UW makes waves in ocean acidification

Photo credit: E. Carrington

Photo credit: E. Carrington

The San Juan archipelago, perhaps most famous for its pod of southern resident killer whales, is also home to the UW’s world-renowned biological field station, the Friday Harbor Laboratory (FHL).

Built in 1910 on the former Point Caution military reserve, FHL has grown from a single building to a sprawling campus with over a dozen specialized laboratories.

A waterfront trail, which meanders past the stand-alone research buildings, serves as a timeline of the facility’s growth. The farther along the trail you go, the newer the labs become. Eventually, the trail dead ends at the newest addition: the Ocean Acidification Environmental Laboratory (OAEL).

Interest in ocean acidification at the UW began with professor of oceanography Richard Feely. Through his work with the National Oceanic Atmospheric Administration’s (NOAA) Carbon Program, Feely highlighted worrisome trends in ocean chemistry and inspired scores of scientists to take a closer look.

“Ocean acidification was really off the radar for everyone 20 years ago,” said Emily Carrington, a professor of biology at the UW and the OAEL’s first director. “Largely because of [Feely’s] efforts and many others, the University of Washington and Washington State [University] are at the forefront of ocean acidification research, regionally and globally.”

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Climate resolve talk with a scientist: Paul Bunje

Paul Bunje is senior scientist for energy and environmental programs at XPRIZE, an awards organization based in Southern California. What does Dr. Bunje do? In his own words: “I work to help solve environmental grand challenges by inspiring and facilitating innovation.” Trained as an evolutionary biologist, Dr. Bunje was founding director of the Los Angeles Regional Collaborative for Climate Action and Sustainability. At XPRIZE, Dr. Bunje is helping to lead the organization’s work on climate change. He talked to Maya Bon for Climate Resolve about ocean acidification and hypoxia, an area of focus for XPRIZE — and what we can do about these threats.

Can you give us a background on ocean acidification — what it is, how it’s caused, what it does to the ocean, and how it relate to climate change?

Paul Bunje: Ocean acidification is essentially the evil twin of climate change, as it is also the consequence of carbon dioxide emissions. About one quarter of the CO2 that we’ve emitted into the atmosphere is absorbed by the world’s oceans. When you put CO2 into water, it forms carbonic acid, which in turn drives down the pH of seawater. The challenge is that this is happening globally — as more CO2 goes into the atmosphere, more goes into the ocean…. [and] upsets the chemical balance of carbonate ions, carbonic acid, and CO2, which changes the chemistry that sea creatures work within.

One of the first identified impacts were the shells of creatures that make their shells out of calcium carbonate — corals, mollusks, bivalves, some important phytoplankton such as coccolithophore, which produces a significant amount of oxygen for the planet. When this chemistry balance is upset, it becomes more difficult to get the carbonate out of the water and these creatures cannot make their shells. In extreme cases, the shells dissolve. There are interesting cases of this occurring with sea butterflies, a microscopic snail, because of ocean acidification. You can actually see their microscopic shells dissolving in water.

Continue reading ‘Climate resolve talk with a scientist: Paul Bunje’

Eutrophication accelerates carbonate dissolution under high pCO2 condition in coral reef ecosystem

Incubation experiments were carried out to determine the effect of eutrophication on carbonate dissolution under high pCO2 (partial pressure of carbon dioxide) condition in coral reef ecosystem at Sesoko Island, Okinawa, Japan. Short incubation (24 h under natural illumination) and long incubations (4 days under dark condition) were carried out using white coral skeleton (without attachment of living organism, control); natural rubble (with associated epilithic and endolithic communities) and natural rubble with addition of dissolve organic matter (glucose and coral mucus). Addition of DOM significantly enhanced bacterial abundance (t-test; p=0.01) and net respiration (t-test; p=0.0001) with increasing pCO2 levels (p < 0.05) under natural illumination. Consistent with increase in respiration, dissolution rates also increased from 136.22±2.04 to 652.38±4.51 µmolm-2d-1. Under dark condition, where photosynthesis was inhibited, dissolution of calcium carbonate further increased with addition of different level of DOM. In addition of DOM incubation bottles, bacterial abundance increased by 3~4 orders of magnitude and the dissolution rates increased by 2.5~10 times more than the control. The results suggest that availability of organic matter in the reefs will enhance metabolic activities (respiration) of microbial communities associated with coral rubble which ultimately increase dissolution of calcium carbonate.

