Times of the Islands Winter 2023/24

green pages newsletter of the department of environment & coastal resources
Their population explodes. In the absence of competitors,
and with no marine predators, they abandon their
troglodytic (cave-dwelling) ways and forage the sunlit
fields of phytoplankton in broad daylight. Another pond
has become refuge to a single species of jellyfish. The
enigmatic, “upside down jellyfish” has adopted the lifestyle
of a plant, tentacles up, harvesting sunlight just as
their distant coral relatives do with the same symbiotic
algae living within their tissues.
In North Caicos’ Cottage Pond, a favorite with visitors
to the Islands, the pond is deep, cavern fed, and supports
a substantial body of fresh water riding over the deeper,
anaerobic layer of salt water. Snorkeling Cottage Pond, we
discovered an incredibly simple world with one species of
freshwater algae (Chara) and in the complete absence of
fish, a population explosion of the endearing water bug,
(Notonecta), a “back-swimmer.” This insect’s only concern
seems to be a single pair of diving grebes. Cottage Pond
is another example of a “species jackpot,” an anchialine
Garden of Eden in which some lucky creature escapes the
pressures of a more complex environment.
It should be noted (and perhaps come as no surprise)
that the greatest threats these endearing “orphaned
oceans” face, each with their one-of-a-kind experiment
in marine colonization, are man-made. Development
without thoughtful planning can compromise not only
the pond communities, but the subterranean network
of caverns that serve as their circulatory system—their
gills. Heavy equipment and incautious excavation near
such fragile wonders can (and has) accidentally collapsed
the caverns, severing their circulation with the sea. Even
visiting them, one hopes to observe without impact. My
team covers our skin with fabric, not sun lotion or insect
repellent, recognizing that in close quarters, our very
presence constitutes a bio-hazard. With respect, we hope
to continue exploring and documenting this enchanting
anchialine archipelago. a
Professor Cole teaches and conducts research with undergraduates
at St. Olaf College in Northfield, Minnesota.
During business hours, he conducts research into cellular
and developmental Biology, but moonlights as an
explorer of the natural history of marine habitats. One
can visit his website (always woefully under-constructed)
at: https://pages.stolaf.edu/colee/.
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