What is fall and spring turnover?

Summer to Fall, and Winter to Spring: The lakes turn over Lake turnover is a phenomenon whereby the entire volume of water in a lake is mixed by wind. Lakes turn over in the fall when the water throughout the lake reaches a uniform temperature. Spring turnover is important for the same reason.

What does spring turnover mean?

The onset of spring brings many changes to our part of the world. Spring lake turnover is the process by which a lake mixes itself, thereby replenishing its oxygen supply. Oxygen is vital for lake quality – it is the gas that drives the life cycles of aquatic plants and animals.

What causes spring and fall turnover?

The sun’s radiation does not reach this cold, dark layer. During the fall, the warm surface water begins to cool. As water cools, it becomes more dense, causing it to sink. This dense water forces the water of the hypolimnion to rise, “turning over” the layers.

What happens during fall turnover?

The thermocline layer prevents mixing of the warm (epilimnion) and cold (hypolimnion) water. In the fall, the surface waters cool until they are as dense as the bottom waters. With the help of the wind, the lake can mix and this is called “fall turnover.”

Why is turnover important in lakes?

Twice a year, unseen forces churn water from the depths of our deeper lakes and deliver oxygen and nutrients essential to aquatic life. This temperature-driven process of lake “turnover” allows aquatic life to inhabit the entirety of the lake as oxygen becomes more available.

Why do lakes turn green?

The green color of many lakes comes from high concentrations of chlorophyll containing algae. Green lakes can support a large number of fish and other organisms, but also may produce harmful algal blooms.

How long does fall turnover last?

It is not a drawn out process that makes for terrible fishing for weeks on end. Typically, on large reservoirs, the actual turning over of the lake only takes about two or three days at the longest; and on small waters, with a good hard rain, it could be overnight,” he says.

How many times a year does a lake turnover?

Lake turn over is a phenomenon that generally occurs twice a year, spring and fall. It is caused by water temperatures being different at the surface and in the lower regions of a lake. Lighter and heavier water switch places. Read more about it here.

What is a blue lake?

Blue water lakes contain low concentrations of algae and other substances, resulting in high clarity and a deep blue color. Water molecules absorb longer, visible wavelengths (e.g. red light, 600-700 nm) while shorter, blue wavelengths (< 500 nm) pass deeper into the water column.

Why are lakes turquoise?

The lakes in the mountains that have vivid blue and green colours are glacier fed. As the melt water from a glacier starts to flow in the spring time it carries with it glacier silt or rock flour. The sunlight that reflects off these particles is what gives the lakes their spectacular turquoise blue or green colour.

How do I calculate my turnover?

To determine your rate of turnover, divide the total number of separations that occurred during the given period of time by the average number of employees. Multiply that number by 100 to represent the value as a percentage.