The phrase "decreasing population" is correct and can be used in written English.
It is commonly used to describe a declining number of people living in a certain area or belonging to a certain group. Example: The government's policies have failed to address the issue of the decreasing population in rural areas.
But rural officials argue that with a decreasing population and few businesses, there are few taxes to collect.
In view of its small and decreasing population, the conservation status of Craveri's Murrelet is assessed as Vulnerable.
Conversely, a stagnant, or worse, decreasing population increases the influence of capital accumulated in previous generations.
Sitting in his cool, stone home, Mifsud Bonnici rejects arguments about the turtle doves' decreasing population, saying the decline is not alarming, even to EU officials.
Our estimates of abundance indicate a gradually decreasing population through 2010 corresponding to drought events and reduced grassland areas.
What is the relation between fish populations and mosquito populations, and what is the effect of the increasing population of night herons on Charles Island on the decreasing population of piping plovers on Milford Point?
This paper examines the social roles of creativity in a Shrinking Society (a society with a decreasing population, a falling birth rate, and ageing members).
The Finn-characteristic haplogroups, however, showed a starkly different pattern, with rapidly decreasing population sizes throughout most of the Holocene, until a period of steep growth that started only as late as around 1,000 ybp.
We built generalised linear models for the whole dataset (global models) and separately for each region within the species range with decreasing population aggregation (core, middle and peripheral).
Further, 27 out of the 85 species found at the alder plantations were of least concern but showing decreasing population trends.
Although it does not have a large estimated range and has a decreasing population trend, it received this categorization due to it still being fairly common and the decline not assessed as rapid (BirdLife International 2014).
