Saturday 7 May 2011
Monday 2 May 2011
THANK YOU.
One final and very quick post to thank my followers of the last 10 weeks. Once again I apologize for the sometime sporadic blogging!! Pre planning is clearly not my strong point. I still haven't discovered how to upload my poster so if anyone would like a copy please feel free to email me and I'll send you one.
Thanks and kind regards,
Emma
SO ARE CORALS FACING A CRISIS?
Simply put YES.
But is there hope? I think so.
· Modern day corals have faced three main extinction highs, each associated with large scale environmental perturbations but they have always survived. In the past, global coral biodiversity has survived climate change by changing its geographic distribution, however abrupt change have caused considerable reductions in diversity e.g. The Permian Mass Extinction.
· Corals unique and complex physiology (water no deeper then 30meters and warmer than 22 ˚ C) instantly sets them at a disadvantage. However it is not only sea level which influences reef formation the community structure is also influenced by wave energy and depth alongside species diversity.
· Modern corals are facing a challenging future with rising temperatures and carbon dioxide levels that both pose major threats through coral bleaching and ocean acidification. Corals have however overcome these issues in the past, what makes this time different is the massive anthropogenic pressure on coral reefs. The greatest challenge currently facing corals is that of human exploitation and interference (e.g. over fishing, destructive fishing practices, pollution, tourism).
· However in my mind there is still hope for the survival of coral reefs:
- Over the last decade, some adaptations to climate change have been seen and species are becoming more resilient.
- This, in addition to widely dispersing larvae and large population sizes of important reef builders, may provide some protection against extinction.
- I don’t believe coral reefs will become extinct they will simply alter and evolve in response to a changing climate. Coral reefs might become increasingly patchy with a lower topographic relief as pioneer corals (quick growing, short lived and thus better adapted to abrupt climate change) tend to be free living solitary corals.
- The development of cryopreservation of corals means endangered species can be preserved and later released in a suitable environment.
· Ultimately the survival of coral reefs will greatly depend on what is done now to protect and conserve them. With an international and local commitment to conservation I think reefs can be saved and we can help ensure a rich diversity of corals for future generations.
CONSERVATION CONCLUSION
The greatest challenge of reef conservation is one that no international regime on its own can fully address, given that so many of these threats are local in nature and thus require local solutions and enforcement. However on the other hand, an international solution to coral reef conservation is absolutely vital, given that two of the biggest threats facing reefs—climate change and ocean acidification—are global in nature and cannot be “fixed” by any one nation alone.
Reef protection needs to be treated on a larger scale as part of who ecosystem or area rather than protecting individual threatened species. Having researched and analysed the possible solutions I believe No Take Areas (NTAs) are the best solution for coral conservation. NTAs, when properly supported and policed, are effective in preserving fish stocks because they change human behaviour. Any conservation project must not solely address the biodiversity aspect they must to accommodate people livelihoods and economic value of the ecosystem. BUT NTA’s do not prevent or hold back warm water, or stop bleaching.
NTAs do not provide a refuge from bleaching, but they can help protect coral reefs from climate change. Overfishing, particularly of herbivorous parrotfish and surgeonfish, affects more than just the size of harvestable stocks it alters the entire dynamics of a reef. Reduced herbivory from overfishing, increased levels of disease, and excess nutrients can impair the resilience of corals and prevent their recovery following acute disturbance events like cyclones or bleaching, leading instead to a phase shift to algal dominated reefs. Resilience is also eroded by chronic human impacts that cause persistently elevated rates of mortality and reduced recruitment of larvae. Although climate change is by definition a global issue, local conservation efforts can greatly help in maintaining and enhancing resilience and in limiting the longer term damage from bleaching and related human impacts. Managing coral reef resilience through a network of NTAs, integrated with management of surrounding areas, is clearly essential to any workable solution. This requires a strong focus on reducing pollution, protecting food webs, and managing key functional groups as insurance for sustainability. NTAs also act to spread risk, whereby areas that escape damage can act as sources of larvae to aid recovery of nearby affected areas. This highly desirable property of NTAs raises the issue of how close they need to be to promote connectivity the migration of larvae and/or adults between them. Critically, coral reef organisms, including different species of corals, vary greatly in their larval biology and potential for dispersal. The clear implication is that NTAs must be substantially more numerous and closer together than they are currently to protect species with limited dispersal capabilities.
CONSERVATION: NON INTERNATIONAL APPROACHES.
So far we have looked at the international approaches but there are two other non international approaches for coral reef conservation and protection which warrant discussion:
- Efforts to address land-based marine pollution affecting coral reefs.
