Archive Page 238

Plastic and toxic chemical induced ocean acidification will cause a plankton crisis that will devastate humanity over the next 25 Years, unless we act now to stop the pollution

Published 22 June 2021 Newsletters and reports , Science Closed
Tags: ,

Planktonic plants and animals at the base of the marine food chain make all life on Earth possible. Without them the atmosphere would be toxic from carbon dioxide, we would have no oxygen and there would be no whales, birds or fish in the oceans.

Over the last 70 years, more than 50% of all marine life has been lost from the world’s oceans, and it continues to decline at rate of 1% year on year. Atmospheric carbon dioxide causes ocean acidification, and a loss of marine plants and animals accelerates the process.

A small increase in acidity caused by carbon dioxide dissolves magnesium calcite and aragonite, forms of calcium carbonate upon which 50% of all marine life including plankton and coral reefs are composed. Over the next 25 years, the pH will continue to drop from pH8.04 to pH7.95, and an estimated 80% to 90% of all marine life will be lost from the oceans. Even if the world achieves net zero by 2045, atmospheric carbon dioxide will still exceed 500ppm and the oceans will still drop to pH 7.95.

Based on current climate change policy of carbon mitigation, we will not be able to stop the loss of most marine life, which includes fish and the food supply for 3 billion people. In addition, we lose the life support system for the planet. This decline has gone largely unnoticed because most of the plants and animals in the oceans are under 1 mm in size and they are not closely monitored. By way of an example: Prochlorococcus, a cyanobacteria responsible for making 20% of our oxygen, was only discovered in the 1985.

Ocean acidification and climate change cannot adequately describe the loss of marine life. 30% of the ocean have high nutrient (nitrate) concentrations but zero or only low plant growth. If it is not the lack of nutrients or trace nutrients, responsible for the loss of marine life, then this just leaves aquatic environmental pollution as the last plausible explanation. The impact of chemical and micro-plastic pollution on planktonic marine life has been almost completed ignored by the scientific community, and as such industry and governments have not been alerted to the impending threat to the oceans.

This is potentially a good news story, because the solution will be to eliminate pollution from plastic and toxic chemicals or develop green alternatives that do not harm to the environment or humans. We still need to reduce carbon from the burning of fossil fuels, but the priority over the next 25 years should be to protect the oceans, because all life on earth depends upon marine life in the world’s oceans.

Questions and answer on GOES Report.

Continue reading ‘Plastic and toxic chemical induced ocean acidification will cause a plankton crisis that will devastate humanity over the next 25 Years, unless we act now to stop the pollution’

Taxing interacting externalities of ocean acidification, global warming, and eutrophication

Published 22 June 2021 Science Closed
Tags: , , ,

We model a stylized economy dependent on agriculture and fisheries to study optimal environmental policy in the face of interacting external effects of ocean acidification, global warming, and eutrophication. This allows us to capture some of the latest insights from research on ocean acidification. Using a static two-sector general equilibrium model we derive optimal rules for national taxes on urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0001 emissions and agricultural run-off and show how they depend on both isolated and interacting damage effects. In addition, we derive a second-best rule for a tax on agricultural run-off of fertilizers for the realistic case that effective internalization of urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0002 externalities is lacking. The results contribute to a better understanding of the social costs of ocean acidification in coastal economies when there is interaction with other environmental stressors.

Recommendations for Resource Managers:

  • Marginal environmental damages from urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0003 emissions should be internalized by a tax on urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0004 emissions that is high enough to not only reflect marginal damages from temperature increases, but also marginal damages from ocean acidification and the interaction of both with regional sources of acidification like nutrient run-off from agriculture.
  • In the absence of serious national policies that fully internalize externalities, a sufficiently high tax on regional nutrient run-off of fertilizers used in agricultural production can limit not only marginal environmental damages from nutrient run-off but also account for unregulated carbon emissions.
  • Putting such regional policies in place that consider multiple important drivers of environmental change will be of particular importance for developing coastal economies that are likely to suffer the most from ocean acidification.
Continue reading ‘Taxing interacting externalities of ocean acidification, global warming, and eutrophication’

Why are surface ocean pH and CaCO3 saturation state often out of phase in spatial patterns and seasonal cycles?

