N.J. town man­ages to mus­cle out gi­ant in­va­sive mus­sels

Baltimore Sun Sunday - - NATION & WORLD - By Wayne Parry

FRANKLIN TOWN­SHIP, N.J. — Most Amer­i­cans know mus­sels as thumb-sized shell­fish that oc­ca­sion­ally adorn restau­rant din­ner plates.

But a colony of mus­sels as big as din­ner plates has re­cently been wiped out from a New Jersey pond, where they had threat­ened to spread to the nearby Delaware River and wreak eco­log­i­cal havoc, as they al­ready are do­ing in other parts of the world.

Fed­eral wildlife of­fi­cials and a New Jersey con­ser­va­tion group say they’re con­fi­dent they have nar­rowly avoided a se­ri­ous en­vi­ron­men­tal prob­lem by erad­i­cat­ing Chi­nese pond mus­sels from a for­mer fish farm in Hun­ter­don County.

The mus­sels, in lar­vae form, hitched a ride to this coun­try in­side the gills of Asian carp that were im­ported for the Huey Prop­erty in Franklin Town­ship and quickly be­gan re­pro­duc­ing. Un­like the mus­sels many Amer­i­cans know, these ones can ap­proach the size of foot­balls.

Their size and ap­petite en­able them to out-com­pete na­tive species for food and space. In many spots in Europe, the Chi­nese mus­sels have taken over water­ways and pushed out not only na­tive shell­fish species, but also have al­tered river bot­tom con­di­tions, harm­ing or chas­ing away some species of fish.

“They can be­come a huge eco­log­i­cal night­mare,” said Emile DeVito, man­ager of sci­ence for the New Jersey Con­ser­va­tion Foun­da­tion. His group bought the land from pri­vate own­ers in 2007 and pre­served it as open space.

Three years later, the pres­ence of the Chi­nese mus­sels was dis­cov­ered, caus­ing great alarm. The nine deep ponds are at the head­wa­ters of the Wick­echeoke Creek, which flows into the Delaware River.

Had the mus­sels spread there, they could wipe out not only na­tive shell­fish, but also harm river bot­tom con­di­tions upon which com­mer­cially and recre­ation­ally im­por­tant fish de­pend, in­clud­ing shad and stur­geon.

The in­fes­ta­tion was the first in North Amer­ica, ac­cord­ing to the U.S. Fish & Wildlife Ser­vice, which part­nered with the New Jersey group on a plan to erad­i­cate them.

First, the wa­ter lev­els were low­ered in the ponds, killing the fish in them, which also in­cluded some in­va­sive big­head carp, them­selves a po­ten­tially se­ri­ous en­vi­ron­men­tal prob­lem if they had es­caped into nearby water­ways.

Then a cop­per-based al­gae killer that also kills mol­lusks was in­tro­duced to the muddy bot­toms. Beth Frei­day, of the wildlife ser­vice, said of­fi­cials are con­fi­dent all the mus­sels were killed, al­though DNA test­ing is planned for next spring or sum­mer to ver­ify that.

Dozens of gi­ant black shells from dead mus­sels were plucked from the mud, giv­ing of­fi­cials a glimpse of just how large the in­va­sive shell­fish grow.

They come from the Amur and Yangtze rivers in China, and in some places are used to cul­ti­vate pearls.

They can live 12 to 14 years.

In­fes­ta­tions have been found in the Czech Re­pub­lic, Italy, France, Aus­tria, Bel­gium, Bul­garia, Ger­many, Hun­gary, Poland, Ro­ma­nia, Spain, Slove­nia, Swe­den and Ukraine. They also have turned up in Costa Rica, the Do­mini­can Re­pub­lic and the Philip­pines.

Erad­i­cat­ing them has proven much trick­ier be­cause low­er­ing wa­ter lev­els is ei­ther im­pos­si­ble or im­prac­ti­cal with­out killing vir­tu­ally ev­ery­thing in a river. Ditto for ap­ply­ing chem­i­cals to kill the mus­sels, par­tic­u­larly in fast­flow­ing water­ways.

Sev­eral Euro­pean sci­en­tists and re­searchers said they knew of no sus­tained ef­forts to erad­i­cate the Chi­nese mus­sels from water­ways there, say­ing the prob­lem has al­ready be­come too big to solve in some places. That is due mainly to their wide­spread dis­tri­bu­tion and the im­prac­ti­cal­ity of treat­ing an en­tire river with chem­i­cals.

That’s why wildlife of­fi­cials in New Jersey were so happy to nip their own mus­sel prob­lem in the bud while they still could.

“Un­der cer­tain con­di­tions, this in­va­sive species could have spread across the east­ern U.S., with New Jersey at the epi­cen­ter,” said Eric Schrad­ing, the wildlife ser­vice’s New Jersey field of­fice su­per­vi­sor.

WAYNE PARRY/AP

Wildlife of­fi­cials hold dead Chi­nese pond mus­sels found in a net­work of ponds in Franklin Town­ship, N.J.

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