Understanding the Science

Grouper, know by many local names in Fiji, is a highly valuable fish to the nation’s economy.

It supports the livelihoods of Fiji’s coastal communities, who sell to both local and tourist markets, and it provides an attractive fish for restaurants and hotels to serve its guests. Groupers are also an important source of protein throughout the country, particularly in rural villages. But in the face of population growth, greater demand for fish and increased demand for cash in Fiji, these prized fish are facing a bleak future if more is not done to reduce fishing during their critical time of reproduction.

What makes grouper, commonly called kawakawa and donu in Fiji, particularly vulnerable to overfishing is the way the fish reproduces. While groupers are typically solitary fishes, during short periods each year individuals swim from their home reefs, sometimes covering great distances, to gather together to spawn (mate, reproduce). Scientists call these gathering spots spawning aggregation sites.

Says the Society of Science and Conservation of Fish Aggregations (SCRFA), which is the scientific advisor to this campaign, “Spawning aggregations of reef fishes … are among the most dramatic, and remarkable, biological phenomena that occur on or around coral reefs worldwide.”

Indeed. Check out this new SCRFA film showing what this looks like in Palau to get a feel for these underwater marvels.

 

In Fiji, the peak months for groupers to gather at aggregation sites to spawn is June through September, typically around a full moon. Traditionally, these sites were well-known to local fishermen and the opportunity to easily fish them for subsistence was a boon. But in modern times, as fishing pressure has increased particularly for commercial sale, the aggregation habit of groupers has made it easy to deplete the fish, as they all gather in one spot, the same spot each year, and predictably at the same time.

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The problem is exacerbated because the fish are taken before they produce the next generation of grouper. So you lose all those fish, plus what could be millions of fertilised fish eggs that create the next generation of grouper. Here are some snapshots from research conducted by Yvonne Sadovy at the University of Hong Kong and the Fiji Department of Fisheries. 

 

According to the Society of Science and Conservation of Fish Aggregations (SCRFA), which is the scientific advisor to this campaign, in extreme cases, when fishing pressure is high, spawning aggregations can entirely disappear, sometimes within just a few years of when heavy fishing begins.

“The long-term consequences of such trends on food supply and livelihoods… are a matter of considerable concern for those countries and communities that depend heavily on the sea.,” reports SCRFA, which provides scientific and management information and participate in international committees, meetings and workshops to promote responsible stewardship of fish aggregations globally.

At the same time, if we protect these fish during the time they spawn, we will have more fish to eat the rest of the year. It’s that simple.

Visit www.scrfa.org to learn more.