Published 22 June 2021 Science Closed
Tags:

Abstract

As two most important metrics for ocean acidification (OA), both pH and calcium carbonate mineral saturation states (Ω) respond sensitively to anthropogenic carbon dioxide (CO2). However, contrary to intuition, they are often out of phase in the global surface ocean, both spatially and seasonally. For example, during warm seasons, Ω is lowest at high-latitude seas where there are very high pH values, challenging our understanding that high-latitude seas are a bellwether for global OA. To explain this phenomenon, we separate spatial and seasonal variations of both pH and Ω into thermal components mainly associated with internal acid-base equilibrium of seawater CO2 systems, and nonthermal components mainly associated with external CO2 addition/removal using a global surface ocean climatological dataset. We find that surface pH change is controlled by the balance between its thermal and nonthermal components, which are out of phase but comparable in magnitude. In contrast, surface Ω change is dominated by its nonthermal components, with its thermal components in phase and significantly smaller in magnitude. These findings explain why surface ocean pH and Ω are often out of phase in spatial patterns and seasonal cycles. When pH is primarily controlled by nonthermal components e.g., gas exchange, mixing and biology, pH and Ω will be in phase because their nonthermal components are intrinsically in phase. In comparison, when pH is primarily controlled by thermal components e.g., rapid seasonal cooling or warming, pH and Ω will be out of phase because thermal and nonthermal components of pH are out-of-phase in nature.

Plain Language Summary

Although both pH and calcium carbonate mineral saturation states (Ω) are good metrics for ocean acidification, in the global surface ocean their spatial patterns and seasonal cycles are often out of phase, which appears counter intuitive. To explain this, we separate pH and Ω changes into thermal and nonthermal components. Thermal components are mainly related to the temperature driven internal acid-base equilibrium of seawater CO2 systems. Nonthermal components are the remaining changes, reflecting the effects of other non-temperature processes such as air-sea gas exchange, mixing and biology or a combination of these processes. We find that pH is controlled by the balance between thermal and nonthermal components, which are out of phase but comparable in magnitude, while Ω is almost always dominated by nonthermal components. These findings explain why surface ocean pH and Ω are often out of phase in spatial patterns and seasonal cycles. When pH is more controlled by nonthermal components than thermal components, pH and Ω will be in phase since their nonthermal components are intrinsically in phase. In contrast, when pH is more controlled by thermal components, pH and Ω will be out of phase because of the out-of-phase between thermal and nonthermal components of pH.

Continue reading ‘Why are surface ocean pH and CaCO3 saturation state often out of phase in spatial patterns and seasonal cycles?’

How life on Earth almost ended once

Published 22 June 2021 Web sites and blogs Closed
The onset of the Permian-Triassic mass extinction based on Jurikova et al. (2020)
The onset of the Permian-Triassic mass extinction based on Jurikova et al. (2020) Credits: Dawid Adam Iurino (PaleoFactory, Sapienza University of Rome)

Life on Earth has never been so close to an end as during the environmental catastrophe that marked the Permian-Triassic boundary – 252 million years ago. Scientists have long speculated what could have triggered the sudden disappearance of so many organism groups – more than 95% of marine and 70% of terrestrial species went extinct. Among the favoured hypotheses have been large-scale volcanism, methane release from hydrate mounds on the seafloor, and an asteroid impact similar to that which ended the reign of the dinosaurs 66 million years ago. The latter has been, however, largely rejected in the recent years as no reliable evidence, direct or indirect, of the impact has been found.

…

To illuminate the causes and consequences of the extinction, we used an innovative approach to reconstruct the seawater pH (acidity) from boron isotope measurements in well-preserved fossil brachiopod shells. Seawater pH is a critical parameter; first, because it has direct implications for marine life. Second, because the ocean and the atmosphere are closely coupled and CO2 is readily exchanged between them, we can use data on ocean pH to directly reconstruct the atmospheric CO2 levels. We paired our pH data with the global carbon isotope records, and assimilated it into a model that quantified both the source and volume of CO2 over the extinction period.

