletons. This is a new tool for studying past environmental changes and combating climate change. Such is the main conclusion of a study led by the Spanish scientist Ismael Coronado Vila, from the Institute of Paleobiology in Warsaw (Poland).

Continue reading ‘Coral skeleton crystals record ocean acidification’

Changing ocean chemistry: a high school curriculum on ocean acidification’s cause, impacts, and solutions

This five-lesson curriculum seeks to increase students’ understanding of ocean acidification (OA) and help them understand that it is an issue they can address. There are five lessons in the unit and a final Call to Action project.

Lesson 1 explores a real-life story about the near collapse of the oyster industry in 2007-2009 along the U.S. west coast. It includes an overview of OA and an exploration of how humans have altered the carbon cycle.

Lesson 2 and 3 focus on the chemistry of OA. Lesson 2 looks at pH and how carbon dioxide “acidifies” the water. In Lesson 3, students learn about changes in the carbonate ion concentration, an essential part of calcifying marine organisms that make shells and hard structures made out of calcium carbonate (e.g., shellfish and corals). Students apply what they learn by interpreting water quality data from Whiskey Creek Shellfish Hatchery.

In Lesson 4, students research the possible impacts of OA on ecosystems and humans. Lesson 5 examines potential solutions to OA. Students brainstorm ways to reduce CO2, emissions, identify barriers to taking action, and explore household actions that have the most significant impact.

Finally, students participate in a Call to Action project where they identify a target audience and try to persuade them to take action.

Continue reading ‘Changing ocean chemistry: a high school curriculum on ocean acidification’s cause, impacts, and solutions’

Ocean acidification climate change lab: teaching tool

Climate change is a hot topic that has been discussed in politics, science and especially in classrooms! This lab is a hands on experience for students to demonstrate the effects of ocean acidification on sea life. Students work collaboratively, collect mass, pH, graph their data, analyze data sets, and use food webs to write a conclusion. Ocean acidification is one of those topics that is not discussed as frequently as it should be! Use this awesome lab in a combination with the climate change Ice core lab and you’re kids will for sure be excited to discuss all the scary side effects of climate change!

Continue reading ‘Ocean acidification climate change lab: teaching tool’

Ocean acidification boosts algal growth but impairs ecological relationships

ocean

Photo Credit: CC0 Public Domain

Shrimp fed on marine algae grown in acidic water do not undergo a sex change that is a characteristic part of their reproductive life-cycle, report Mirko Mutalipassi and colleagues at Stazione Zoologica Anton Dohrn in Italy in a study publishing June 26 in the open-access journal PLOS ONE.

The marine shrimp Hippolyte inermis lives in coastal meadows of the seagrass Posidonia oceanica and it has two breeding seasons a year, with some males born in spring developing rapidly and turning into females that produce eggs the following autumn. This depends on a bioactive compound produced by microalgae present in their spring diet (Cocconeis scutellum parva) that triggers male endocrine cells to die. To investigate the impact of ocean acidification on this unusual reproductive cycle, the researchers fed shrimp on algae grown in waters at either pH 8.2 representing current conditions, or pH 7.7 representing forecasted levels of ocean acidity by 2100.

Continue reading ‘Ocean acidification boosts algal growth but impairs ecological relationships’

Shellfish growers are feeling climate change’s effects now

Shellfish growers are feeling climate change’s effects now

Ralph Solomon checks on crops of oyster seed at the Lummi Shellfish Hatchery on June 18. Photo Credit: Mathew Roland / BBJ

Shellfish farming in Washington is a multimillion-dollar industry with a history as deep as Puget Sound. However, recent decades of warming oceans and higher levels of ocean acidification continue to challenge shellfish farming practices.

In and around Whatcom County there are several aquaculture farms, such as Lummi Shellfish Hatchery, Drayton Harbor Oyster Co., Blau Oyster and Taylor Shellfish in Samish Bay. Each farm varies in size, number of employees and type of shellfish produced, but they share one thing in common: the water quality of Puget Sound.

