Long Term Recovery and Environmental Remediation
Remediation of the Natural Environment:

In the immediate wake of a tsunami, the activities of main importance will be related to saving of lives and finding emergency housing for all the people affected. Soon, however, the long-term sustainability of the affected region must be addressed. Not only is the natural environment valuable for its intrinsic natural beauty, various aspects of the environment contribute indirectly and directly to the economies and social characteristics of the world’s nations. Recently, there seems to have been a shift in policy from containing nature to using nature’s strength in the protection of humanity. Especially after the December 2004 tsunami in Southeast Asia, the media has looked at the protective power of the environment in a new light (Onion 2000, Perez 2002, and others). Two specific parts of the environment that have come into public perception as possible protections from future disasters are also highly endangered. Evidence from the recent tsunami in Southeast Asia shows that mangroves and coral reefs act as natural energy dissipaters to greatly reduce the inland range of damage (Hoffman 2005). In addition, both of these ecosystems help prevent erosion and proper management of these natural resources, as discussed in the section of this page on economics, can bring much greater monetary benefits than the cost of remediation. For these reasons and others, we have identified restoring the environment to its pre-tsunami condition as one of the four main goals in the reconstruction and remediation stage.

The first step of any reconstruction project should be to assess the damage and prioritize based on cost-benefit analysis. During a tsunami, both coral reefs and mangroves, which have shallow roots, may be torn from the ground and tossed about in the water. This leads to the dual problem of clearing out the debris before it causes more damage and fixing the original damage. In the case of the two ecosystems we are considering, pre-reconstruction will involve a careful look at whether long-term damage caused by past improper treatment of the ecosystems has brought them to an irreparable state (Spurgeon 1998). Bleaching, breakage, and lack of biodiversity are problems that currently plague coral reefs (Richmond, Kelty, et al 2001), while deforestation and shrimp farming decimate mangroves. If the environment has sufficiently changed, mangroves will not be able to thrive (Mangrove Action Project News 2005). While planning to repair these ecosystems to the best of our ability, we must take into account that their damage may be beyond repair. In this case, the need of a quick reaction limited funding may cause us to sacrifice less promising areas to the success of remediation in other areas that are more likely to respond to human intervention. Once the damaged areas have had initial evaluations as to whether they can be remediated, a task force must quickly work to stabilize the affected areas. First we will discuss the remediation of mangroves, then that of coral reefs.

For our purposes, mangroves are a complete ecosystem consisting of mangrove trees as well as other flora and the fauna that live amongst the trees. There are many different species that grow in different parts of the world, but they all have a certain level of resilience in common. A tsunami is most likely to destroy mangroves by altering their growing environment. Therefore, the best way to remediate a mangrove ecosystem would be to make the environment in a location that once had mangroves more like it used to be, or more similar to other places that have mangroves of the same species as the ones that once grew in the damaged area (Lewis 2005). All aspects of the environment, from the amount of slope of the ground, to the salinity of the soil, to the stipulation that the area must lie in the intertidal zone all will affect whether mangroves can grow. In most cases, mangroves will naturally undergo secondary succession in areas that are suitable for their growth. In any situation, proper growing conditions must be established before any attempts to plant mangroves. Also, if other types of trees are present, shade-tolerant species must be chosen to maximize the probability of success. If an area does not have mangroves close enough to bear seeds, artificial methods may be used. These methods range from transplanting seedlings from other locations to planting seeds to growing seedlings in a laboratory. If the ecosystem is not recovering naturally, these artificial methods may be the change that makes it possible for mangroves to begin to thrive (Field 1998).

From what is currently known, we have formulated a timeline for the response to the effects of a tsunami on mangroves. As noted above, the first step would be a thorough survey of all mangrove damage, which should use satellite images to get a complete view of all damage. Because it is probable that some of the mangroves will be damaged beyond repair and that others will recover without intervention, the extra time taken to assess the damage will be well spent. The first step of the assessment would be to check for the presence of propagules, which include seeds and any part of the trees that can grow into a new tree. Usually the presence of many propagules means that the ecosystem is already recovering (Lewis 2005). If this is the case, human intervention is not needed, and remediation money is best spent elsewhere. If there are no propagules present, mangroves will not grow. However the presence of seagrasses is a sign that the location may be a good place for mangroves. If there are seagrasses, other factors, like the inclination of the ground, soil salinity, amount of time spent submerged, and the presence of other plants must be noted. Ideally, other groves of mangroves will be in close enough proximity to seed the area naturally. Because natural succession generally creates the healthiest ecosystems for the least amount of money and effort, it is usually the first choice of how to rebuild damaged mangrove ecosystems (Spurgeon 2005).

