If anything is clear to me from researching this series, it is that the oceans of the future will look a lot different from the oceans of today. What exactly do these changes mean to the human population? Although it's not easy to imagine, the changes brought about by ocean acidification (OA) will undoubtedly reverberate through food webs, bringing extensive change to fisheries and aquaculture.
How can we begin to understand how future oceanic ecosystems will look? It's not plausible to run experiments at such large scales; however, mathematical models can be employed to extrapolate from multiple data sets. In the concluding presentation of the OA session at the recent American Association for the Advancement of Science meeting in Vancouver, Shallin Busch, a researcher at the National Oceanic and Atmospheric Administration (NOAA), presented some cutting-edge work in the area of ecological modelling. Models are a powerful predictive tool, allowing researchers to manipulate timeframes, environmental factors and biological data in a myriad of ways. Busch is focused on modelling the food web in Puget Sound, concentrating on species that are commercially harvested. She is able to combine physical, chemical and biological data to create scenarios for future oceans.
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For example, one of the clearest results coming from laboratory work on single species is that ocean acidification will harm calcifying organisms. Using data from the Puget Sound ecosystem, Busch completed models for three levels of decreased productivity for calcifying organisms: five, 15 and 25 per cent declines. She asked, "What happens to other animals when the productivity of calcifiers is decreased to these levels?" The graph shows what her models predicted for a timeframe of 50 years at the 15 per cent decline in calcifier productivity. Although the graph is complex (as are the modelling methodologies from which they are derived), the key point to note here is this: There will be clear winners and clear losers. In this scenario, organisms like crabs and shrimp will experience a drastic decrease in overall biomass, whereas some fish species like ling cod and flat fish will experience an increase. In other general scenarios, organisms like mussels, oysters and abalone are negatively affected, whereas sea stars experience increased population levels.
Carin Bondar is a biologist, TV host and science communicator with a PhD in population ecology from the University of British Columbia. She blogs for Scientific American and Huffington Post and has appeared in a scientific capacity on various international television networks. Her writing has been featured online at National Geographic Wild, Jezebel, Forbes, The Guardian, The Daily Beast and the Richard Dawkins Foundation. Find Dr. Bondar online, on twitter or on her Facebook page. Look for her blogs on science topics in the coming weeks on the David Suzuki Foundation website.