Tsunami impacts on marine environment

17/10/2009 00:53

By Cherelle Jackson 

APIA - The Samoa Tsunami Rapid Environmental Impact Assessment (EIA) conducted last week concluded in some areas affected, there was significant impact on the marine environment.

Conducted by the United Nations, Conservation International and the Secretariat of the Pacific Regional Environment Programme (SPREP) the Rapid Assessment expect high impact on submerged marine habitat such as coral reefs, lagoons and sea-grass in Aleipata and Falealili.

According to published documentation on the survey the impact on submerged habitat becomes patchy but still significant towards Tafitoala area.



The Assessment says that it was clear that the ava (channels) funnelled the wave inland causing greater damage in the exposed areas.

Paul Anderson SPREP Marine Conservation Analyst told Environment Weekly that the characteristics of the coast played a part in diverting the waves in the coast.

"Coastal geomothology played a major role in areas being missed or hit by the wave," he said.

The Assessment also noted physical damage to corals, which will predispose them to disease therefore causing further loss to reef biodiversity.

Beaches and foreshore were also heavily impacted by significant removal of sand and adjacent land based sediment.


Risk Factors

The Assessment recommends that natural recovery should be monitored and additional stressors be minimized, like reclamation sand

mining and commercial fishing harvest.

"Channel impact patterns need to be considered in terms of rebuilding settlements because they

indicate permanent higher hazard zones," the EIA stated.

Anderson agrees saying: "Protection provided by the reefs, mangroves and trees were notable."

According to him such features were noted in areas less impacted by the tsunami.

The EIA says that the areas affected requires stabilization in the short term to prevent further sand or sediment loss especially in advance

of rainy season and restoration in the longer term. 



New reclamations and mining should not be allowed in impacted areas, the study noted. 

They also say that increased use or repair of seawalls needs to be carefully considered because their use can be negative, by giving the wave “teeth.”

New impacts such as reclamations and mining are also discouraged by the assessment.

 It states that multi-disciplinary approach to restoration is required.

There will be a more in depth study of the environmental impact of the affected area in the coming weeks.