climate change, ocean acidification and marine ecotoxicology: how to

Australasian Journal of Ecotoxicology
Vol. 15, pp. 1-4, 2009
Ecotoxicology and a high C02 world
o p i n i o n
p i e c e
Climate Change, Ocean Acidification and Marine Ecotoxicology: How to
Migrate to Greater Policy Relevance and Impact
Ross Jeffree
Radioecology Laboratory, IAEA Marine Environment Laboratories, Monaco.
Manuscript received, 4/5/2009; accepted, 10/6/2009.
The year of 2009 marks the 150th anniversary of the
publication of the Origin of Species by Charles Darwin,
where he explained the origins of biodiversity. And now
only one and a half centuries on we repeatedly hear the death
knell for substantial proportions of that very biodiversity; not
necessarily from the effects of the chemical pollutants that
we typically study as ecotoxicologists, but from the levels of
carbon dioxide (CO2) emissions into the atmosphere.
If ecotoxicologists want to remain relevant to the most
important environmental issues and challenges then they
need to find ways to scientifically face the ‘elephant in the
living room’ viz. climate change and related effects of CO2.
But how do we migrate to there from where we currently
sit as ecotoxicologists? Fortuitously for an ecotoxicologist/
radioecologist, the effects of CO2 on oceans has been an
area of focus here at IAEA MEL, where the clear chemical
outcome is one of increasing acidity, that is quickly being
recognised as an over-arching and global chemical driver of
changes to marine biodiversity (EPOCA 2009). Particularly
as an Australian it is hard to imagine that the Great Barrier
Reef may start to disappear in 40-50 years, but this is the
risk we now face.
This article is concerned with one possible answer to this
question of how to adapt ecotoxicological studies to also
consider ongoing changes in climate and marine chemistry
with climate change. Another goal is to find some leverage
points so that our science may effectively influence both
public opinion and the political will to adequately mitigate
carbon emissions to limit reductions in biodiversity. The
Australasian regional economic imperatives to do so by
removing the links between economic activity and greenhouse
gas emissions have been strongly pointed out recently in the
Garnaut Report (2008).
Alternatively we are left to only engage in ‘hand wringing’
environmental concern, albeit relatively well informed.
Overview of ocean acidification
Ocean acidification (OA) is a rapidly evolving area of
environmental science and its potential effects on marine
ecosystems are well reviewed by Guinotte and Fabry (2008).
In brief, it is the process of declining pH in seawater that
results from the ocean’s absorption of anthropogenic CO2
from the atmosphere. The average pH of the surface ocean
has already declined by 0.1 of a pH unit to 8.1 since the
beginning of the industrial revolution and is predicted to
decline by another 0.2 to 0.4 units by 2100. The carbonate
ion concentration has also declined by more than 10%
*Author for correspondence, email: [email protected]
already relative to the pre-industrial level. The carbonate
concentration in seawater is the prime determiner of whether
biogenic calcium carbonate either precipitates or dissolves;
hence there is growing concern for those organisms with
shells of calcium carbonate, particularly those made of
aragonite that dissolves more readily than calcite. This
growing concern is already well justified by the experimental
studies undertaken so far of OA effects on calcifiers,
for realistic carbon emission scenarios provided by the
Intergovernmental Panel on Climate Change (IPCC 2007).
The majority of corals tested reduce calcification, by up to
56% (Kleypas et al. 2006), an effect that can be enhanced
by increased temperature (Reynaud et al. 2003). A more
recent study suggests that when atmospheric CO2 doubles
to 560 ppm almost all coral reefs will cease to grow and
start to dissolve (Silverman et al. 2009). Thus, there is great
concern for the future of coral reefs and the ecosystems that
depend on the physical habitat that they provide. Calcification
rates in commercially valuable molluscs decrease linearly
with increasing CO2 in short-term exposures, with adverse
effects also observed on early life stages of several species
of shellfish. Important species of calcareous phytoplankton
called coccolithophores show reduced calcification at lower
pH but there is a species-dependent response to OA, and
biogeochemical cycles may also be affected (from summary
by Martin et al. 2008; Gazeau et al. 2007; Parker et al. 2009;
Talmage and Gobler 2009).
