The water molecules pack together tighter as pressure increases-the pressure increase with depth, due to the weight of the water above, and causes the greatest density changes in seawater with depth (greater than the density changes due to temperature and salinity changes).eawater Properties that Control Density. Density is defined as the mass of water per unit volume and has units of grams per cubic centimeter (g /cm3), kilograms per liter (kg/ L) or kilograms per cubic meter (kg/m3). The density of fresh water at 4 C is 1.0000 g/cm3 or 1.000 kg/liter or 1000 kg/m3.
Answer Wiki. Swans live for approximately 20 to 30 years. Some variations exist between the more common swan species. The trumpeter swan, which is the largest swan in North America, lives for an average of 24 years in the wild but has been known to live for 33 years in captivity. A mute swan lives for an average of 19 to 20 years; the tundra swan has a similar life span.
Trumpeter swans wings are 3.4 meters long. This beautiful bird with large neck is the largest bird of North America. These birds feed on aquatic plants and normally found in marshes and lacks. As far as the danger of extinction is concerned there is no serious risk of extinction to this bird.