Archive for the 'Media coverage' Category

Could seaweed be a salve to debate over salmon farming?

Seaweed is great at dealing with the waste from salmon farms and providing producers with another cash crop, says researcher Thierry Chopin. Photo by Steve Backman.

For well over a decade, scientists on Canada’s coasts have demonstrated how growing seaweed or shellfish alongside salmon farms can provide a host of benefits — economic and ecological.

Researcher Thierry Chopin has been pitching the idea of co-cultivating multiple species together, or Integrated Multi-Trophic Aquaculture (IMTA), since the late 1990s.

The notion behind co-cultivation, or IMTA, is that extractive species like seaweed, mussels, or sea cucumbers can filter or flourish from the uneaten feed, waste, and byproducts from fish farms.

Continue reading ‘Could seaweed be a salve to debate over salmon farming?’

Lobster research explores ocean warming effects

ORONO — A team of researchers from the University of Maine’s Darling Marine Center in Walpole and Bigelow Laboratory for Ocean Sciences in East Boothbay and the Maine Department of Marine Resources in West Boothbay Harbor recently published their research on the effects of ocean warming and acidification on gene expression in the earliest life stages of the American lobster.

The work was published in the scientific journal Ecology and Evolution with collaborators from the University of Prince Edward Island and Dalhousie University in Canada.

The team’s experiments examined the gene regulatory response of post-larval lobsters to the separate and combined effects of warming and acidification anticipated by the end of the 21st century. They found that genes regulating a range of physiological functions, from those controlling shell formation to the immune response, are either up- or down-regulated. Importantly, they observed that the two stressors combined induced a greater gene regulatory response than either stressor alone.

The results from the study indicate that changes in gene expression of post-larval lobster may act as a mechanism to accommodate rapid changes in the ocean environment. Team leader Maura Niemisto noted that “there is still need for further study to determine how rapidly populations of the species may be able to adapt to changing conditions. To better understand how gene regulation in response to environmental changes functions within the species, we should look at subpopulations and multigenerational studies to determine the extent of species’ capacity to respond to altered environmental conditions.”

Continue reading ‘Lobster research explores ocean warming effects’

Ocean acidification commission creates council

BOSTON – The Ocean Acidification Commission recently hosted its final public hearing to discuss falling pH levels and rising temperatures in the state’s surrounding waters, and the risk it presents to the states shell fishing industries.

The changing pH levels are particularly dangerous for shell fishing industry. When pH levels drop shellfish, such as oysters, and lobsters are unable to form strong shells.

As a result, fewer organisms make it past the larvae stage and those who do make it to adulthood are much more susceptible to predation.

Continue reading ‘Ocean acidification commission creates council’

One-two punch against corals: how stress factors interact

A new study in the prestigious journal Science Advances shows that stress from rising water temperatures reduces ability of corals to adapt to ocean acidification.

About a quarter of the carbon emissions driving global warming are absorbed by the oceans, leading to lower pH values in the water and making it more acidic. Global warming is also causing water temperature in the oceans to rise, which leads to the bleaching of coral reefs worldwide. Now, a new study reveals that increased CO2 levels in the water and ocean warming can interact to threaten reef-building corals.

The international team of authors, led by the University of California, included Professor Hildegard Westphal and Dr. Claire Reymond from the Leibniz Centre for Tropical Marine Research (ZMT), as well as Professor Justin Ries, a former fellow of the Hanse-Wissenschaftskolleg and visiting scientist at the ZMT. Furthermore, researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven and the Max Planck Institute for Marine Microbiology in Bremen were involved in the study.

Continue reading ‘One-two punch against corals: how stress factors interact’

Interrelation of quality parameters of surface waters in five tidewater glacier coves of King George Island, Antarctica

Highlights

  • Repeated investigation in unprecedented proximity of 5 glacial fronts in Antarctica
  • Analysis of physical, chemical and biological water quality parameter interrelations
  • Correlations found between glacial meltwater and physicochemical parameter shifts
  • pH values shown rising with glacial meltwater presence
  • Varied biological parameter trends dependent on the distance from the glacial front

Abstract

For further understanding of glacial meltwater’s (GMW) impacts on marine environments, five coves adjacent to diverse glaciers of King George Island, Antarctica were investigated through surface measurements of water quality parameters. Measurements were conducted 49 times during January, February and March of 2019, with sampling performed in unprecedently close proximity to glacial fronts (< 50 m distance from glacier termini in each cove) to create a unique dataset. Four out of five of the coves were inspected through vertical profiling to show water-column stratification. The findings showed synchronized GMW influence causing decreases of salinity, temperature, and dissolved organic matter contents, combined with increased pH, turbidity, and dissolved oxygen values. GMW presence was most correlated with dissolved organic matter content (93% of the cases >0.5 correlation noted with either turbidity or salinity) and least correlated with water temperature (from 22% to 77% of the cases with >0.5 correlation, dependent on the cove). In contrast to previous studies, the pH values of seawater infused with GMW were higher than those of the surrounding water. GMW was shown to stay in the boundary surface layer of the water column. Phytoplankton pigment quantities depending on the localization, time and distance from the glacial termini presented varied response to GMW (positive, negative or ambivalent with hotspots of simultaneous high GMW and phytoplankton quantities). The positive response to glacial water input was more often noted in measurements of phycoerythrin (from 0 to 80% of the cases depending on the cove) rather than chlorophyll A (from 0 to 25%) and maximum quantities of both biological pigments were found at a depth of approximately 5-10 m.

