Archives de catégorie : biology+acidification

biology+acidification, climate-debate

CRYING WOLF OVER THE GREAT BARRIER REEF

by Peter Ridd, August 12, 2019 in GWPF

The scare stories about the Great Barrier Reef started in the 1960’s when scientist first started work on the reef. They have been crying wolf ever since.

Scientists from James Cook University have just published a paper on the bleaching and death of corals on the Great Barrier Reef (GBR) and were surprised that the death rate was less than they expected because of the adaptability of corals to changing temperatures. It appears as though they exaggerated their original claims and are quietly backtracking. To misquote Oscar Wilde, to exaggerate once is a misfortune, to do it twice looks like carelessness, but to do it repeatedly looks like unforgivable systemic unreliability by some of our major science organisations.

It is a well-known phenomenon that corals can adapt very rapidly to high temperatures and that if you heat corals in one year, they tend to be less susceptible in future years to overheating. It is the reason why corals are one of the least likely species to be affected by climate change, irrespective of whether you believe the climate is changing by natural fluctuations or from human influence.

…

biology+acidification, climate-debate

STRANGE CORAL SPAWNING IMPROVING GREAT BARRIER REEF’S RESILIENCE

by University of Queensland, August 7, 2019 in GWPF

The discovery was made by University of Queensland and CSIRO researchers investigating whether corals that split their spawning over multiple months are more successful at spreading their offspring across different reefs.

Dr Karlo Hock, from UQ’s School of Biological Sciences, said coral mass spawning events are one of the most spectacular events in the oceans.

“They’re incredibly beautiful,” Dr Hock said.

“On Australia’s Great Barrier Reef, all coral colonies typically spawn only once per year, over several nights after the full moon, as the water warms up in late spring.”

Study co-author Dr Christopher Doropoulos from the CSIRO Oceans & Atmosphere said sometimes however, coral split their spawning over two successive months.

“This helps them synchronise their reproduction to the best environmental conditions and moon phases,” he said.

“While reproductive success during split spawning may be lower than usual because it can lead to reduced fertilisation, we found that the release of eggs in two separate smaller events gives the corals a second and improved chance of finding a new home reef.”

The research team brought together multi-disciplinary skills in modelling, coral biology, ecology, and oceanography, simulating the dispersal of coral larvae during these split spawning events, among the more than 3800 reefs that make up the Great Barrier Reef.

…

biology+acidification

Thirty years of unique data reveal what’s really killing coral reefs

by P. Homewood, July 24, 201 in NotatLotofPeopleKnowThat

Coral reefs are considered one of the most threatened ecosystems on the planet and are dying at alarming rates around the world. Scientists attribute coral bleaching and ultimately massive coral death to a number of environmental stressors, in particular, warming water temperatures due to climate change.

A study published in the international journal Marine Biology, reveals what’s really killing coral reefs. With 30 years of unique data from Looe Key Reef in the lower Florida Keys, researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute and collaborators have discovered that the problem of coral bleaching is not just due to a warming planet, but also a planet that is simultaneously being enriched with reactive nitrogen from multiple sources.

Improperly treated sewage, fertilizers and top soil are elevating nitrogen levels, which are causing phosphorus starvation in the corals, reducing their temperature threshold for “bleaching.” These coral reefs were dying off long before they were impacted by rising water temperatures. This study represents the longest record of reactive nutrients and algae concentrations for coral reefs anywhere in the world.

“Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area during our long-term study,” said Brian Lapointe, Ph.D., senior author and a research professor at FAU’s Harbor Branch.

…

 

 

https://phys.org/news/2019-07-years-unique-reveal-coral-reefs.html

 

There is the usual armwaving about climate change, but no evidence is presented as to why a small increase in CO2 levels should have the slightest effect on water temperatures or coral development, when the climate has been much warmer for most of the period since the end of the ice age.

As is usually the case with environmental degradation and species decline, it is the obvious factors which are responsible.

biology+acidification, climate-debate

What’s really killing the Coral Reefs?

by Carly Cassella, July 20, 2019 in WUWT

Coral reefs are one of the most threatened ecosystems on our planet, and in the past two decades alone, half of the coral in Florida has died off completely. Global warming is known to be a deadly factor, but rising ocean temperatures are only part of the story.

Thirty years of research in the Looe Key Sanctuary Preservation Area (LKSPA) on the southern tip of the Florida Keys has now revealed the cost of a devastating threat to coral that rivals even climate change: direct human pollution.

