Twenty Years of Underwater Observations: What's Changed?



2015 will mark my agency’s 23^rd year of photographing freshwater fish, underwater in the wild.  As I thought about that, I began to reflect on two trends I’ve noticed over the past two decades, especially in lakes in Wisconsin and Northern Michigan where I live.  A few things stand out regarding fish sizes and abundance and general lake quality. 

Water Clarity:

As an underwater photographer, water clarity is critically important for getting good images.  Because of that, we make it our business to know where the clearest waters are.  One disturbing trend over the past 20 years is that we seem to be losing many of our historically clear lakes in Wisconsin.  More than a dozen lakes that were once very clear are no longer suitable for underwater photography because they simply are no longer clear enough.  Whether it’s because of run off, phosphorus overload or natural eutrophication is unknown.  But since these dramatic changes have occurred over such a short period of time, it suggests that the causes are not natural and are probably indications of damage we as lake users are facilitating.  On the other hand, there are also lakes that were once turbid or had poor water clarity that are now excellent.  The bad news is that virtually every lake that has significantly improved water clarity, it’s because of the presence of zebra mussels.  That may be a nice byproduct for snorkelers and divers, but the expansion of invasive species may also cause long-term negative consequences that aren’t as desirable as clearer water.

Changes in Fish Size and Abundance:

In Wisconsin’s inland lakes I’ve noticed some real changes in the last twenty years in fish abundance and sizes. In the interest of brevity, rather than detail and discuss each one at length here, I’ve decided to instead post a chart of what my personal observations have been over the past two decades. 

Table 1 Change in abundance and average size of Wisconsin fish species I've observed: 1993-2014

SPECIES	ABUNDANCE	AVERAGE SIZE
Muskie	Unchanged	Unchanged
Northern Pike	Decreased	Decreased
Walleye	Increased	Increased
Largemouth Bass	Increased	Decreased
Smallmouth Bass	Increased	Increased
Yellow Perch	Decreased	Decreased
Bluegill	Unchanged	Decreased
Black Crappie	Unchanged	Decreased
Rock Bass	Decreased	Decreased

It’s interesting to note that many of my personal and subjective observations regarding fish abundance and size structure mirrors what Wisconsin DNR fish biologists have also found over this same time period.  Walleyes and Smallmouth Bass are doing better these days but panfish in general are probably being overexploited in many areas, especially what fish managers consider to be quality fish.  (The Wisconsin DNR is in the early stages now of implementing new panfish regulations that hopefully will reverse a 70 year long trend of ever- increasingly smaller fish.)

 

The Future:

 

So what does these mean for us?  For someone like me who’s trying to photograph large gamefish underwater or fisherman who like to catch them, it means that in many cases, there are fewer trophy fish swimming in Wisconsin waters than there used to be.  Today, for me, it’s easier than ever to encounter and photograph nice-sized smallmouth and walleyes, but it’s getting harder and harder to find larger pike and quality sized panfish.  The future isn’t necessarily a bleak one however.  It’s my hope that we can turn this around.  Today, with camera phones being ubiquitous and replica mounts being both stunning and affordable, there’s little reason not to release not just the trophies but ALL the larger fish we catch.  If these same trends continue for the next twenty years, as fishermen, we’ll have no one to blame but ourselves.