'a population decline' is correct and usable in written English.
You can use it when referring to a decrease in the number of people in a certain demographic, area, or species. For example: Last year, researchers noted a significant population decline among monarch butterflies in the Midwest.
Towns said that's why the census shows they had a population decline.
The entire Tohoku region in northern Japan, of which Fukushima is a part, saw a population decline of about 5%.
The State Statistics Committee reported a population decline of 505,900 people in the first six months of 2002, to 143.4 million.
But hammerheads appear to have fared worse, the scientists said, with a population decline of 89percentt from 1986 to 2000.
WHEN Connecticut lost a Congressional seat because of a population decline, and voting districts were redrawn last December, the Fifth District race for the United States House was poised to be the toughest contest in the state this fall.
Like many shore towns, especially those on the barrier islands at the state's southern tip, Sea Isle City has wrestled in recent years with an economic paradox — a real-estate frenzy, but a population decline.
The growing sense of urgency in official circles about these issues is driven largely by the projections of a population decline that could cause huge labor shortages over the next half-century and possibly even economic collapse.
Mr. Medvedev faces steeply rising inflation, an outsize bureaucracy, pervasive corruption, a weak judicial system and a population decline fueled by a low birthrate, substandard health care and poor public health.
With Canada's population of 30 million aging and its birthrate plummeting -- Canadian women currently have 1.49 children on average -- the government says that it, like some European countries, must rely on increasing immigration to ward off a population decline.
Decline in the French share of North Atlantic fisheries and the rural depopulation seen elsewhere in France at the beginning of the 20th century led to a population decline in Brittany of more than 11 percent between 1911 and 1946.
[The Guardian, Sea Shepherd] The state of Minnesota proposes adding the moose to its list of "species of concern," a sign that it is worried about a population decline even though it is not ready to outlaw moose hunting.
