• Rules for what fish must be brought back to port and what fish can be returned to the sea.
• The offences and penalties regime.
• Streamlining the ministerial decision-making process for setting catch limits.
• Technical changes to the Fisheries Act.
The discussion document said the current rules can be difficult to comply with and hard to monitor.
Currently anything under a minimum legal size that applies to 19 species must be tossed back to the sea, regardless of whether the fish is dead or alive.
The Government's favoured option is to scrap minimum legal sizes except for shellfish, eels and crustacean species.
Rules allowing other fish to be thrown back would only apply to species with no or negative economic value, such as ammoniating sharks.
This would create better incentives for good practices and for innovation for fishing methods to be more selective.
But it would add costs to the industry because of the need for more monitoring and increase the number of in small, lower-value fish in the market.
Minimum sizes for recreational fishing would not be changed.
Nash said the proposals were designed to encourage a "culture change" in the industry so that "every fish is valued by the commercial industry".
"That will require the industry to be more accountable, maximise the value of the catch, report accurately, and verify what is caught."
The proposals include penalties that fit the level of harm; for example, a $10,000 fine for illegally returning fewer than 50 fish to the sea, but a $100,000 fine for illegally discarding 50 or more.
They also include infringement notices to address offending that involves small amounts of fish.
The current penalty - a fine up to $250,000 - does not distinguish between different levels of offending behaviour.
The discussion document said the rules to adjust catch limits was robust, but time-consuming.
Currently Fisheries New Zealand has good information on 165 stocks but only the capacity to adjust the catch limit for about 10 to 30 stocks annually.
"It can take a significant period to determine abundance, and then due to regulatory procedures, it can be a further year until a decision is made," the discussion document said.
Instead, Fisheries New Zealand proposes using harvest control rules (HCRs) to adjust catch limits, which are currently used in rock lobster fisheries and has helped rebuild those species from a depleted state.
Ten nationwide meetings will be held up and public consultation will be open until March 17. New legislation will be introduced later this year.
Nash also said that the plan to enforce on-board cameras for fishing vessels - which was originally meant to be in place by October last year - would go through a separate public consultation process.
The delay has upset the Green Party as well as environmental groups including Greenpeace.
Nash said it was important to get the policy settings right.
"I need to first ensure the regulations are practical to implement, the technology is operationally ready to go, the systems are in place, and the fisheries management framework is clearly understood.
"I expect to soon provide an update to Cabinet."