Continue reading ‘Interrelation of quality parameters of surface waters in five tidewater glacier coves of King George Island, Antarctica’

Assimilating synthetic Biogeochemical-Argo and ocean colour observations into a global ocean model to inform observing system design

A set of observing system simulation experiments was performed. This assessed the impact on global ocean biogeochemical reanalyses of assimilating chlorophyll from remotely sensed ocean colour and in situ observations of chlorophyll, nitrate, oxygen, and pH from a proposed array of Biogeochemical-Argo (BGC-Argo) floats. Two potential BGC-Argo array distributions were tested: one for which biogeochemical sensors are placed on all current Argo floats and one for which biogeochemical sensors are placed on a quarter of current Argo floats. Assimilating BGC-Argo data greatly improved model results throughout the water column. This included surface partial pressure of carbon dioxide (pCO2), which is an important output of reanalyses. In terms of surface chlorophyll, assimilating ocean colour effectively constrained the model, with BGC-Argo providing no added benefit at the global scale. The vertical distribution of chlorophyll was improved by assimilating BGC-Argo data. Both BGC-Argo array distributions gave benefits, with greater improvements seen with more observations. From the point of view of ocean reanalysis, it is recommended to proceed with development of BGC-Argo as a priority. The proposed array of 1000 floats will lead to clear improvements in reanalyses, with a larger array likely to bring further benefits. The ocean colour satellite observing system should also be maintained, as ocean colour and BGC-Argo will provide complementary benefits.

Continue reading ‘Assimilating synthetic Biogeochemical-Argo and ocean colour observations into a global ocean model to inform observing system design’

Some fish develop larger sex organs when CO2 levels are high

A new study from the University of Adelaide has revealed that some fish develop larger sex organs when they are exposed to high levels of CO2.

A new study from the University of Adelaide has revealed that some fish develop larger sex organs when they are exposed to high levels of CO2. The experts report that the reproductive capacity of these fish will increase as the oceans continue to absorb carbon emissions.

The researchers said that far from the negative effects expected under the elevated CO2 levels in our oceans predicted for the end of the century, these fish capitalize on changes to the underwater ecosystems to produce more sperm and eggs.

“The warming oceans absorb about one-third of the additional CO2 being released into the atmosphere from carbon emissions, causing the oceans to acidify,” said study lead author Professor Ivan Nagelkerken.

Continue reading ‘Some fish develop larger sex organs when CO2 levels are high’

Ocean acidification affecting California mussels (text and audio)

Buoys in the water at the Carlsbad Aquafarm where owners grow oysters and mus...
PHOTO BY ERIK ANDERSON
Above: Buoys in the water at the Carlsbad Aquafarm where owners grow oysters and mussels on Aug. 26, 2019.

A UC San Diego researcher says an increasingly acidic ocean is having an impact on shellfish that live in the nearshore environment.

Graduate student Elizabeth Bullard studied recent mussel samples and compared them to records of mussels captured along the California coast 60 years ago.

Bullard expected to find that the animal’s shells were harder and contained more of the carbonate mineral aragonite as the shellfish adjusted to a warming ocean.

Continue reading ‘Ocean acidification affecting California mussels (text and audio)’

New edition of the “OA-ICC Highlights”, July-December 2020

Continue reading ‘New edition of the “OA-ICC Highlights”, July-December 2020’

Volcanic eruptions directly triggered ocean acidification during Early Cretaceous

Around 120 million years ago, the earth experienced an extreme environmental disruption that choked oxygen from its oceans.

Known as oceanic anoxic event (OAE) 1a, the oxygen-deprived water led to a minor — but significant — mass extinction that affected the entire globe. During this age in the Early Cretaceous Period, an entire family of sea-dwelling nannoplankton virtually disappeared.

By measuring calcium and strontium isotope abundances in nannoplankton fossils, Northwestern earth scientists have concluded the eruption of the Ontong Java Plateau large igneous province (LIP) directly triggered OAE1a. Roughly the size of Alaska, the Ontong Java LIP erupted for seven million years, making it one of the largest known LIP events ever. During this time, it spewed tons of carbon dioxide (CO2) into the atmosphere, pushing Earth into a greenhouse period that acidified seawater and suffocated the oceans.

Continue reading ‘Volcanic eruptions directly triggered ocean acidification during Early Cretaceous’

Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,428,650 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book

Archives