Physical and chemical changes in the ocean over basin-wide zones and decadal or longer time-scales: perspectives on current and future conditions - Ocean Sustainability in the 21st Century - page 113

of their important role in global material and ecosystem balances and their increasing
vulnerability to many other linked processes. These include overfishing, aquaculture, and
transportation.
The effects of warming are not well quantified, with several feedbacks (cf. Pörtner
and Farrell, 2008 ). Ocean changes reflected in the hydrological cycle, the role of aerosols,
and variations in cloudiness are likewise not well quantified. Changes in extreme weather
events are documented, but it is not clear how the frequency and duration of such events
are changing, even if it seems that they are coupled with climate variability and change.
The protection of biodiversity in international waters and on the seabed is not ad-
equately covered by existing conventions, and the impact of changes in the biodiversity in
these large zones is not known.
Human health is affected by organisms transmitting disease, increasing harmful algal
blooms and red tides, which are coupled to changing ecological conditions. Changes or
imbalances in the established biodiversity may trigger such occurrences and generation of
large medusa. The consequences of change in the oceanic foodweb are significant but re-
main poorly quantified. However, recent progress in 'end-to-end' foodweb models (e.g.
Fulton, 2010 ; Moloney et al ., 2011 ) provides a process-based modelling approach to make
projections of the future state of oceanic ecosystems and living marine resources, when
suchmodelsareembeddedinIPCC-classmodelsofachangingclimate(Stock et al ., 2011 ) .