- Efforts to educate the public about threats to coral reefs and how our choices as consumer can impact the survival of reefs.
As part of the international year of the coral reef (1997) the NOAA publish 25 things you can do to save coral reefs. They range from ..
Number 10: Don’t pollute. Never put garbage or human waste in the water. Don’t leave trash on the beach.
.. to...
Number 20: If you dive, don’t touch! Take only pictures and leave only bubbles! Keep your fins’ gear, and hands away from the coral, as this contact can hurt you and will damage the delicate coral animals. Stay off the bottom because stirred-up sediment can settle on coral and smother it.
For the complete list please visit this link
NO TAKE ZONES.
NO take zones take the marine protected area one step further. They are areas e.g. New Zealand’s marine reserves, where all forms of exploitation are prohibited and severely limit human activates. Generally a No Take Zone can cover the whole MPA or specific vulnerable portions that enjoy elevated protection.
The Great Barrier Reef.
One well known reef, the Great Barrier Reef became a no take zone as part of a controversial decision in 2004. However despite initial hesitation the decision to halt commercial and recreational fishing across vast areas of the reef has proven remarkably effective for reviving coral trout numbers.
Fishing was totally banned across a third of the park, more than 100,000km2 including parts of 70 biologically distinct bioregions.
Within 18 months of the fishing ban, coral trout stocks had increased by 60% in two areas (Palm Island and the Whitsundays) within the no take zone. In contrast coral trout numbers in nearby fished areas did not change at all. In the long term it is hoped that the number build up in the protected areas and over spill and spawning means number will thus increase in unprotected areas too.
This recovery was further supported by a second team of scientists led by Hugh Sweatman of the Australian Institute of Marine Science in Townsville. They found coral trout number had increased significantly in no take zones around reefs from 32 to 200 kilometres off shore. In four of these offshore regions, numbers of coral trout were between 31 and 64% higher compared to unprotected regions nearby, just two years after the zoning took place. It is a very positive result but the full recovery of coral trout will take 10-15years to access.
The no take reserve has also seen other benefits; protecting corals reefs from the predatory starfish, Acanthaster planci is one of them. The crown-of-thorns starfish, Acanthaster planci, is a predator of corals that is a major management issue on coral reefs (Sweatman 2008). It occurs throughout the Indo–Pacific and shows boom–bust population dynamics with low background densities and intermittent outbreaks. Three waves of population outbreaks have affected Australia's Great Barrier Reef since the 1960s. The waves of outbreaks cause major losses of living coral on many reefs across a large area and dwarfing losses from other disturbances such as storms or coral bleaching over the same period. Humans can potentially influence starfish population dynamics by exploiting predators. Extensive surveys in the Great Barrier Reef Marine Park show that protection from fishing affects the frequency of outbreaks: the relative frequency of outbreaks on reefs that were open to fishing was 3.75 times higher than that on no-take reefs in the mid-shelf region of the GBR, where most outbreaks occur, and seven times greater on open reefs if all reefs were included. Although exploited fishes are unlikely to prey on starfish directly, trophic cascades could favour invertebrates that prey on juvenile starfish.
NO take zones clearly have their benefits for coral reefs but to make a significant difference more needs to be done.
A newspaper article by Eccleston (2008) states “current conservation zones ‘no take zones’ are too small, vulnerable to climate change and are in the wrong place to prevent reefs collapsing”. This statement was based upon joint research by Newcastle University and the Wildlife Conservation Society, New York. This team concluded that existing conservation zones should not be removed but new zones are urgently needed to protect coral reef and to aid their recovery from mass die offs caused by rising temperatures.
References.
Sweatman 2008: doi:10.1016/j.cub.2008.05.033
Russ et al. 2008: doi:10.1016/j.cub.2008.04.016
Sunday 1 May 2011
VIDEO BLOG: MARINE PROTECTED AREAS.
The first few minute briefly review what a coral reef is, the threats faced by them and looks at their importance as a biodiversity hotspot, as protection to islands and as a food source for subsidence farmers.
Approximately half way through (at 11.30mins) they start to discuss some of the local effects and their management methods: the very effective conservation method of over spill from Marine Protected Areas. They specifically look at Tanzania and Madagascar to describe this management tool.
Marine protected areas help by reducing stress such as destructive fishing practices and over fishing. This makes these ecosystems more resilient and so less vulnerable to other threats like global warming, pollution and sediment run off from the land.
One key point made by this video is that conservation and protection isn’t simply about helping the corals biodiversity it also works to maintain livelihoods and ensure economic success.
NOTE: Like everything technical I cannot get the video to upload!!! So I attach the link from which the video can be down load. It is a natural history question time video. ENJOY.
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