Ocean Acidification Impacts on Sea-Surface Biology, Biogeochemistry and Climate

Lead Research Organisation: Plymouth Marine Laboratory
Department Name: Plymouth Marine Lab

Abstract

The burning of fossil fuels is releasing vast quantities of extra carbon dioxide to the Earth's atmosphere. Much of this stays in the atmosphere, raising CO2 levels, but much also leaves the atmosphere after a time, either to become sequestered in trees and plants, or else to become absorbed in the oceans. CO2 staying in the atmosphere is a greenhouse gas, causing global warming; CO2 entering the sea makes it more acidic, and the ongoing acidification of seawater is seen in observational records at various sites where time-series data are collected. The changing chemistry of seawater due to ocean acidification is mostly well understood and not subject to debate. What is much less well known is the impact that the changing chemistry will have on marine organisms and ecosystems, on biogeochemical cycling in the sea, and on how the sea interacts with the atmosphere to influence climate. We will look to investigate these questions in terms of how the surface waters of the world's oceans, and the life within, will respond to ocean acidification. Most of what we know about biological impacts, and the source of the current concern about the impact on marine life, comes from experimental studies in which individual organisms (e.g. single corals) or mono-specific populations (e.g. plankton cultures) have been subjected to elevated CO2 (and the associated lower pH) in laboratory experiments. These laboratory experiments have the advantage of being performed under controlled conditions in which everything can be kept constant except for changes to CO2. So if a response is observed, then the cause is clear. However, there are also limitations to laboratory studies. For instance, organisms have no time to adapt evolutionarily, and there is no possibility of shifts in species composition away from more sensitive forms towards more acid-tolerant forms, as might be expected to occur in nature. Another shortcoming is the absence of food-web complexity in most experiments, and therefore the absence of competition, predation, and other interactions that determine the viability of organisms in the natural environment. We seek to advance the study of ocean acidification by collecting more observations of naturally-occurring ecosystems in places where the chemistry of seawater is naturally more acidic, and/or where it naturally holds more carbon,as well as locations which are not so acidic, and/or hold more usual amounts of carbon. By contrasting the two sets of observations, we will gain an improved understanding of how acidification affects organisms living in their natural environment, after assemblage reassortments and evolutionary adaptation have had time to play out. Most of the planned work will be carried out on 3 cruises to places with strong gradients in seawater carbon and pH: to the Arctic Ocean, around the British Isles, and to the Southern Ocean. As well a making observations we will also conduct a large number of experiments, in which we will bring volumes of natural seawater from the ocean surface into containers on the deck of the ship, together with whatever life is contained within, and there subject them to higher CO2 and other stressors. We will monitor the changes that take place to these natural plankton communities (including to biogeochemical and climate-related processes) as the seawater is made more acidic. A major strength of such studies is the inclusion of natural environmental variability and complexity that is difficult or impossible to capture in laboratory experiments. Thus, the responses measured during these experiments on the naturally-occurring community may represent more accurately the future response of the surface ocean to ocean acidification. In order to carry out this experimental/observational work programme we have assembled a strong UK-wide team with an extensive track record of successfully carrying out sea-going scientificresearch projects of this type.

Publications

10 25 50
 
Description Changes in the pH of seawater are likely to have both direct and indirect impacts on marine chemistry, marine biology and on the ability of the oceans to take up anthropogenic carbon dioxide. We have focused our research in this project on the production of climate active gases by the ocean and how the production of these gases might respond to ocean acidification. We found that the marine production of nitrous oxide, a potent greenhouse gas, might decline in the polar oceans in response to increasing acidification. This might help offset the impact of rising carbon dioxide levels in the atmosphere. There was no clear effect on the cycling of nitrogen in polar waters. There was no clear effect of increasing CO2 on the surface production of N2O in UK shelf waters.

