The secretary of the Smithsonian Institution, Leonard Carmichael, had posed a version of this question to AEC director Glenn Seaborg back in the spring of 1963, when U.S.- Panama tensions, the resumption of nuclear testing, and the negotiations over the test ban treaty generated widespread publicity for the Panatomic Canal idea.22 Carmichael had likely been prompted by an employee of the Museum of Natural History, oceanographer I. Eugene Wallen, who had spent years studying the faunal effects of nuclear testing in the South Pacific.
Carmichael wound up dropping the offer to help conduct baseline taxonomic and ecological research along the proposed canal routes, but his successor, or-nithologist S. Dillon Ripley, saw a great opportunity (fig. 5.1).23 Determined to improve the Smithsonian’s waning reputation for biological excellence, Ripley re-established contact with the AEC in the summer of 1964.24 Later that year, days after President Johnson announced the sea- level canal plans, Wallen submitted a
$2 million proposal “to determine the potential damage by canal construction to the populations, distributions and abundances of marine and terrestrial organisms on the two proposed routes” in Panama and Colombia.25 However, the AEC chose the Battelle Memorial Institute, a private organization that in turn subcontracted with university- based teams.26 Deeply disappointed, Wallen and Ripley regrouped to consider their options.27 One of the veterans of the Chariot affair, AEC En-vironmental Sciences Branch chief and plant ecologist John Wolfe, provided an encouraging boost: “In such massive engineering proposals,” he wrote Wallen in reference to the sea- level canal, “biology is no longer a flower girl, she’s the bride.”28
Figure 5.1. U.S. president Lyndon B. Johnson presenting a plaque to Smithsonian Institution secretary S. Dillon Ripley, June 13, 1967. Ripley and other Smithsonian
officials tried but failed to secure federal funds from Johnson’s canal study commission for a ten- year baseline inventory of marine life on either side of the
proposed seaway. Smithsonian Institution Archives, 92- 1656.
For Ripley, the canal feasibility studies held the promise of attracting new funds not only for the Museum of Natural History, but also for one of the Smithsonian’s far- flung research facilities. Decades earlier, in 1937, he had vis-ited Barro Colorado Island (BCI) in Panama’s Canal Zone while voyaging from Philadelphia to New Guinea for a zoological expedition.29 BCI was an artifact of the construction of the canal, as the reservoir created by Gatun Dam left only the highest hilltops of the Chagres River valley unsubmerged. The island was also a testament to the Smithsonian’s embrace of the isthmus as a model study site, beginning with the prescient 1910–12 biological survey of the Panama Canal Zone, which generated several studies documenting the area’s marine and ter-restrial biota.30 The survey led the governor of the Canal Zone to designate BCI a reserve in 1923, and over the next two decades, the research station drew more scientific visitors than any other tropical research facility.31 BCI and the associ-ated Canal Zone Biological Area (CZBA) became a Smithsonian bureau after the war and by the late 1950s had provided the setting for hundreds of articles on tropical forest biota and dynamics. However, the CZBA lacked facilities for long- term terrestrial and marine research. Expanding the institutional base of tropical biology gained urgency as tropical nations decolonized and sought to accelerate deforestation for development.32
Another influential source of encouragement for expanding the CZBA was Ernst Mayr, an old friend of Ripley and fellow ornithologist, the head of Har-vard’s Museum of Comparative Zoology, and the mentor of BCI director Mar-tin Moynihan. Mayr had gained fame in the 1940s as a proponent of the Mod-ern Synthesis of evolutionary biology and the concept of allopatric (geographic) speciation, a topic for which the Panamanian isthmus provided an ideal research setting.33 Knowing the approximate period of the geological emergence of the Central American land bridge made it possible to date the origin of evolutionary differences between marine species on either side of the isthmus.34 The 1910–12 Smithsonian survey had built upon a few pioneering studies to expand knowl-edge of the marine fishes of the Atlantic and Pacific coasts and associated evolu-tionary effects of geographic isolation.35 Naturalists subsequently documented some other taxonomic groups west and east of the isthmus that appeared similar but were not identical, as Mayr substantiated for shallow- water sea urchins in a foundational paper that called for more research on modes of speciation in marine organisms. But like several other such researchers, he based his results not on a visit to the biogeographical barrier in question, but rather on an earlier taxonomist’s work.36