For years, agricultural run-off and improperly treated sewage have flowed into Florida’s ocean waters from the northern Everglades, elevating the sanctuary’s nitrogen levels and lowering the reef’s temperature threshold for bleaching, researchers say.

As a result of this deadly combination, coral cover in the region has declined from nearly 33 percent in 1984 to less than 6 percent in 2008.

In their analysis, the authors found that three mass bleaching events that occurred during these years only happened after heavy rainfall and increased land-based runoffs. In other words, if we can reduce the amount of local pollution that makes its way into our oceans, we might be able to reduce the worst of the damage.

…

Klein & Orlando, Bulletin of Marine Science, 1994

biology+acidification

New Study Reveals True Cause Of Coral Bleaching (And It’s Not Global Warming)

by Brook Hays, July 16, 2019 in ClimateChangeDispatch

Corals are disappearing across the world’s oceans, and most scientists have pointed to warming water temperatures — the result of climate change — as the primary driver.

But new research suggests nitrogen pollution is the main cause of coral bleaching in Florida.

The study, published this week in the journal Marine Biology, was compiled using the three-decades worth of observational data collected at the Looe Key Reef in the lower Florida Keys.

“Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area,” lead study author Brian Lapointe, research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, said in a news release.

Data collected at the test site showed nutrient runoff has boosted the nitrogen-phosphorus ratio in reef algae.

As more and more treated sewage and fertilizers from commercial farms rinse into local waterways and flood the oceans with nutrients, including reactive nitrogen, corals are unable to absorb sufficient levels of phosphorous.

“Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area,” lead study author Brian Lapointe, research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, said in a news release.

…

biology+acidification, climate-debate

How deep-ocean vents fuel massive phytoplankton blooms

by Stanford’s School of Earth, Energy & Environmental Sciences, June 5, 2019 in WUWT

More “settled science” of the carbon cycle~ctm

Stanford study shows how hydrothermal vents fuel massive phytoplankton blooms — and possible hotspots for carbon storage

Researchers at Stanford University say they have found an aquatic highway that lets nutrients from Earth’s belly sweep up to surface waters off the coast of Antarctica and stimulate explosive growth of microscopic ocean algae.

Their study, published June 5 in the journal Nature Communications, suggests that hydrothermal vents – openings in the seafloor that gush scorching hot streams of mineral-rich fluid – may affect life near the ocean’s surface and the global carbon cycle more than previously thought.

Mathieu Ardyna, a postdoctoral scholar and the study’s lead author, said the research provides the first observed evidence of iron from the Southern Ocean’s depths turning normally anemic surface waters into hotspots for phytoplankton – the tiny algae that sustain the marine food web, pull heat-trapping carbon dioxide out of the air and produce a huge amount of the oxygen we breathe. “Our study shows that iron from hydrothermal vents can well up, travel across hundreds of miles of open ocean and allow phytoplankton to thrive in some very unexpected places,” he said.

Kevin Arrigo, a professor of Earth system science and senior author of the paper, called the findings “important because they show how intimately linked the deep ocean and surface ocean can be.”

…

biology+acidification

Des coraux qui s’adaptent aux températures plus élevées

by Paul Berth, 31 mai 2019 in ScienceClimatEnergie

Selon certaines prédictions, basées sur des modèles informatiques, de nombreux récifs coralliens auront disparu des océans tropicaux au cours des 80 prochaines années[1]. La cause est bien évidemment le réchauffement climatique pouvant provoquer un blanchiment des coraux. Par exemple, en 2014–2017, a eu lieu un évènement global de blanchiment, le 3e au cours des 20 dernières années, et de nombreux coraux furent affectés sur des milliers de kilomètres carrés[2],[3]. Les médias, avides de catastrophisme, en ont beaucoup parlé avec des titres une fois de plus très alarmistes (exemple ici).

