Geoscience Reference
In-Depth Information
Figure 5.4
Analogues from extent reefs on the Great Barrier Reef of the state of coral
reefs under ocean warming and acidification in the future
Source: Based on Hoegh-Guldberg et al., 2007
Notes
a Scenarios CRS-A, CRS-B, and CRS-C are outlined in the accompanying table. The
[CO
2
]
atm
and temperature increases shown are those for the scenarios and do not refer
to the locations photographed.
b (A) Reef slope communities at Heron Island.
c (B) Mixed algal and coral communities associated with inshore reefs around St. Bees
Island near Mackay.
c (C) Inshore reef slope near the Low Isles, North Queensland.
At a more general level, much of Australia's marine resources, and those of its
regional neighbours, will degrade significantly as we approach sea temperatures
of 2°C above preindustrial period, which is widely seen as the 'guardrail target'
sought by current international climate negotiations (Richardson et al., 2009a;
Richardson et al., 2009b; 2011). These changes will require more substantial and
innovative approaches to the management of marine resources. For example, the
projected increase in the overlap of yellowfin and southern bluefin tuna habitat
on the east coast of Australia indicate that the problems faced by management
today, as a result of two species with different stock status sharing similar habitat,
are likely to increase in the future (Hartog et al., 2011). In the wider South Pacific
region, changes in the distributions of tuna and billfish stocks will have poten-
tially serious implications for some small island nations who depend on tuna for
food security and their economies and implications for fisheries governance such
as licensing of foreign fishing vessels (McIlgorm, 2010; McIlgorm et al., 2010).
Impacts such as reduced water quality along coastlines, the overexploitation of
key functional groups of species and other effects arising from local stresses will
need to be further reduced as Australia's marine ecosystems are pushed close to
their physiological and ecological limits. It is very clear, however, that pushing
