Complex organisms need cells that can perform many different functions. they need to be supported on a cellular level. Without specialized cells you they won't be able to perform different functions.
Factors such as temperature, water salinity, amount of light, nutrient levels, and saturation state are all environmental conditions that can suppress the growth of marine life.
The viscosity of water is the thickness of water (it might also be considered the stickiness when talking about other fluids). Water has many properties, and the viscosity of water influences in many of them. We can take the surface tension of a liquid as an example. The more viscous a substance is, higher will the surface tension be and vice versa since there will be a higher and lower attraction between molecules respectively.
→ The surface tension of water is something really important since it contributes in many ways to the environment and if you think about it, if the water was a little less viscous, there wouldn't be water since the viscosity of water makes it resistant to evaporation to a certain degree.
Hope it helped,
BioTeacher101
