Excerpt from The Great Blue Hole
Rebecca Sparling
"The poor water circulation inside most blue holes
makes them anoxic. This means that oxygen levels
are extremely low at certain depths. The
unfavorable environment makes it difficult for
marine plants and animals to survive, but large numbers of bacteria seem to
flourish in these holes. Some divers claim to spot the occasional shark in the
deeper parts of the hole where the water is much clearer. Explorers and
scientists believe that a series of underwater tunnels might connect the hole
to the mainland. The hazards of exploring such a network make this theory
difficult to verify
According to section four of this passage, bacteria flourish inside the Great Blue
Hole. From this information you can tell that
the Great Blue Hole is polluted
bacteria thrive in deeper waters
bacteria are not well understood
bacteria need little oxygen to survive