Look at it in water. Look at it from over the net. Do you think it’s big enough to keep or release? That’s one part biology, another part regulation.
When do you expects a fish that size to be a rainbow trout? How much longer until it hits its full growth? Turn that guessing game into a sure thing by knowing what a fish of that size should weigh.
Why Fish Weight Matters for Anglers
See that chart? That’s how you know where the dividing line is between a good-sized fingerling and a massive trophy. We think things go up in a straight line when we double the size, that’s not the way biology works. If you have an eight inch trout that doesn’t weigh much, but a twenty four inch one are heavy. Look at that graph. It explains why. It shows how their weight jump once they get bigger.
That’s important on your gear. Small fish on light tackle. A larger fish from a lake might break you off on light tackle. Match the size of the fish you expect to catch with the line strength and you keep the fish fighting longer while saving your rod.
For those who do not know, the difference between a steelhead and a resident rainbow can be confusing, but numbers make it easy. Ocean-going rainbows called steelhead feeds on marine proteins. They also tend to be fatter, heavier and bigger then their freshwater counterparts for the same length. For example, if you land a twenty-two inch trout in an ocean connected river, it will weigh more than its counterpart from a high alpine lake. That’s what comparison section points out.
Selecting lures and setting limits is two different things. Setting the hook at the wrong speed and using lighter tackle is not how to handle a steelhead. Not understanding this mean losing fish. Add another wrinkle, the hatchery raised trout. Raised for efficiency, these guys have been fed pellet after pellet and have grown round bellies with high condition factors. In contrast, hatchery fish has rounder bodies with high condition factors; while wild trout have leaner frames from foraging hard for insects and minnows, they’re often healthier in the long run. The chart illustrates how a wild trout will weigh less then its hatchery counterpart at the same length. This isn’t a defect, it’s an adaption. To avoid predators and move through current, wild fish maintains their sleek appearance. Hatchery fish survive because we feed them.
Knowing this can help you modify what lures you throw. A plump hatchery fish may attack chunky bait where a skinny wild trout won’t even blink twice.
The ratio of meat to bone is also very seasonal. Post-spawn rainbows in spring are light and lean. Winter/early spring reproduction can cause them to lose up to 10% of their bodyweight. Conversely, fall is when they start putting on the pounds. Food abounds, water cools off and trout feed greedily in preparation for the cold weather. Trout gets fat and store lots of energy. If you fish in October, be prepared for heavier bites than in April. The seasonal factors in guide will explain why your catch weights vary throughout the year. It is not because you are getting less skilled as an angler. It is just the naturaly rhythm of the season.
The laws differ from state to state and even within states for certain bodies of water. For example, some states like Montana have bigger minimum size requirements because their fish is considered wild stock. Others, like California, have smaller minimums you can keep. Always make sure to get to know the rules of the waters you’re fishing before you cast your first lure. It’s a basic law, but something easy to forget that will cost you if you don’t pay attention. Make sure you carry the fishing code for your state when you head out. It’s boring advice I know, but it could of saved you headaches down the road.
Finally, it’s about measuring it right. Pinch the tail fin together and then measure from the tip of its mouth to that tail fin. This is total length. Measure girth at the widest point behind the pectoral fins. If you don’t have a scale and need an approximate weight, plug them into formula above. For record keeping or simply out of curiosity, knowing how to accurately weigh a bass are imperative.
You’ll know when it’s time to let one go because it’s a healthy fish and you did it by the numbers, not by hoping. That’s the difference between fishing smart and fishing blind.