Continue reading ‘How life on Earth almost ended once’

Robotic boat begins Atlantic crossing (text & video)

Published 22 June 2021 Web sites and blogs Closed

IBM’s Mayflower Autonomous Ship (MAS400) has set sail across the Atlantic ocean without a crew or human control. The autonomous trimaran left Plymouth, England on June 15 and hopes to reach Plymouth, Massachusetts in about three weeks.

The voyage of the robotic Mayflower follows the path of the original Mayflower, which brought the Pilgrim settlers to New England in 1620. The 50-foot long, 20-foot wide craft is made of aluminum and carbon composites, displaces five tonnes, and is propelled by a solar-powered hybrid motor with a diesel backup, giving it a top speed of 10 knots.

Supervised by a command center in Plymouth, UK, the Mayflower navigates using over 50 sensors, including six IBM AI Vision cameras and an IBM deep learning system to identify and avoid obstacles, hostile currents, and bad weather while adhering to international navigation rules. Data processing is by onboard computers backed up by an IBM Power Systems AC922 onshore.

Onboard is a scientific payload of 1,500 pounds that includes acoustic, nutrient, and temperature sensors, as well as water and air samplers. These are gathering scientific data to help with future studies of ocean chemistry, acidification, sea level height and wave patterns; microplastics; and marine mammal conservation, among other topics. In addition, the autonomous technology could find applications in shipping, oil and gas industries, telecommunications, security, defense, fishing, and aquaculture.

Continue reading ‘Robotic boat begins Atlantic crossing (text & video)’

Transcriptional changes revealed water acidification leads to the immune response and ovary maturation delay in the Chinese mitten crab Eriocheir sinensis

Published 21 June 2021 Science Closed
Tags: , , , , ,

Highlights

  • Water acidification delays the oocyte maturation of Eriocheir sinensis.
  • Water acidification induces significant changes in gills and ovaries at transcriptomic level.
  • E. sinensis increased immune response to response in the water acidification.

Abstract

Nowadays, due to increasing carbon dioxide released, water acidification poses a series of serious impacts on aquatic organisms. To evaluate the effects of water acidification on crustaceans, we focused on the Chinese mitten crab Eriocheir sinensis, which is a spawning migration and farmed species in China. Based on histological and oocyte transparent liquid observation, we found that the acidified environment significantly delayed the ovarian maturation of E. sinensis. Moreover, RNA-seq was applied to obtain gene expression profile from the crab’s gills and ovaries in response to acidified environment. Compared with control groups, a total of 5471 differentially expressed genes (DEGs) were identified in acidified gills and 485 DEGs were identified in acidified ovaries. Enrichment analysis indicated that some pathways also responded to the acidified environment, such as PI3K-Akt signaling pathway, Chemokine signaling pathway, apoptosis and toll-like receptor signaling pathway. Subsequently, some DEGs involved in immune response (ALF, Cathepsin A, HSP70, HSP90, and catalase) and ovarian maturation (Cyclin B, Fem-1a, Fem-1b, and Fem-1c) were selected to further validate the influence of water acidification on gene expression by qRT-PCR. The results showed that the expression level of immune-related genes was significantly increased to response to the water acidification, while the ovarian maturation-related genes were significantly decreased. Overall, our data suggested that E. sinensis was sensitive to the reduced pH. This comparative transcriptome also provides valuable molecular information on the mechanisms of the crustaceans responding to acidified environment.

