Tag Archives: warming oceans

Coral fights back slowly from ocean heating

EMBARGOED until 2301 GMT on Thursday 6 June The good news is that some coral can recover from periodic warming of the oceans: the bad news is it might take too long. LONDON, 6 June – Marine biologists’ worst fears seem to be confirmed: coral colonies take a long time to recover from catastrophic climate events. British and Brazilian biologists report in the Public Library of Science One – better known simply as PLoS One – that the richest habitats of the sea could also be among the most vulnerable to climate change. For more than 17 years, conservationists from Plymouth University in the UK worked with researchers from the Federal University of Bahia in Brazil to analyse the diversity and density of coral reefs and colonies off the coast of South America. Quite early in that 17 year span, there was an  El Niño event. This is a periodic eruption of unprecedented ocean temperatures: it is a natural phenomenon and seems to have happened periodically through recorded human history, distinguished by droughts and wildfires in those places that normally expect high rainfall, and floods on otherwise normally arid coasts. Rising temperatures The 1997-98 event lasted for 18 months and was considered one of the most devastating of all, with sea temperatures reaching a global record. Tropical coral reefs were affected almost everywhere; there were also devastating storms and floods in California and forest fires in Borneo. Corals are peculiarly sensitive to sea temperatures – they tend to bleach if seas get hotter – and many corals live and flourish at near the limits of their tolerance. Coral reefs are also home to an estimated 25% of all marine species, so the loss of a reef has a serious effect on marine biodiversity, as well as on the incomes of local fishermen – and local tourist operators. The British and Brazilian scientists monitored eight species of Scleractinian or stony corals and worked with the Brazilian Meteorological Office to build up a complete picture of the environmental conditions and the way these affected species behavior. Slow recovery During 1998, all the monitored corals showed increased mortality and one species disappeared completely from the reefs for at least seven years. Then, as temperatures dropped, the corals started to grow again. Recent measurements show that the coral colonies have fully recovered, and are now back to the levels recorded before 1998. That’s the good news. The bad news is that recovery took so long. “El Niño events give us an indication of how changing climate affects ecosystems as major changes within the Pacific impact the whole world,” said one of the authors, Martin Attrill of Plymouth’s Marine Institute. “If the reefs can recover quickly, it is probable they can adapt and survive the likely changes in water temperatures ahead of us. However, we found it took 13 years for the coral reef system of Brazil to recover, suggesting they may be very vulnerable to climate-related impacts.” – Climate News Network

EMBARGOED until 2301 GMT on Thursday 6 June The good news is that some coral can recover from periodic warming of the oceans: the bad news is it might take too long. LONDON, 6 June – Marine biologists’ worst fears seem to be confirmed: coral colonies take a long time to recover from catastrophic climate events. British and Brazilian biologists report in the Public Library of Science One – better known simply as PLoS One – that the richest habitats of the sea could also be among the most vulnerable to climate change. For more than 17 years, conservationists from Plymouth University in the UK worked with researchers from the Federal University of Bahia in Brazil to analyse the diversity and density of coral reefs and colonies off the coast of South America. Quite early in that 17 year span, there was an  El Niño event. This is a periodic eruption of unprecedented ocean temperatures: it is a natural phenomenon and seems to have happened periodically through recorded human history, distinguished by droughts and wildfires in those places that normally expect high rainfall, and floods on otherwise normally arid coasts. Rising temperatures The 1997-98 event lasted for 18 months and was considered one of the most devastating of all, with sea temperatures reaching a global record. Tropical coral reefs were affected almost everywhere; there were also devastating storms and floods in California and forest fires in Borneo. Corals are peculiarly sensitive to sea temperatures – they tend to bleach if seas get hotter – and many corals live and flourish at near the limits of their tolerance. Coral reefs are also home to an estimated 25% of all marine species, so the loss of a reef has a serious effect on marine biodiversity, as well as on the incomes of local fishermen – and local tourist operators. The British and Brazilian scientists monitored eight species of Scleractinian or stony corals and worked with the Brazilian Meteorological Office to build up a complete picture of the environmental conditions and the way these affected species behavior. Slow recovery During 1998, all the monitored corals showed increased mortality and one species disappeared completely from the reefs for at least seven years. Then, as temperatures dropped, the corals started to grow again. Recent measurements show that the coral colonies have fully recovered, and are now back to the levels recorded before 1998. That’s the good news. The bad news is that recovery took so long. “El Niño events give us an indication of how changing climate affects ecosystems as major changes within the Pacific impact the whole world,” said one of the authors, Martin Attrill of Plymouth’s Marine Institute. “If the reefs can recover quickly, it is probable they can adapt and survive the likely changes in water temperatures ahead of us. However, we found it took 13 years for the coral reef system of Brazil to recover, suggesting they may be very vulnerable to climate-related impacts.” – Climate News Network

