Scheme: Wolfson Research Merit Awards
Organisation: University of Bristol
Dates: May 2015-Apr 2020
Summary: The ocean serves us in many ways from regulating climate to providing food, livelihood and recreation. Human societies depend on these ecosystem services. Anthropogenic emissions of CO2 to the atmosphere affect the ocean either directly (acidification, OA) or indirectly though climate change (warming and deoxygenation). Crucially, shelf-sea benthic ecosystems, among the most diverse ecosystems on the planet, are predicted to be most affected.
Understanding about impacts of individual stressors on marine ecosystems in general and calcifiers in particular has grown in recent years. Responses vary strongly between species, studies, with acclimation time and food supply. Some species build thinner walls, some reduce calcification; some change their chemical composition while others can calcify even in a warmer more acidic ocean.
Shelf ecosystems depend on species who build physical structures, providing habitats for others. Coralline algae are major habitat former on the UK shelf, forming biodiversity hotspots. While they are able to continue calcifying in undersaturated conditions, a change in geometry results in changes in the stress distribution in their skeleton, creating potential zones of weakness which could lead to structural failure. To date, no one has addressed if thinner, less dense skeletal structures will allow these organisms to fulfil their role in the marine ecosystem. It is critical that this research is conducted now as to avoid widespread and severe damage to marine ecosystems from OA which ultimately may lead to extinctions.
This research is exciting as it combines a wide range of techniques from research areas which do not have a tradition in working together. The research will provide strategies for management of coastal habitats to limit the impact of climate change. It will offer a framework for policy makers to plan Marine Protected Areas and ensure that these habitats will be there for future generations.
Scheme: University Research Fellowship
Dates: Oct 2011-Nov 2015
Summary: Human activity has led to an increase in carbon dioxide levels. Rising atmospheric CO2 is leading to warming and changes in the carbonate chemistry of the oceans, a process termed “ocean acidification”. While the chemistry is well understood, its ecological consequences are one of the emerging risks of the last IPCC report.
Climate change and ocean acidification alter the physical, chemical and biological properties of the ocean. At the current rate of CO2 uptake, the ocean pH will be lower and, importantly, will have changed faster than anything experienced by marine organisms over the million years. This implies a risk for mankind as ocean acidification has to potential to significantly alter marine ecosystems: the base of the food chain, economically important fishery or structural integrity of habitat formers.
The species-specific responses to climate change limit our ability to make projections about the future of marine ecosystems. Additionally, the factors affecting individuals and ecosystems are notoriously complex and may be scale-dependent. There are important questions I want to answer: Does climate change have an effect on mineral properties and structure of marine calcifiers and do these changes weaken the skeleton? Has climate change in the last 100 years had an effect on the skeletal structure of marine calcifiers or are the organisms able to use their own “tool box” to deal with these challenges? By comparing a number of “model” species I aim to identify common strategies as a response to ocean acidification and hence hep to upscale our understanding from individual species to overarching principles.
This information will make a fundamental contribution to the assessment of the risk of climate change for the future ecosystem services and provide information for governmental organisations concerned with managing and protecting the marine resources.
Dates: Oct 2006-Sep 2011
Summary: We are burning large quantities of fossil fuels, thereby emitting carbon dioxide into the atmosphere. Based on measurements from ice cores, atmospheric CO2 levels were between 260 and 280 ppm during the last 10,000 years. Anthropogenic carbon emissions to the Earth’s atmosphere and ocean are small compared to the natural fluxes in ocean-atmosphere-biosphere system, but they are large enough to cause significant changes in the surface environment of the Earth. The atmospheric CO2 at the moment is ~ 380 ppm, and is predicted to reach 450-550 by 2050 and as high as 800 by 2100.
The ocean is taking up a significant part of this CO2. As a consequence of CO2 uptake, the pH (the acidity) of the oceans are changing to values which have been seen only rarely in the geological record. To understand how organisms and ecosystems are reacting to future ocean acidification we can interrogate the geological record of acidification. Were there time interval which has a similar rate of change to what is happening now and how did organisms react to this change? My results suggest that acidification of the ocean today is bigger and faster than anything geologists can find in the fossil record. Indeed, its speed and strength — ten times the rate of anything in the past 65 million years — is a likely thread to many marine species, particularly ones that live in the deep ocean.
To go the next step, we have to understand how organisms calcify to be able to predict the effect of ocean acidification in the future. We need to be able to quantify how much energy it will cost to calcify if this becomes chemically more and more difficult due to ocean acidification. This information will allow us to assess potential impacts on calcifying algae in the ocean, important for the marine food chain, or organisms like mussels, we like to eat ourselves, or deep sea coral ecosystems, the nursing grounds for fish all along the North Atlantic sea board.