Continue reading ‘Transcriptional changes revealed water acidification leads to the immune response and ovary maturation delay in the Chinese mitten crab Eriocheir sinensis’

Guidance in computer-supported collaborative inquiry learning: capturing aspects of affect and teacher support in science classrooms

Published 21 June 2021 Science Closed
Tags:

Technology-enhanced collaborative inquiry learning has gained a firm position in curricula across disciplines and educational settings and has become particularly pervasive in science classrooms. However, understanding of the teacher’s role in this context is limited. This study addresses the real-time shifts in focus and distribution of teachers’ guidance and support of different student groups during in-person computer-supported collaborative inquiry learning in science classrooms. Teachers’ self-perceptions of their guidance and affect were supplemented with students’ self-reported affect. A mixed-methods approach using video analyses and questionnaire data revealed differences between teacher guidance and support associated with teacher perceptions and group outcomes. Groups’ prior science competence was not found to have an effect on teacher guidance and support, rather the teachers guided the groups they perceived as motivated and willing to collaborate. Teacher affect was compounded by student affect, suggesting that consideration of the reciprocal perceptions of teachers and students is necessary in order to understand the teachers’ role in collaborative learning.

Continue reading ‘Guidance in computer-supported collaborative inquiry learning: capturing aspects of affect and teacher support in science classrooms’

Rising temperature is a more important driver than increasing carbon dioxide concentrations in the trait responses of Enhalus acoroides seedlings

Published 21 June 2021 Science Closed
Tags: , , , , , , ,

Increasing temperature and CO2 concentration are among the most important factors affecting marine ecosystems under climate change. We investigated the morphological, biochemical, and physiological trait responses of seedlings of the tropical seagrass Enhalus acoroides under experimental conditions. Trait responses were greater under temperature effects than increasing CO2 concentration. Seedlings under rising temperatures showed enhanced leaf growth, lower leaf nutrient content, and stimulated down-regulating mechanisms in terms of photo-physiology. Increasing CO2 concentrations did not show any significant effects independently. There was a significant interaction for some of the trait responses considered, such as leaf number and carbon content in the roots, and trends of higher starch concentrations in the leaves and lower rETRmax under combined enriched CO2 and high temperature, even though none of these interactions were synergistic. Understanding the single and interactive trait responses of seagrass seedlings to increasing temperature and CO2 concentration is of importance to determine the relative responses of early life stages of seagrasses, which may differ from adult plants, in order to form a more holistic view of seagrass ecosystem health under climate change.

Continue reading ‘Rising temperature is a more important driver than increasing carbon dioxide concentrations in the trait responses of Enhalus acoroides seedlings’

Will Bay fish feel the bite from ocean acidification? ‘Hooked on OA’ series shares latest science

Published 21 June 2021 Web sites and blogs Closed

Ocean waters are becoming more acidic — but how does that affect the Chesapeake Bay? And what does it mean for fish and the people fishing for them?

The ‘Hooked on Ocean Acidification’ webinars answered these questions for mid-Atlantic Anglers in March and April. The four webinars walked through recent research about acidification in coastal waters and out in the open ocean. The webinars were hosted by the Mid-Atlantic Coastal Acidification Network, in collaboration with other mid-Atlantic partners.

In the mid-Atlantic, there are many pieces in the puzzle of acidification

Globally, the oceans absorb carbon dioxide from the atmosphere — and since the industrial revolution, human activities are adding carbon dioxide to the atmosphere 10 times faster than the earth has experienced in the last 50 million years. As the ocean absorbs carbon dioxide, the water becomes more acidic. This effect is known as ocean acidification.

But the effects of acidification aren’t uniform across all water, and the mid-Atlantic region gets its ocean water from several sources, explained Grace Saba, an assistant professor at Rutgers University. The mid-Atlantic continental shelf gets currents of cold water, which can be more acidic, and also warmer, less acidic water from the Gulf stream.

Continue reading ‘Will Bay fish feel the bite from ocean acidification? ‘Hooked on OA’ series shares latest science’

Combined effects of seawater acidification and benzo(a)pyrene on the physiological performance of the marine bloom-forming diatom Skeletonema costatum

Published 18 June 2021 Science Closed
Tags: , , , , , , ,

Highlights

  • Skeletonema costatum was tolerant to low and moderate benzo(a)pyrene concentrations.
  • The high benzo(a)pyrene concentration remarkably inhibited growth and photosynthesis.
  • Negative effects of ocean acidification were detected at the high benzo(a)pyrene level.

