Arctic Research Ogotoruk Creek

In 1957, the US Atomic Energy Commission established the Plowshare Program and gave it the task of exploring peaceful uses of atomic energy. One proposed project, Project Chariot, was to use an atomic explosion to construct a harbor on the Chukchi Sea coast at the mouth of Ogotoruk Creek (68.06° N 165.46° W) on Cape Thompson, Alaska. In preparation for this exercise in "geographical engineering," the environment of Cape Thompson was thoroughly studied from 1959 to 1961. Project Chariot was abandoned, but the reports of the ecological studies stand as models of excellence in Arctic research. Cape Thompson, a typical expression of Arctic tundra, lies to the west of the DeLong Mountains that, save for some low hills fronting the ocean, are the most westerly expression of the Brooks Range. There are numerous temporary and permanent ponds, a few lakes and streams, and several brackish lagoons. The freshwater habitats (including some brackish waters) yielded 708 different kinds (but generally low numbers) of algae (desmids, diatoms, blue-green algae, and others) and many species of zooplankton.

Zoologists at the University of Wisconsin have conducted laboratory experiments showing that selected pharmaceuticals used in human and veterinary medicine, when applied alone or in combination, sometimes cause deleterious effects in populations of Daphnia magna, an important link in freshwater food webs. D. magna was not found at Cape Thompson, but D. middendorffiana and D. pulex were present, along with many other species of crustacean zooplankters, including 14 species of Cladocera and 38 species of Copepoda (some collected from brackish waters).

Several kinds of aquatic plants were taken from tundra ponds and their margins, including common marestail (Hippuris vulgaris), several members of the buttercup family (Ranunculus spp.), boreal bur-reed (Sparganium hyperboreum), marsh cinquefoil (Potentilla palustris), water sedge, pendant grass (Arctophila fulva), marsh marigold (Caltha palus-tris), and two kinds of pondweeds (Potamogeton pectinalis, P. filiformis). The lowest temperature recorded during the Ogotoruk Valley studies was -42°C. Most tundra and taiga locations around the world would experience long periods of winter temperatures in this order of magnitude. When exposed to such low temperatures, most bodies of water would readily freeze to some depth and most would stay frozen throughout the winter, but wide variations from this basic theme would be expected because of the general North-South average winter temperature gradient—lowest in the High Arctic, but less severe the farther south, because of the influence of relatively warm ocean currents and/or warm winds from the tropics in some localities, and because of local geothermal inputs (Iceland immediately comes to mind because of its remarkably abundant geothermal resources). In the vicinity of Pt Barrow, shallow ponds (1.7-2 m) freeze solid, but in deeper ponds, a few inches/cm of bottom water usually remain unfrozen. Probably some benthic organisms remain active in this ice-free zone all through the winter.

Water samples from Ogotoruk Creek and four shallow ponds ranged in pH from 5.8 to 7.7. Pond water temperatures were essentially comparable to the ambient air temperatures, usually in the low 10°C in the summer but subject to wide fluctuations from hour to hour. Creek water temperatures registered only a degree or two below that of the ponds at the same hour. Generally, ponds less than 1 m deep were most productive, with one such pond containing in excess of 38,000 benthic organisms per square meter (90% of these were midges, Chironomidae)—deeper Arctic lakes tend to be much less productive. Other invertebrates, such as planaria (Turbellaria), worms (Nematoda, Oligochaeta, Polychaeta), water bears (Tardigrada), rotifers (Rotifera), circumpolar fairy shrimp, antlered fairy shrimp (Branchinecta hazeni) and other Crustacea, beetles (Coleoptera), caddisfly larvae, stonefly larvae and pea mussels (Pisidium sp.), were collected from ponds. Only a few fish (Arctic char, Salvelinus alpinus; usually inhabit lakes in Alaska) were found in Ogotoruk Creek, but invertebrates, such as planarians, oligochaete worms, and immature stages of black flies, midges, mayflies (Ephemeroptera), stoneflies, and caddisflies, were often collected.

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