We found that concentrations of DMS increased in UK shelf sea waters in response to ocean acidification. This was the opposite of what we had seen in experiments off Norway and in the Arctic. A increase in the flux of DMS to atmosphere, if replicated in the remote oceans might lead to an increase in atmospheric aerosol and hence an increase in cloud cover.
Exploitation Route Findings should be used in regional and global modelling studies to assess how emissions of climate active gases might amplify or reduce the impact of rising carbon dioxide levels in the atmosphere
Sectors Education,Environment

 
Description Results feed into the IPCC reports and hence to governments and policy makers.
First Year Of Impact 2014
Sector Environment
 
Title N-cycling in the Acrtic and Antarctic regions 
Description Two research cruises was undertaken in the Arctic and Antarctic Oceans to investigate how the microbial community may respond to the global warming related phenomena of Ocean Acidification. The way in which nitrogen is recycled within the surface ocean was investigated, including the impact on green-house gas production. This data will contribute to the wider understanding of how the ocean-atmosphere interactions are modified by climate change and what the effect will be on the foundation of marine food webs. This information will contribute to the development of global modelling efforts, ultimately informing environmental management, policy development and mitigation strategies. 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact papers 
 
Title N-cycling in the UK Shelf sea 
Description A research cruise was undertaken in the UK Shelf Sea to investigate how the microbial community may respond to the Global warming related phenomena of Ocean Acidification. The way in which nitrogen is recycled within the surface ocean was investigated, including the impact on green-house gas production. This data will contribute to the wider understanding of how the ocean-atmosphere interactions are modified by climate change and what the effect will be on the foundation of marine food webs. This information will contribute to the development of global modelling efforts, ultimately informing environmental management, policy development and mitigation strategies. 
Type Of Material Database/Collection of data 
Year Produced 2012 
Provided To Others? Yes  
Impact Papers 
 
Title N2O during Arctic and Antarctic ocean acidification experiments 
Description Impact of Ocean acidification on the production of N2O during 48 hour incubation experiments 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact Publication: Rees, A.P., Brown, I.J., Jayakumar, A. and Ward, B.B. (2015) The inhibition of N2O production by ocean acidification in cold temperate and polar waters. Deep-Sea Res.II http://dx.doi.org/10.1016/j.dsr2.2015.12.006i 
 
Title Nitrous oxide under natural and OA conditions of CO2 
Description A research cruise was undertaken in the UK Shelf Sea to investigate how the microbial community may respond to the Global warming related phenomena of Ocean Acidification. The way in which nitrogen is recycled within the surface ocean was investigated, including the impact on green-house gas production. This data will contribute to the wider understanding of how the ocean-atmosphere interactions are modified by climate change and what the effect will be on the foundation of marine food webs. This information will contribute to the development of global modelling efforts, ultimately informing environmental management, policy development and mitigation strategies. 
Type Of Material Database/Collection of data 
Year Produced 2012 
Provided To Others? Yes  
Impact Papers 
 