Rising Acidity Threatens Squid

Embargoed until 2301 GMT Saturday 1 June Creature at centre of ocean ecosystem faces uncertain future as waters warm LONDON, 1 June – That jet-propelled cephalopod of the seas, the squid, could be in for a hard time. As atmospheric carbon dioxide levels rise, so the oceans become more acid, and this is not good news for one of the most important animals of the ocean ecosystem. Aran Mooney of the Woods Hole Oceanographic Institution in the US and other colleagues decided to take a look at what changing pH levels might do for the creature sometimes served up diced into rings, and fried, as calamari, or sometimes as the sauce in a pasta, cooked in its own ink. The researchers took both male and female longfin squid – a commercially-prized variety – from the waters of Vineyard Sound off the coast of Massachusetts and kept them in a laboratory tank until they mated. Some of the eggs were transferred to an experimental tank, some kept in existing seawater. Experiments One sample tank in effect “breathed” today’s air. The other was subjected to air enriched with higher carbon dioxide levels – dissolving as carbonic acid – until the tank water reached the higher acidity levels predicted 100 years from now. Then they noted how the baby squid developed. The scientists reported in the journal PLoS One that animals raised in the highly acidic water took longer to develop, were five per cent smaller on average, and some developed malformed statoliths – carbonate crystals that help the squid orient itself while swimming. Food chain “The fact that we found an impact in everything we measured was pretty astounding,” said Dr Mooney. “Squid are at the centre of the ocean ecosystem – nearly all animals are eating or eaten by squid. So if anything happens to these guys, it has repercussions up the food chain and down the food chain.” In 2011 US fishermen landed $100 million worth of squid: the creature is also food for tuna and hake, both commercially valuable catches. The next step in the research is to look at the effects of differing acidic levels and on the impact of changing sea temperatures.  Climate change isn’t the only challenge that confronts the creatures of the sea: overfishing and ocean pollution are also big and growing problems. But warm water fish can migrate to cooler temperatures, and have already begun to do so. Struggle to adapt Governments can regulate fish catches and establish marine reserves – and have begun to do so. But the research into the changing chemistry of the seas really is a voyage of discovery: animals evolved over millions of years to adapt very precisely to today’s conditions, and as they develop they quite literally fashion themselves with the materials in the sea water around them. Swift changes in ocean chemistry – and in evolutionary terms, a century is a very short time – could affect ocean ecosystems in unprecedented and unpredictable ways. – Climate News Network    

Embargoed until 2301 GMT Saturday 1 June Creature at centre of ocean ecosystem faces uncertain future as waters warm LONDON, 1 June – That jet-propelled cephalopod of the seas, the squid, could be in for a hard time. As atmospheric carbon dioxide levels rise, so the oceans become more acid, and this is not good news for one of the most important animals of the ocean ecosystem. Aran Mooney of the Woods Hole Oceanographic Institution in the US and other colleagues decided to take a look at what changing pH levels might do for the creature sometimes served up diced into rings, and fried, as calamari, or sometimes as the sauce in a pasta, cooked in its own ink. The researchers took both male and female longfin squid – a commercially-prized variety – from the waters of Vineyard Sound off the coast of Massachusetts and kept them in a laboratory tank until they mated. Some of the eggs were transferred to an experimental tank, some kept in existing seawater. Experiments One sample tank in effect “breathed” today’s air. The other was subjected to air enriched with higher carbon dioxide levels – dissolving as carbonic acid – until the tank water reached the higher acidity levels predicted 100 years from now. Then they noted how the baby squid developed. The scientists reported in the journal PLoS One that animals raised in the highly acidic water took longer to develop, were five per cent smaller on average, and some developed malformed statoliths – carbonate crystals that help the squid orient itself while swimming. Food chain “The fact that we found an impact in everything we measured was pretty astounding,” said Dr Mooney. “Squid are at the centre of the ocean ecosystem – nearly all animals are eating or eaten by squid. So if anything happens to these guys, it has repercussions up the food chain and down the food chain.” In 2011 US fishermen landed $100 million worth of squid: the creature is also food for tuna and hake, both commercially valuable catches. The next step in the research is to look at the effects of differing acidic levels and on the impact of changing sea temperatures.  Climate change isn’t the only challenge that confronts the creatures of the sea: overfishing and ocean pollution are also big and growing problems. But warm water fish can migrate to cooler temperatures, and have already begun to do so. Struggle to adapt Governments can regulate fish catches and establish marine reserves – and have begun to do so. But the research into the changing chemistry of the seas really is a voyage of discovery: animals evolved over millions of years to adapt very precisely to today’s conditions, and as they develop they quite literally fashion themselves with the materials in the sea water around them. Swift changes in ocean chemistry – and in evolutionary terms, a century is a very short time – could affect ocean ecosystems in unprecedented and unpredictable ways. – Climate News Network