People often talk about loss of habitat as the cause of species disappearing. What is harder to imagine is the loss of spawning grounds. These are the very specific areas within the overall habitat that have the properties necessary for successful spawning. The bottom composition must be just so and at a depth that is just right. They are always in demand and fish often share them on a basis of temperature preference. I have witnessed it first hand over the years. Huge areas of shallow water, bays and creek mouths are now nearly or completely useless to nature.
Nothing can use them. No fish, no insects, no crayfish and no plants. They have become huge expanses of death. Thick layers of detritus, (Silty, organic muck that reeks of decay). Methane bubbles rise from the ooze. A black anaerobic slime lies just beneath the surface. Disturb it and the stink is pungent. In places where I’d seen thousands of perfectly spaced spawning nests there are now none. The bottom is useless because the eggs sink in and suffocate. If spawning is not done in mass like this, the statistical probabilities of survival are slim. The only possible remedy for this situation is the natural ice flow. The sweeping and scouring of the ice cleanses the bottom in ways perfectly suited to this environment. There is no substitute. The very laws of physics, with its razor thin margins, controls the ice flow perfectly to do this essential job in nature. The Niagara River is supposed to be a clean sand and gravel bottom river. It has degenerated into what looks like a swamp. Loads of decaying matter with all of the nutrients lie in perpetual waste. The very angle of descent that the bottom followed has changed. All of the eroding shores have put deeper water that much further out. You see people extending there docks all the time. The water line moves further in shore and the soil makes for very shallow waters. This can’t continue.