Update 12.30pm: MODIFICATIONS to the North Coast's shark nets have been slammed by Ballina MP Tamara Smith.
She said three years ago the government pledged they would use evidence-based data science to inform their strategies.
"The report came in and it said 'epic fail'," she said.
"It said it didn't catch target species but it did catch many other endangered and critical species."
She said the modification of larger mesh was a "crazy notion" that "didn't make any sense".
Local marine conservationists are taking measures to show they feel the same way.
Skipper of marine conservation yacht Migaloo 2, Dean Jefferys, has organised a protest event on Saturday at Lennox Head in response the deployment of nets.
"Concerned people will swim under the shark nets to help dispel the fallacy that the nets are a total barrier and that sharks and like humans, can swim under the nets," he said.
"The plan is to meet on the beach in front of Lennox Head surf club at midday Saturday November 25 and spell out some large words with bodies and boards then paddle out to the shark nets that are planned to be about 500 to 800m off shore.
"There are many more effective non-lethal alternatives to shark nets, like drone surveillance, tagging, smart bouys, Shark Shields, spotters and shark smart awareness programs.
"One point for swimming under the nets is to show what sharks do and how ineffective the nets are at keeping sharks away from swimming areas.
"Shark nets only go down 6m and are around 186m long, in a straight line."
Mr Jefferys said he also sent a letter to the Ballina Chamber of Commerce and the Ballina Mayor asking for a meeting.
The letter stated: "Seeing as they have opted for the shark nets as opposed to non-lethal alternatives, it seems like we have no option than to proceed with the international campaign to encourage local people and overseas tourist to visit and spend their money at non netted beaches where there is a priority to look after and protect the local and migrating marine life and provide more effective, non-lethal shark mitigation technology."
Original story 6.30am: SHARK nets will be installed on five North Coast beaches today.
Primary Industries Minister Niall Blair said the latest trial would provide more data to address some of the issues raised by the community.
"The results from the first trial showed the community felt safer, however they remain concerned about the levels of by-catch," he said.
"The safety of beachgoers remains our number one priority but we have undertaken a review of the first trial and made some modifications in a bid to reduce by-catch.
"It can be difficult to get the balance right, but I hope these modifications reduce entanglements of non-target species this summer. The second trial will provide more data to inform long-term decisions on the future of the nets."
The nets will have a larger mesh size and will sit closer to the surface. Once again, the nets will be fitted with dolphin 'pingers' and whale alarms.
The NSW Department of Primary Industries (DPI) is also opening today a community drop-in stand at Ballina's Lighthouse Beach to inform and educate the public about the six month trial.
Parliamentary Secretary for the North Coast, Ben Franklin said the benefits of the State's Shark Management Strategy were flowing with local tourism improving and beaches proving popular again.
"Nets won't be the only defence in place, we have up to 35 SMART drumlines deployed daily (weather permitting), as well as aerial surveillance," Mr Franklin said.
"We are using the best technology available in the world to increase protection for beachgoers here in NSW."
The beaches are Seven Mile Beach (Lennox Head), Lighthouse, Sharpes and Shelly beaches (Ballina) and Evans Head and the trial will be undertaken in accordance with State and Commonwealth approvals.