Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implications for scallop aquaculture in an upwelling- influenced area off northern Chile

Chair: Tommy Moore

Nelson A. Lagos (1)*, Samanta Benítez (1), Cristian Duarte (2), Marco A. Lardies (3), Bernardo R. Broitman (4), Christian Tapia (5), Pamela Tapia (5), Steve Widdicombe (6) & Cristian A. Vargas (7)

1 Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Santiago, Chile.
2 Departamento de Ecología y Biodiversidad, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago Chile
3 Facultad de Ingeniería & Ciencias y Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile
4 Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
5 Cultivos Invertec Ostimar S.A., Tongoy, Coquimbo, Chile
6 Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, UK
Laboratorio de Funcionamiento de Ecosistemas Acuáticos (LAFE), Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, Chile

Coastal upwelling regions already constitute hot spots of ocean acidification as naturally acidified waters are brought to the surface. This effect could be exacerbated by the ocean acidification and warming, both caused by rising concentrations of atmospheric CO2. Along the Chilean coast, upwelling supports highly productive fisheries and aquaculture activities. However, during recent years, there has been a documented decline in the national production of the native scallop Argopecten purpuratus.

We assesses the combined effects of temperature and pCO2-driven ocean acidification on the growth rates and shell characteristics of this species farmed under the natural influence of upwelling waters occurring in northern Chile (30°S, Tongoy Bay).

Regular observations of pH and temperature showed that the experimental conditions representing current ambient conditions (14°C/pH~8.0) were typical of natural values recorded in Tongoy Bay, whilst conditions representing the low pH scenario were typical of an adjacent upwelling area (pH~7.6). Shell thickness, weight and biomass were reduced under conditions of decreased pH (pH~7.7) and increased temperature (18ºC). At ambient temperature (14°C) and low pH (pH~7.7), scallops showed increased shell dissolution and low growth rates. However, elevated temperatures ameliorate the impacts of low pH, evidenced by an increase in the calcification rate of A. purpuratus.

The impact of low pH at current temperature on scallop growth, suggests that the upwelling could increase the time taken for scallops to reach the marketable size. Mortality of the harvestable scallops is discussed in relation with our observation on multiple environmental stressors in this upwelling–influenced area.

Bioengineering slow flow habitats as refugia for coastal calcifiers from ocean acidification

Chair: Jessica Ericson

Catriona L. Hurd (1)*, Katherine Schmutter (2), Merinda Nash (3), Will Howard (4)

1 Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia, catriona.hurd@utas.edu.au
2 Fenner School of Environment and Society, The Australian National University, Canberra, ACT 2601, Australia
3 Research School of Physics and Engineering, Electronic Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
4University of Melbourne, Earth Sciences Department, Melbourne, Victoria, 3010, Australia

Ocean acidification is the ongoing decline in the pH of surface waters, and the projected 0.4 unit pH decrease by 2100 is likely to negatively impact benthic coastal organisms that fabricate calcium carbonate ‘skeletons’. Coralline algae are considered the most vulnerable of all benthic calcifying organisms to ocean acidification, and calcifying invertebrates are also highly vulnerable. Research has focussed on identifying susceptible species but we also need to identify refuge habitats to enable their protection.

The susceptibility of coralline algae to ocean acidification depends on the pH at their surface, and this is regulated by the interplay between algal metabolism and water motion. Using pH microprobes, we show that algal metabolism causes local increases (photosynthesis, nitrate uptake) and decreases (calcification, respiration, ammonium uptake) in the pH at the algal surface; pH at the surface of a seaweed can thus fluctuate by ±0.5 units on a daily cycle.

Water motion sets the thickness of the diffusion boundary layer, and thick DBLs have been shown to ameliorate the negative effects of ocean acidification on coralline algae via their action of retaining metabolically-produced high-pH seawater at the algal surface, thereby preventing dissolution of calcium carbonate (Cornwall et al. 2014). Seawater velocities within beds of canopy forming seaweed, including members of the orders Laminariales and Fucales, are much reduced (75-95%) compared to the mainstream seawater velocity.

Slow-flow habitats may provide natural, low-cost refugia for coastal calcifiers from ocean acidification. We explore how bioengineering coastal habitats will locally mitigate the effects of ocean acidification, resulting in more resilient ecosystems with greater conservation value.

