The federal government is considering changes to Australia’s marine reserves to implement a national system. This week The Conversation is looking at the science behind marine reserves and how to protect our oceans.
While academics often focus on biodiversity objectives for marine parks, the public and political debate tends to come down to one thing: fishing.
When former federal MP Rob Oakeshott cast one of the deciding votes in support of the Commonwealth marine parks plan in 2013, he explained that he believed they benefit fisheries. The federal government has also emphasised the benefit of marine parks to fisheries production.
There’s also an academic debate. When a study showed that the Great Barrier Reef marine park had harmed fisheries production, there was a passionate response from other experts. This is despite advocates arguing that reserves are primarily about biodiversity conservation, rather than fishing production.
Clearly, fishing is a hot issue for marine parks. So what does the science say?
How do marine parks protect fish?
The proposed benefits to fisheries from marine parks include: protection or insurance against overfishing; “spillover”, where larvae or juveniles from the parks move out and increase the overall production; habitat protection from damaging fishing gear; and managing the ecosystem effects of fishing such as resilience against climate change.
Marine parks regulate activities, mainly fishing, within a specified area. They come in a variety of categories. Some allow fishing, but the most contentious are “no-take” marine parks.
Fishery managers also sometimes close areas of the ocean to fishing. This is different to how no-take marine parks work in two ways: the legislative authority is different (being through fisheries rather than environmental legislation); and the closures usually target a specific fishery, whereas no-take marine parks usually ban all fishing.