Peru is in deep shit. No, seriously: thanks to an exceptionally dry climate, islands off the Peruvian coast are awash in preserved bird guano, which the country has long exported as non-chemical fertilizer. But while 60 million seabirds were pooping on Peru in the 19th century, the birds now number 4 million; with synthetic-fertilizer costs and interest in organic food rising, the Peruvian government is concerned that guano supply will be depleted by high demand. Guano collection has been restricted to two islands per year, lizards have been introduced to eat seabird-bothering ticks, and armed guards have been posted to ward off threats to birds. But guano preservationists despair of keeping commercial fisherfolk from depleting the anchoveta, a fish that’s both the seabirds’ favorite food and in high demand for factory-farm-bound fishmeal. Without fishing restrictions, biologists estimate that the anchoveta, the seabirds, and the guano could be gone by 2030.