Abstract

The combined effects of polycyclic aromatic hydrocarbons and seawater acidification are poorly understood. Hence, we exposed the bloom-forming diatom Skeletonema costatum to four concentrations (0, 0.1, 1 and 10 μg L-1) of benzo(a)pyrene and two pCO2 levels (400 and 1000 μatm) to investigate its physiological performance. The growth and photosynthesis of S. costatum were tolerant to low and moderate benzo(a)pyrene concentrations regardless of the pCO2 level. However, the highest benzo(a)pyrene concentration had remarkably adverse effects on most parameters, decreasing the growth rate by 69%. Seawater acidification increased the sensitivity to high light stress, as shown by the lower relative maximum electron transport rate and light saturation point at the highest benzo(a)pyrene concentration. Our results suggested that benzo(a)pyrene could be detrimental to diatoms at a habitat-relevant level, and seawater acidification might further decrease its light tolerance, which would have important ramifications for the community structure and primary production in coastal waters.

Continue reading ‘Combined effects of seawater acidification and benzo(a)pyrene on the physiological performance of the marine bloom-forming diatom Skeletonema costatum’

Physiology, niche characteristics and extreme events: current and future habitat suitability of a rhodolith-forming species in the Southwestern Atlantic

Published 18 June 2021 Science Closed
Tags: , , , , , , , , , , , , , ,

Highlights

  • Global climate change and local stressors are the main threats to reef-building organisms and habitats they build, such as rhodolith beds.
  • Through an experimental essay and ecological niche modelling, we were able to determine the environmental factors that determine the distribution and affect the physiology of an important rhodolith-forming species in the southwestern Atlantic.
  • Our results raise the possibility of some rhodolith-forming species being resilient to future environmental change based on our current understanding of their distributions, a perspective that will need to be further explored by future studies.
  • This information is helpful in informing policies for the conservation of priority areas, aiding the preservation of marine biodiversity in the South Atlantic.

Abstract

Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a short-term experiment, including the recovery of individuals after stressor removal. Furthermore, we developed an ecological niche model to establish which environmental conditions determine its current distribution along the Brazilian coast and to project responses to future climate scenarios. Although L. crispatum suffered a reduction in photosynthetic performance when exposed to stressors, they returned to pre-experiment values following the return of individuals to control conditions. The model showed that the most important variables in explaining the current distribution of L. crispatum on the Brazilian coast were maximum nitrate and temperature. In future ocean conditions, the model predicted a range expansion of habitat suitability for this species of approximately 58.5% under RCP 8.5. Physiological responses to experimental future environmental conditions corroborated model predictions of the expansion of this species’ habitat suitability in the future. This study, therefore, demonstrates the benefits of applying combined approaches to examine potential species responses to climate-change drivers from multiple angles.

Continue reading ‘Physiology, niche characteristics and extreme events: current and future habitat suitability of a rhodolith-forming species in the Southwestern Atlantic’

Alumni lecture in Auckland: Coral reefs and climate change

Published 18 June 2021 Events Closed

Date: 30 Jun 2021

Time: 6:00 pm – 8:00 pm

Location: Level 4, 50 Kitchener Street, Auckland CBD

Add to calendar

Register

Registration is essential

Description

As the oceans warm, what’s happening to the marine species beneath the waves?

Join us at an upcoming alumni lecture at the University’s Auckland premises on the evening of Wednesday 30 June.

Hear about some of our latest research from award-winning marine biologist Dr Christopher Cornwall.

Fresh from his Prime Minister’s MacDiarmid Emerging Scientist Prize, he’ll share what we’re learning about how the world’s coral reefs, marine algae and the species that depend on them will respond to ocean acidification.

There’s good news – thanks to the adapabilty of organisims – but still challenges ahead. Whether you have a background in the sciences or just enjoy catching up on the latest research, hear the full story during this deep dive into the big blue sea.

