|Dr Saifullah Ariffin Jaaman says threats were discovered during surveys by scientists and researchers|
Dr Saifullah Ariffin Jaaman, a lecturer on marine mammal and fishery sciences with Universiti Malaysia Sabah, said the threats were discovered during surveys conducted on marine mammals in the two states by scientists and researchers.
"Many jungles, especially upstream of rivers in the two states, have been logged. The land is being cultivated now or turned into large-scale oil palm plantations."
Saifullah said this in a paper presented at a recent Conference of the European Ce-tacean Society.
He said that these areas contained many drifting logs and debris, especially during the northeast monsoon.
"In some areas left cleared, rain pushes sediments into the rivers and bays. This increases the turbidity of the water, thereby decreasing water quality."
Waste, especially plastic bags, from urban and industrial areas, are also a common sight in rivers near coastal towns.
Aquaculture farms have resulted in the loss of large areas of mangrove along the eastern coast of Sabah. Much of it has also been chopped for wood chips or firewood.
"Their disappearance has led to sediment erosion, water pollution and loss of nursery habitats for young fish."