Part of the answer, I believe, is found in consideration of the
Stern Review: The Economics of Climate Change (2007) and
the leverage it has already had on shifting governmental policy
with respect to mitigating carbon emissions. The Garnaut
Report (2008) has also supported this position in the national
Australian context. The Stern Review has convincingly
demonstrated the economic costs of climate change, the costs
and benefits of action to reduce the emissions of greenhouse
gases, and the economic benefits of strong early action on their
reductions, i.e. within the next 10-20 years. The voluminous
and compelling science of climate change has undergirded
this economic assessment. But it was finally the economic
analysis per se which demonstrated that timely mitigation is
a highly productive economic investment that has ultimately
persuaded Government to seriously move now on the climate
change issue. The Stern Review also mentions OA and the
“possible adverse consequences on fish stocks”. As ‘profit
and loss’ economic arguments are eminently influential in
government policy formulation and decision-making at the
highest level, then I would propose that part of the answer to
the question posed above is as follows.
Australasian Journal of Ecotoxicology
Ecotoxicology and a high C02 world
Clearly now, it is more important to know about the imminent
future global and Australasian regional environment, given
the accelerating rates of climate change. The mathematically
modelled future is our best window to the physical and
chemical conditions that will be faced by marine biodiversity.
The models can be repeatedly revised as more information
comes to light in this rapidly emerging area of scientific
investigation. The Intergovernmental Panel on Climate
Change is the premier international body to provide the best
advice on future climate scenarios.
Based on current knowledge, the modelling and empirical
evaluation of biological and ecological outcomes that are
needed include the following, with an Australasian focus:
Scanning for OA effects in a broader range of marine taxa
of commercial value and those keystone species that support
them, to identify those that will suffer most in the acidified
ocean of the future;
collaborations with natural resource economists to begin
to value the scale of possible regional economic losses
associated with seafood depletions due to OA and the
provision of this advice on potential revenue losses to regional
governments and relevant international organisations that are
also active in the region, e.g., FAO Fisheries, UNEP; IOCUNESCO; UNDP;
engagement with the fisheries and aquaculture industries
to motivate them as a powerful group with a strong vested
interest in lobbying government on carbon emission reduction
targets. This is particularly relevant as internationally
the aquaculture industry is positioning itself with a ‘blue
revolution’ in aquaculture, as the aquatic analogue of the
agricultural ‘green revolution’ that began in the 1960s,
to provide a major part of the projected shortfall in food
production from agriculture and the attendant food crisis
associated with increases in world population over the coming
decades (Sachs 2007);
comparisons of dissolution or reduced calcification rates
in commercially valuable shellfish, including those from
developing countries, to identify any differential rates so
as to rank species in their relative sensitivity to OA, hence
providing the aquaculture industry with advice on the more
OA-resilient species for adaptive responses; and
modelled predictions on what cuts in carbon emissions are
required to mitigate negative impacts on seafoods, beginning
with calcifiers for which there is a clear and specific
mechanism of detriment already identified.
The OA-related ecotoxicological effects already demonstrated
experimentally, based on predicted pH values, appear to
eclipse most other current concerns in marine ecotoxicology.
If this is the case, then appropriate re-focussing of expertise in
ecotoxicology should be directed to undertaking the science
needed to better predict the extent of OA impacts on marine
diversity to the end of the century.
Vol. 15, pp. 1-4, 2009
What is being contributed by IAEA MEL
Research programme: Future coastal marine
environments and the sustainability of fisheries
and biodiversity
Our research programme has specifically focussed on
areas in which there is currently less scientific activity
compared to other areas under investigation (i.e. corals and
other calcifiers), which integrate with ongoing studies in
ecotoxicology and radioecology, and which respond to the
socio-economic priorities of IAEA Member States. There
is increasing societal concern about the likely effects of
climate change and increasing levels of various contaminants
including carbon dioxide on the ocean, its fisheries and
biodiversity. Mathematical modelling in combination with
radiotracer studies on marine organisms that are valued
as seafoods can provide information on what the future
holds. This information can support better environmental
management decisions by Member States with regard to both
mitigation of carbon emission rates and societal adaptation
to future marine environments.
A series of experimental radiotracer studies is continuing
on various species of commercial seafoods to provide a first
assessment of the potential impacts of ocean acidification
on their biological processes. The fish species chosen were
seabream (Sparus aurata) and seabass (Dicentrarchus
labrax), that are the most important species for finfish
aquaculture along the Mediterranean and Eastern Atlantic
coasts, with global production of 108 000 tons of sea bream
($595 million US) and 60 000 tons of sea bass ($386 million)
in 2006. The cephalopod species chosen is the cuttlefish
(Sepia officinalis). Cephalopod catch was more than 50 000
tonnes in the Mediterranean according to FAO (2000) and
is becoming more important as finfish catches decline. Also
the early life stages of both fish and cuttlefish were chosen
as they may be the most sensitive stages. The experimental
parameters we used were based on projected scenarios
of ocean pH and temperature, as derived from various
models of carbon emissions to the year 2100, that had been
previously predicted by IAEA-MEL staff (Orr et al. 2005).
