Fish in Muddy Creek

     For about an hour in the afternoon of September 8, 2015, I went to a hundred-yard, slow-moving stretch of Muddy Creek in Lancaster County, Pennsylvania farmland to see if any warblers and other kinds of migrant small birds were in the trees along the shores of that waterway.  Because we had not received rain for the last few weeks, the water level of the creek was down and the shallow water was clear.  I could see the rocks on the creek's bed.  But I didn't see any critters in the water, however.  So I continued my search for migrant birds, but still with "half an eye" in the water just in case.
     I hadn't really ever search this section of creek for any kind of fish in the past, mainly because I was always searching the shoreline trees for birds.  And, usually, the water level is deeper than now, and more filled with silt, making fish hard to see.
     But as I stood along the shore, i noticed a couple of fish swim into a "hole" of deeper water with little current.  There they faced the sluggish current and swam in it just enough to maintain their positions and watch for any critters, either aquatic or terrestrial, small enough for them to eat.  I looked at the fish with my 16 power binoculars and noticed they were adult bluegill sunfish, a species that has been introduced to farm ponds in this area for years.  When one starts seeing critters, often more and more pop into view.  I started to see several more bluegills of varying sizes in the current and in depressions on the bottom.
     To me, sunfish are interesting in creeks like this.  They are chunky fish, not streamlined for live in a stream's current.  They, and large-mouthed bass, have been abundantly introduced to farm ponds in this area over the years.  But the adaptable sunfish seem able to cope with slow currents in the deeper parts of many local streams and creeks.  They even spawn there in May of each year.  And, in time, sunfish born with more streamlined body shapes will be better able to cope with faster currents and become stream fish.
     How bluegills got into this creek, any most other creeks in this area, is a mystery.  This species is not native to that habitat.  Either they were introduced to creeks by local people for fishing, or they were washed out of farm ponds and into waterways during heavy rains and flooding.
     As I watched the bluegills, I noticed a few half-grown white suckers in the current.  Suckers are stream-lined, long and lean, ideal body builds for living in stream currents.  So  the suckers were native to that creek habitat where they live all their lives and spawn each April among the rocks on the bottom of that waterway and many others. 
     Suckers have down-turned mouths adapted to feeding on plant and animal material, dead or alive, on the bottoms of waterways.  Therefore, suckers reduce competition with bluegills for food.
     As I watched the bluegills and suckers in the water with my field glasses, I was pleasantly surprised to see a big large-mouthed bass, then another and another.  These large fish are already streamlined to chase down prey such as bluegills and other, smaller fish, frogs and other creatures in impoundments large and small.  It was a joy to see those long, lean bass swimming gracefully into the current of Muddy Creek as they watched for prey.  They swim so powerfully that they barely moved their tails to navigate upstream with ease.
     Since I was along Muddy Creek for only an hour in mid-afternoon, I didn't see many other critters.  But other creatures, small and large, must be there since the fish are.  I didn't poke among the rocks on the bottom, but crayfish and aquatic insect larvae must be there to help feed the fish.  And invertebrates fall into the water from the trees and other plants hanging over the water and are snatched up by fish.  No doubt schools of minnows were hiding under the stream banks and bottom rocks to avoid being eaten by the bigger fish.
     And although I didn't see any during my stop at Muddy Creek on September 8, I do occasionally spot a heron, kingfisher, merganser ducks or an osprey along this creek.  They, of course, are there to catch fish.  And I would not doubt mink are there to catch fish at night.
     Sometimes a habitat may seem devoid of life at first, but wait patiently and watch carefully and wildlife will become visible.  Few habitats on Earth don't have life.