From time to time we see articles in the media highlighting importance of reducing greenhouse gas emissions as soon as possible. However, usually these articles focus on land creatures and negative effects of climate change on our own lives. Now scientists at the University of Adelaide have conducted a world-first global analysis of marine responses to climbing human CO2 emissions and it revealed grim truth. Because of human caused atmosphere pollution entire food chain in the oceans may collapse.
Such dark picture of future fisheries and ocean ecosystems was drawn because research suggest that the expected ocean acidification and warming most likely will determine a reduction in diversity and numbers of various key species that underpin marine ecosystems around the world. This process of reducing number of species in the ecosystem is called “simplification of oceans” and will have serious consequences.
Inevitably people who live on the coastlines and rely on oceans for food and trade will be affected the most, but entire human population is very likely to suffer from the consequences of increasing acidity and warming of the oceans. Analysis that revealed such a grim picture of the future of ocean ecosystems concludes many other researches.
Scientists performed a ‘meta-analysis’ of the data from 632 published experiments covering tropical to artic waters, and a range of ecosystems from coral reefs, through kelp forests to open oceans.
Professor Sean Connell, one of the authors of the study, explained: “we know relatively little about how climate change will affect the marine environment. Until now, there has been almost total reliance on qualitative reviews and perspectives of potential global change. Where quantitative assessments exist, they typically focus on single stressors, single ecosystems or single species. This analysis combines the results of all these experiments to study the combined effects of multiple stressors on whole communities, including species interactions and different measures of responses to climate change.”
Although some scientists have argued that most species would adapts themselves to increasing acidity and temperature, this research revealed that only few species will escape the negative effects of increasing CO2. Research showed that there will be a large reduction in species diversity and abundance across the globe. However, not all organisms in the ecosystems will suffer only negative effects.
Scientists forecast that microorganisms are very likely to increase in number and diversity. However, looking at the food chain, scientists do not expect other species to benefit from increasing number of plankton. In other words, warm water will host more plankton, but it will not benefit the second level of the food web – the zooplankton and smaller fish. This indicates the decreased productivity under ocean acidification.
This, in turn, means that there will be less food for carnivores ─ the bigger fish that fisheries industries are based around. Scientists say that entire food chain will collapse from the top down. Scientists also revealed that there will be tremendous negative effect on habitat-forming species for example coral, oysters and mussels.
As usual is the case, damage to these species will damage entire ecosystems formed around them. Finally, the study showed that acidification of the oceans may lead to a decline in dimethylsulfide gas production by plankton. Production of this gas helps cloud formation and therefore in controlling the Earth’s heat exchange, which means that the effect will be noticeable in the long term in the entire planet.