Global Warming Jeopardizes World's Most Diverse Marine Ecosystem

The scientists gathered last week in Batangas City, Philippines for a workshop organized by Conservation International, which is based in Washington, DC. After assessing the impacts of climate change on the Verde Island Passage, they painted a grim picture for the unique area.

Whale sharks live in the Verde Island Passage, as this diver discovered. (Photo by Phil Colla courtesy CI)

Climate change will not only affect marine habitats and species but also fisheries and the tourism industry of this popular destination with consequences for the well-being of nearly two million people who rely on them for food and income.

"The marine habitats and species of the Verde Island Passage are already threatened by human impacts, like overfishing, pollution and coastal infrastructure development," said Dr. Giuseppe Di Carlo, Conservation International's marine climate change manager.

"Climate change is intensifying these impacts, with severe consequences for the well-being of the people of the area, since they depend on fishing and tourism industry," said Di Carlo.

The Verde Island Passage has the highest concentration of marine species of any region in the world's oceans, including whale sharks, Rhincodon typus, giant clams, Tridacna gigas, and the iconic Banggai cardinalfish, Pterapogon kauderni.

But the panel of scientists cautioned that the impacts of climate change in combination with over-exploitation of resources already are threatening the marine habitats.

They found that increasing ocean temperatures are causing coral bleaching - meaning that corals can no longer support the array of plants and animals that rely on them.

Sea level rise is causing coral drowning as the water gets deeper and coral growth is inhibited, the scientists say.

Sea level rise is also damaging mangroves - a key costal habitat that protects the coastline and coastal communities from storms, reduces the impacts of floods and provides important habitats for juvenile fishes.

Coral reef in Mabini, Verde Island Passage, Philippines (Photo by Sterling Zumbrunn courtesy CI)

And increased storm frequency and intensity is affecting the marine habitats as well as coastal settlements and the tourist trade in the area.

Corals are becoming increasingly vulnerable to climate related threats as ocean temperatures increase, sea level rises and the ocean becomes more acidic as it absorbs the greenhouse gas carbon dioxide, a process that undermines corals' ability to grow their skeletons.

The scientists were joined by government officials and local people who discussed the changes in the environment, how the local community is being affected and what needs to be done to adapt.

The islands are facing the collapse of fish populations, damage from aquaculture activities like shrimp farming, and falling tourist revenues.

"This workshop tried to offer concrete solutions to adapting to the effects of climate change, so that the unique biodiversity of this place can survive for future generations," Di Carlo said.

The scientists recommended a series of measures to protect the area, including ensuring that seagrass beds, mangroves and other habitats that provide important ecological services are included in protected areas.

They also recommended the promotion of alternative livelihoods such as seaweed farming for area residents, and construction of ports on stilts to allow sediments to move freely, reducing sediment loads that harm corals and other coastal marine ecosystems.

Copyright Environment News Service, ENS, 2009. All rights reserved.