Equipping smart coasts with marine water quality IoT sensors


• This micro-manuscript describes a university/industry collaboration to study water quality at a shellfish hatchery.

• We designed a real-time communications system including hardware, firmware, and web visualization/analysis software.

• A dashboard is located at sccoos.org/ocean-acidification/ and code at github.com/SUPScientist/Equipping-Smart-Coasts.


Ocean acidification, the decrease in seawater pH as a result of increasing carbon dioxide, has been shown to be an important driver of oyster mortality in West Coast shellfisheries [1]. Yet carbon chemistry is only sparsely measured, especially relative to its high variability in coastal ecosystems, due to the complexity and cost of appropriate sensors and their maintenance. Worse, data are rarely communicated in real time to water quality or aquacultural managers. In the Agua Hedionda Lagoon (AHL) in Carlsbad, CA, researchers from Scripps Institution of Oceanography and industry representatives from the Carlsbad Aquafarm have come together through a NOAA-facilitated project to alleviate this data shortage using a combination of cutting-edge research technology alongside off-the-shelf and easy-to-implement IoT communications packages.

Continue reading ‘Equipping smart coasts with marine water quality IoT sensors’

Dungeness crab larvae already showing effects of coastal acidification

This infographic shows the location of larval Dungeness crab sampling in 2016, examples of impacts from ocean acidification, as well as photos of a larval (left) and adult (right) crab. Credit: Nina Bednarsek, SSCWRP.

A new NOAA-funded study has documented for the first time that ocean acidification along the US Pacific Northwest coast is impacting the shells and sensory organs of some young Dungeness crab, a prized crustacean that supports the most valuable fishery on the West Coast.

Analysis of samples collected during a 2016 NOAA research cruise identified examples of damage to the carapace, or upper shell, of numerous larval Dungeness crabs, as well as the loss of hair-like sensory structures crabs use to orient themselves to their surroundings.

The study was published in the journal Science of the Total Environment.

Continue reading ‘Dungeness crab larvae already showing effects of coastal acidification’

Transcriptomic response to decreased pH in adult, larval and juvenile red king crab, Paralithodes camtschaticus, and interactive effects of pH and temperature on juveniles

Ocean warming and acidification are expected to influence the biology of the ecologically and economically important red king crab, Paralithodes camtschaticus. We investigated transcriptome responses of adult, larval and juvenile red king crab to assess sensitivity to reduced pH and elevated temperature. In adults, gill tissue (but not heart or cuticle) responded to reduced pH by differentially regulating many genes involved in metabolic, membrane and cuticular processes, but not ionic or acid/base regulation. In larval crabs, we found little evidence for a strong transcriptomic response to pH, but did observe large differences in the transcriptomes of newly hatched and one-week old larvae. In juvenile crabs, we found that there was a strong transcriptomic response to temperature across all pH conditions, but that only extreme low pH caused transcriptomic shifts. Most of the genes in juveniles that were differentially expressed were for cuticular and calcification processes. While inferences regarding the specific biological responses associated with changes in gene expression are likely to change as resources for red king crab genomics enabled studies continue to improve (i.e. better assemblies and annotation), our inferences about general sensitivities to temperature and pH across the life stages of red king crab are robust and unlikely to shift. Overall, our data suggest that red king crab are more sensitive to warming than acidification, and that responses to acidification at the transcriptomic level occur at different levels of pH across life stages, with juveniles being less pH sensitive than adults.

Continue reading ‘Transcriptomic response to decreased pH in adult, larval and juvenile red king crab, Paralithodes camtschaticus, and interactive effects of pH and temperature on juveniles’

Response of coralline algae Porolithon onkodes to elevated seawater temperature and reduced pH

Coralline algae (CA), a type of primary calcifying producer presented in coastal ecosystems, are considered one of the highly sensitive organisms to marine environmental change. However, experimental studies on coralline algae responses to elevated seawater temperature and reduced pH have documented either contradictory or opposite results. In this study, we analysed the growth and physiological responses of coralline algae Porolithon onkodes to the elevated temperature (30.8°C) and reduced pH (7.8). The aim of this analysis was to observe the direct and combined effects, while elucidating the growth and photosynthesis in this response. It was demonstrated that the algae thallus growth rate and photosynthesis under elevated temperature were depressed by 21.5% and 14.9% respectively. High pCO2 enhanced the growth and photosynthesis of the thallus at ambient temperature, while they were deceased when both temperature and pCO2 were elevated. CA is among the most sensitive organisms to ocean acidification (OA) because of their precipitate high Mg-calcite. We hypothesize that coralline algae could increase their calcification rate in order to counteract the effects of moderate acidification, but offset by the effect of elevated temperature. Accordingly, our results also support the conclusion that global warming (GW) is a stronger threat to algal performance than OA. Our findings are also proposed that coralline algae may be more
resilient under OA than GW.

Continue reading ‘Response of coralline algae Porolithon onkodes to elevated seawater temperature and reduced pH’

Biogenic acidification of Portuguese oyster Magallana angulata mariculture can be mediated through introducing brown seaweed Sargassum hemiphyllum


• Monoculture of oysters produces excess CO2, affecting carbon fluxes.

• Seaweed can eliminate CO2 released by oysters.

• Multi-trophic culture of oysters and seaweed can mitigate oysters monoculture negative impacts.