There’ll also be the opportunity to catch up with fellow graduates during the event over light refreshments.

There is no charge for this event, but places are limited.

Please register via the button above at your earliest convenience to ensure you don’t miss out.

For more information contact: Heidi Stedman

alumni@vuw.ac.nz

Continue reading ‘Alumni lecture in Auckland: Coral reefs and climate change’

Bering science winter 2020/2021

Published 18 June 2021 Events Closed

Event Type: Webinars and Virtual Events

Title: Sharing science in and around the Bering Sea

When: 22 June 2021

Where: Online: 10:00-11:00 am AKDT, 2:00-3:00 pm EDT

More information: Link to Webinar Webpage

Summary

The Bering Sea is experiencing many changes. Loss of sea ice and record high ocean and air temperatures continue to impact wildlife and all aspects of life for coastal communities. Through the Bering Region Ocean Update project, the Alaska Ocean Observing System works to increase regional data sharing among federal, state, community and private sector partners. Join us for an overview of the Winter 2020/2021 Bering Science report which is a resource to state, federal, community and university partners to share recent observations from in and around the Bering Sea with community members and other scientists and management agencies. This year’s report includes sections on storms, erosion, fish, crab, ocean acidification, plankton, HABs, marine mammals, marine debris and seabirds. The discussion will also provide updates on scientific research taking place during summer 2021 in the Bering Sea region.

Please follow the link above to register.

Speakers

  • Rick Thoman, ACCAP at the University of Alaska Fairbanks
  • Katie Howard, Alaska Department of Fish and Game
  • Bob Foy or Maggie Mooney-Seus – NOAA Alaska Fisheries Science Center
Continue reading ‘Bering science winter 2020/2021’

Ocean acidification data for coasts

Published 18 June 2021 Web sites and blogs Closed

NOAA spearheads North American collaboration

Photo of Caribe coast and horizon

Vulnerable coastal areas now have a tool to assess the status and impacts of ocean acidification (OA). NOAA and collaborators have compiled data about OA conditions for the entire continental shelves of North America, from Alaska to Mexico in the west and from Canada to the Caribbean in the east.

Acidified water can harm fish, oysters, clams, sea urchins, shallow water corals, and deep-sea corals, among other living organisms.

Ocean acidification results from the ocean’s absorption of carbon dioxide (CO2) from the atmosphere and increases the acidity of seawater. Although this process helps reduce levels of CO2 in the atmosphere and thus slows down global climate change, it comes at a cost to aquatic ecosystems and local fisheries. Acidified water can harm fish, oysters, clams, sea urchins, shallow water corals, and deep-sea corals, among other living organisms. 

The Coastal Ocean Data Analysis Product for North America (CODAP-NA) fills a gap for information about the water column that can indicate acidification. Prior to now, no such data products existed for the coastal ocean where most of the OA-susceptible commercial and recreational fisheries and aquaculture industries are located. Previous OA products have mostly been focused on the open ocean, although the majority of the fisheries yield is located in the coastal ocean.

Continue reading ‘Ocean acidification data for coasts’

Asteroid impact in Earth’s past caused brief bloom of algae and substantial ocean species’ extinction

Published 18 June 2021 Web sites and blogs Closed

The asteroid that likely caused dinosaur extinction 66 million years ago triggered strong global cooling and a massive bloom of algae, causing mass extinction also in marine ecosystems. This is the result of a new study from scientists of the Potsdam Institute for Climate Impact Research (PIK). The researchers simulated the ocean productivity before and after the asteroid impact – and found a brief global algal bloom peaking at a productivity seven times higher than in the pre-impact ocean. Since the algae likely produced toxins, their increase could have contributed to the extinction of species in the ocean.