Addressing the Drivers of societal vulnerability to ocean acidification and warming

Chair: Tommy Moore

Dr. Alexandre K. Magnan (1)

1 Institute for Sustainable Development and International Relations (IDDRI), Paris, 75007, France

Ocean warming and acidification (OA&W) pose serious threats to marine and coastal organisms and ecosystems, and to their services to humans. Impacts are already detectable from high to low latitudes, and are expected to increase drastically even in the RCP 2.6 scenario that is in line with the +2°C (air temp.) 2100 target. Impacts of OA&W are thus now partly unavoidable, which means that besides international emissions mitigation efforts, adaptation must be promoted from national to local scales in both developing and developed countries. Accordingly, a key challenge consists in better understanding vulnerability to OA&W (forms, drivers, timescales, etc.) in order to identify relevant and context-specific adaptation pathways.

This communication builds on the author’s 10-year research experience in vulnerability and adaptation to climate change to propose a framework for addressing vulnerability to OA&W, an emerging scientific and policy issue.

Two major ideas are promoted. First, vulnerability to OA&W results from interactions between natural and anthropogenic drivers. A framework based on 7 generic drivers is proposed to address vulnerability in a comprehensive way. Second, assessing current and future vulnerability requires to address the root causes of vulnerability, which can be done by going back into the past decades to identify the drivers (and their combinations over time) that generated a territory’s or a sector’s vulnerability. This refers to the Trajectory of Vulnerability (TOV) approach that aims answering 3 interrelated questions: How have the vulnerability of a coastal territory or economic sector to OA&W changed over time? What factors and processes are driving these changes? And to what extent do TOVs provide insights to design robust adaptation pathways?

The TOV approach provides two major benefits to the understanding of adaptation, namely a dynamic conceptualisation of vulnerability, and the identification of pragmatic ways to avoid maladaptation to OA&W.

Ocean acidification and the political agenda

Chair: Zoë Hilton

Kirsten Isensee(1), Dorothée Herr(2)

1 Intergovernmental Oceanographic Commission of UNESCO – Ocean Science Section, Paris, France
2 International Union for Conservation of Nature – Global Marine & Polar Programme, Berlin, Germany

Annually 25% of all anthropogenic CO2 emissions are absorbed by the ocean. Consequently sea water is becoming more acidic. Ocean Acidification (OA) happens in parallel to ocean warming and deoxygenation. The interaction between these stressors is often additive or even multiplicative resulting in impacts that worse combined than either would have been separately. Changes in species growth and reproduction as well as ecosystem alterations will threaten food security, harm fishing industries, and decrease natural shoreline protection, thereby hampering climate change adaptation and disaster risk reduction.
Science coordination and observation systems are well advanced (e.g. GOOS; GOA-ON). The scientific results are however not adequately translated into actions as part of international policy regimes, e.g. UNFCCC.

OA can be reflected in and translated into international conventions and treaties using different opportunities.
The current INDC and SBSTA processes offer possibilities to create additional urgency to reduce CO2 emissions, and to reflect on the need of additional climate indicators alongside atmospheric temperature in the UNFCCC. A special IPCC report on the ocean could be another avenue to highlight issues regarding OA.
In parallel, ocean acidification is already acknowledged in the S.A.M.O.A. Pathway, which reaffirms, that it will affect ecosystem services and therefore human wellbeing.
The post 2030 agenda asks to ‘Conserve and sustainably use the oceans, seas and marine resources’ (SDG14). Corresponding targets request to minimize and address the impacts of OA, including through enhanced scientific cooperation at all level.


The recognition of OA in international legislation provides the basis for sustained research funding to improve climate forecasting and predictions efforts on earth. The incorporation of new targets and indicators within the post 2030 agenda and UNFCCC would lead to increased political recognition and national financial obligations to protect the ocean – the major player in climate regulation.

Development and delivery of scientific knowledge and policy guidance on high latitude ocean acidification through different international organizational platforms

Chair: Zoë Hilton

Richard Bellerby (1,2)*, Howard Browman (3), Wenting Chen (2), Andrew Constable (4), Sam Dupont (5), Haruko Kurihara (6), Mario Hoppema (7), Andrew Lenton (8), Nikki Lovenduski (9), Claire Lo Monaco (10), Jeremy Mathis (11), Eugene Murphy (12), Elizabeth Shadwick (13), Coleen Suckling (14), Scarlett Trimborn (7)

