Shifting Baseline Syndrome
Daniel Pauly, fisheries scientist, 1995, in a one-page essay for Trends in Ecology and Evolution: “Each generation of fisheries scientists accepts as a baseline the stock size and species composition that occurred at the beginning of their careers.”
The editor needed a one-page filler. Pauly gave them what became one of his most-cited papers — no numbers, no equations, just an observation about collective amnesia.
The mechanism: fisheries scientists studying cod in the 1990s compared stocks to the 1960s peak. But the 1960s were already depleted compared to pre-industrial levels. A recent study reconstructed 1,100 years of Atlantic cod fishing and found Viking-era cod were 25% larger and lived three times longer than today’s fish.
Each generation’s “normal” is the previous generation’s decline.
Older Caribbean divers describe reefs that exploded with color, fish so dense they blocked the sun. Today’s certified divers explore the same coordinates and see scattered formations. Both think they’re seeing “a coral reef.” One witnessed an underwater metropolis. The other is swimming through its ruins.
Younger fishers in the Caribbean perceive less species decline than older ones. They mention fewer fish species as depleted. Their reference point started lower.
The syndrome extends beyond ecology:
Cities: Each generation accepts traffic congestion, noise pollution, and the absence of public space as baseline urban conditions. The generation that remembered walkable cities before cars dies out.
Work: Expectations of availability — checking email at night, responding on weekends — ratchet upward. What felt intrusive a decade ago feels normal now.
Politics: What was radical becomes moderate. What was moderate becomes conservative. The Overton window shifts, and the shift is invisible to those inside it.
Conservation targets aimed at returning Caribbean reefs to 1970s conditions ignore that 1970s reefs were already severely degraded from pre-1900 baselines. The goal is to restore a ruin to a slightly less ruined state.
Memory is infrastructure. What we remember constrains what we fight for. What we’ve forgotten, we can’t miss.