Continue reading ‘Eutrophication accelerates carbonate dissolution under high pCO2 condition in coral reef ecosystem’

Effects of seawater acidification on the growth rates of the diatom Thalassiosira (Conticribra) weissflogii under different nutrient, light, and UV radiation regimes

Effects of ocean acidification (OA) on marine organisms are suggested to be altered by other environmental drivers, such as low nutrient, increased light, and UVR exposures; however, little has been documented on this aspect. Thalassiosira (Conticribra) weissflogii, a marine diatom, was used to examine the OA effects under multiple stressors on its growth. The specific growth rate was inhibited by low nutrient (LN), though it increased with increased sunlight regardless of the nutrient supplies. Presence of UVR reduced the maximal growth rate (μmax) in low CO2 (LC) conditions (both LN and HN) and inhibited the apparent growth light use efficiency (α) in the cells acclimated to LN under both low (LC) and high (HC) CO2 conditions. The HC-grown cells grew faster under HN and low light levels. Conclusively, presence of UVR with high solar radiation, LN and OA acted synergistically to reduce the diatom growth, though, in contrast UVR and OA enhanced the growth under HN.

Continue reading ‘Effects of seawater acidification on the growth rates of the diatom Thalassiosira (Conticribra) weissflogii under different nutrient, light, and UV radiation regimes’

Linking rising pCO2 and temperature to the larval development and physiology of the American lobster (Homarus americanus)

Few studies have evaluated the joint effects of elevated temperature and pCO2 on marine organisms. In this study we investigated the interactive effects of Intergovernmental Panel on Climate Change predicted temperature and pCO2 for the end of the 21st century on key aspects of larval development of the American lobster, Homarus americanus, an otherwise well-studied, iconic, and commercially prominent species in the northeastern United States and Atlantic Canada. Our experiments showed that larvae (stages I–III) and postlarvae (stage IV) reared in the high temperature treatments (19 °C) experienced significantly lower survival, developed twice as fast, and had significantly higher oxygen consumption rates, than those in ambient treatments (16 °C). Larvae from the ambient temperature/high pCO2 (750 ppm) treatment had significantly longer carapace lengths, greater dry masses in stages I–III and higher C: N ratios in stage IV than larvae from all other treatments. Stage IVs raised in the high pCO2 treatment at 19 °C had significantly higher feeding rates and swimming speeds than stage IVs from the other three treatments. Together these results suggest that projected end-century warming will have greater adverse effects than increased pCO2 on larval survival, and changing pCO2 may have a complex effect on larval metabolism and behaviour. Understanding how the most vulnerable life stages of the lobster life cycle respond to climate change is essential in connecting the northward geographic shifts projected by habitat quality models, and the underlying physiological and genetic mechanisms that drive their ecology.

Continue reading ‘Linking rising pCO2 and temperature to the larval development and physiology of the American lobster (Homarus americanus)’

Future climate stimulates population out-breaks by relaxing constraints on reproduction

When conditions are stressful, reproduction and population growth are reduced, but when favourable, reproduction and population size can boom. Theory suggests climate change is an increasingly stressful environment, predicting extinctions or decreased abundances. However, if favourable conditions align, such as an increase in resources or release from competition and predation, future climate can fuel population growth. Tests of such population growth models and the mechanisms by which they are enabled are rare. We tested whether intergenerational increases in population size might be facilitated by adjustments in reproductive success to favourable environmental conditions in a large-scale mesocosm experiment. Herbivorous amphipod populations responded to future climate by increasing 20 fold, suggesting that future climate might relax environmental constraints on fecundity. We then assessed whether future climate reduces variation in mating success, boosting population fecundity and size. The proportion of gravid females doubled, and variance in phenotypic variation of male secondary sexual characters (i.e. gnathopods) was significantly reduced. While future climate can enhance individual growth and survival, it may also reduce constraints on mechanisms of reproduction such that enhanced intra-generational productivity and reproductive success transfers to subsequent generations. Where both intra and intergenerational production is enhanced, population sizes might boom.

Continue reading ‘Future climate stimulates population out-breaks by relaxing constraints on reproduction’

Missing the boat: Critical threats to coral reefs are neglected at global scale

Coral reefs have experienced a global decline due to overfishing, pollution, and warming oceans that are becoming increasingly acidic. To help halt and reverse this decline, interventions should be aimed at those threats reef experts and managers identify as most severe. The survey included responses from 170 managers, representing organizations from 50 countries and territories, and found that respondents generally agreed on the two major threats: overfishing and coastal development. However, resource allocation did not match this consensus on major threats. In particular, while overfishing receives much attention, coastal development and its attendant pollution are largely neglected and underfunded. These results call for a re-examination of how resources are allocated in coral reef conservation, with more attention given to aligning how money is spent with what are perceived to be the primary threats.

Continue reading ‘Missing the boat: Critical threats to coral reefs are neglected at global scale’

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Ocean acidification in the IPCC AR5 WG II

OUP book