Hidden Ecological Functions and Ecological Hysteresis

BatfishThe paper by coral reef researchers Bellwood, Hughes, & Hoey, Sleeping functional group drives coral-reef recovery in Current Biology (2006 16(24):2434 -9) shows that hidden ecological functions can be critical for ecological restoration and provides further evidence for the importance of hysteresis in ecological regime shifts.

The researchers were examining the frequently observed shift of coral reefs from being dominated coral to macroalgae. This change is often due to the overharvesting of herbivorous fishes, particularly parrotfishes and surgeonfishes, that maintain the coral regime. They showed that a shift to the marcoalgae dominated regime on the Australian Great Barrier Reef was reversed not by parrotfishes or surgeonfishes, but rather by a species of batfish, Platax pinnatus, which is relatively rare on the Great Barrier Reef, and was thought to feed only on invertebrates.

Their finding suggests three things:

  1. that conserving ecosystem functioning is important for both for the maintenance and recovery of ecosystems,
  2. that successful functional conservation requires that we need to greatly increase our functional understanding of ecosystems, and
  3. that research into ecosystem functioning should examine function in different ecological contexts.

Interestingly, this research finding is similar to that of common property researchers who have discovered that many local resource management institutions contain “hidden” resources management practices, that are only activated during special environmental conditions – for example a fishery may have alternative property rights emerge during periods low fish abundance.

Press coverage of this research can be found in a press release from James Cook University, the New Scientist, and the Washington Post.

One thought on “Hidden Ecological Functions and Ecological Hysteresis”

  1. Interesting piece. I’d argue that while the piece shows that an inverebrate feeder may in some cases be more important than some herbivores in the system (a key habitat engineer, as it were), that rather than arguing against management for diversity, if anything, it shows that diversity can be of key importance as it is important to maintain all functional guilds. Who knows what hidden direct or indirect intereactions may be due to the actions of one particular guild or species.

    I think Bellwood said it best in the Post piece.

    “This study shows that fishes can have unexpected roles…Just because we don’t know their roles at the moment doesn’t mean it is safe to remove them.”

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