Geoscience Reference
In-Depth Information
articles also increased from 2004 to 2010. For exam-
ple, the Aquatic Science and Fisheries Abstracts
(ASFA) database, published by Cambridge Scientii c
Abstracts, comprises 53 357 papers published in
2004 and 88 962 papers published in 2010 (as of 1st
June 2011). Therefore, the increase in the publica-
tion rate in the i eld of ocean acidii cation was con-
siderably higher than in marine science in general
(482% vs. 67% increase). This wave of research effort
devoted to ocean acidii cation in the last few years
can probably be explained by the increased atten-
tion from society, largely thanks to several impor-
tant reports and the outcome of international
conferences (Section 1.5.2, Fig. 1.3), resulting in
increased funding opportunities. In addition to
peer-reviewed scientii c publications, recommen-
dations from such reports and conferences have
probably contributed to the launch of several large-
scale research projects (see Section 1.5.3.1).
amount of work devoted to the biological response
to ocean acidii cation during recent years.
1.4.3.3 Taxonomic groups
Studies have historically been focused on macro-
algae (Fig. 1.2B), with the i rst study published in
1919 and a steep yearly increase between 1989 and
1994 (an average of 3 new articles per year), but
interest in this group has somewhat decreased in
recent years and articles now more frequently
study phytoplankton and corals. Overall, phyto-
plankton is the most studied group, with a total of
113 articles, against 67 papers on corals, 64 on mol-
luscs and 50 on macroalgae. The obvious early
choices of model organism were the calcii ers and
photosynthesizers, because both calcii cation and
photosynthesis could be directly affected by the
increased CO
2
in seawater (Section 1.3). Studies of
other organisms that might show more subtle
effects of ocean acidii cation (e.g. on performance,
reproduction, etc.) were limited until very recent
years (data not shown). This is also rel ected by the
imbalance in the number of studies devoted to pri-
mary production, growth, and calcii cation com-
pared with other processes (a total of 136, 138, and
136 papers, respectively, compared with e.g. 43 on
physiology, 42 on reproduction, and 14 on nitrogen
i xation; Fig. 1.2D). The large number of articles on
phytoplankton probably rel ects the numerous
studies carried out on
Emiliana huxleyi
and other
coccolithophores, the major pelagic calcii ers,
because of their possible sensitivity to changes in
ocean carbonate chemistry and their signii cance in
the biogeochemical cycles of carbon, calcium car-
bonate, and sulphur.
1.4.3.2 Type of study
The biological response to ocean acidii cation has
dominated the publication efforts (63% of the total
number of articles in the database; Fig. 1.2A).
Articles dealing with palaeo-oceanography, model-
ling, biogeochemistry, and chemistry, as well as
review papers, represented 13, 11, 10, 25, and 14%,
respectively, of the total number of publications.
The fact that several studies were allocated two or
more keywords (see above) explains that the sum of
the percentages exceeds 100%.
The trends of articles on the biological response
to ocean acidii cation follow the overall tendency
with a fairly stable number of publications per
year from 1989 to 2003 (on average eight articles
per year) followed by a steep increase from 2004
to 2010 (18 and 112 papers, respectively, a more
than sixfold increase; Fig. 1.2A). For the other cat-
egories (palaeo-oceanography, modelling, chem-
istry, biogeochemistry, and review), the number of
papers increased slowly between 1988 and 2004 (2
and 14 articles, respectively) and more drastically
from 2005 to 2010 (28 and 164 papers, respectively;
corresponding to an almost sixfold increase). The
relatively solid knowledge that already exists on
the chemical aspects of ocean acidii cation com-
pared with the poor understanding of the conse-
quences for marine life might explain the large
1.4.3.4 Study region
When looking at the geographical distribution of
study sites, the North Atlantic, North Pacii c, South
Pacii c, and the Mediterranean (38, 27, 12, and 11%,
respectively, of the articles indicating a geographical
location) have been investigated to a larger extent
than the Indian, South Atlantic, Arctic, and Southern
Oceans, and the Baltic, Red, and Black Seas (18%;
Fig. 1.2E). The number of articles that studied polar
regions (Arctic and Southern Oceans; 5 and 7%,
respectively) is relatively low considering that these
regions have been identii ed as the most sensitive to
