16 Remote Sensing of Coral Reefs and Their Environments . . .
331
sensing section above). This work integrated products issued from both direct and
indirect remote sensing data towards one management goal. The authors emphasized
that choosing an appropriate approach ultimately depends on scientific and political
factors including representation targets, likelihood of adoption, and persistence goals.
The portfolio created by Allnut et al. (2012) using a variety of remotely sensed data
offered a quantitative integrated decision support tool. Similar approaches will likely
rise in the future to support the sound implementation of international and national
conservation targets.
16.5 Conclusion and Perspectives
The review of applications presented here highlights a fair diversity of valuable
applications useful to tackle science and management questions at a variety of spatial
and temporal scales. However, as in 2012, remote sensing still remains a tool poorly
used routinely for coastal management in the Red Sea and Western Indian Ocean.
This statement holds in fact for most regions supporting coral reefs (Andréfouët
2008). Applications remain often limited to academic studies, while a number of
applications could be performed routinely in the real world. Thus, the full potential
of space technology for the monitoring and management of coral reefs, seagrass and
mangroves of these regions is not achieved. Even technically simple priority tasks,
such as habitat mapping, have not been fully accomplished.
One of the first priorities remains ecosystem inventory and change detection. Accurate ecosystem inventories remain scarce in most countries. To date, no complete
and consistent seagrass or mangroves inventories are available for the entire region.
While geomorphological coral reef maps exist from Landsat data, the number of
benthic habitat maps achieved at very high resolution (both thematic and spatial)
remains extremely limited. The immediate benefits of these inventories would be
to enhance management plans with proper estimates and optimization of costs and
benefits related to the loss or preservation of ecosystem services. Obviously, conservation planning is a complex task where political, social and economic imperative
are often more important than the background environmental analysis. Yet, the provision of accurate, updated and spatially explicit data is a key to the effectiveness
of a conservation planning project. Furthermore, accurate inventories are essential
when resilience is at stake. Indeed, basic requirement to maximize resilience within a
network of protected areas is to have enough patches of habitats and enough replications spaced adequately. Without accurate inventories, this is impossible to achieve
realistically (Mora et al. 2006; Wabnitz et al. 2010).
Another priority is certainly to continue developing indices of relevant climate
stressors at adequate spatial resolution (1–4 km) and optimize them locally. Thus far,
the environmental characterizations seen in the literature remain too coarse for local
use in coral reef management plans and these need to be addressed. Although SST
remains of high importance for coral stress, local variations are explained by other
factors and processes as well (e.g. local hydrodynamics). The multi-variable work
331
sensing section above). This work integrated products issued from both direct and
indirect remote sensing data towards one management goal. The authors emphasized
that choosing an appropriate approach ultimately depends on scientific and political
factors including representation targets, likelihood of adoption, and persistence goals.
The portfolio created by Allnut et al. (2012) using a variety of remotely sensed data
offered a quantitative integrated decision support tool. Similar approaches will likely
rise in the future to support the sound implementation of international and national
conservation targets.
16.5 Conclusion and Perspectives
The review of applications presented here highlights a fair diversity of valuable
applications useful to tackle science and management questions at a variety of spatial
and temporal scales. However, as in 2012, remote sensing still remains a tool poorly
used routinely for coastal management in the Red Sea and Western Indian Ocean.
This statement holds in fact for most regions supporting coral reefs (Andréfouët
2008). Applications remain often limited to academic studies, while a number of
applications could be performed routinely in the real world. Thus, the full potential
of space technology for the monitoring and management of coral reefs, seagrass and
mangroves of these regions is not achieved. Even technically simple priority tasks,
such as habitat mapping, have not been fully accomplished.
One of the first priorities remains ecosystem inventory and change detection. Accurate ecosystem inventories remain scarce in most countries. To date, no complete
and consistent seagrass or mangroves inventories are available for the entire region.
While geomorphological coral reef maps exist from Landsat data, the number of
benthic habitat maps achieved at very high resolution (both thematic and spatial)
remains extremely limited. The immediate benefits of these inventories would be
to enhance management plans with proper estimates and optimization of costs and
benefits related to the loss or preservation of ecosystem services. Obviously, conservation planning is a complex task where political, social and economic imperative
are often more important than the background environmental analysis. Yet, the provision of accurate, updated and spatially explicit data is a key to the effectiveness
of a conservation planning project. Furthermore, accurate inventories are essential
when resilience is at stake. Indeed, basic requirement to maximize resilience within a
network of protected areas is to have enough patches of habitats and enough replications spaced adequately. Without accurate inventories, this is impossible to achieve
realistically (Mora et al. 2006; Wabnitz et al. 2010).
Another priority is certainly to continue developing indices of relevant climate
stressors at adequate spatial resolution (1–4 km) and optimize them locally. Thus far,
the environmental characterizations seen in the literature remain too coarse for local
use in coral reef management plans and these need to be addressed. Although SST
remains of high importance for coral stress, local variations are explained by other
factors and processes as well (e.g. local hydrodynamics). The multi-variable work