Biology Reference
In-Depth Information
Low-tide habitats at the Palo Alto baylands. (Jude Stalker)
tory of Human Changes”). Development reduced open waters by 50 per-
cent and wetlands by 80 percent, and urbanized 50 percent of the sur-
rounding uplands.
The Marine Nursery
Like all good parents, aquatic organisms seek to give their young the most
advantageous upbringing they can. The bay's many amenities make it an
appealing site for marine species to rear their young. Gentle waves, a con-
sistent supply of food, turbid waters that offer cover from predators, and
warmer waters than the open ocean make the bay a nurturing environ-
ment for many kinds of helpless juveniles.
Some marine species, like herring, lay their eggs in the bay itself. But
many others reproduce in the rich coastal waters just outside the Golden
Gate. The majority breed in winter, when upwelling is at its weakest and
less likely to carry young away from the shore. When spring arrives, up-
welling produces plentiful food for their tiny offspring.
Species such as flatfish and Dungeness Crab travel into the bay during
early life stages and remain to mature. Breeding out in the ocean, their
parents strive to deposit eggs near enough to the coast for hatchlings to