“The impact of a large asteroid near Chicxulub, Mexico, is increasingly recognised as the trigger of the dinosaur extinction, causing global darkness and a pronounced cooling,” explains Julia Brugger, lead author of the study published in the Geophysical Research Letters and now at the Senckenberg Biodiversity and Climate Research Centre Frankfurt (SBiK-F). “However, the links between this impact and the changes in the marine biosphere are still not fully understood. For the first time, using an enhanced Earth-system model that can simulate how the ocean biosphere reacts to changes in climate and nutrient supply, we were now able to show that the asteroid impact caused a relatively short-lived, yet massive algal bloom – this is an important new aspect helping us to understand what happened in the aftermath of the Chicxulub impact.”

Continue reading ‘Asteroid impact in Earth’s past caused brief bloom of algae and substantial ocean species’ extinction’

EPA: coastal acidification (text & video)

Published 18 June 2021 Presentations Closed

Coastal Acidification” – description of one part of our climate change research that focuses on coastal acidification is. The presentation defines what coastal acidification is and why it’s important, and it describes our research on its causes and how to predict how and when acidification events are likely to occur.

Continue reading ‘EPA: coastal acidification (text & video)’

“14: life below water”​at South Pointe Elementary

Published 18 June 2021 Web sites and blogs Closed
Picture

“14: Life Below Water”
Augmented Reality Mural, June 2021
South Pointe Elementary School
1050 4th St, Miami Beach, FL 33139

UN Sustainable Development Goal 14: Life Below Water is to conserve and sustainably use the oceans, seas and marine resources for sustainable development. 

Our oceans are in trouble. Marine biodiversity is threatened by overfishing, pollution, plastics and ocean acidification from climate change. Year after year, we have been pushing the boundaries of the ocean’s sustainability, and in so doing we have been challenging our own.

  • Nearly 90% of the world’s marine fish stocks are overexploited or depleted. 
  • Every day around 8 million pieces of plastic makes their way into our oceans. 
  • Ocean heat is at record levels, causing widespread marine heatwaves.

This mural is the first of a mural series for the Miami-Dade Public School District to raise awareness for the UN Sustainable Development Goals (SDGs). The SDGs are a collection of 17 interlinked global goals designed to be a “blueprint to achieve a better and more sustainable future for all”. 

The Before It’s Too Late team worked alongside students from South Pointe Elementary, Miami Beach Senior High and Miami Lakes Technical school to create this mural. The mural comes alive as an underwater coral reef designed by students using Tilt Brush, Blender and Unity. 

…

Continue reading ‘“14: life below water”​at South Pointe Elementary’

Impacts of ocean acidification on growth and toxin content of the marine diatoms Pseudo-nitzschia australis and P. fraudulenta

Published 17 June 2021 Science Closed
Tags: , , , , ,

Highlights

  • P. fraudulenta and P. australis strains were able to acclimate and maintain high growth rates at current pH (8.07) and projected pH in 2100 (7.77) compared to the lowest pH level (7.40).
  • Domoic acid content was significantly higher for all P. australis toxic strains acclimated at the ambient pH level (8.07), and lowest at pH (7.77).
  • Strong inter- and intra-specific variation related to the geographical area and the culturing history of Pseudo-nitzschia strains.

Abstract

This paper present the effects of ocean acidification on growth and domoic acid (DA) content of several strains of the toxic Pseudo-nitzschia australis and the non-toxic P. fraudulenta. Three strains of each species (plus two subclones of P. australis) were acclimated and grown in semi-continuous cultures at three pH levels: 8.07, 7.77, and 7.40, in order to simulate changes of seawater pH from present to plausible future levels. Our results showed that lowering pH from current level (8.07) to predicted pH level in 2100 (7.77) did not affect the mean growth rates of some of the P. australis strains (FR-PAU-17 and L3-100), but affected other strains either negatively (L3-30) or positively (L3.4). However, the growth rates significantly decreased with pH lowered to 7.40 (by 13% for L3-100, 43% for L3-30 and 16% for IFR-PAU-17 compared to the rates at pH 8.07). In contrast, growth rates of the non-toxic P. fraudulenta strains were not affected by pH changing from 8.07 to 7.40.

