Turning Science into Sustainable Fishing

A man holds his spear as he fishes in the mangrove trees at dusk.
© Michael Hanson / Getty Images
Alex MacLennan
 

The Fijian people have a centuries-old tradition of setting aside no-fishing areas, called tabu areas.

Typically, these areas are closed on a temporary basis—sometimes for a few months or years as an act of respect when a local chief dies—and then reopened to fishing. More recently, melding cultural tradition and modern science, some villages have begun using tabu to protect spawning grounds and depleted fish stocks. One village, Nagigi, had imposed a traditional tabu as recently as 2004, reopening the area to fishing two years later.

Now, after hearing the results of a recent scientific study by Conservation International (CI), the village plans to set aside part of its coral reef as a permanent no-fishing area.


Local Fish Diversity

The study, which was conducted by Boston University scientist Joshua Drew through CI’s Marine Management Area Science (MMAS) program and included numerous informative discussions with village and government leaders, discovered that five well-known types of fish are unique to the region—they carry DNA that is distinct from similar fish found across the South Pacific.

IN DEPTH: CI is working to ensure that people everywhere have access to nutritious food.

Research focused on five types of fish: Barber’s clownfish (Amphiprion barberi), Talbot’s damselfish (Chrysiptera talboti), dotted wrasse (Cirrhilabrus punctatus), lemon damselfish (Pomacentrus moluccensis) and bluestreak cleaner wrasse (Labroides dimidiatus), and indicated that if too many of these fish are caught on Fiji’s reefs it is unlikely that young fish from other islands would replenish them.


Bringing it Home

According to common wisdom, each type of fish is a single species that is widespread across the South Pacific Ocean, and those found in Fiji are not unique. Drew’s research turned the common wisdom upside down.

Like many fish, these five species begin life as tiny larvae. Until recently, scientists believed that these larvae drift with ocean currents, eventually settling onto sometimes distant reefs where they live the rest of their lives. Under this assumption, all cinnamon clownfish, for example, make up one large population across Melanesia, mixed by the drifting of the larvae.

The new research found that is not the case. Through DNA analysis, Drew discovered that young fish tend to settle near their birthplaces. Drew collected DNA from hundreds of reef fish near Indonesia, Papua New Guinea, Solomon Islands and Fiji. For each species in the study, the DNA showed that all of the individuals from Indonesia to the Solomon Islands shared a similar genetic fingerprint—but fish from Fiji had a different genetic pattern.

In fact, the genetic differences are so strong that the Fijian fish may actually be separate species from their Melanesian counterparts.

EXPLORE: The Asia-Pacific region.

“We have underestimated Fiji’s marine biodiversity,” said Drew. “There is so much more to discover.”


Supporting Protection

The findings have important implications for fisheries management and conservation in Fiji.

Most importantly, Fiji cannot assume that young fish coming from other places in Melanesia would replenish its fish stocks if the fisheries crash. Lacking a supply of young from outside Fiji, the fish stocks could take many years to recover—if they recover at all.

It is also crucial to view Fiji as having a fairly independent fish population, with interconnections along the archipelago. This means that local fisheries need to be managed as part of a Fiji-specific network which includes tabu areas and is coordinated to ensure sustainable fishing.


Sharing Results

As Drew obtained results from his study, he collaborated with Loraine Sivo, Fiji’s MMAS Science to Action Coordinator, to share the findings with the community.

In August 2008 with assistance from provincial officials, they met with Nagigi’s chief and village elders to discuss the uniqueness of the village’s fish populations and the need for local management. Later that year, Nagigi community members expressed interest in setting up a permanent no-fishing area to protect their reef. CI then helped present a workshop for villagers to learn how to design a successful protected area and to identify potential sites to protect.

As this community-based process moves ahead, MMAS is continuing to provide scientific information so communities and the government can make well-informed conservation decisions.

“I have learned so much of the things that surround us and how they contribute to our daily lives,” said Nagigi resident Repeni Nanalo. “I have also learned how [a protected area] can contribute to improving our source of livelihood, and why we need to protect it.”

READ MORE: Open Your Eyes to Coral

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