It is not recommended to eat spawning trout for several reasons.
The eating quality of trout deteriorates during the spawn.
Trout exhaust a lot of energy and condition to spawn, so they are in a weak, malnourished state and the eating quality is much lower compared with other times of the year. Spawning is so stressful on trout that many trout die from exhaustion or fungal infections brought on by the rigours of the spawning activity.
I have never eaten a spawning trout, but have heard first hand that the flesh is mushy and often with an off taste.
Disturbing spawning trout and redd can threaten future generations of trout.
Spawning is the most important time in a trout’s life cycle, they have a very important job to do. During the spawn, the female trout creates a nest in shallow gravel called a redd. There she lays her eggs and the male fertilizes them. Without a successful spawn, there will be no next generation of wild fish.
To protect the future generation of trout, fishing for trout while they spawns not recommended. Not only do anglers disturb the parents, causing them to abandon their redds, but careless fishermen are also known to trample right through the spawning ground destroying countless eggs.
During the spawn, it is best to leave the trout alone to do their business. There is plenty of time and opportunity to target them before and after the spawn.
Targeting trout during the spawning migration?
It is generally seen as acceptable to target trout as they are on their migration upstream to spawn. As lake resident trout enter the rivers and run upstream is some of the best fishing of the year.
Trout prior to spawning are usually in good condition and are of good eating quality, but as the spawn approaches. The trout feed less and their condition start to suffer.
During the spawning run, for the most part, I personally practice catch and release, but in most waterways, there is probably little long term harm in harvesting the occasional trout on their spawning run.
Can you eat trout roe?
Often when a hen is kept during the spawning run, it will be full of orange color roe or fish eggs. Many anglers throw it away, but fish roe is actually edible and can be cooked just like the rest of the trout.
My wife always makes me keep the fish roe, it is seen as a delicacy in her culture and she always cooks it as part of the meal. I personally find it more of an acquired taste, the texture is also a bit strange.
So next time you are cleaning a hen full of roe, do not throw it away. But fry it in some butter and give it a try.
When do rainbow trout spawn?
(Check here for a more comprehensive answer on when trout spawn)
Rainbow trout spawn in the spring. Usually when the water temperature is between 42 to 44 °F (6 to 7 °C). In more mild climates spawning can begin as early as April, while at higher elevations or further north spawning can extend into July.
The opposite months apply for trout spawning in the Southern Hemisphere. While rainbow trout typically spawn from July through to October.
When do brown trout spawn?
Brown trout spawn from late autumn into winter, generally between the months of September and December. Brown trout prefer to spawn when the water temperature is between 42 and 48 degrees, 6-9°C )
When do brook trout spawn?
Brook trout spawn at a similar time to brown trout, between the months of September and November. Brook trout typically start their spawn at slightly lower temperatures.