The P. australis strains produced DA at all pH levels tested, and the highest particulate DA concentration normalized to cell abundance (pDA) was found at pH 8.07. Total DA content (pDA and dissolved DA) was significantly higher at current pH (8.07) compared to pH (7.77), exept for one strain (L 3.4) where no difference was found. At lower pH levels 7.77 – 7.40, total DA content was similar, except for strains IFR-PAU-17 and L3-100 which had the lowest content at the pH 7.77. The diversity in the responses in growth and DA content highlights the inter- and intra-specific variation in Pseudo-nitzschia species in response to ocean acidification. When exploring environmental responses of Pseudo-nitzschia using cultured cells, not only strain-specific variation but also culturing history should be taken into consideration, as the light levels under which the subclones were cultured, afterwards affected both maximum growth rates and DA content.

Continue reading ‘Impacts of ocean acidification on growth and toxin content of the marine diatoms Pseudo-nitzschia australis and P. fraudulenta’

Effect of seawater acidification and plasticizer (Bisphenol-A) on aggregation of nanoparticles

Published 17 June 2021 Science Closed
Tags: , , ,

This study investigated the effect of an organic pollutant (Bisphenol A, an endocrine-disrupting chemical) on the stability of a mixture of nanoparticles (NPs). Experiments were conducted in seawater chemistry condition with TiO2/ZnO NP concentration ratio: 0.01, 10.1, 1, 10,100; pH: 7.4 and 8.1; BPA concentration: 1 and 10μg/L. The presence of BPA was found to increase the size of NP. Lower pH of 7.4 increased size of NPs from 3 to 297% (at 1 μg/L BPA; NP ratio = 0.1 to 100). Aggregation rate constant values ranged between 0.17 and 1.81nm/sec in pH 7.4 suspension and between 0.48 and 56nm/sec in pH 8.1 suspension. Factors such as pH and NP mass concentration had major effects on size change for suspension having the same ratio of TiO2/ZnO. NP aggregate was comprised of 97% ZnO NP, 3% TiO2 NP and had 1.39mg/kg BPA. Overall, this study found dominance of van der Waals forces of attraction in mixture suspension of NPs and BPA. The obtained result on NP persistence in seawater can now be used in estimating exposure doses of a mixture of nanoparticles during inadvertent exposure.

Continue reading ‘Effect of seawater acidification and plasticizer (Bisphenol-A) on aggregation of nanoparticles’

Effect of coastal development on larval fish abundance in Klang Strait (Malaysia)

Published 17 June 2021 Science Closed
Tags: , , , , , , , ,

Highlights

  • BACI model detects larval fish abundance before and after 30 years of development.
  • Lower larval diversity and abundance at impact than at offshore control stations.
  • The inshore-offshore cline in abundance can be related to lower SST and higher pH.
  • Total larval fish abundance increased despite changes in zooplankton composition.
  • 1st and 2nd stage larvae of certain families increased after development impact.

Abstract

Changes in larval fish assemblages were studied before (1985-86) and after (2013–2014) rapid coastal development in the Klang Strait, Malaysia, based on a Before-After-Control-Impact (BACI) experimental design. Fish larvae were sampled by bongo-nets along an 18-km transect from the impact station at the Kapar power station (KPS) to four control stations in increasingly offshore waters. Families Gobiidae, Clupeidae, Sciaenidae and Engraulidae were most abundant at both sampling periods, demonstrating their adaptability and resilience to the natural and anthropogenic disturbances. Coastal development has reduced larval fish abundance at KPS, inevitably shifting higher larval abundance to the control stations. This shift is related to lower sea surface temperature and higher pH. Despite the coastal disturbances, there was an overall increase in total larval fish abundance attributed to the preflexion stage of the Gobiidae, Sciaenidae, Engraulidae, Cynoglossidae and Callionymidae, and the yolk-sac and preflexion larvae of unidentified taxa.

Continue reading ‘Effect of coastal development on larval fish abundance in Klang Strait (Malaysia)’

Subscribe

Search

  • Reset

OA-ICC Highlights

Resources