by Scott Sadil

When the grackles start up at sunset, whistling and catcalling on power lines outside the Great House Inn, as if rowdy soccer fans voicing boisterous complaint, I’m quick to imagine I’ve fallen into a scene out of a Conrad novel, or at least one by Graham Greene, especially as traces of lightning linger, piercing the humid skies in the wake of thunderstorms that shut down flights, all afternoon, in and out of Belize. 

Not many commercial airline flights, come to think of it, in Conrad’s day.

What else is new?

Besides the ouster of colonial powers throughout the Caribbean, and the phenomenonal growth of the region’s tourist industry, including waves of shoreline development that cause even a student of coastal blight such as yours truly to sit up and take notice, a startling migrant seems to have invaded, a longtime visitor that has now grown pervasive, blinking brightly on the radar of anyone who likes to fish, or recreate in any way, in these rare and inviting and usually crystalline waters.


Sargassum, the well known brown algae, also known as gulfweed, found throughout the western North Atlantic, the Caribbean, and Gulf of Mexico, has always been around, a vital component in maintaining the balance of coastal ecosystems. 

But for the past dozen years or so, seasonal blooms of Sargassum have increased as much as 200 fold, inundating coastal areas in amounts never before seen, much less imagined.

It’s kind of a nightmare—especially if what you happen to be promoting, or selling, includes white-sand, palm-lined, postcard beaches and, especially, the promise of inshore fly fishing right out your front door.

So what’s going on?

Or, more important, perhaps—for readers here at least—how do these waves of Sargassum, piled up on beaches like snow drifts in a Wyoming blizzard, or breaking up along cays and rafting as though kelp beds in the mangrove, affect the fishing?

Glad you asked.

The first question, concerning the “why” behind the unprecedented amounts of Sargassum now riding the trade winds from the western Atlantic across the Gulf of Mexico, demands we gaze upstream, if you will, and examine the sort of environmental changes in faraway places that cause dramatic changes elsewhere.

Florida has its share, too.

Researchers have recently discovered that the Sargasso Sea, long known as a source of seasonal sargassum blooms, may no longer be the point of origin of these new “inundating events.”  With its warm, oxygen-poor water and low nutrient levels, the Sargasso Sea has always had limits to its Sargassum production.   

Now, however, new influxes of nutrients from both the Amazon and Congo river basins, where  deforestation has led to industrial-scale agriculture and sudden influxes of chemical nutrients, especially nitrogen, phospates, and iron, mean that the Sargassum blooms are essentially nourished by human practices.  Consider, as well, the effects of inefficient or nonexistent waste-water treatment systems.  Add this increase of nutrient loads, along with rising ocean temperatures, and you have the perfect formula for what scientists refer to as “eutrophication” – the process by which your farm pond or summer lake or vacation reservoir turns into a scummy, algae-choked puddle.

Do the fish care?

Do the fish care?  We know, for certain, that the decomposition of large quantities of organic matter—i.e., Sargassum—consumes oxygen, creating oxygen-depleted areas that can result in dying fish.  But the sea is big: Can’t fish just go somewhere else?

Well, yes and no:  When I’m in Belize, out on Ambergris Cay, I’d like to find my sport there.

The good news, I’m happy to report, is that the Sargassum not only hasn’t driven fish away, it offers some new habitat wrinkles that seem but fresh threads to follow in the fabric of the game. Bonefish love the cover of sargassum rafting along the shore.  Tarpon, tucked into the mangrove, move in and out of sargassum canopies as they search for unsuspecting bait.  

Permit?  Dude, sargassum is the least of your worries.

Back here in my room, waiting in my novel-like setting for the weather to relent, I can tell you right now, it’s not the sargassum that’s going to haunt me.

Gray’s angling editor, Scott Sadil, believes an important lesson in fishing, if not elsewhere, is learning to deal gracefully with conditions beyond our control.