Cependant, les choses ne sont pas si simples. Des données satellitaires et des études de terrain ont montré que tous les récifs coralliens ne se comportent pas de la même manière: de nombreux récifs n’ont pas blanchi pendant le dernier épisode El Niño, une très grande partie des coraux a résisté au stress thermique, et de fortes variations locales et régionales ont été observées dans le blanchiment[4]. La relation entre température élevée de l’eau de mer et blanchiment des coraux n’est donc pas évidente. Afin d’éclaircir la situation une équipe américaine a récemment publié une analyse globale des évènements de stress thermique en considérant 3351 sites différents dans 81 pays (Sully et al. 2019, dans Nature Communications[5]). Cette analyse globale est unique et démontre que les coraux sont en train de s’adapter par sélection naturelle et sont désormais un peu plus résistants au blanchiment. Nous avons ici une belle démonstration du fait que les modèles informatiques sont parfois bien loin de la réalité de terrain et qu’il ne faut pas tirer de  conclusions toujours hâtives!

…

biology+acidification

CO2 and ocean chemistry

by Dr. Daniela Mazza, May 18, 2019 in WUWT

Oceans cover about 71% of the earth surface, but their influence on climate change is not only due to high heat capacity of water , not only to the ocean’s water circulation, but to a fact which is widely underestimated : the pH (acidity level) of sea-water is substantially alkaline, ranging from 8.0 to 8.7 . This means that the balance between positive and negative ions is reached by accounting for OH– ,hydroxide ions, in a far larger amount in respect to H+ hydrogen ions.

The pH value higher than 7 allows seawater to dissolve and react huge amounts of CO2 , carbon dioxide, thus affecting the amount of this gas in the atmosphere by absorbing excess of it. To calculate this excess in respect to what would be the true equilibrium value in the air, all of the chemical reactions involved have to be simultaneously computed, accounting for their equilibrium constants, which in turn depend on temperature.

1 – CO2 (gas) + H2O <==> H2CO3* (H2CO3* is the sum of dissolved CO2 and H2CO3)

2 – H2CO3 <==> H+ + HCO3–

3 – HCO3– <==> H+ + CO3– –

4 – H2O <==> H+ + OH–

5 – Ca++ + CO3– – <==> CaCO3 (calcite)

6 – Ca++ + OH– <==> Ca(OH)+

7 – Mg++ + OH– <==> Mg(OH)+

…

 

Conclusions : CO2 is at 410 ppm far above the equilibrium value (315) , provided a standard seawater composition and an average ocean temperature of 17°C (taken from wikipedia). No doubt that solubility will force more CO2 to be stored in oceans . Moreover if we consider CaCO3 formation (seawater has overshot the solubility of this salt nearly 50 times but nucleation and growth are slow) still more CO2 will be stored by limestone.

biology+acidification, sciences-general

Low oxygen levels could temporarily blind marine invertebrates

by Scripps Institution of Oceanography at the University of California San Diego, May 8, 2019 in ScienceDaily

These results, published recently in the Journal of Experimental Biology, are the first demonstration that vision in marine invertebrates is highly sensitive to the amount of available oxygen in the water.

Oxygen levels in the ocean are changing globally from natural and human-induced processes. Many marine invertebrates depend on vision to find food, shelter, and avoid predators, particularly in their early life stages when many are planktonic. This is especially true for crustaceans and cephalopods, which are common prey items for other animals and whose larvae are highly migratory in the water column.

Research on terrestrial animals has shown that low oxygen levels can affect vision. In fact, humans can lose visual function in low oxygen conditions. Pilots flying at high altitude, for instance, have been shown to experience vision impairment if aircraft fail to supplement cockpits with additional oxygen. Additionally, health problems such as high blood pressure and strokes, both associated with oxygen loss, can damage vision.

…

biology+acidification

More Evidence for Rapid Coral Adaptation

by Jim Steele, April 2, 2019 in WUWT

Good news continues to accumulate regards corals’ ability to rapidly adjust to changing climates. The view of coral resilience has been dominated by the narrative of a few scientists. In the 1990s they advocated devastating consequences for coral reefs due to global warming, arguing coral cannot adapt quickly enough. Since the Little Ice Age ended, they believed rising ocean temperatures had brought coral closer to a “bleaching threshold”, a more or less fixed upper temperature limit above which corals cannot survive. Their model predicted the speed of recent global warming “spells catastrophe for tropical marine ecosystems everywhere”. Their assertions that “as much as 95% of the world’s coral may be in danger of being lost by mid-century” was guaranteed to capture headlines and instill public fear. However, a growing body of scientific research increasingly casts doubts on such alarming predictions. Unfortunately, that good news gets much less attention.

A recent peer-reviewed paper titled A Global Analysis of Coral Bleaching Over the Past Two Decades (Sully 2019) compared 20 years of ocean temperatures at which coral bleaching was initiated. From 1998 to 2006, the average sea surface temperature that initiated bleaching was 82.6 °F. But that temperature limit proves not to be “fixed” as earlier researchers incorrectly believed. From 2007 to 2017 the average temperature limit that initiated bleaching was higher, 83.7 °F. This indicates coral have been rapidly adapting to warmer regional climates much faster than once believed.

…

Biodiversity, biology+acidification, climate-debate

Global Warming off the hook? Alien species are primary cause of recent global extinctions

by University College London, March 3, 2019 in WUWT

Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers.

They found that since 1500, alien species have been solely responsible for 126 extinctions, 13% of the total number studied.

Of 953 global extinctions, 300 happened in some part because of alien species, and of those 300, 42% had alien species alone listed as the cause of their demise.

The study, published today in Frontiers in Ecology and the Environment, used data from the 2017 IUCN Red List on the total numbers of species that are considered to have gone extinct globally since 1500.

In total, 261 out of 782 animal species (33.4%) and 39 out of 153 plant species (25.5%) listed aliens as one of their extinction drivers. In contrast, native species impacts were associated with only 2.7% of animal extinctions and 4.6% of plant extinctions.

 

…

 

biology+acidification

Coral Reefs in West Hawaiʽi Showing Signs of Recovery

by P. Homewood, February 21, 2019 NotaLotofPeopleKnowThat

…

Surveys identified 25 coral species in West Hawaiʻi. Lobe coral (Porites lobata), one of the area’s most dominant species, proved to be the most resilient—with only 50% bleaching in 2015. Cauliflower corals (Pocillopora meandrina) were hardest hit—with 98% bleaching—but recent surveys show that they are beginning to recover.

…

biology+acidification

Analysis Finds Oceans Have Become LESS ‘Acidic’ With Rising CO2, Challenging The ‘Acidification’ Narrative

by K. Richard, February 14, 2019 in NoTricksZone

A modest long-term (1800s-present) declining trend in ocean pH values predominantly occurred prior to 1930, or before anthropogenic CO2 emissions began rising precipitously. Since 1930, seawater pH trends have risen slightly, meaning sharply rising CO2 has been coincident with less, not more, ocean “acidification”

 

I

Image Source (lower graph): Wei et al., 2015

 

 

better to know...?, biology+acidification, climate-debate

GWPF Call For Insect Decline Paper To Be Withdrawn

by P. Homewood, February 11, 2019 in NotaLotofPeopleKnowThat

London, 11 February: The scientific paper behind newspaper claims that insect populations were threatened with extinction was based on data known to be unreliable. That’s according to the Global Warming Policy Foundation, which today called for the paper to be withdrawn.

The paper, by US scientists Bradford C Lister and Andres Garcia, claimed that a rapid decline in insect populations in a rainforest in Puerto Rico was the result of rising temperatures. The Washington Post called the study “hyperalarming”, while the Guardian discussed climate change causing “insect collapse”.

However, the authors’ evidence that temperatures had, in fact, risen turns out to be based on a single weather station, which was known to be unreliable because of undocumented changes to equipment and location resulting in a substantial and abrupt increase in recorded temperatures in September 1992.

Since 1992, temperatures at this station have actually declined.

…

better to know...?, biology+acidification, climate-debate

The Obvious Biomass Emissions Error

by Steve Goreham, February 7, 2019 in WUWT

When Thomas Edison established his Pearl Street power plant in New York City in 1892, he used coal for fuel, not wood. Wood fuel could not compete with the cost of coal in 1892 and it still can’t today. Nevertheless, burning of biomass is widely regarded as sustainable and promoted as a solution for climate change, especially in Europe.

Today, Europe produces about 17 percent of its energy and 29 percent of its electricity from renewable sources. Biomass accounts for about 19 percent of the electricity generated from renewables. Since 2000, Europe’s biomass consumption for energy production is up 84 percent.

For example, biomass fuel produced 18 percent of Denmark’s electricity in 2017. For the last two decades, Denmark has been reducing coal-fired power plant output, but adding biomass-powered plants. Since 2000, Denmark’s use of coal fuel for electricity decreased 63 percent. But the use of biomass fuel for electricity in Denmark increased by a factor of five, almost exactly replacing the decline in coal output. About three-quarters of the biomass consumed by Denmark is wood, with most of it imported.

…

biology+acidification, sciences-general

New islands, happy feet: Study reveals island formation a key driver of penguin speciation

by Molecular Biology and Evolution (Oxford University Press), February 5, 201 in ScienceDaily

Ever since Darwin first set foot on the Galapagos, evolutionary biologists have long known that the geographic isolation of archipelogos has helped spur the formation of new species.

Now, an international research team led by Theresa Cole at the University of Otago, New Zealand, has found the same holds true for penguins. They have found the first compelling evidence that modern penguin diversity is driven by islands, despite spending the majority of their lives at sea.

“We propose that this diversification pulse was tied to the emergence of islands, which created new opportunities for isolation and speciation,” said Cole.

Over the last 5 million years, during the Miocene period, (particularly within the last 2 million years), island emergence in the Southern Hemisphere has driven several branches on the penguin evolutionary tree, and also drove the more recent influence of human-caused extinctions of two recently extinct penguin species from New Zealand’s Chatham Islands.

…

biology+acidification, climate-debate

Study: Much of the surface ocean will shift in color by end of 21st century

by Charles the moderator,  February 5, 2019 in WUWT

Climate-driven changes in phytoplankton communities will intensify the blue and green regions of the world’s oceans

From the Massachusetts Institute of Technology

Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.

…

biology+acidification, sciences-general

Scientists identify two new species of fungi in retreating Arctic glacier

by Research Organization of Information and Systems, January 15, 2019 in ScienceDaily

Two new species of fungi have made an appearance in a rapidly melting glacier on Ellesmere Island in the Canadian Arctic, just west of Greenland. A collaborative team of researchers from Japan’s National Institute of Polar Research, The Graduate University for Advanced Studies in Tokyo, Japan, and Laval University in Québec, Canada made the discovery.

The scientists published their results on DATE in two separate papers, one for each new species, in the International Journal of Systematic and Evolutionary Microbiology.

“The knowledge of fungi inhabiting the Arctic is still fragmentary. We set out to survey the fungal diversity in the Canadian High Arctic,” said Masaharu Tsuji, a project researcher at the National Institute of Polar Research in Japan and first author on both papers. “We found two new fungal species in the same investigation on Ellesmere Island.”

…

biology+acidification

Algae thrive under Greenland sea ice

by Bigelow Laboratory for Ocean Sciences, January 8, 2019 in ScicneDaily

Microscopic marine plants flourish beneath the ice that covers the Greenland Sea, according to a new study. These phytoplankton create the energy that fuels ocean ecosystems, and the study found that half of this energy is produced under the sea ice in late winter and early spring, and the other half at the edge of the ice in spring.

…

better to know...?, biology+acidification

CORAL REEFS CAN TAKE THE HEAT, UNLIKE EXPERTS CRYING WOLF

by Peter Ridd, December 26, 2018 in GWPF

Scientists from James Cook University have just published a paper on the bleaching and death of corals on the Great Barrier Reef and were surprised that the death rate was less than they expected, because of the adaptability of corals to changing temperatures.

It appears as though they exaggerated their original claims and are quietly backtracking.

To misquote Oscar Wilde, to exaggerate once is a misfortune, to do it twice looks careless, but to do it repeatedly looks like unforgivable systemic unreliability by some of our major science organisations.

The very rapid adaptation of corals to high temperatures is a well-known phenomenon; besides, if you heat corals in a given year, they tend to be less susceptible in the future to overheating. This is why corals are one of the least likely species to be affected by climate change, irrespective of whether you believe the climate is changing by natural fluctuations or because of human influence.

Corals have a unique way of dealing with changing temperature, by changing the microscopic plants that live inside them. These microscopic plants, called zooxanthellae, give the coral energy from the sun through photosynthesis in exchange for a comfortable home inside the coral. When the water gets hot, these little plants effectively become poisonous to the coral and the coral throws them out, which turns the coral white — that is, it bleaches.

…

 

better to know...?, biology+acidification

Ocean Acidification Background Context

by ‘Guest Blogger’, December 23, 2018 in WUWT

Obiter dictum. We acknowledge that seawater is basic and cannot truly acidify (pH<7). But that is a losing semantic quibble, not a winning skeptical argument. The generally accepted linguistic convention—for better or worse–is that lowering seawater pH means ‘acidification’. There is no doubt that adding dissolved CO2 does lower pH. The relevant questions are how much and whether that amount matters. This post answers both questions (a little, not much) without the two specific false alarms that motivated the ebook version.

There are certainly some ocean related AGW consequences beyond any scientific doubt. Henry’s Law requires that the partial pressures of atmospheric and dissolved ocean CO2equilibrate. Rising atmospheric CO2 must increase dissolved seawater CO2. That is long established simple physical chemistry.

This lowers pH by increasing carbonic acid. NOAA PMEL has documented this in the central Pacific at Station Aloha off Mauna Loa where sea surface pH has declined from 8.11 to 8.07 since 1991, as dissolved pCO2 increased from ≈325 to ≈360μatm while atmospheric CO2 increased from about 355 to 395 ppm. That is Δ0.04 pH in 24 years.

…

See also here (in French)

biology+acidification

La biomasse globale : de larges incertitudes, également sur le cycle du carbone!

by Prof. Paul Berth, 14 décembre 2018 in ScienceClimatEnergie

Dans un article récent de juin 2018[1], le biologiste Yinon Bar-On et ses collaborateurs ont estimé la biomasse totale de la biosphère actuelle (Bar-On et al. 2018). Pour cela, ils ont simplement estimé les nombres de bactéries, protozoaires, plantes et animaux dans tous les écosystèmes de la planète. En connaissant le poids moyen de chaque organisme, les auteurs ont ensuite réalisé des sommes. Ils arrivent au chiffre final de 550 gigatonnes (Gt) de carbone. Ce chiffre est-il élevé ? Avec quoi peut-on le comparer? Est-il précis ? Quels sont les organismes les plus importants dans la biosphère ? Quelles sont les conséquences pour le cycle du carbone, et donc pour la concentration de CO2 atmosphérique ? Voici toute une série de questions que l’on doit se poser. Nous allons voir que les résultats de Yinon Bar-On sont assez étonnants et qu’ils induisent des conséquences majeures pour le cycle du carbone dans la biosphère.

…

 

Figure 1. Biomasse totale de la biosphère, en gigatonnes (Gt). Bar-On et al. (2018)

…

biology+acidification, climate-debate, press and newspapers

‘Glimmer Of Hope’ For Great Barrier Reef As Study Shows Tolerance To Climate Change

by Nick Visser, December 10, 2018 in Huffpost

Last year’s oceanic heat wave wasn’t as destructive as one the year before, scientists said.

The Great Barrier Reef fared better during an oceanic heat wave last year than during sizzling weather a year earlier that caused hundreds of miles of corals to bleach, according to a study published Monday that suggests the massive structure may be growing more tolerant to climate change.

The report in the journal Nature Climate Change analyzed how corals along the Great Barrier fared in back-to-back mass bleaching events. The reef ― a UNESCO World Heritage Site and the largest living structure on the planet ― was cooked by overheated seawater in 2016 and again in 2017, with images of sickly white coral horrifying people around the globe.

…

See also here

biology+acidification

A Brachiopod’s Twelve-Decade Response to Ocean Acidification and Warming

by Cross et al., November 29, 2018 in CO2Science

Paper Reviewed
Cross, E.L., Harper, E.M. and Peck, L.S. 2018. A 120-year record of resilience to environmental change in brachiopods. Global Change Biology 24: 2262-2271.

…

In light of all their findings, Cross et al. conclude that “these rhynchonelliform brachiopods have therefore been unaffected in their abilities to construct and maintain their extensive skeletons by the change in ocean acidity and temperature over the last 120 years.” And this is a noteworthy conclusion, given that C. inconspicua is one of the most calcium-carbonate-dependent species globally, and is therefore presumed to be highly susceptible to ocean acidification. It would thus appear that proper incorporation of species’ adaptation and/or acclimation potentials is essential if scientists are to get predictions of the impacts of ocean acidification on marine life correct.

biology+acidification, climate-debate

Thriving reef fisheries continue to provide food despite coral bleaching

by Lancaster University, November 29, 2018 in ScienceDaily/Nature

The unexpected results of a 20-year study into reef fisheries published in the journal Nature Ecology and Evolution this week showed fisheries being maintained despite extreme coral bleaching. Remarkably, rapid proliferation of fishes with low dependence on corals led to catches remaining stable or even increasing.

But the results also showed fishing success was ‘patchy’ and more dependent on fewer species.

Around six million people fish on coral reefs. Each year their catch — estimated to be between 1.4 and 4.2 million tonnes — provides a critical source of food and income for many millions more.

…