Continue reading ‘Shellfish growers are feeling climate change’s effects now’

Ocean acidification influences plant-animal interactions: the effect of Cocconeis scutellum parva on the sex reversal of Hippolyte inermis

Ocean acidification (O.A.) influences the ecology of oceans and it may impact plant-animal interactions at various levels. Seagrass meadows located at acidified vents in the Bay of Naples (Italy) are considered an open window to forecast the effects of global-changes on aquatic communities. Epiphytic diatoms of the genus Cocconeis are abundant in seagrass meadows, including acidified environments, where they play key ecological roles. A still-unknown apoptogenic compound produced by Cocconeis triggers the suicide of the androgenic gland of Hippolyte inermis Leach 1816, a protandric hermaphroditic shrimp distributed in P. oceanica meadows located both at normal pH and in acidified vents. Feeding on Cocconeis sp. was proven important for the stability of the shrimp’s natural populations. Since O.A. affects the physiology of diatoms, we investigated if, in future scenarios of O.A., Cocconeis scutellum parva will still produce an effect on shrimp’s physiology. Cell densities of Cocconeis scutellum parva cultivated in custom-designed photobioreactors at two pH conditions (pH 7.7 and 8.2) were compared. In addition, we determined the effects of the ingestion of diatoms on the process of sex reversal of H. inermis and we calculated the % female on the total of mature individuals-1 (F/mat). We observed significant differences in cell densities of C. scutellum parva at the two pH conditions. In fact, the highest cell densities (148,808 ±13,935 cells. mm-2) was obtained at day 13 (pH 7.7) and it is higher than the highest cell densities (38,066 (±4,166) cells. mm-2, day 13) produced at pH 8.2. Diatoms cultured at acidified conditions changed their metabolism. In fact, diatoms grown in acidified conditions produced in H. inermis a proportion of females (F/mat 36.3 ±5.9%) significantly lower than diatoms produced at normal pH (68.5 ±2.8), and it was not significantly different from that elicited by negative controls (31.7 ±5.6%).

Continue reading ‘Ocean acidification influences plant-animal interactions: the effect of Cocconeis scutellum parva on the sex reversal of Hippolyte inermis’

Aprender a interpretar la acidificación oceánica con recursos on-line y experimentación contextualizada

In this paper we present an introductory experience of the process of Ocean Acidification –decrease in the pH of sea water–, as part of the Experimental Sciences course of the Bachelor’s Degree in Primary Education. The experience involved the use of on-line resources and contextualized experimentation, in order to promote student’s development of scientific competences and to formulate proposals of improvement within the framework of education for sustainability. Satisfactory results are shown in terms of knowledge acquisition, interpretation of the process analyzed here and awareness of environmental problems. We suggest improvements in the educational curriculum and formulate questions which can generate new research. Finally, limitations of the experience regarding its novelty and the lack of adequate educational resources are discussed.

En este artículo se presenta una experiencia de introducción al proceso de acidificación oceánica –disminución del pH del agua del mar– en aulas de Ciencias Experimentales del Grado en Educación Primaria, utilizando recursos on-line y experimentación contextualizada, para contribuir al desarrollo de competencias científicas y formular propuestas de mejora del currículo en el marco de la educación para la sustentabilidad. Se ha contribuido a la adquisición de conocimientos, a la interpretación del proceso estudiado y a la concienciación ambiental. Se han hecho propuestas de mejora del currículo y se han formulado preguntas que darán origen a nuevas investigaciones. Finalmente, se señalan limitaciones de la experiencia relativas a su novedad y a la escasez de recursos didácticos adecuados.