If it is discovered that the ecosystem is not recovering naturally, the next step is to find the reason that the mangroves are not recovering. Weeds and barnacles have been known to overgrow decimated mangroves and choke out any mangroves that attempt to grow (Lewis 2005). Also, there are many species of mangroves, but each species only grows in a very narrow set of conditions (Field 1998). Small changes in the environment may wipe out one species but make the land suitable for another species. In this case the decision is whether to replant the original species or the one that currently is best suited for the new soil composition. Generally, it is best to find a comparable location and to plant a species that naturally grows in the similar conditions (Lewis 2005). If the environment has totally changed, the next decision is whether to attempt to return it to its pre-tsunami situation or to encourage a new type of ecosystem to grow. Since the types of vegetation that grow in a certain location are those that support the local animal life and are probably the best suited to the climate, the plan of action after it has been determined that secondary succession of mangroves is not taking place should be to help recreate mangroves as similar to the original ones as possible. First, the slope of the soil should be fixed, and in the case of extreme erosion, soil should probably be brought in. Next, mangroves should be planted. There are several ways of going about planting mangroves. The most time and money effective method, as well as that most likely of success, is to plant propagules in small, biodiverse groves spread out over the area that has been damaged. If this is not plausible because there is intense weed competition, or for some other reason, mangroves may be “artificially” restored. The method of artificial restoration most likely to be successful is to transplant seedlings from an unaffected area. Another method that is likely to work is to grow mangroves in a laboratory and then transplant them. Due to high monetary and time investments, this method of remediation is not recommended. Similarly, manmade covers that protect mangrove seedlings from weed invasion until they grow large enough to resist may be successful in the short term, but they also may weaken the trees in the longterm and make them unable to survive on their own (Lewis 2005). Since the goal of remediation is to make destroyed mangroves vibrant and self-sustainable, we don’t want to waste time and money on efforts that are likely to be unsuccessful if that money would be better spent on a project that is more likely to work well.

Assuming that remediation seems to work well over a few months or years, the effort will still not be over. One of the major shortcomings of many past projects has been the lack of follow-up. Due to a desire of autonomy, many groups do not distribute data from their projects, especially those that are unsuccessful. Also, funding tends to run low when there is no longer a state of emergency (Rinkevich 2005). A minimum time for watching over the newly growing mangroves should be three to five years, although ten years for slightly damaged regions to as long as thirty years for drastically damaged areas is not unreasonable (Field 1998). Those people responsible for overseeing the effects of remediation, ideally environmental engineers, should record all aspects of the mangroves. How the environment has changed, the rate of growth and overall health of the mangrove trees, and the return of other fauna and flora should all be observed. Care should be taken to track all populations, not just those of a few target species that are economically valuable. Since even those species that are not directly related to the economy interact with those species that do (Lewis 2005), and biodiversity is a sign of a healthy ecosystem, all species should be watched for imbalances until each mangrove has reached a state of equilibrium.

Coral reefs, unlike mangroves will probably all need intense amounts of human intervention. Bleaching, breakage, and a worldwide trend in loss of coral mean that every coral reef on earth constantly increases in value (Rinkevich 2005). The first step to remediate coral, after an initial estimate of damage is to prevent more damage from occurring. A tsunami will wash some corals to sea, break others, and cause abrasive debris to move with the tides through those corals that survive the initial disaster. Those corals that are broken should be cemented back together so that they can begin to reform their characteristic shapes. Abrasive debris should be removed as soon as possible to prevent them from further breaking the coral (Rinkevich 2005). If some of this debris is stabilized on the ocean floor, it could serve as the basis of new coral locations. Small pieces of coral can also be taken from the ocean and grown in laboratories to increase the rate of growth before being put back into the ocean (Onion 2005). These corals can be transplanted onto debris, existing coral reefs, and sunken boats, or rigid manmade surfaces like limestone. Other types of surfaces have been tried, but with less success than limestone (Rinkevich 2005). Like mangroves, the corals may be damaged beyond repair, so the most likely corals to recover should be the ones that have the most time and money spent on them. Also, coral reefs should be monitored on a timeline similar to that of mangroves.

