Jurassic Wildlife and a Secret River

At GRID-Arendal, the Marine Environment programme works with cross-cutting marine challenges, such as ecosystem functioning, nature-based solutions, carbon storage in marine ecosystems and the development of a sustainable blue economy. To support the management and protection of important wetland ecosystems like mangrove forests, it is important to recognize the multiple benefits these ecosystems support. These benefits can include ecotourism, food security, fish and wildlife habitats, and coastal protection. 

Steven Lutz, Senior Programme Officer and Blue Carbon Lead, is advancing the concept of Blue Carbon through the UN Environment Blue Forests Project (Blue Forests Project | GRID-Arendal (grida.no), which explores how countries can harness the value of carbon sequestration to support mangrove conservation while fulfilling pledges mitigate climate change. Here, he shares a recent experience in rediscovering a mangrove trail in Key Biscayne, Miami.

During my first visit to the park, I searched for the entrance to the old trail. Walking up and down the boundary of kept, green grounds of the park, I made multiple forays into the brush. After an hour with palm fronds in my face, I finally located the trail entrance, much overgrown and partially blocked, at one corner of the park grounds. I couldn’t venture much further on this visit as it was high tide, and the salt water from Biscayne Bay comes quite far into the mangrove forest, almost to the edges of the park grounds.

I returned later, a bit more prepared, with drinking water, a baseball hat, shorts, sandals, and lots of mosquito repellant sprayed on myself and my long sleeve shirt. The covered brush entrance of the trail opened into a more accessible area, fringed by thicker mangroves, which was underwater on my first visit. In my childhood, this first open area was completely exposed to the sky, and I remember many fiddler crabs scuttling in the mangrove mud. Now it is partially overgrown with mangrove roots snaking across. Breaking to the right, a dirt berm appeared – the mangrove trail had been found!

The berm is part of the remains of the largest coconut plantation in the United States and dredged spoils for coastal development planned before the area was set aside for conservation in the 1940’s – a paradise for nature was preserved, but the property developers’ dreams were not dashed due to a causeway linking the island to the mainland. Making my way along the berm I remembered to pick up a fallen stick and wave it in front of me as moved forward. This prevents you from getting a face full of spiders and their webs. About midway on the trail, I found the ‘secret river’, a dredged area with current still flowing in and out of the bay. Many fish swam among the mangrove roots, which serve as vital habitat for many commercially and recreationally important fish species.

In my youth we could easily walk all the way to Biscayne Bay and find horseshoe crab shells. During this trip, I believe I made it about two-thirds down the trail before it started to become impassable. With a lineage stretching as far as 480 million years ago, horseshoe crabs are Key Biscayne’s most ancient residents. Hopefully I can meet them again on my next trip re-exploring the Calusa Park Mangrove Trail.

The conservation of mangroves is recognized by the United Nations Intergovernmental Panel on Climate Change as an important nature-based solution for mitigating the impact of climate change. The Key Biscayne Village Council is currently considering potential park expansions, including a nature trail. Perhaps a fully restored mangrove trail will help visitors realize how these marvelous mangroves support us locally and help address the threat of climate change globally.