Continue reading ‘Aprender a interpretar la acidificación oceánica con recursos on-line y experimentación contextualizada’

Modelling the environmental niche space and distributions of cold-water corals and sponges in the Canadian northeast Pacific Ocean

Highlights

• We present the first comparison of realized niche space among six major, habitat-forming cold-water coral and sponge (CWCS) groups (sponge classes: Hexactinellida, Demospongiae; coral orders: Alcyonacea, Scleractinia, Antipatharia, Pennatulacea) occurring in the Northeast Pacific region of Canada (NEPC).
• The environmental gradients influencing CWCS niche space and breadth is driven by dissolved inorganic carbon, total alkalinity, and dissolved oxygen.
• Significant niche separation occurs among CWCS groups; high tolerance and marginality generally identify CWCS as specialists occurring in uncommon habitat conditions within the NEPC.
• Species distribution models developed for each CWCS group all share severely low dissolved oxygen ([O2] < 0.5 ml L−1) as a major predictor of habitat.
• Areas that are predicted to be suitable habitat for multiple CWCW groups primarily occurs primarily within 500–1400 m bottom depths on the continental slope and at offshore seamounts that have summits that reach into this depth range.

Abstract

Cold water coral and sponge communities (CWCS) are important indicators of vulnerable marine ecosystems (VMEs) and are used to delineate areas for marine conservation and fisheries management. Although the Northeast Pacific region of Canada (NEPC) is notable for having unique CWCS assemblages and is the location of >80% of Canadian seamounts, the extent of potential CWCS-defined VMEs in this region is unknown. Here, we used a diverse set of environmental data layers (n=30) representing a range of bathymetric derivatives, physicochemical variables, and water column properties to assess the primary factors influencing the niche separation and potential distributions of six habitat-forming groups of CWCS in the NEPC (sponge classes: Hexactinellida, Demospongiae; coral orders: Alcyonacea, Scleractinia, Antipatharia, Pennatulacea). The primary environmental gradients that influence niche separation among CWCS are driven by total alkalinity, dissolved inorganic carbon, and dissolved oxygen. Significant niche separation among groups indicates CWCS to be primarily specialists occurring in rare habitat conditions in the NEPC. Species distribution models (SDMs) developed for each CWCS group shared severely low dissolved oxygen levels ([O2] < 0.5 ml L−1) as a top predictor for habitat suitability in the NEPC. Niche separation is further emphasized by differences in the model-predicted areas of suitable habitat among CWCS groups. Although niches varied among taxa, the general areas of high habitat suitability for multiple CWCS groups in the NEPC occurred within the 500–1400 m bottom depth range which is strongly associated with the extensive oxygen minimum zone (OMZ) characterizing this region. As a result, the largest continuous area of potential CWCS habitat occurred along the continental slope with smaller, isolated patches also occurring at several offshore seamounts that have summits that extend into OMZ depths. Our results provide insight into the factors that influence the distributions of some of the most important habitat-forming taxa in the deep ocean and create an empirical foundation for supporting cold-water coral and sponge conservation in the NEPC.

Continue reading ‘Modelling the environmental niche space and distributions of cold-water corals and sponges in the Canadian northeast Pacific Ocean’

As the oceans acidify, these oyster farmers are fighting back

Volunteers from Hog Island Oyster Co. in Marshall, California, help scientists from the University of California, Davis monitor native oyster populations in Tomales Bay on June 6. Hog Island Oyster Co. has been collaborating with researchers to better understand the effects of ocean acidification on oysters and other shellfish and how the company can adapt and stay resilient. Photo Credit: Amanda Paulson/The Christian Science Monitor

It’s often hard to notice ecological changes, even when they threaten catastrophe. One oyster company in California hopes to change that.

When visitors to Hog Island Oyster Co. shuck Pacific oysters at picnic tables overlooking Tomales Bay, it’s the final stage in a story that founding partner Terry Sawyer likes to tell about the shellfish, the bay, and all the steps that went into bringing the briny delicacies to the plate just a few hundred meters from where they were harvested.

It’s a story that now also touches on the carbon cycle, climate change, and the ways in which the very chemistry of the ocean is shifting and how small businesses like Hog Island – along with the entire ocean ecosystem – are struggling to adapt.

Continue reading ‘As the oceans acidify, these oyster farmers are fighting back’

PICRC intern to study ocean acidification in Palau

A Palauan student attending University of Hawaii at Hilo, is participating in Palau International Coral Reef Center’s (PICRC) 2019 Summer Internship Program.