The physiological responses of aquaculture organisms (e.g., oyster and seaweed) have the potential to affect seawater carbon fluxes and subsequently are affected by these seawater changes. In this study, a laboratory experiment and a field mesocosm experiment were carried out in Daya Bay, southern China. In the laboratory experiment, Portuguese oyster Magallana angulata and the brown seaweed Sargassum hemiphyllum were mono-cultured in 20-L transparent glass bottles for 24 h. Water sample were collected at four incubation time points (i.e. 0 h, 4 h, 12 h and 24 h) to examine their physiological responses across the incubation period. The results showed that the oyster calcification rate was not significantly changed among 4 h, 12 h and 24 h. On the other hand, during the 24 h incubation time, the oyster respiration rate, seawater pH, dissolved oxygen (DO), and CO32– concentration were significantly declined, but the seawater CO2 concentration was increased. For the seaweed, from 0 h to 12 h, seawater CO2 and HCO3– concentrations were significantly declined. However, the seawater pH and DO concentration were increased. In the field experiment, oyster and seaweed were cultured in mesocosm bags. The effects of different culture models of M. angulata and S. hemiphyllum (i.e. oyster monoculture, seaweed monoculture and oyster-seaweed co-culture) on seawater CO2‑carbonate system and air-sea CO2 flux (FCO2) were investigated after 24 h incubation. The results showed that DIC, HCO3– and CO2 concentrations and the partial pressure of CO2 in co-culture bags were significantly lower than the control bags (without any culture organisms) and oyster bags, indicated that S. hemiphyllum can effectively absorb the CO2 released by the oysters. The negative values of air-sea FCO2 in the co-culture bags represent a CO2 sink from the atmosphere to the sea. These results demonstrated that aquaculture organism monoculture could result in a stress for itself, and there could be an interspecies mutual benefit for both M. angulata and S. hemiphyllum in the co-culture system. The negative environmental impacts of mono-trophic oyster aquaculture in this view could be mediated with the multi-trophic inclusion of seaweed.

Continue reading ‘Biogenic acidification of Portuguese oyster Magallana angulata mariculture can be mediated through introducing brown seaweed Sargassum hemiphyllum’

Paradise lost: end‐of‐century warming and acidification under business‐as‐usual emissions have severe consequences for symbiotic corals

Despite recent efforts to curtail greenhouse gas emissions, current global emission trajectories are still following the business‐as‐usual RCP8.5 emission pathway. The resulting ocean warming and acidification have transformative impacts on coral reef ecosystems, detrimentally affecting coral physiology and health, and these impacts are predicted to worsen in the near future. In this study, we kept fragments of the symbiotic corals Acropora intermedia (thermally sensitive) and Porites lobata (thermally tolerant) for 7 weeks under an orthogonal design of predicted end‐of‐century RCP8.5 conditions for temperature and pCO2 (3.5 °C and 570 ppm above present‐day respectively) to unravel how temperature and acidification, individually or interactively, influence metabolic and physiological performance. Our results pinpoint thermal stress as the dominant driver of deteriorating health in both species because of its propensity to destabilize coral‐dinoflagellate symbiosis (bleaching). Acidification had no influence on metabolism but had a significant negative effect on skeleton growth, particularly when photosynthesis was absent such as in bleached corals or under dark conditions. Total loss of photosynthesis after bleaching caused an exhaustion of protein and lipid stores and collapse of calcification that ultimately led to A. intermedia mortality. Despite complete loss of symbionts from its tissue, P. lobata maintained small amounts of photosynthesis and experienced a weaker decline in lipid and protein reserves that presumably contributed to higher survival of this species. Our results indicate that ocean warming and acidification under business‐as‐usual CO2 emission scenarios will likely extirpate thermally‐sensitive coral species before the end of the century, while slowing the recovery of more thermally‐tolerant species from increasingly severe mass coral bleaching and mortality. This could ultimately lead to the gradual disappearance of tropical coral reefs globally, and a shift on surviving reefs to only the most resilient coral species.

Continue reading ‘Paradise lost: end‐of‐century warming and acidification under business‐as‐usual emissions have severe consequences for symbiotic corals’

Sperm motility impairment in free spawning invertebrates under near-future level of ocean acidification: uncovering the mechanism

Ocean acidification (OA) refers to the decrease in ocean water pH resulting from the increasing absorption of atmospheric CO2. This will cause changes in the ocean’s carbonate chemistry system with a resulting impact on reproduction of marine organisms. Reproduction is the fundamental process that allows the conservation of the species; in free-spawning marine invertebrates, this process is highly sensitive to changes in seawater quality and chemistry. To date, the majority of the studies concerned OA effects on reproduction has been focused on embryo and larval development. Despite several evidence for the impairment of reproductive success by environmental perturbations through altering gamete quality, sperm physiological responses to OA are poorly investigated. In this study, we evaluated the effects of exposure to acidified seawater (AcSW) (pH 7.8), which approximate the predicted global averages for oceanic surface waters at the end of this century, on sperm quality of the mussel Mytilus galloprovincialis and the ascidian Ciona robusta by evaluating several endpoints, such as motility, vitality, mitochondrial activity, oxidative state, and intracellular pH (pHi). Following sperm exposure to AcSW, the percentage of motile spermatozoa, mitochondrial activity and pHi decreased in comparison to the current seawater pH of 8.1, whereas vitality and oxidative state were unaffected by the low external pH in both the species. In broadcast spawners, a relationship between sperm intracellular pH and the initiation of motility are well known. Spermatozoa are immotile in the testes and motility is induced after the spermatozoa are released into seawater; the alkaline pH of seawater, in fact, increases the pHi activating motility and mitochondrial respiration. The results of this study suggest that the lowering of seawater pH as predicted to occur for 2100, through the inhibition of pHi increase, prevent sperm motility activation. Sperm motility is a key determinant of fertilization success; consequently, a corresponding drop in fertilization success would be expected with important implications for the fitness and the survival of marine invertebrates.

Continue reading ‘Sperm motility impairment in free spawning invertebrates under near-future level of ocean acidification: uncovering the mechanism’

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Ocean acidification in the IPCC AR5 WG II

OUP book