Something I'd Never Really Thought About Before

A couple days ago, I went looking for some background info on the amount of drag different reels have. Specifically, I was researching baitcast reels with only 10 pounds or so of drag. Didn't really find anything worthwhile there, but happened across a couple of items on another topic that piqued my attention. That topic is the swimming speed of different fish species. Can't say I've ever given any thought to this matter before, and figured there might be a few others out there "in the same boat," so to speak...thus, my reason for sharing what I learned.

According to one account I found, there have been a lot of studies done that measure fish-swimming speeds in two ways: sustained speeds and burst speeds. Burst speed is how fast the fish can swim for very short periods (seconds). Sustained speed is how fast the fish can swim for longer periods (several minutes and up).

Even so, determining exact swimming speeds for various fish species is, as one expert reported, "difficult because there are so many variables to consider: water temperature, water speed, water depth, fish size, and fish health. In the studies I've seen," he continued, "the best they can do is to observe individual fish and record those speeds. For example, a famous statistic reports that marlin can reach speeds of 68 mph. No one put a marlin on an aquatic treadmill to figure this out, nor did they work out a complex mathematical equation with friction coefficients and such. Instead, a marlin presumably was observed making that speed, so we now assume that other marlin can swim at least that fast."

There are many studies that also try to predict fish speed, based on things like muscle mass, body type, fin shape, etc., but that's all pretty sketchy and speculative. Nevertheless, it's a known fact that a long, skinny fish, such as a pike or barracuda, derives most of its forward motion from the muscle wave. Part of this is due to the fact that such a long fish can generate more waves in its body than a stubbier and thicker fish. Also note that a pike's fins have a relatively small surface area, compared with the length of the body, and the small tail fin provides a correspondingly smaller amount of forward motion during the tail snap.

On the other hand, a stockier species, like the largemouth bass or grouper, gets most of its speed from the snap of its relatively large tail--not as much forward thrust, though, from the muscle wave of its stubbier body.

So, you can't put a sticker on each of these species and say that brown trout go 4.2 mph, and smallmouth bass go 3.9. However, such information probably wouldn't help much, anyway. You don't know how fast your lure is traveling, or how fast the stream is, or how far it is from the lakeshore to the end of the pier, so it's not like you can make any helpful calculations.

However, you can generalize. Most freshwater game fish swim in the 1-to-5-mph range but can attain burst speeds in the neighborhood of 10 to 20 mph. In general, brown trout, smallmouth bass, and largemouth bass all swim at sustained rates of about the average human walking speed (3.1 mph). Their burst speeds are equal to the average human running speeds (10 to 15 mph), or a little faster.

Of course, it seems to us like they must be much faster, but that's mostly because of their rapid acceleration. Most fish can go from standstill to maximum speed instantly. So, even though their burst speed may not be all that fast, it sometimes seems to us that they simply vanish. One mile per hour equates to about 1.5 feet per second, meaning even a slow fish can move 10 to 20 feet in the time it takes us to blink our eyes.

Trout are among the fastest freshwater fish on earth, if you measure by burst speed. Large steelhead (oceangoing rainbow trout) can go from zero to more than 20 mph inside one second, though they can maintain max speed only for short periods. Pike and salmon have similar speed statistics. Bass are likewise high in burst speed but generally are slower swimmers overall. Panfish and carp are much slower.

If nothing else, I now better understand why it sometimes seems nearly impossible to reel fast enough when a fish starts swimming straight at your boat. Hope y'all learned something, too.