Masu salmon congregate around sunken woody debris in the river after they have left the nest.

Wood Debris Effects on Juvenile Salmon

In rivers where there is plenty of sunken woody debris or over hanging trees and shrubs, there are healthier populations as they are able to hide from predators.

Research from several sources showed that significant debris from tress and shrubs also contributed to deeper pools and a slowing of the river current, which contributes to a healthier population.

As water moves around the tree roots and sunken logs, the water acts as a dredge, removing the river bottom and creating deep pools. The debris also gets in the way of the current, slowing it down.

Debris also contributes to a healthy river. Other fish species and insects are also attracted. Every creature of the river prefers cover.

Fishing Regulations to Protect River Habitat

Mining and forestry operations along the rivers and streams in many states and regions have tough environmental regulations that keep them from dumping effluent in the river and altering the water turbidity, flow and current.

Areas were logging and mining have few regulations have resulted in the eradication of many fish species from the river.

It does not take much to change the habitats to eradicate fish from an otherwise healthy stream. It does not take chemical dumping to kill a stream, simply storing up sediment too much can lead to the death of a river.

Ideal Masu Salmon Habitat

Masu Salmon spend much of their life in the rivers and streams of their distribution. As such, river and stream habitat is critical to their existence.

Good Masu Salmon habitat consists of six essential elements: water depth, cover, current velocity, pool volume, gravel coarseness and cover area.

Adult Masu Salmon require deeper water over shallow water, large cover is also required. The current should be slow and sustainable for them to be happy in their summer habitat.

They prefer gravel that is small in size and embedded within the river enough that it does not move with the current.

They also prefer underwater debris or physical structures that both provide cover and help protect the environment.

Masu Salmon Water Temperature

Masu Salmon prefer water temperatures between 47°F to 57°F/8.5°C to 14°C. Temperatures below 8.5°C do not see much action. They ted to enter a semi hibernation state in order to conserve energy.

Other Salmon species can tolerate water temperatures much lower than this, but still preferring that general water temperature range. In fact, Masu Salmon water temperature preferences are close to that of fresh water bass than they are to ocean going fish.