Masasinge T. Hideos is interning with PICRC for the time. During this internship, Masasinge will be studying ocean acidification (OA) in Palau. As carbon dioxide (CO2) levels continue to increase, many of the CO2 will dissolve in the ocean, changing its chemistry, lowering its pH and making the ocean more acidic. The lowering of ocean pH or the ocean getting more acidic, is referred to as ocean acidification.

Continue reading ‘PICRC intern to study ocean acidification in Palau’

Upcoming webinar: ocean acidification – high-frequency long -term measurements of pH and deployment best practices

Time: Thursday 18 July 2019, 1:00pm Eastern Time (ET)

Description: Ocean acidification is happening. We can predict it through climate models, see it in pitted calcium carbonate shells, and feel it through aquaculture collapse. However, pH sensors are in dire need of an overhaul before we can confidently track this problem with the necessary quantitative accuracy. While the prevailing technology—glass electrode pH sensors—has served us well for years, inherent limitations of these instruments prevent them from taking part in the long-term installations that have redefined how ocean scientists gather data.

Keep up to date on the latest changes in ocean pH measurement technology by attending Sea-Bird Scientific’s upcoming webinar on ISFET pH sensors. During this live Webinar, our Senior Chemist Charles Branham, Ph.D. will cover technical information and advantages of using ISFET pH sensors. Our Content Development Manager Greg Ikeda will talk about best practices for deploying and maintaining the SeaFET V2 and SeapHOx V2, two moored ISFET pH sensors offered by Sea-Bird Scientific.

Continue reading ‘Upcoming webinar: ocean acidification – high-frequency long -term measurements of pH and deployment best practices’

Spatiotemporal variability in seawater carbonate chemistry at two contrasting reef locations in Bocas del Toro, Panama

There is a growing concern for how coral reefs may fare in a high-CO2 world. The majority of laboratory and mesocosm experiments have revealed negative effects on the growth and calcification of reef builders exposed to elevated CO2 conditions. However, coral reefs are highly dynamic systems and the interplay between different biogeochemical and physical processes on reefs results in large variability of seawater carbonate chemistry on different functional scales. This can create localized seawater conditions that can either enhance or alleviate the effects of ocean acidification (OA). Consequently, in order to predict how coral reef ecosystems may respond to OA in the future, it is necessary to first establish a baseline of natural carbonate chemistry conditions. This includes characterizing the range and variability of carbonate chemistry and the physical and biogeochemical controls across a broad range of environments over both space and time. Here, we have characterized the spatial and temporal physiochemical variability of two contrasting coral reef locations in Bocas del Toro, Panama that differed in their benthic community composition, reef morphology, and exposure to open ocean conditions, using a combination of research approaches including stationary autonomous sensors and spatial surveys during the month of November 2015. Mean and diurnal temporal variability in both physical and chemical seawater parameters were remarkably similar between sites and sampling depths, although, the magnitude of spatial variability was quite different between the sites. Spatial gradients in physiochemical parameters at Punta Caracol reflected the cumulative modification from terrestrial runoff and benthic metabolism. Based on graphical vector analysis of salinity normalized TA-DIC data, reef metabolism was dominated by organic carbon cycling over inorganic carbon cycling at both sites, where the outer reef reflected net heterotrophy likely owing to remineralization of organic matter from terrestrial inputs. Altogether, the results of this study highlight the strong influence of terrigenous runoff on reef metabolism and seawater chemistry conditions and demonstrate the importance of considering external inputs of alkalinity in reefs when interpreting TA-DIC data in systems with large freshwater inputs. Predicting future changes to coral reef ecosystems requires an understanding of the natural complexity of these systems in which various physical, ecological and biogeochemical drivers interact creating large variability in seawater chemistry over space and time.