We used a suite of radiotracers to assess short-term rates of
incorporation of essential elements such as Ca and Zn, and
trace contaminants also expected to increase in the future with
industrial growth and increased nuclear power production to
mitigate carbon emissions.
Our first results on the eggs and larvae of seabream and
cuttlefish have shown both morphological and physiological
impacts of ocean acidification on these two commercially
important taxa, and also the increasing accumulation of some
metal contaminants (Lacoue-Labarthe et al. 2009). Other
recently-published studies of the effects of OA on marine
fish have included impairment to olfactory discrimination and
homing ability and enhancement of otolith growth (Munday
et al. 2009; Checkley et al. 2009). Radiotracer studies on
commercial seafoods can identify negative effects of OA on
their viability or rates of increase. These effects can be valued
economically, in the context of what their decline would
represent to the future profits of the aquaculture and fisheries
industries, reductions in gross national products, etc. Such
Australasian Journal of Ecotoxicology
Ecotoxicology and a high C02 world
information has greater potential to readily enter economic
valuation so as to clarify the full social cost of carbon, and
so support better-informed decision-making in countries on
the management of the marine environment.
A new Centre of Excellence in Environment and
To constructively move forward with this strategic approach
we have recently developed a new working group within the
Monaco scientific and economic community. To begin to
develop links between environmental science and economics,
the Group plans to hold a first Workshop in Monaco entitled
Bridging the Gap between Ocean Acidification Impacts and
Economic Valuation, with financial support from the Prince
Albert II Foundation. The objectives of the Workshop are
as follows:
To bring together the leading scientific investigators of ocean
acidification and natural resource economics, to discuss
both what is currently known about ocean acidification,
its biological effects and its predicted global impacts, and
ways to evaluate its potential economic costs to fisheries,
aquaculture and tourism.
Through this interaction between scientists and economists
to develop plausible scenarios of the scales of the costs
associated with ocean acidification, as related to different
carbon emission predictions from the IPCC.
To provide a venue where high-level governmental policy
makers, relevant international organisations (e.g. FAO
Fisheries, UNEP, UNDP, IOC) and private industry (e.g.
Aquaculture, Fisheries and Tourism) can be advised in a
timely fashion of the likely magnitudes of these societal costs
associated with ocean acidification, that are in addition to
those carbon costs previously estimated for climate change
scenarios (i.e. the Stern Review).
To support the more rapid de-carbonisation of the world
economy through better valuation of the full social costs of
carbon emissions and the benefits of policy actions for their
We have also begun operationally with a preliminary
assessment of future economic impacts of ocean acidification
on the Mediterranean seafood industry (Hilmi et al. 2009).
Within the Australian context it is obvious that the demise
of the Great Barrier Reef would have very serious negative
economic consequences for the tourism and associated
industries, and it is now important to economically value its
loss. Whereas there is current political interest in Australia
to protect ‘trade exposed industries’ such as coal production
from carbon trading, we should also draw political attention to
those ‘climate change industries’ like coral reef-based tourism
that will suffer from delaying action on carbon mitigation
agreements and mechanisms at the international level.
Vol. 15, pp. 1-4, 2009
Summary and conclusion
Marine ecotoxicologists can further enhance their
environmental and societal relevance by embracing the issue
of ocean acidification in their experimental studies. Because
of the enhanced importance of seafood consumption for the
lives and livelihoods of increasing coastal populations in Asia,
the predicted detriments to marine biodiversity from ocean
acidification are particularly important. The socioeconomic
significance of the potential impacts of OA warrants that
research should be re-focussed to acknowledge CO2 as a
critical contaminant, that will probably also affect the impacts
of many other contaminants in the marine environment
in the near future. We should also seek out opportunities
to collaborate with natural resource economists so that
the science that we undertake has the potential for greater
relevance in political decision-making with regard to carbon
Two anonymous referees are thanked for their comments that
helped to improve the paper.
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Ecotoxicology and a high C02 world
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