SYDNEY, June 28 (Xinhua) -- New gillnet fishing Exclusion Zones in 33 locations have come into effect on Thursday, to protect Western Australia's (WA) endangered sea lion colonies.

Used predominantly by commercial fishing vessels to catch gummy, dusky, whiskery and sandbar sharks, gillnets are hung vertically in the water and can sometimes inadvertently trap sea lions.

With around 12,000 Australian sea lions left in the wild, it is estimated that there are just 2,000 located on the country's west coast.

"The protection from fishing impacts offered to WA's Australian sea lion colonies through these exclusion zones is essential to prevent the extinction of this highly vulnerable species," senior program manager at Humane Society International Alexia Wellbelove said.

"The Australian public expects that their seafood does not come at the expense of endangered ocean wildlife."

"Most Western Australians would want to know that their fish and chips don't cause the deaths of our unique Australian sea lions."

Covering around 17,000 square km, the net-free areas will range from six to 33 km around each colony, to protect sea lions that may be foraging for food.

"The network of zones seek to balance Australian sea lion conservation concerns, with the need to maintain a viable commercial fishery that delivers economic and social benefits to the community," WA fisheries minister Dave Kelly said.

"We have negotiated with the federal government to ensure that these new zones are based on science and around known sea lion breeding colonies."

The effects of the Exclusion Zones will now be monitored and studied over the next three years in order to understand the impacts on the species and the fishing industry.