It seems that there are so many equipment problems which is the vast majority of issues causing loss of production.
Most operations have good equipment and very little downtime from equipment problems. But that doesn't make good TV. We have secondary and tertiary backups for every critical component, can make on board the dredge every hydraulic hose we use, etc, etc.
why doesn't someone aquire investor(s) prior and have proven divers and dredgers with experience working well together?
They do. The trouble is that the profit margin isn't enough. For a 6" dredge, it's not worth it unless it's one guy that owns/operates and has no deckhand. For an 8" you might be able to afford a deckhand or have two divers/owners that deckhand while the other dives. The problem is getting the ground worth mining. The 10" guys on the couple good areas can run shifts and have separate managers, but the cuts get slim quick the more people that are involved.
why is ice dredging so much less productive?
The ice gets in the way. Dredges constantly are moving a foot, ten feet, 50 feet. The ice slows down the moving, and makes one more willing to work weaker ground only because it's within reach of the hole. The ice is four feet thick. There are other reasons but that is the main one. There are also winter restrictions on size and horsepower.
Lastly I was wondering why more people don't dredge or gain permits for dredging where the rivers and creeks dump into the ocean.
They do. There are restrictions on sizes and horsepower near salmon streams (designated as supporting anadromous fish). These restrictions change for certain date ranges.
has anyone investigated the source?
Yes, that's been done long ago. There are some interesting USGS publications from 1960's and other years. Thousands of drill holes showing the extend into the ocean, etc, etc. The original load source was the upland areas around Nome. The second to last glaciation period (150,000 to 300,000 years ago) pulverized and thrust the material out across what is now Nome and into the ocean, stopping about 2.5 miles offshore, and extending a few miles east of Nome, and up to 12 miles west. Dropping three major gravel/pay bands above, and two to three below current seawater line.
Is it frequent for people to dredge in off limit places?
No. This is a serious offense and is policed by locals, landowners, DNR, and other dredgers. Most often it's people using too powerful of motors for the area, or too large of a suction hose. People can lose their permits and get banned.