With oral arguments happening on Thursday, I thought there might be some interest in an article published in Hamline's Journal of Public Law and Policy on the topic.

The article looks at the legal aspect of the Indian fishing and netting rights.

http://digitalcommons.hamline.edu/cgi/viewcontent.cgi?article=1006&context=jplp

An excerp from the GLIFWC spearing and netting regs show that even the tribes know that netting during the spawn is bad and have a closed season on every lake BUT Mille Lacs:
http://www.glifwc.org/Regulations/MN_SpearingNetting.pdf

Lakes other than Mille Lacs.
Net fisheries in lakes other than Mille Lacs are intended to provide opportunity for subsistence harvest of walleye; so muskellunge and sturgeon may not be kept, nor can northern pike in excess of the bag limit, nor can commercial nets be 
set. Subsistence gillnetting is allowed from June 1 to March 1 in any lake that is 1,000 acres or larger and in all lakes identified in 
9.08(2) of the Model Code. In lakes 1,000 acres or larger, the allowable mesh sizes (bar) are 1.5 to 1.75 inches. In identified lakes under 1,000 acres, only 1.75 inch mesh (bar) may be used. Nets may be up to 100 feet in length and 4 feet deep. 

Mille Lacs Lake.
Gillnetting in Mille Lacs Lake is allowed year around. Only subsistence netting may occur from March 2 - May 31. 
Subsistence nets during this and other times may be up to 100 feet in length and 4 feet deep. The allowable mesh sizes (bar) for subsistence nets during this and other times are 1.25 to 1.75 inches. From June 1 - March 1 both subsistence and commercial netting may be authorized. If authorized by your tribe, allowable mesh sizes (bar) for commercial nets are the same as for subsistence nets (i.e. 1.25 to 1.75 inches); however, commercial nets may be up to 300 feet in length and six feet in depth. All nets must comply with lifting, marking, and safety requirements. For gill-nets targeted at tullibee, only 1.75 inch mesh (bar) is authorized. 

The mesh sizes still target young males as do the current "slots". This was a big problem that was condemned two years ago, but now seems to be just fine with management.