By TOM RICHARDSON/ecoRI News contributor
The annual return of blueback herring and alewives this spring to the region’s coastal rivers and streams will be celebrated, but there’s another aquatic migrant that will have the attention of poachers.
Elvers, also known as glass eels, are juvenile American eels, and they enter coastal waterways from Texas to Nova Scotia each spring, after developing from eggs and then larvae and then carried by currents from the species’ spawning grounds in the Sargasso Sea, in the middle of the North Atlantic. They are “catadromous” fish, spawning in salt water and spending most of their lives in fresh water — although some eels remain in salt or brackish waters after arriving on the coast.
I had never seen elvers in the flesh until I was checking out a local herring run in late March a few years ago. I noticed some in the freshwater pond above the dam. Maybe I had never really looked for them, but the more I looked, the more elvers I saw.
Every minute or so, one of the 3-inch-long, flagellate-like animals would wriggle through in the tea-colored water, occasionally scooting in to hide among the mossy vegetation that grew on the rocks.
I returned the next day, intent on capturing a few of the critters with a dipnet. This proved difficult, however, as elvers turn out to be very fast and very slippery. This should come as no surprise to anyone familiar with adult American eels — perhaps the slimiest creatures on earth next to hagfish.
The baby eels need to be even more elusive, since almost everything eats them, from herons to trout. Humans, too. Glass eels — so-called for their transparent bodies — command a huge price in Asia, where they are grown to maturity and sold as a delicacy. The high price of eels spawned a gold-rush fishery that eventually led to U.S. limits on their harvest. Poaching remains a problem in some areas, as a pound of elvers can fetch up to $2,200.
In 2013, Rhode Island environmental police apprehended four out-of-state men as they pulled their catch from eel traps in the Seekonk River in Pawtucket. One of the men was carrying a bucket containing about 2.5 pounds of elvers. Police also confiscated a large cooler containing elvers in the back of their SUV. The men were charged with misdemeanor offenses of exceeding the daily catch limit, possession of undersize American eel, fishing without a commercial license and obstruction of migratory fish passage. They told police they sell the fish for about $1,000 a pound.
Maine, Florida and South Carolina allow limited fishing of elvers, while most other Atlantic Coast states prohibit such fishing. Maine generated some $40 million in sales of glass eel in 2012.
Aside from a gauntlet of predators, elvers must also contend with fish ladders and dams during their odyssey from the sea to freshwater rivers, ponds and lakes, where most will mature.
They feed on a variety of detritus, and provide a source of food for striped bass and birds. Once the eels reach maturity — they can grow up to 4 feet long, weigh 9 pounds and live up to 20 years — they return to the ocean and make their way back to the Sargasso Sea, where they die after spawning.
Whether because of overfishing, habitat destruction, disease, increased predation, a naturally occurring cycle or some combination of factors, the coast-wide population of eels in the United States has declined in the past decade, prompting the federal government to consider listing the species as threatened.
Such a listing would make eels off-limits to harvest, both for food and for sale as bait.
Marion, Mass., resident Tom Richardson writes for New England Boating.