B is for Biscayne

Tim Iverson
Naturalist

(12/2020) Throughout winter many people’s thoughts are turned toward snowscapes and ice-kissed imagery. However, if you need a break or a change of scenery, Biscayne National Park is a veritable watery wonderland. Located on the outskirts of metropolitan Miami, Florida is a 173,000 acre natural marine oasis. Only 5% of the park is dry land so if you want to see the other 95% you’ll have to dive down into the shallow aquamarine waters.

Just below the surface you will find manatees and sea turtles grazing among verdant beds of sea-grass, the world’s third largest coral reef adorned with an array of colorful fish, and hidden treasures among sunken ruins alluding to the rich human history above the blue. Between 10,000 years of human history and four distinct ecosystems, the diversity found within this park both above and below the surface of the water is unparalleled.

Along the shoreline, among the tangled roots of the mangrove trees the lazily lapping waves find their terminus. The impenetrable knot of roots reaching up from the water just along the shoreline provides much more than a wavebreak. Mangrove trees slow the freshwater flow from the land into the bay keeping the salinity balance in check for a clean brackish water estuary. The densely jumbled roots provide shelter and a nursery for both commercial and endangered species alike. As the emerald mangrove leaves fall into the nursery below they break down becoming food for the tiny organisms nestled within the safety of the root system.

Away from the shoreline and protective shelter of the mangroves the park extends outward to Biscayne Bay. On a tranquil day it appears as if the sky melts into the sea as the sun skips across the horizon. Hidden within the lush seagrasses below the surface are countless species of fish, crustaceans, turtles, manatees, and more. These seagrass meadows are critically important to the overall health and ecology of the bay. As the fresh water flows bring nutrients from inland areas the grasses photosynthesize the light of the Florida sun turning both into valuable food sources while stabilizing the water quality. This shallow estuary is one of the most productive ecosystems in the park.

A little further out, small islands begin rising from the water. These are the beginning of the Florida Keys and they buttress Biscayne Bay from the Atlantic Ocean just beyond. Like pearls on a string, approximately 40 keys extend in a north-south line about 8 miles from the mainland. The islands provide crucial habitat for the endangered Schaus’ Swallowtail and Miami Blue butterflies. The islands also bear witness to the human history that has occurred within the park. The Tequesta Indians had extensive hunting and fishing camps throughout the islands. Mid-century pioneers farmed, fished, and salvaged what they could from shipwrecks on the nearby coral reefs. Today, modern history features wealthy Miami elites building private party compounds, complete with ornamental lighthouses.

As the island shore slips below the surface, the land gradually descends further into the Atlantic away from metropolitan Miami towards an undersea city. Beyond the barrier islands forming the edge of Biscayne Bay are the coral tracts that form the northern edge of the Florida Reef system. Coral reefs are the most biologically diverse ecosystems on earth, with seemingly every square inch inhabited or occupied. The park is home to over 500 species of fish, each featuring a unique array of colors, shapes, and sizes. Fluorescent neons zoom past as an olive drab Moray Eel slinks back into its lair, while purple fans sway in the current surrounded by the colony.

Polyps are tiny coral animals that form the backbone of the community. They get calcium from the seawater and inturn use it to build cup-like exoskeletons to protect themselves. Generation after generation of these polyps consistently build up and create colonies. Colonies can form a variety of shapes, appearing as antlers, flowers, mounds, or other abstract designs. In the end, they collectively create the infrastructure the rest of the ecosystem lives and depends upon. Like reef systems across the globe, the Florida Reef system faces existential threats. Documented declines in overall fish species and bleaching are taking their toll on a fragile and taxed system. Warming ocean temperatures, an imbalance in water salinity, and the regularly recurring problems of "Red Tide," or algae blooms in Florida’s waters are damaging the reefs. However, the conservation status as a National Park offers some protections which creates an environment that experiences fewer negative impact than reefs outside of park boundaries.

Biscayne National Park is rich with natural and biological resources, but it’s also full of historical and cultural resources as well. Throughout the course of history there has been a parade of people leaving their mark on the landscape. 10,000 years ago the water level was considerably lower than present day. Approximately 4,500 years ago the seas began to rise and the bay was flooded, submerging the archaeological sites that are now frozen in time standing silent witness to the Tequesta and Glades people who inhabited these areas. As the Europeans began exploring these areas, their ships braved these shallow and treacherous waters. Many succumbed to shallow reef impacts, while others were brought down by pirates and privateers. Like a snapshot in time these underwater wrecks also provide a stationary window to the people who occupied this place in time.

A quirky village of elevated platform houses, known as Stiltsville, was erected in the 1930’s to avoid Prohibition Era alcohol constraints. Today only seven of the original 30 elevated structures remain. As time marched forward wealthy industrialists and land developers of the early to mid-20th century built private and exclusive party encampments on the islands now contained in the park. The non-functioning ornamental lighthouse found on Boca Chita Key, the unofficial symbol of Biscayne National Park, is a remnant of this bygone era and the elite Cocolobo Club - which attracted Presidents Hoover, Kennedy, Johnson, and Nixon at various times in their lives.

Both above and below the aquamarine water Biscayne National Park is a testament to the diversity of the natural, cultural, and historic resources found there. From the shoreline, in the shade of the mangrove trees, you can look out across the bay reflecting the pillowy clouds overhead and wonder where the sky ends and the sea begins. Interconnected ecosystems mix together creating a dazzling dance of colors and rhythms between the corals, keys, undersea grasses, and trees. While adjacent to one of the largest cities in the United States Biscayne National Park seems worlds away from the bustle of neighboring Miami.