American eels are born in the Sargasso Sea. In the mid-Atlantic Ocean, thousands or millions of eels convene and copulate, only here. It is impossible to raise eels in aquatic farms, the way we harvest some species of fish and shrimp. Each spring, the sea spawns thousands of tiny pseudo-transparent bodies, "glass eels." Clear with the exception of a black spine and black eyes, the form adapts to life and predation in the ocean. From the Sargasso Sea, the bodies ride the currents of the Gulf Stream up into freshwater tributaries, into the Hudson River, into Tivoli Bays.

Along the way, over time, the eels of glass grow to be several inches long-too small to be earthworms, too large to be parasites. In the freshwater rivers of the east coast, the eels begin to consume aquatic insects and dead organic matter, sacrificing the previous diet of plankton. Growing, no longer needing the same innate protection, the skin of the eels loses its clear pigment and takes on a brownish hue. Their name changes from glass to elvers.

Eel populations have been in decline over the years, and nobody knows why. Some say global climate change and shifting ocean patterns. Others say overfishing and dam construction. Some compromise and say both. Aiming to study eel migration patterns, the New York Department of Environmental Conservation has a collaborative study between scientists, students, and community volunteers to collect data on glass eels along the Hudson River tributaries. Along the way, the study gives its members experience in science, rivers, ecosystems. It is both research and pedagogy.

Today I caught seventeen glass eels. Our hands reached into the black and green fyke net to rummage for a glimpse of crystalline white. The mesh net is large, and was placed south of the small waterfall leading into the Bay. It captures the tiny bodies that attempt to swim upstream as they migrate. It is one o'clock in the afternoon and the tide is still low. Our hands are covered in invertebrates-they look like small alien shrimp. In the net are hundreds of them, crawling upon one another. As we reach in, they envelop our hands, scuttling in an attempt to move and escape. From the yellow-brown pulsing mass comes brief flashes of white amongst the bland color palette.

Amongst these masses, our hands grasp the minute eels between our fingers. A bucket filled with a few inches of bay-water becomes a temporary home for the seventeen. Our hands thrust down into the low-tide water of the Bay to wash of the excess bodies that stubbornly cling. The glass eels spasm amongst one another. I can't decide which is stranger, the feeling of a dozen invertebrates in one's hand, or a living squirming eel, nearly invisible.

Throughout the day I feel the pinch and scuttle of invertebrates and eels. I am in class, typing in the lab, eating with a fork and knife. The creatures are not there anymore, now swimming upstream again along the waters of the Bay, visible in their absence.