Continue reading ‘Spatiotemporal variability in seawater carbonate chemistry at two contrasting reef locations in Bocas del Toro, Panama’

Increased intestinal carbonate precipitate abundance in the sea bream (Sparus aurata L.) in response to ocean acidification

Marine fish contribute to the carbon cycle by producing mineralized intestinal precipitates generated as by-products of their osmoregulation. Here we aimed at characterizing the control of epithelial bicarbonate secretion and intestinal precipitate presence in the gilthead sea bream in response to predicted near future increases of environmental CO2. Our results demonstrate that hypercapnia (950 and 1800 μatm CO2) elicits higher intestine epithelial HCO3- secretion ex vivo and a subsequent parallel increase of intestinal precipitate presence in vivo when compared to present values (440 μatm CO2). Intestinal gene expression analysis in response to environmental hypercapnia revealed the up-regulation of transporters involved in the intestinal bicarbonate secretion cascade such as the basolateral sodium bicarbonate co-transporter slc4a4, and the apical anion transporters slc26a3 and slc26a6 of sea bream. In addition, other genes involved in intestinal ion uptake linked to water absorption such as the apical nkcc2 and aquaporin 1b expression, indicating that hypercapnia influences different levels of intestinal physiology. Taken together the current results are consistent with an intestinal physiological response leading to higher bicarbonate secretion in the intestine of the sea bream paralleled by increased luminal carbonate precipitate abundance and the main related transporters in response to ocean acidification.

Continue reading ‘Increased intestinal carbonate precipitate abundance in the sea bream (Sparus aurata L.) in response to ocean acidification’

Ocean acidification sessions at Oceans Sciences meeting, 16-21 Feb 2020

Title: Ocean Sciences Meeting 2020

Date: 16-21 February 2020

Location: San Diego, CA

Continue reading ‘Ocean acidification sessions at Oceans Sciences meeting, 16-21 Feb 2020’

Modelling carbon exchange in the air, sea, and ice of the Arctic Ocean

The purpose of this study is to investigate the evolution of the Arctic Ocean’s carbon uptake capacity and impacts on ocean acidification with the changing sea-ice scape. In particular, I study the influence on air-ice-sea fluxes of carbon with two major updates to commonly-used carbon cycle models I have included. One, incorporation of sea ice algae to the ecosystem, and two, modification of the sea-ice carbon pump, to transport brineassociated Dissolved Inorganic Carbon (DIC) and Total Alkalinity (TA) to the depth of the bottom of the mixed layer (as opposed to releasing it in the surface model layer). I developed the ice algal ecosystem model by adding a sympagic (ice-associated) ecosystem into a 1D coupled sea ice-ocean model. The 1D model was applied to Resolute Passage in the Canadian Arctic Archipelago and evaluated with observations from a field campaign during the spring of 2010. I then implemented an inorganic carbon system into the model. The carbon system includes effects on both DIC and TA due to the coupled ice-ocean ecosystem, ikaite precipitation and dissolution, ice-air and air-sea carbon exchange, and ice-sea DIC and TA exchange through a formulation for brine rejection to depth and freshwater dilution associated with ice growth and melt. The 1D simulated ecosystem was found to compare reasonably well with observations in terms of bloom onset and seasonal progression for both the sympagic and pelagic algae. In addition, the inorganic carbon system showed reasonable agreement between observations of upper water column DIC and TA content. The simulated average ocean carbon uptake during the period of open water was 10.2 mmol C m−2 day−1 (11 g C m−2 over the entire open-water season).

Using the developments from the 1D model, a 3D biogeochemical model of the Arctic Ocean incorporating both sea ice and the water column was developed and tested, with a focus on the pan-Arctic oceanic uptake of carbon in the recent era of Arctic sea ice decline (1980 – 2015). The model suggests the total uptake of carbon for the Arctic Ocean (north of 66.5N) increases from 110 Tg C yr−1 in the early eighties (1980 – 1985) to 140 Tg C yr−1 for 2010 – 2015, an increase of 30%. The rise in SST accounts for 10% of the increase in simulated pan-Arctic sea surface pCO2. A regional analysis indicated large variability between regions, with the Laptev Sea exhibiting low sea surface pH relative to the pan- Arctic domain mean and seasonal undersaturation of arag by the end of the standard run.