1 SKLEC-NIVA Centre for Marine and Coastal Research, East China Normal University, Shanghai 200062, China
2 Norwegian Institute for Water Research, Oslo 0349, Norway
3 Institute of Marine Studies, Bergen 5005, Norway
4 Australian Antarctic Division, Kingston 7050, Australia
5 University of Gothenburg, Kristineberg 566, Sweden
6 University of the Ryukyus, Okinawa, 609-0213, Japan
7 Alfred Wegener Institute, Bremerhaven D-27570, Germany
8 CSIRO Marine and Atmospheric Research, Hobart, Australia
9 Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80303, USA
10 Pierre and Marie Curie University, Paris 6, France
11 NOAA Arctic Research Program, Silverspring, MD 20910, USA
12 British Antarctic Survey, Cambridge CB3 0ET, UK
13 Virginia Institute of Marine Science, Gloucester Point, VA, USA
14 School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB, UK

The high latitudes are undergoing rapid ocean acidification resulting from a complex interplay between anthropogenic carbon dioxide uptake, a rapidly changing cryosphere and associated perturbed hydrological cycles, large organic carbon fluxes from land and modifications to natural ocean circulation. A growing interest in ecosystem health, resource harvesting, concern over the livelihoods of native inhabitants and an increasing awareness of the important role of the high latitudes in global climate control has led to focused efforts into understanding high latitude ocean acidification. The Scientific Committee for Antarctic Research (SCAR) and the Arctic Council, through the Arctic Monitoring Assessment Program (AMAP), commissioned independent reports to describe the state-of-the-art knowledge in, respectively, the Southern and Arctic Oceans.

These research-policy organs assigned two teams of researchers to deliver the state-of-the-art understanding of the chemical, ecological, social and cultural and economic consequences of ocean acidification for the two regions. Using two funding approaches, degrees of “hands-on” direction and with differing levels of top-down involvement, the two writing teams were challenged and encouraged with diverse effect. Communication and outreach of the scientific findings and policy recommendations was undertaken through an institution-researcher partnerships through representation at high level meetings (e.g. Antarctic Treaty Consultative meetings; Arctic Council of Ministers meetings); scientific conferences, dialogue with ends users including indigenous communities, industry; and through other channels (e.g. films, internet, institutional websites).

We report the approaches adopted by the two institutions that initiated and sponsored the reports. We discuss the authors´ experiences in preparing, writing and delivering the reports. We compare dialogue with the two institutions, balancing their expectations, funding models and resources, assistance, subject knowledge and how their connections to end-users aided the report writing and delivery. We discuss the effectiveness of communication and outreach during the process of report development, and both during and post-publication. Interactions with policymakers and managers throughout the writing processes significantly enhanced the relevance of the final submission and recommendations.

The two approaches to facilitating the development of the reports and the strategies for promoting the underway and final results differed considerably. Funding of researcher time and the provision of greater mobility enabled more regular meetings with end-users, policymakers and researchers and is a major factor in the efficiency, outreach and communication of the reports. The connectivity of the institution with the policymakers is deemed as important as funding in targeting the utility of the recommendations to the end users, whilst at the same time maintaining researcher independence. We discuss the methods and their success in delivering the findings to the various policymakers and their subjects. We counsel a series of suggestions for future science-policy reporting of coupled natural-social science systems and institutional approaches to the publication of the reports and facilitating of contact and promotion with end-users.

Resilience Approaches to Management of Near-term ocean acidification

Chair: Jessica Ericson

Terrie Klinger(1)

1 School of Marine and Environmental Affairs, University of Washington, Seattle, WA, 98105, USA

The impending effects of ocean acidification on coastal ecosystems remain poorly resolved, in large part due to the organizational complexity and adaptive capacity inherent in marine ecosystems. As a consequence, managers are challenged to implement strategies under conditions of substantial uncertainty. Appropriate strategies will forestall abrupt changes in coastal ecosytems and “buy time” as scientific understanding and management options improve.

In the U.S., existing provisions for ecosystem-based fisheries management, spatial protections (e.g., MPAs), and coastal ecosystem management all can be used to support ecological resilience, offering opportunities to address OA through immediate action. I use specific examples from the U.S. west coast of to illustrate the utility of a resilience approach to managing ocean acidification in the near-term.

Under prevailing conditions of uncertainty, resilience approaches offer a framework for shaping practical responses to the likely biological and ecological effects of OA in coastal systems. Such approaches can be implemented under many existing management regimes, thereby avoiding lengthy delays associated with the establishment of new regulations.

Management approaches that support ecological resilience offer a practical means of addressing the near-term impacts of ocean acidification under conditions of uncertainty. Such approaches can be implemented immediately under existing management regimes, are generalizable across geographic and governance domains, and can be tuned to improve outcomes in specific settings.