Zero to three meters below sea
level – this was the elevation I listed as I filled in my third field notebook
entry. For the first time this semester, we swapped out our boots, field
clothing, insect repellent and notebooks, and were instead armed with flippers,
snorkels, life-jackets and a nifty little PVC cuff that we could write on
underwater. Given that we have spent the majority of time in terrestrial
environments, this change was naturally welcomed. Additionally, it didn’t hurt
that we could collect an additional stamp in our passport since we were headed
out of the country into neighboring Panama.
Growing up in the fringes of the
coral triangle region in South East Asia, I have always been intrigued and
amazed by the diversity of the coral reef ecosystem and had a relatively good
understanding of them. I knew that they generally grew in shallower waters due
to their need of sunlight but was surprised to learn that herbivory played a
huge role in determining the health of the coral reef ecosystem. This idea of
top down control through herbivory was far from my expectations given that
plants do not form the bulk of the biomass in the coral reef ecosystem.
However, a series of lectures with guest faculty Andy Shantz as well as a
faculty led project on the topic of herbivory levels in reefs slowly shed light
on how herbivory shapes the coral reef ecosystem. By controlling the growth of
algae, another light loving organism, herbivores ensure that there is
sufficient real estate for corals to grow and receive sunlight that they
require for photosynthesis. In that regard, herbivores act as gardeners,
pruning and removing “weedy” species within the reef. Interestingly, each
herbivore “prunes” the coral reef in a unique way due to the various types of
feeding apparatus they possess. For example, sea urchins possess unique mouth
parts comprising of five sharp blades, known as Aristotle’s lantern, which
leads them to feed on different algal communities compared to parrotfishes who
feed with beaks instead. As such, having a diversity of herbivores on the reef
is important in controlling different algal communities to maintain coral diversity.
Beyond understanding the ecological
concepts of bottom-up and top-down control of ecosystems, my biggest takeaway from
our time spent at Bocas del Toro is that we need to constantly improve our
understanding of ecosystems in order to apply suitable conservation and
management decisions. During our lecture on ecological traps, it was disheartening
to learn that some well-intentioned biodiversity management actions had
backfired and led to population declines, putting some species at a greater
risk of local extinction. These examples only serve to show that while we
continue to brainstorm and roll out initiatives to protect wildlife, it is
imperative for us to be proactive in research concerning animal behavior and
the ecology of the habitats they live in. Only by doing so can we make well
informed management decisions that serve to promote the protect of
biodiversity.
Donovan Loh
Duke University
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