Two sensitivity studies were performed to assess the effects of sea-ice algae and the sea-ice carbon pump in the pan-Arctic, with a focus on sea surface inorganic carbon properties. Excluding the sea ice-carbon-pump showed a marked decrease in seasonal variability of sea-surface DIC and TA averaged over the Arctic Ocean compared to the standard run, but only a small change in the net total carbon uptake (of 1% by the end of the no icecarbon- pump run). Neglecting the sea ice algae, on the other hand, exhibits only a small change in sea-surface DIC and TA averaged over the pan-Arctic Ocean, but a cumulative effect on the net total carbon uptake of the Arctic Ocean (reaching 5% less than that of the standard run by the end of the no-ice-algae run).

Continue reading ‘Modelling carbon exchange in the air, sea, and ice of the Arctic Ocean’

Effects of chronic hypercapnia and elevated temperature on the immune response of the spiny lobster, Jasus lalandii

Highlights

• Lobsters are very efficient at rendering an injected dose of bacteria non-culturable.
• There is an interactive effects of temperature and pH on lobster immunity.
• Haemocyte numbers are reduced following chronic exposure to hypercapnia/high temperature.
• Chronic exposure to hypercapnia/high temperature does not affect the ability of J. lalandii to defend itself against bacterial infection.

Abstract

The West Coast rock lobster (WCRL), Jasus lalandii, inhabits highly variable environments frequented by upwelling events, episodes of hypercapnia and large temperature variations. Coupled with the predicted threat of ocean acidification and temperature change for the coming centuries, the immune response in this crustacean will most likely be affected. We therefore tested the hypothesis that chronic exposure to hypercapnia and elevated seawater temperature will alter immune function of the WCRL. The chronic effects of four combinations of two stressors (seawater pCO2 and temperature) on the total number of circulating haemocytes (THC) as well as on the lobsters’ ability to clear (inactivate) an injected dose of Vibrio anguillarum from haemolymph circulation were assessed. Juvenile lobsters were held in normocapnic (pH 8.01) or hypercapnic (pH 7.34) conditions at two temperatures (15.6 and 18.9 °C) for 48 weeks (n = 30 lobster per treatment), after which a subsample of lobsters (n = 8/treatment), all at a similar moult stage, were selected from each treatment for the immune challenge. Baseline levels of haemocytes (THC ml−1) and bacteria (CFU ml−1) in their haemolymph were quantified 24 h prior to bacterial challenge. Lobsters were then challenged by injecting 4 × 104 V. anguillarum per g body weight directly into the cardiac region of each lobster and circulating haemocyte and culturable bacteria were measured at 20 min post challenge. No significant differences in THC ml−1 (p < 0.05) were observed between any of the treatment groups prior to the bacterial challenge. However lobsters chronically exposed to a combination of hypercapnia and low temperature had significantly higher (p < 0.05) THCs post-challenge in comparison with lobsters chronically exposed to hypercapnia and high temperature. A significant interactive effect was recorded between temperature and pH for the post-challenge THC data (two-way ANOVA, p = 0.0025). Lobster were very efficient at rendering an injected dose of bacteria non-culturable, with more than 83% of the theoretical challenge dose (∼1.7 × 105 Vibrio ml−1 haemolymph) inactivated within the first 10 min following injection. Although differences in the inactivation of V. anguillarum were observed between treatment groups, none of these differences were significant. Clearance efficiency was in the following order: Hypercapnia/low temperature > normocapnia/high temperature > normocapnia/low temperature > hypercapnia/high temperature. This study demonstrated that despite chronic exposure to combinations of reduced seawater pH and high temperature, the WCRL was still capable of rapidly rendering an injected dose of bacteria non-culturable.

