MAB programme
machine
macroalgae
macroeconomic costs
macroeconomic effect
macrophytes
macrozoobenthos
maglev train
magnesium
magnetism
main road
maintenance
maize
maize starch
major accident
MAK value
malachite green
malaria
mammal
management
manganese content
manure
map
maple
mapping
mapping of lichens
marginal land
mariculture
marine accident
marine biodiversity
marine biology
marine botany
marine chemistry
marine ecosystem
marine energy
marine fish
marine fishery
marine fuel
marine geoengineering
marine geology