Kolkata, Feb 2 (IANS): Accumulation of salts in the soil leading to reduced fertility (salinisation) is a "poorly understood" process and is a "silent" threat to the Sunderbans mangrove forests, a World Bank report said Monday.

The strategy report 'Building Resilience For Sustainable Development of the Sunderbans' was presented by the organisation at the conclusion of a three-day international workshop in West Bengal Saturday.

The report said the role of future climate change adaptation is less urgent in comparison to current challenges, but climate change casts a long shadow over ongoing degradation of the resource base.

The findings highlight the adverse impact of increasing salinity on agriculture and biodiversity.

"A silent threat is the real but poorly understood process of salinisation which is a result of anthropogenic and geomorphological factors as well as natural events including sea level rise and climate change.

"Salinity kills crops and adversely impacts people, soil, water supplies and biodiversity. In some areas, salinity has increased beyond the safe threshold for agricultural production," the release said.

Salinisation is defined as accumulation of soluble salts of sodium, magnesium and calcium in soil to the extent that soil fertility is severely reduced.

The study also noted that nearly 70 percent of the residents have no access to safe drinking water and stressed on enhancing the resilience of the region given its crucial protective role.

"Flooding from past sea level rise and land subsidence as well as increasing cyclonic storm intensity call for enhancement of the resilience of the biophysical system, especially the resilience of the mangrove system, given its important protective and productive functions," the report said.

The workshop was organised by the West Bengal Disaster Management department in collaboration with WWF-India and EnGIO.

Sunderbans, the largest mangrove forest system in the world, is home to numerous threatened species such as the Royal Bengal tiger and several species of river dolphin.

About 40 percent of the nearly 10,000 square km of the Sundarbans forest lies within West Bengal in India and the rest is in Bangladesh.

A Unesco World Heritage Site, the forests of the Indian Sundarbans form a powerful natural barrier that protects Kolkata's roughly 14 million inhabitants and other human settlements from cyclones, rising sea tides and other adverse natural events.