Title Published dataset: Ocean acidification impacts on sea surface biology and biogeochemistry in Northwest European Shelf Seas: a high-replicated shipboard approach. 
Description The goal of this study was to quantitatively investigate the links between changes in the ocean carbonate system and organism physiology and morphometry (including CaCO3 shells), biogeochemical rates, plankton biodiversity and community structure, food webs and climate-relevant processes. For that purpose we devised and implemented a series of highly replicated (n=8), short term (2-4 days) multi-level (>=4 conditions) carbonate chemistry (E1-E5)/nutrient manipulation (E2b, E3b and E5b) experiments on a range of natural microbial communities sampled in the surface mixed layer (<20 m) of Northwest European shelf seas. The cruise was conducted at a time of year with enhanced biological productivity and coccolithophore abundance (June/July 2011; PSO Achterberg). The cruise covered areas of different pH, seasonally stratified and perennially mixed seas, areas of coccolithophore abundance and absence, and areas (e.g. eastern North Sea, influence of Baltic inflow) where low alkalinity decouples CaCO3 from sea surface temperature. The experiments were performed within a purpose-built experimental laboratory container allowing acute temperature and light control. The temperature in the container was set up to match the in situ at the time of the water collection. The light (100 µE m-2 s-1) was provided by LED panels and followed a 16/8 h L/D cycle. In order to provide enough water to measure the multiples variables in triplicate, 9 bottles were dedicated to each time point. A total of 72 bottles were used for each bioassay. The additional bioassays (E2b, E4b and E5b) were run in triplicates for 2 days with a unique sampling point at the end of the incubation. This study provided up to 39 variables measured in each main bioassay. This work constitutes a UK contribution that complements existing/planned international OA research. To our knowledge this study represents the first attempt to link pelagic ocean carbonate system variations with sea-surface biology, biogeochemical rates and climate processes in such a comprehensive manner. Up to 18 scientists from 4 UK institutions (University of Southampton, University of Essex, PML and UCL) were involved in this team effort as part of the Sea Surface Consortium of the UK Ocean Acidification Research Program (UKOA). S Richier, EP Achterberg, SD Archer, L Bretherton, I Brown, D Clark, C Dumousseaud, RJ Holland, FE Hopkins, GA MacGilchrist, CM Moore, A Poulton, A Rees, T Shi, M Stinchcombe, D Suggett, MV Zubkov, J Young, T Tyrrell (2014) Ocean acidification impacts on sea surface biology and biogeochemistry in Northwest European Shelf Seas: a high-replicated shipboard approach. British Oceanographic Data Centre - Natural Environment Research Council, UK. doi:10/s8r. PML contributed measurements of dimethyl sulphide (DMS) and dimethyl sulphoniopropionate (DMSP) to this dataset. PML also contributed changes in nitrous oxide concentrations and rates of inorganic nitrogen regeneration. 
Type Of Material Database/Collection of data 
Year Produced 2012 
Provided To Others? Yes  
Impact The generation of this data set resulted in 2 publications from PML. 
URL https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/f44043b2-b9f0-71f2-e044-000b5de...
 
Title Published dataset: UK Ocean Acidification programme D366 cruise around the British Isles CTD bottle sample measurements 
Description M Ribas Ribas, EP Achterberg, SD Archer, D Bakker, D Clark, FE Hopkins, CM Moore, HE Lawson, G Lee, M Palmer, A Poulton, S Richier, T Shi, M Stinchcombe, D Suggett, T Tyrrell, J Young (2014) UK Ocean Acidification programme D366 cruise around the British Isles CTD bottle sample measurements. British Oceanographic Data Centre - Natural Environment Research Council, UK. doi:10/thr. PML contributed CTD bottle measurements of dimethyl sulphide (DMS) and dimethylsulphoniopropionate (DMSP) to this dataset. PML also contributed measurements of nitrous oxide concentration and the rates of inorganic nitrogen assimilation and regeneration. 
Type Of Material Database/Collection of data 
Year Produced 2013 
Provided To Others? Yes  
Impact Resulted in 2 publications. 
 
Title Response of DMS and DMSP to ocean acidification in the polar regions 
Description Two research cruises were undertaken in the Arctic and Antarctic Oceans to investigate the response of surface ocean microbial communities to ocean acidification. Through a series of shipboard community bioassay experiments, we assessed the response of the concentrations of dimethyl sulphide (DMS) and its algal precursor dimethyl sulphoniopropionate (DMSP) to OA in these vulnerable polar waters. This data will contribute to the wider understanding of how the ocean-atmosphere interactions are modified by anthropogenically-induced changes to the environment. This information will contribute to the development of global modelling efforts, ultimately informing environmental management, policy development and mitigation strategies. 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact Will result in a publication reporting the results of the UKOA Arctic and Southern Ocean cruise datasets. 
 
