Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis

This study investigated the effects of seawater pH (i.e., 8.10, 7.85 and 7.60) and temperature (16 and 19 °C) on (a) the abiotic conditions in the fluid surrounding the embryo (viz. the perivitelline fluid), (b) growth, development and (c) cuttlebone calcification of embryonic and juvenile stages of the cephalopod Sepia officinalis. Egg swelling increased in response to acidification or warming, leading to an increase in egg surface while the interactive effects suggested a limited plasticity of the swelling modulation. Embryos experienced elevated pCO₂ conditions in the perivitelline fluid (>3-fold higher pCO₂ than that of ambient seawater), rendering the medium under-saturated even under ambient conditions. The growth of both embryos and juveniles was unaffected by pH, whereas ⁴⁵Ca incorporation in cuttlebone increased significantly with decreasing pH at both temperatures. This phenomenon of hypercalcification is limited to only a number of animals but does not guarantee functional performance and calls for better mechanistic understanding of calcification processes.

Oceans’ rising acidity a threat to shellfish — and humans

As carbon dioxide continues to build up in the atmosphere as a result of burning fossil fuels, the seas absorb much of it.The full effects have yet to be felt

Peering into the microscope, Alan Barton thought the baby oysters looked normal, except for one thing: They were dead.

Slide after slide, the results were the same. The entire batch of 100 million larvae at the Whiskey Creek Shellfish Hatchery had perished.

It took several years for the Oregon oyster breeder and a team of scientists to find the culprit: a radical change in ocean acidity.

Ocean acidification puzzles fish and shellfish

Researchers who participated in a recent international meeting state that the more acidic oceans become, the more hyperactive and puzzled some fish and shellfish turn, approaching their predators instead of trying to escape from them.

And the French scientist Jean-Pierre Gattuso, of Villefranche Oceanography Laboratory, warned that “ocean conditions are changing 100 times faster than at any time in the past.”

Gattuso is one of nearly 600 scientists from around the world, who presented their research results at the third symposium ‘The Ocean in a High-CO2 World: Ocean Acidification,’ held in the city of Monterey, United States, reported IPS.

Scientists adopt tiny island as a warming bellwether

TATOOSH ISLAND, Wash. — From a stretch of rocky shoreline on this tiny island, one can, on any given morning, watch otters floating on their backs, elephant seals hauling out of the water and a bald eagle flying past murres huddled along a cliff face. The startled birds perform a synchronized dive into the sea, their ovoid black-and-white bodies resembling miniature penguins.

Murres and gulls perched along a cliff face on Tatoosh Island, off the coast of Washington State. Researchers who have studied the island for decades have noticed that the historically hardy populations of the birds are now only half what they were 10 years ago.

International coordination to address ocean acidification

Ocean acidification experts expressed increasing concerns with how marine organisms will adapt to new ‘corrosive’ conditions during an international symposium on the subject last week, warning that life throughout the world’s oceans will have to adapt rapidly to changing conditions. A new ocean acidification tour was launched in Google Earth on this occasion. It explores the phenomenon of ocean acidification and explains why even small changes to ocean carbon chemistry could have profound implications for marine life and future economic activities.

Research fellow – Coral reef ecology

at Griffith University

Reference: 495618
Element: Australian Rivers Institute
Work type: Fixed term (2 years)

Overview:
Griffith University has a long-established reputation for research excellence in the environmental sciences, especially in relation to the water sciences. This research is currently focused within the Griffith School of Environment and the Australian Rivers Institute. The Institute has over 175 staff and postgraduate students at the University’s Nathan and Gold Coast campuses and undertakes high quality research and postgraduate training in freshwater, estuarine, and coastal ecology.

Dr Diaz-Pulido’s research program focuses on understanding the consequences of human impacts on coral reef ecology, coral-algal dynamics, and in particular, ocean acidification on coral-macroalgal interactions. While significant progress has been made to understand the biological and physiological consequences of human-induced ocean acidification on algae and corals, very little is known about the ecological ramifications on coral reefs.

This is a fixed term (2 years), full time position based at the Nathan campus.

