Summary from our conversation with Joe Smith (the fish prophet)

  1. Alien species…also known as exotic, invasive, non-native, non-indigenous
  2. Predators can be keystone species and have large ecosystem impacts through interactions. For examples, predators can lead to having more diverse species assemblages by opening up space, etc…
  3. ┬áThe Red Queen Hypothesis: an evolutionary arms race…where predator and prey are constantly co-evolving (e.g. bat and sonar-jamming moths)
  4. Sacramento/San Jaquin so important socially as it supplies water for agriculture and major population centers in cities such as LA, San Diego, Fresno, etc… Area where over 50% of all produce grown in CA. Water is political!
  5. California gripped in drought. Water withdrawls, land-use change all interact with climate change.
  6. Extremely low survival of smolt emigration (0-1%) through the delta and past the Golden Gate bridge
  7. It is not clear what proportion of juvenile mortality can be attributed to predation.  Main bad guys, stripped bass, largemouth bass, and two species of catfish (white and channel).
  8. Stripped bass move far more than any other predator (largemouth most sedentary and catfish intermediate in movement)
  9. Highest proportion of stomachs with Chinook in stomachs was channel catfish…a bit of a surprising result given the expectation that stripped bass were presumed to be the top predator. However…the the abundance of stripped bass is much higher so can have a more impact on the total salmon consumed
  10. The faster the water moves the higher change of predation…at least as recorded from the Predation Event Recorders
  11. The native predator community would have looked dramatically different prior to modification to the Sac Delta

Leave a Reply

Your email address will not be published. Required fields are marked *