Protecting the Giant Groupers of the Deep

When it comes to the ocean’s biggest animals, you probably think of whales, or perhaps fast and flashy fish like blue marlin.  Well, let me introduce you to the giant groupers.  These are massive and amazing fish, but like the other species I’ve profiled recently, such as red snapper and black sea bass, their faltering populations need our help.

Let’s begin with “the smallest” – the Nassau grouper.  They only grow to about 55 pounds, but what they lack in size (compared to those you’ll read about in a moment), they make up for in other ways.  Consider, for instance, that each year Nassau groupers collect to spawn in specific spots, once upon a time in groups of up to 100,000 fish.  Then consider their outsized personality.  They’re what’s known as “ambush suction foragers,” which means they sit calmly, hardly stirring, until something unsuspecting fins by.  Whoosh—the grouper’s big mouth opens so quickly it creates a current that draws the doomed fish or crab into the abyss.  Yet, when they need a good cleaning, they float patiently while cleaner shrimp groom away unwanted parasites (check out this cool video).

Next up, on the scale – the Warsaw grouper.  This creature can grow to over seven feet long and greater than 400 pounds, and often swallows its prey whole.  Like the South Atlantic black sea bass, it undergoes a mid-life sex change.  Adult Warsaws typically live around the edge of the continental shelf, up to 1,700 feet below the surface.  So, like many other deep-dwelling organisms, this grouper grows slowly, but can live to over 40 years old.

Last, but clearly not least – the Goliath grouper.  Its name pretty much says it all –this fish can grow to an astounding 800 pounds.  I strongly encourage you to check out these photos depicting anglers posing with these incredible sea monsters (as well as some footage of the grouper in its natural habitat).  For another sense of their girth, regulations now stipulate that an angler must cut his or her line rather than “boat” an adult Goliath.  Why’s that?  Out of water, its skeletal structure can’t support its own bulk, which can lead to internal damage or death.  Goliaths live in shallower waters, and are known to eat turtles and stingrays.  They’re also known to stalk and try, unsuccessfully, to eat divers.

These fish are feats of nature.  But, they're also in trouble.  Twenty years ago, Nassau grouper was listed as a species of concern under the Endangered Species Act and the South Atlantic Fishery Management Council prohibited its catch.  Throughout its range, its population declined by an estimated 60 percent in about 30 years due to overfishing and habitat destruction.  Disturbance of sites where they aggregate to spawn limits their reproductive success.  They also live in coral reefs, which are under intense ecological pressure from changing water chemistry and temperature resulting from global warming.

By contrast, catching Warsaw grouper was outlawed in the South Atlantic only this year. It’s high time for such action, though the prohibition on catching Warsaw may not be enough to end the overfishing of this depleted animal.  Late last year, fishery managers determined that the only way to reduce the rate of fishing mortality below sustainable limits was by closing an area where Warsaw are inadvertently caught as "bycatch" while fishermen are targeting other co-occurring species.  Now, just months after this closure went into effect, it's on the chopping blocks due to intense opposition from fishermen.

The Goliath grouper’s story is similar in many ways, but also provides hope of recovery.  Catching Goliaths has been outlawed for the past two decades following years of overfishing.  Early indications show that the species is slowly recovering throughout its historic range.  However, sparse data continues to limit our understanding of just how much this impressive fish has recovered from its losses over previous decades.  And, continued loss of the species' coveted mangrove habitat could slow or even reverse its recovery.

These huge fish are not merely awe-inspiring. Because giant groupers are high up on the food chain, they are also useful indicators of overall ocean health.  That their populations have declined so sharply is worrisome, but if we take care of these elephantine beings by protecting their habitats and safely releasing them when they’re caught, then there is hope that future generations will continue to experience these incredible creatures of the deep.  

To help, send a message to the South Atlantic Fishery Management Council in support of strong measures to prevent overfishing and protect essential fish habitat for these and other similar species of snapper and grouper.  These measures must include science-based annual catch limits and accountability measures (as discussed in this blog post), and smartly designed bycatch reduction strategies to protect severely depleted and vulnerable fish like the giant groupers profiled above.  This grassroots support for conservation truly bolsters NRDC's advocacy on these important issues, so please take a minute and write a quick email.     

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