Our oceans are under immense pressure due to human activity. Global warming, acidification and pollution are just a few of the burdens we impose on our oceans, and it is forecast to get worse. Hence the need to find ways to conserve our marine ecosystems and begin to repair the damage. A tried and true method of doing just this is already to hand: marine reserves.
Marine reserves meet both conservation objectives and other human needs. In fact they are the only way identified thus far to protect oceanic ecosystems in their entirety.
Marine reserves benefit four biological factors: marine organism density, biomass, scale and diversity. Socially, they benefit people through education, and by boosting tourism.
No-take reserves can quadruple the biomass of animals and plants in their proximity, typically leading to at least a doubling of marine life density while the size and health of individual species rises.
In New Zealand our governments have committed to protecting 10% of our coastal waters and marine areas by 2020. In contrast overfishing has removed 63% of fish biomass (93% of shark biomass) from coastal areas.
The International Union for Conservation of Nature (IUCN) defines marine reserves areas as ‘clearly well-defined geographical space that are managed through legal or other effective means, to achieve long-term conservation by maintaining ecosystems’.
The establishment of more and larger marine reserves would allow us to begin to define where truly ‘healthy’ marine ecosystems exist, while illuminating issues on how to manage pollution, climate change, and overfishing.
About 3.1 billion people depend on the ocean for almost 20% of their dietary needs, and over 500 million people earn their livelihoods from ocean-related activities. Yet at present marine reserves globally account for less than 1% of the oceans compared to national parks on land which make up 12%.
Replenishing fish stocks
Marine reserves are well documented for replenishing fish stocks (eg see Dive 163 re snapper). Over fishing occurs in half of our oceans with 58% of fish stocks on the point of becoming endangered. Globally some 11 to 26 million tonnes of fish are lost each year due to illegal fishing. Marine reserves go some small way to rebalance this (self) destruction.
To rebuild fish stocks, increase our resilience to climate change, and prevent the further loss of marine life, many scientists are saying we need to protect 20% to 40% of the oceans through a global network of reserves and sanctuaries.
New Zealand’s marine environment extends to 500 million hectares of ocean and we have just 44 marine reserves which equates to just 0.3% of the total area. 99% of that consists of two reserves, the Auckland and Kermadec Islands, both of which are smaller than our smallest National Park, Abel Tasman.
Currently, the average size of a marine reserve is just five square kilometres. Given the diversity and extent of our marine environment, surely, for instance, we should be aiming to establish larger reserves, and in deep water offshore.
Climate and pollution related benefits
Reserves also assist with eliminating pollution and help remediate climate change. Most causes of marine pollution (80%) are from the land, such as plastics washing down rivers, and agricultural runoff. An example of how this is being addressed is the Great Barrier Reef Water Quality Protection Plan, a brilliant system under development that aims to better manage agrarian effects and the impacts of pollution from catchments near the reef.
Climate change is forecast to see the world’s salt marshes shrink by 50%, the loss of 35% of mangroves, 30% of our coral reefs, and 20% of our seagrass areas. (see also Soundings on page 9 in this issue of Dive)
Discovering health benefits
Marine reserves could also be where marine organisms that show promise for assisting with human health could be nurtured. Organisms such as corals and sponges are known to produce antibiotic compounds. A sponge thriving in the Red Sea creates substances that act to suppress the AIDS virus. The marine snail and the Caribbean Sea Whip produce composites that assist with inflammatory diseases such as arthritis, a condition resistant to standard medical treatment thus far.
Only getting worse
Globally sea-based industries are predicted to double their contribution to the world’s ‘value-added’ by 2030. By then marine aquaculture is expected to triple, while industrial-scale capture fisheries, port activities, and maritime and coastal tourism are expected to double. The pressure on aquatic ecosystems is projected simply to multiply exponentially.
Where there’s hope
Marine reserves present places to study marine ecosystems relatively free from the influence of human activity. But more, larger, and widely dispersed reserves, and in deep water, are needed to determine the natural age, fertility, mortality of fish populations and other marine species, for us to gauge and establish credible sustainable management goals.
Marine reserves represent our best way forward for understanding our marine ecosystems in their natural state. By investing in their protection we allow marine life to recover while countering the risks inherent to ourselves from overfishing, pollution, and climate change. Surely a no brainer approach.
Case study: Goat Island Marine Reserve
The Marine Reserve Act of 1971 allowed the establishment of New Zealand’s first marine reserve in 1975 at Cape Rodney/Okakari Point, better known as Goat Island Marine Reserve, and one of the world’s first no-take reserves. Before it the area was dominated by kina due to a lack of large snapper and crayfish predating them, a result of overfishing. Within eight years of the reserve’s protective status, 30% of the reef was transformed from bare rock to kelp forests swarming with species rarely seen hitherto.
Goat Island reserve was ostensibly created so scientists could observe and learn how a healthier, more natural ecosystem could function. Auckland University operated from the Leigh Marine Laboratory on site. Now the reserve is home to over 1,000 species, and has become an excellent place for children and adults to see for themselves, and interact with an ocean environment.
Consequently Goat Island has become a tourism magnet attracting more than 350,000 snorkelers, divers and marine scientists annually. Their value to the area is estimated worth over $8 million each year, with visitors becoming advocates for tthe reserve, spreading awareness of it, and the vital job it does. Indeed the emotional response of visitors may well far exceed the financial benefits.
Article by Ria Loveder.
In the next edition of Dive we will feature Samara Nicholson’s work with “Experiencing Marine Reserves.” Here she is in her role as Lead
Coordinator in Blue Maomao Arch at the Poor Knights Island Marine