Exotic species are, by definition, organisms that have moved beyond their natural geographical range either via human
induced, accidental, or purposeful introductions. Invasive species are known to have a negative impact on the ecosystem
of a particular habitat or another species. Some of these foreign invaders come to our shores as seeds adrift in the
ocean. Additionally, cargo ship bilges introduce invasive marine species and new invasive species are still arriving
today. The threats invasive species pose to biodiversity and natural ecosystem function translate directly into negative
economic consequences through crop failures, forest loss and negative effects on fisheries. The Exotic Pest Plant Council
lists several species found within the BBAP, including Australian pine (Casuarina ssp.), Brazilian pepper
(Schinus teribinthifolius) and seaside mahoe (Thespia populnea). Both Miami-Dade County Department of
Natural Resource Management and Parks and Recreation Department crews have worked for decades to remove these plants from
the shoreline of Biscayne Bay and to replace them with native species.
Several exotic marine animals have been documented within Biscayne Bay. These include a species of blue crab native to
South America and several mollusk species. Several fish were introduced into marine waters of Biscayne Bay, in 1992 as a
result of Hurricane Andrew. One of the largest problem species introduced to Biscayne Bay and surrounding waters is the
Indo-Pacific red lionfish (Pterois volitans). Biscayne Bay is vulnerable to many exotic introductions because it
is home to The Port of Miami with interoceanic cargo and cruise vessels. Ballast water is collected in the hull of the
vessel to add to stability then released in other parts of the ocean. This water can transport a variety of species and
introduce exotic species that have a planktonic life stage.
Green (Iguana iguana), black spinytail (Ctenosuara similis), and Mexican spinytail (Ctenosaura
pectinata) iguanas are three exotic species with established breeding populations on lands adjacent to BBAP.
Green iguanas are native to neotropics, but since 1966, have been found on Key Biscayne and in other urban areas in
south Florida (Dalrymple, 1994). This species is extremely popular in the pet trade and is frequently escapes or is
released. In January 2010, many iguanas died off due to three consecutive days below freezing and were reported to
freeze and fall out of trees, due to the abnormal temperatures. Extreme weather conditions, such as this, help to
reduce the number of all invasive or exotic species in south Florida.
Photo: Joe Marino