Environment: excess nutrients speed up ocean acidification

CO2 from decaying algae blooms adds to ocean woes

SUMMIT COUNTY — Runoff from agricultural and urban areas is speeding up ocean acidification in some coastal areas, adding to the woes resulting from increased concentration of atmospheric carbon dioxide.

A new study by researchers with the National Oceanic and Atmospheric Administration and the University of Georgia found that CO2 released from decaying algal blooms intensifies acidification, which is already taking a toll on shellfish populations in some areas.

Ocean acidification occurs when the ocean absorbs carbon dioxide from the atmosphere or from the breakdown of organic matter, causing a chemical reaction to make it more acidic. Species as diverse as scallops and corals are vulnerable to ocean acidification, which can affect the growth of their shells and skeletons.

Low calcification in corals in the Great Barrier Reef

Reef-building coral communities in the Great Barrier Reef—the world’s largest coral reef—may now be calcifying at only about half the rate that they did during the 1970s, even though live coral cover may not have changed over the past 40 years, a new study finds. In recent decades, coral reefs around the world, home to large numbers of fish and other marine species, have been threatened by such human activities as pollution, overfishing, global warming, and ocean acidification; the latter affects ambient water chemistry and availability of calcium ions, which are critical for coral communities to calcify, build, and maintain reefs. Comparing data from reef surveys during the 1970s, 1980s, and 1990s with present-day (2009) measurements of calcification rates in One Tree Island, a coral reef covering 13 square kilometers in the southern part of the Great Barrier Reef, Silverman et al. show that the total calcification rates (the rate of calcification minus the rate of dissolution) in these coral communities have decreased by 44% over the past 40 years; the decrease appears to stem from a threefold reduction in calcification rates during nighttime.

Assessment of sample storage techniques for total alkalinity and dissolved inorganic carbon in seawater

The borosilicate glass bottle sealed with a ground stopper and vacuum grease is a high quality container for preserving seawater samples for total alkalinity (TA) and dissolved inorganic carbon (DIC); it is recommended in the standard methods, even though this bottle is expensive and hard-to-handle. As there is an increased demand for sample storage and transportation by laboratories involved in biological and ocean acidification research, we explore alternative sample storage techniques by testing four types of containers. The results demonstrated that over a period of 47 d, TA values from seawater samples stored in polypropylene (PP) bottles and high density polyethylene (HDPE) bottles were not statistically different from those stored in the benchmark borosilicate glass bottles, both at room and refrigerated temperatures. In addition, DIC concentrations from a seawater sample stored in soda-lime glass bottles and small volume borosilicate glass vials with screw caps were not statistically different from those stored in the borosilicate glass bottles over at least 148 d. However, the TA value of seawater stored in soda-lime glass bottles increased significantly with increasing storage time, indicating that this type of soft glass bottle is not suitable for TA sample storage. Therefore, we suggest that PP or HDPE bottles can be used for TA sample storage and small volume borosilicate glass vials with screw caps can be used for DIC sample storage for a period of at least 1.5 months. These storage containers provide economical and easy-to-transport alternatives to the recommended high-quality borosilicate glass bottles.

Ocean acidification and warming reduce juvenile survival of the fluted giant clam, Tridacna squamosa

Anthropogenic carbon dioxide (CO₂) emissions are causing ocean acidification and ocean warming; however, the synergistic effects of these stressors on giant clams are completely unknown. Juveniles of the fluted giant clam, Tridacna squamosa Lamarck, 1819, were exposed to present-day control seawater (416 µatm pCO₂) and seawater treated with CO₂ to simulate ocean conditions predicted for the next 50–100 years (622 µatm pCO₂ and 1019 µatm pCO₂). These CO₂ treatments were cross-factored with seawater temperatures of ~28.5 °C, ~30.0 °C and ~31.5 °C. The majority of mortality occurred between 40 and 60 days. Survival of juveniles decreased with increasing pCO₂ and decreased with increasing seawater temperature. The combination of the highest pCO₂ and both the moderate and highest seawater temperatures resulted in the lowest survival of <20 % indicating survival of T. squamosa could be reduced considerably at ocean conditions predicted to occur around the end of this century.