Continue reading ‘Effects of chronic hypercapnia and elevated temperature on the immune response of the spiny lobster, Jasus lalandii’

Quantifying susceptibility of marine invertebrate biocomposites to dissolution in reduced pH

Ocean acidification threatens many ecologically and economically important marine calcifiers. The increase in shell dissolution under the resulting reduced pH is an important and increasingly recognized threat. The biocomposites that make up calcified hardparts have a range of taxon-specific compositions and microstructures, and it is evident that these may influence susceptibilities to dissolution. Here, we show how dissolution (thickness loss), under both ambient and predicted end-century pH (approx. 7.6), varies between seven different bivalve molluscs and one crustacean biocomposite and investigate how this relates to details of their microstructure and composition. Over 100 days, the dissolution of all microstructures was greater under the lower pH in the end-century conditions. Dissolution of lobster cuticle was greater than that of any bivalve microstructure, despite its calcite mineralogy, showing the importance of other microstructural characteristics besides carbonate polymorph. Organic content had the strongest positive correlation with dissolution when all microstructures were considered, and together with Mg/Ca ratio, explained 80–90% of the variance in dissolution. Organic content, Mg/Ca ratio, crystal density and mineralogy were all required to explain the maximum variance in dissolution within only bivalve microstructures, but still only explained 50–60% of the variation in dissolution.

Continue reading ‘Quantifying susceptibility of marine invertebrate biocomposites to dissolution in reduced pH’

In vivo 31P-MRS of muscle bioenergetics in marine invertebrates: future ocean limits scallops’ performance

Object

Dynamic in vivo 31P-NMR spectroscopy in combination with Magnetic Resonance Imaging (MRI) was used to study muscle bioenergetics of boreal and Arctic scallops (Pecten maximus and Chlamys islandica) to test the hypothesis that future Ocean Warming and Acidification (OWA) will impair the performance of marine invertebrates.

Materials & methods

Experiments were conducted following the recommendations for studies of muscle bioenergetics in vertebrates. Animals were long-term incubated under different environmental conditions: controls at 0 °C for C. islandica and 15 °C for P. maximus under ambient PCO2 of 0.039 kPa, a warm exposure with +5 °C (5 °C and 20 °C, respectively) under ambient PCO2 (OW group), and a combined exposure to warmed acidified conditions (5 °C and 20 °C, 0.112 kPa PCO2, OWA group). Scallops were placed in a 4.7 T MR animal scanner and the energetic status of the adductor muscle was determined under resting conditions using in vivo 31P-NMR spectroscopy. The surplus oxidative flux (Qmax) was quantified by recording the recovery of arginine phosphate (PLA) directly after moderate swimming exercise of the scallops.

Results

Measurements led to reproducible results within each experimental group. Under projected future conditions resting PLA levels (PLArest) were reduced, indicating reduced energy reserves in warming exposed scallops per se. In comparison to vertebrate muscle tissue surplus Qmax of scallop muscle was about one order of magnitude lower. This can be explained by lower mitochondrial contents and capacities in invertebrate than vertebrate muscle tissue. Warm exposed scallops showed a slower recovery rate of PLA levels (kPLA) and a reduced surplus Qmax. Elevated PCO2 did not affected PLA recovery further.

Conclusion

Dynamic in vivo 31P-NMR spectroscopy revealed constrained residual aerobic power budgets in boreal and Arctic scallops under projected ocean warming and acidification indicating that scallops are susceptible to future climate change. The observed reduction in muscular PLArest of scallops coping with a warmer and acidified ocean may be linked to an enhanced energy demand and reduced oxygen partial pressures (PO2) in their body fluids. Delayed recovery from moderate swimming at elevated temperature is a result of reduced PLArest concentrations associated with a warm-induced reduction of a residual aerobic power budget.
Continue reading ‘In vivo 31P-MRS of muscle bioenergetics in marine invertebrates: future ocean limits scallops’ performance’

Climate change may turn important marine organisms into ‘junk food’

Microscope image of a small, red marine crustacean on a black background

A calanoid copepod, closely related to the species studied by San Francisco State University scientists. Photo Credit: Mike Stukel

Study shows that predicted future ocean conditions make tiny algae, vital to ocean food webs, less nutritious

A new experiment by San Francisco State University scientists shows that the oceans of the future may make some types of microscopic algae poor eating for the creatures that feed on them, a shift that would have a big impact on fish and other marine animals we eat.

Continue reading ‘Climate change may turn important marine organisms into ‘junk food’’


  • Reset

Subscribe

OA-ICC Highlights


%d bloggers like this: