[News] The coral reef crisis: The critical importance of <350 ppm CO2

[Michaelangelica]

The coral reef crisis: The critical importance of <350 ppm CO2

Temperature-induced mass coral bleaching causing mortality on a wide geographic scale started when atmospheric CO2 levels exceeded 320 ppm.

 

Should CO2 levels reach 600 ppm reefs will be eroding geological structures with populations of surviving biota restricted to refuges.

Domino effects will follow, affecting many other marine ecosystems.

ScienceDirect - Marine Pollution Bulletin : The coral reef crisis: The critical importance of <350 ppm CO2

 

1. Introduction

Temperature-related effects of global warming on coral reefs are highly visible, well-defined and extensively documented. Correlations between rising CO2 levels, rising ocean temperature and the biological responses of reefs are therefore known in detail, providing a particularly well-grounded basis for future prediction. The more recently recognised effects of atmospheric CO2 on ocean acidification will have even more profoundly detrimental long term effects on reefs but the full range of biological responses is, as yet, incompletely understood.

 

1.1. The importance of coral reefs

 

Although they make up only 0.2% in area of the marine environment, coral reefs are the most biodiverse ecosystems of the ocean, estimated to harbour around one third of all described marine species ([Reaka-Kudla, 1997] and [Reaka-Kudla, 2001]), most of which are found nowhere else. Their intricate three-dimensional landscapes promote elaborate adaptation, richly complex species interdependencies, and a fertile source of medically active compounds (Fenical, 2002 W. Fenical, Coral reef pharmacopeia, Issues in Science and Technology 18 (4) (2002), pp. 19–20.[Fenical, 2002] and [bruckner, 2007]). The extensive ramparts formed by reefs shield thousands of kilometres of coastline from wave erosion, protecting essential lagoon and mangrove habitat for vulnerable life stages of a wide range of commercial and non-commercial species (Johnson and Marshall, 2007).

 

More than 100 countries have coastlines with coral reefs (Moberg and Folke, 1999) and almost 500 million people (8% of the world’s population) live within 100 km of a reef (Bryant et al., 1998). Consequently, tens of millions of people depend on reef ecosystems for protein and other services (Costanza et al., 1997). Resulting exploitation, combined with lack of regulation, has resulted in severe depletion of many reef resources and has caused widespread reef degradation particularly in highly populated regions (Pet-Soede et al., 1999). Despite these impacts, human dependence on reefs continues to increase. The values of goods and services provided by reefs have not been accurately determined, but estimates range from $172 billion to $375 billion per year ([Moore and Best, 2001], [Wilkinson, 2002], [Fischlin et al., 2007] and [Martínez et al., 2007]). This is probably underestimated given that many of the benefits of coral reefs pass through non-market economies (Donner and Potere, 2007) or involve intangible ecosystem services such as sand production and gas exchange.

 

Importantly, the consequences of coral reef destruction would not be limited to the loss of the value of these goods and services, for the demise of reefs would also mean the extinction of a large part of the Earth’s total biodiversity – something never experienced before in human history.

[Moontanman]

Interesting they didn't mention the recovery of corals via new more temperature tolerant zooxanthellae recolonizing bleached corals. I have been involved in the farming of live coral for much of the last 30 years. Corals are far more resilient that current researchers give them credit for.

 

New England Aquarium - Phoenix Islands Expedition Blog

 

The bleacing is more complex than just temperature increases.

 

Resilience and recovery of Coral Reefs and Coastal Habitats | UNEP/GRID-Arendal - Publications - Our Precious Coasts

 

Corals can recover, the bleaching events do not wipe out all corals wholesale and most areas show signs of either recovery or colonization by other species of coral or both.

[BrianG]

If you care about coral, stop shitting in the ocean. Raw sewage, agricultural run off is pollution, I don't believe 390ppmv [ce]CO2]/ce] is as harmful as untreated wastes from large coastal cities and larger agricultural operations. Corals need carbon, too:

 

"Corals are made up of a few generally known chemicals. The most known being aragonite, because aragonite, which is calcium carbonate, makes up the skeleton of the corals. In order to grow, corals calcify with the help of the zooxanthellae in them. Studies have been done that show that corals with zooxanthellae in them calcify nineteen times faster than corals without them (Druffel, 8356). The calcification of the corals is greatly affected by the carbon dioxide chemistry and the nutrient concentrations in the seawater (Marubini, 117). From the study done by Marubini, he found that the effects of low concentrations of carbonate and pH on corals are not permanent and that when introduced into normal waters the effects were immediate and reversible (Marubini, 117). The carbon cycle of coral reefs is driven by biological processes"

 

The Chemistry of the Oceans and Coral Reefs

 

Calcium carbonate acts like the fossil fuel of the coral world. Life abounds, at least the seas will smell better, if we quit dumping so much **** in them. Carbon dioxide is odorless at projected atmospheric concentrations.

[Michaelangelica]

The Fate of the Great Barrier Reef » ABC Queensland

 

Considering that nearly a third of the world's reefs have already been lost and some 58% of what is left is under direct threat, the Great Barrier Reef. . .

The Fate of the Great Barrier Reef » ABC Queensland

 

The most significant threat to the Great Barrier Reef is climate change.[50][51] Mass coral bleaching events due to rising ocean temperatures occurred in the summers of 1998, 2002 and 2006,[52] and coral bleaching will likely become an annual occurrence.[53] Climate change has implications for other forms of life on the Great Barrier Reef as well - some fish's preferred temperature range lead them to seek new areas to live, thus causing chick mortality in seabirds that prey on the fish. Climate change will also affect the population and available habitat of sea turtles.[54]

Great Barrier Reef - Wikipedia, the free encyclopedia

 

The health of the Great Barrier Reef, the world’s largest World Heritage Area, is a key indicator of global climate change. Increases in sea temperature of as little as 1°C may lead to coral bleaching, the eventual death of corals and cause severe damage to dependent ecosystems. In 1998 and 2002 the Great Barrier Reef experienced two mass coral bleaching events and climate change is widely considered to pose the greatest long-term threat to the reef. It is predicted that without substantial reductions (“deep cuts”) in global emissions of anthropogenic greenhouse gases, the corals of the Great Barrier Reef will be decimated and coral cover worldwide will decrease to less than 5 per cent on most reefs by 2050.

Global climate change, the Great Barrier Reef and our obligations - On Line Opinion - 19/11/2004

 

 

Action on pollution:- no action on CO2.

9 Oct 2009 ... Queensland's Parliament passed legislation last night to reduce run-off from farming land onto the Great Barrier Reef. ... ..

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'Putrid' Barrier Reef run-off laws approved - ABC News (Australian Broadcasting Corporation)

 

A WATERSHED DAY FOR THE GREAT BARRIER REEF

8 Oct 2009 ... The Great Barrier Reef gained historic protection in State Parliament tonight ... She said under the new legislation to take effect from 1 January 2010, ... "Cutting down on one major threat - the harmful run-off of ...

http://www.mysunshinecoast.com.au/.../a-watershed-day-for-the-great-barrier-reef,15085 -