Description Collaboration with Princeton University 
Organisation Princeton University
Country United States 
Sector Academic/University 
PI Contribution Experimental investigation of the impact of ocean acidification on nitrogen biogeochemistry and nitrous oxide production
Collaborator Contribution Molecular characterisation of nitrifying communities and statistical interpretation of the impact of ocean acidification on these communities
Impact Manuscript in preparation
Start Year 2011
 
Description GESAMP 44 side event, WMO Geneva, Switzerland 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Frances Hopkins gave an invited presentation at the 44th Annual Meeting of UN-GESAMP in Geneva, Switzerland. The session was titled: CO2 in the atmosphere-ocean system: impacts and feedbacks, and the talk title was: changing ocean acidity as a modulator of atmospheric biogeochemistry and climate.
Year(s) Of Engagement Activity 2017
 
Description GESAMP WG 38 Impact of OA on fluxes of non-CO2 climate active species 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Working group off experts to initiate publications relating to trace gases and their impact by ocean acidification and multiple stressors
Year(s) Of Engagement Activity 2017
 
Description GESAMP WG 38 workshop, Impact of ocean acidification on fluxes of non-CO2 climate-active species 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact This workshop focused on the impacts of ocean acidification on the oceanic sources of a range of non-CO2 gaseous species as well as aerosol precursors that are influential in regulating radiative forcing, atmospheric oxidizing capacity and atmospheric chemistry. Participants included international scientists working in this field of research. The workshop has the following Terms of Reference:

1. Review and synthesize the current science on the direct impacts of ocean acidification on marine production and emissions to the atmosphere of key species important for climate and atmospheric chemistry.
2. Identify the primary needs for new research to improve process understanding and to quantify the impact of ocean acidification on these marine fluxes (i.e., provide recommendations on the specific laboratory process studies, field measurements and model analyses needed to support targeted research activities and improved understanding on this topic).
3. Publish the results of this activity in the open peer-reviewed scientific literature.
4. Provide input to and interact with national and international research programs on ocean acidification (e.g., UKOA, NOAA-OAP) and with relevant WMO programs (e.g., Global Atmosphere Watch (GAW)) to build on their recent relevant activity in achieving the above objectives.
Year(s) Of Engagement Activity 2017
 
Description Presentation to Local Womens Group 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Gave presentation on NERC funded research to approx. 20 members of a local womens group. Questions and discussion followed.
Year(s) Of Engagement Activity 2017
 
Description Presentation to students at the University of Exeter 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Undergraduate students
Results and Impact Lecture to Geography BSc students at the University of Exeter's Penryn campus on marine trace gases and their role in atmospheric chemistry and climate.
Year(s) Of Engagement Activity 2016
 
Description Presentation to undergraduate students at the University of Plymouth 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact 70 undergrads attended a lecture on the role of chemistry in marine sciences

interest in work placement opportunities
Year(s) Of Engagement Activity 2014
 
Description Royal Society for Chemistry; Chemistry at Work; event 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Schools
Results and Impact Outreach and knowledge exchange activity: Devised, organised and ran an Ocean Acidifcation workshop for 14/15 year olds as part of a Royal Society for Chemistry;Chemistry at Work event, held at the Marine Academy (Plymouth). The workshop was run five times over the course of one day, and involved the participation of ~150 students.

School requested a further visit to their Science Club.
Year(s) Of Engagement Activity 2012
 
Description Royal Society lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact 2-day public meeting was attended by nearly 200 people and was a full programme of presentations from world-leading experts and well as discussions and networking sessions, all themed around the progress of OA research over the last 6 years, the impact OA is likely to have on the environment and society and future plans for further OA studies
Year(s) Of Engagement Activity 2015
URL http://www.oceanacidification.org.uk/Latest_News/Royal_Society
 
Description SOLAS Open Science Conference (Germany) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Participation in working group on N2O and CH4 time series and presentation of poster: The inhibition of N2O production by ocean acidification in cold temperate and polar waters.
Year(s) Of Engagement Activity 2015
 
Description SOLAS Sumer School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Sparked questions and discussions, training of the next generation of scientists and policy makers

requests for further information, further discussions, improved links/interactions between UK and scientists from both developed and developing countries
Year(s) Of Engagement Activity 2009,2011,2013
URL http://www.solas-int.org/summerschool/welcome.html
 
Description Schools Talks 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Gave a three talks and ran a series of practical experiments to Yr 9 students at a local secondary school

requests for further information and for work experience at PML
Year(s) Of Engagement Activity 2010