WITH five years to go before Panama takes over its richest asset, the Canal, environmentalists' hackles have been raised over a proposed ocean-to-ocean highway that would cut through Central America's most-accessible tropical forest, endangering rare animals.
The proposed four-lane road will be designed to do what the current Transisthmian Highway can't do: rapidly move container cargo from Panama City on the Pacific coast to Colon on the Atlantic Ocean, facilitating further expansion of Panama's trade and service-based economy.
There are only two hangups. One is that the proposed highway ``passes right through two national parks created deliberately to protect the Canal watershed,'' says Nora Scott of the Audubon Society of Panama.
The other is that the proposed route of the road will pass so close to the eastern bank of the Canal that the construction could increase the amount of silt filling the waterway.
Nature researchers have found the habitat fascinating since the Canal was completed in 1913.
The Smithsonian Institution's Tropical Research Institute, located on Barro Colorado Island in the middle of the Canal's waterway (which includes a lake), has been a leader in tropical forest studies since the 1920s.
``Along the Central American isthmus, Panama is the only country where you can visit a real tropical forest teeming with wildlife within a half-hour drive from the capital city,'' says Bill Adsett, a former Audubon director.
The Canal, the property around it, and the United States military base and equipment there - worth between $6 billion and $30 billion - could become the hub of the country's future development after 1999, when the US leaves as they agreed to in 1979 treaties. The highway proposal is one part of Panama's current development plans for the final takeover.
Carlos Mendoza, head of the board for the Interoceanic Regional Authority that originated the project and has authority over all decisions for development of the Canal Zone, insists that ecologists opposing the highway are being stubborn. He says his route will protect the environment.
The road will have limited access: Once a vehicle gets on, it won't be able to get off except at the other end.
And much of it will be built on piles, allowing wildlife to move underneath, inhibiting human settlement, and preserving possibilities for ecotourism.
Mendoza says the alternative, a route mapped out by Japanese experts in the 1980s near the present Transisthmian Highway, would be worse. ``The Japanese route has exits everywhere, and it will stimulate the already serious population and deforestation problems in the Canal Basin,'' he argues.
But ecologists say that if you build a road, people will come. They favor the Japanese road because it will run through areas already spoiled by humans, doing little additional damage.
For Smithsonian researchers, the road is a threat both to wildlife and their studies.
Ornithologist George Angehr notes that since 1913, 7,080 bird species, including the great Curacao, the royal flycatcher, and numerous species of wrens have disappeared from Barro Colorado, the small island left stranded when the Canal was filled with water from the Chagres River.
``Most of these species still survive in Soberania Park because the block of forest there is large enough, but they won't [survive] if you whittle it away by running a road through it,'' Mr. Angehr says.
Environmentalists also worry about noise pollution from container trucks rolling down the highway. And there's the potential for erosion. ``They're going to be moving earth right next to the Canal,'' Mr. Adsett says. ``One of the Canal's biggest problems is dredging, and the last thing you need is more silt.''
One of the agencies that will have a say in where the road is built, the binational Panama Canal Commission, refuses to comment until it sees a finished proposal from the Interoceanic Regional Authority.
Eventually, one of the two routes will form part of a master plan for Canal Zone development now being farmed out to a US consulting firm.
The consultants will be asked to sift through economic and environmental issues to find a balance between development and environmental objectives. But Panama's government will make the final decision.
Under President Ernesto Perez Balladares, who took office earlier this year, the government says it is trying to make policies by consensus, consulting affected groups before decisions are made. But environmentalists say by the time they are consulted, the development may already be too far along to stop.