None of the recommended plans, however, can occur without someone in charge of implementing them. The environmental remediation will be led by a small task force of ecologists, environmental engineers, biologists, and oceanologists. This task force will be a committee on the larger task force that deals with the overall reconstruction of the affected nation. Other groups will work closely with the task force. There are many charities that work to protect mangroves and coral reefs, as well as individuals in other nations, who will be willing to help in the wake of a tsunami. Time, money, and personnel from agencies specialized in environmental remediation will be highly valued. In addition, education on how to protect the environment and a campaign in which individuals sponsor an individual tree or coral reef should provide much needed funds. Initial money for all of these projects will come from grants of aid to reconstruct the damaged nations. Afterwards, the productivity of the ecosystems will increase and bring in revenue. If mangroves are allowed to become dense then half of the trees in the mangrove are cut down every year, those trees that are cut can be used for fuels and sale to support further remediation and the other trees will be provided with nutrients from the roots that remain in the ground (Mangrove Action Project 2005). An important part of remediation will be to involve the locals. Only with local support are most environmental projects successful. Education about the value of the environment will play a large role in the effectiveness of reconstruction, as will the efforts of those people who live in the area. Eventually, successful environmental remediation will improve on the pre-disaster state of the environment, while improving the overall health of the earth and quality of life of locals.

Sources:

 Field, C.D. (1998). Rehabilitation of Mangrove Ecosystems: An Overview. Marine Polution Bulletin, (37)8-12, 383-392.

Hoffman, W. (2005) A Logistics Nightmare. From Traffic World. Newark: Jan 10, 2005 p. 10-12. Retrieved October 4, 2005 from http://proquest.umi.com/pqdweb?did=776886481&Fmt=3&clientId=5482&RQT=309&VName=PQD.

Lewis, R. (2005) Ecological Engineering for Successful Management and Restoration of Mangrove Forests. From Ecologiscal Engineering Vol 24 Issue 4 pp. 413-418.

"Mangrove Action Project News, 150th Edition." (2005) Mangrove Action Project, Retrieved October 2, 2005 http://www.earthisland.org/map/ltfrn_150.htm#stories.

Onion, A. (2000) Reef Replacement: New Project Hopes to Restore Coral Reefs by Growing them. ABC News. Retrieved October 10, 2005 from http://www.artificialreefs.org/Articles/transplantCorals/transplant.html.

Perez, R. (2002?) A Survey of Impacts of Climate Variability and Change in the Philippines: Coastal Zone System. National Disaster Reduction Branch (PAGASA/DOST), Retrieved September 23, 2004 from http://scholar.google.com/scholar?hl=en&lr=&q=cache:DFz8ES8dEFoJ:www.wwf.org.ph/uploads/coastal.pdf+Micronesia+coastal+animals.

Richmond, R., Kelty, R., Craig, P., et al (after 2001?) Status of the Coral Reefs in Micronesia and American Samoa: US Affiliated and Freely Associated Islands in the Pacific. Retrieved September 23, 2005 from http://www.aims.gov.au/pages/research/coral-bleaching/scr2002/pdf/scr2002-12.pdf.

Rinkevich, B. (2005). Conservation of Coral Reefs through Active Restoration Measures: Recent Approaches and Last Decade Progress. From Environmental Science and Technology, American Chemical Society, 39 (12), 4333 -4342, 2005. 10.1021/es0482583 S0013-936X(04)08258-6 Retrieved 26 October 2005 from http://pubs.acs.org/cgi-bin/article.cgi/esthag/2005/39/i12/html/es0482583.html.

Spurgeon, James. (1998). The socio-economic costs and benefits of coastal habitat rehabilitation and creation. Marine Pollution Bulletin, (37)8-12, 373-382.