Mayr’s recognition of the evolutionary importance of the Central American isthmus shaped his mixed reaction to President Johnson’s December 1964 an-nouncement. As he expressed to a colleague on the President’s Science Advisory Committee, the consequences of conjoining two distinct oceans raised daunting questions beyond the issue of radioactivity:
I have been worrying for some time about the contemplated sea- level canal across the Isthmus of Panama. There is little doubt that such a salt water connection between the two great oceans will have many and drastic ef-fects on the marine faunas and floras. There are closely related species liv-ing on either side of the Isthmus and no one can predict with certainty what will happen if such species come in contact with each other. Will one wipe out the other, or will it hybridize with it? How many disease organisms will be carried from one ocean into the other? What will the tidal currents do in the canal? Will the inflow of the more silty waters of the Pacific damage coral reefs on the Atlantic side? I do not know what the situation is in commercial fisheries, and other utilisation of marine or-ganisms, but . . . I am sure that the opening of the canal will produce many problems, and world science would never forgive us for not being prepared for such eventualities.37
In addition to expanding marine stations in Panama, Mayr argued the United States should appoint a board to oversee the research needed to answer such questions, perhaps involving the National Academy of Sciences. In this regard, he noted, “I might add parenthetically that organismic biology is, on the whole, poorly represented on high level boards in Washington. This is not injurious in most instances, but it may lead occasionally to the neglect of an important problem, as I believe is the case with respect to the Panama Canal.”38 Mayr’s aside was more than parenthetical, for he had been promoting organismic biology as a means of counteracting the growing dominance of molecular approaches to the life sciences.39 Also, conservation was not a prominent theme of his career, though he had published a few articles decades earlier about bird protection.40 Mayr’s interest in both the ecological risks and research opportunities of the proposed waterway spoke to the spectrum of positions among the biologists who would play major roles in the sea- level canal story.
Mayr had an important informant who helped shape his thoughts about the sea- level canal—his recent graduate student Ira Rubinoff. During visits to the CZBA in 1961 and 1962, Rubinoff had begun collecting and breeding fish from
the Caribbean and Pacific coasts to delineate evolutionary divergence in species separated by the isthmus. Conducting such research in the Canal Zone entailed unusual occupational hazards, from having to pass checkpoints manned by surly sentries to missing optimal tides due to the lack of gas stations that serviced military vehicles on weekends.41 But the Canal Zone provided protection and amenities for North American and European researchers, and the efforts to ex-pand the CZBA paid off in 1965, when Moynihan secured leases with the U.S.
military for two Atlantic and Pacific marine stations, the Smithsonian hired Rubinoff as assistant director for marine biology, and Congress raised the appro-priation from the original $10,000 to $350,000.42 Ripley announced the name change to Smithsonian Tropical Research Institute (STRI) the following year.43 As STRI’s marine director, Rubinoff provided an energetic on- the- ground com-plement to the D.C.- based Smithsonian campaign of Ripley, Wallen, and As-sistant Secretary for Science Sidney Galler, a former Office of Naval Research biologist.
In July 1965, Rubinoff published the first article on the sea- level canal’s poten-tial nonradiological effects, the Natural History essay that likely caught Irwin’s attention.44 Several outcomes seemed possible, including large- scale extinctions, as suggested by principles of ecology and genetics, morphological comparisons of Caribbean and Pacific shore fishes, and historical human- facilitated intro-ductions of organisms to new areas. Dutch elm disease and the Australian rabbit invasion were infamous in the annals of pest outbreaks; other cases like the canal- facilitated migration of voracious Atlantic sea lampreys into the U.S.
Great Lakes were less well known but equally devastating to local ecosystems and fishing- based communities. Rubinoff assured readers that the sea- level canal would “not provide every species with a free pass to a new ocean.” But why leave anything to chance? A strategic research program such as that of the Interna-tional Indian Ocean Expedition, one of several large- scale geophysical initiatives of the Cold War era, would begin to demystify the uncertain effects of marine faunal mixing.45