November SPEAKER: WHAT LIES BENEATH – THE SECRET SAUCE OF SEAGRASS
DR. RACHEL HARRIS,
DR. MADDISON MELCHIONNA and
SARAH MARMION
Seagrass by Benjamin L. Jones at projectseagrass.org
Bring a friend and join SFDI for an unforgettable evening of discovery beneath the water!
Join SFDI Wednesday, November 4th for an exciting Evening!
What makes some seagrass meadows thrive while others struggle? Join SFDI on Wednesday, November 4th, as we explore the hidden world of tiny organisms that live alongside seagrass and may help these important underwater plants to stay healthy and resilient. Two Palm Beach Atlantic University professors and a local conservation leader will share with us a behind-the-scenes look at research being conducted in conjunction with Friends of Manatee Lagoon. Researchers are comparing healthy and stressed seagrass from the Loxahatchee River and Lake Worth Lagoon, as well as seagrass grown in nursery settings, to better understand what helps these plants survive and flourish. We will discover how this work could lead to better restoration strategies and give transplanted seagrass a stronger chance to thrive throughout South Florida.
ABOUT DR. RACHEL HARRIS
Dr. Rachel J. Harris is an Assistant Professor of Biology and Oceanography at Palm Beach Atlantic University (PBA), specializing in coastal and estuarine ecology with a focus on habitat dynamics and environmental stressors. She earned her B.A. in Psychology with a minor in Environmental Studies from Florida Atlantic University, an M.Sc. in Environmental Science from Florida Gulf Coast University, and a Ph.D. from the University of Waikato, New Zealand.
Dr. Harris’s research examines how environmental stressors—including eutrophication (when mineral and nutrient rich water cause excessive plant and algae growth), contamination, and water quality degradation—affect the structure and function of critical coastal habitats.
She has published in over 17 international, peer-reviewed scientific journals, with work emphasizing biotic–abiotic interactions in estuarine systems, the fate of contaminants in shallow benthic environments, and the resilience and restoration of marine habitats.
Her applied research has included extensive work in South Florida, where she investigated seagrass health and water quality in the Jupiter region, Florida’s West Coast, and the Florida Keys. Through this work, she has helped advance strategies for habitat restoration and the management of stress impacts on coastal ecosystems.
At PBA, Dr. Harris teaches biology as well as marine and environmental sciences, while continuing to pursue research on coastal habitat resilience, restoration ecology, and the responses of mangrove, seagrass, and sponge systems to stress.
ABOUT DR. MADDISON MELCHIONNA
Dr. Maddison Melchionna is an Assistant Professor of Biology at PBA, specializing in Microbiology and Molecular Biology. She earned a B.S. in Biology with a minor in Chemistry from The University of Tennessee (UT)-Chattanooga and a Ph.D. in Biochemistry, Cellular, and Molecular Biology from UT-Knoxville. Dr. Melchionna’s research investigates the molecular mechanisms that bacteria use to sense and respond to environmental stress. Her work combines genetic, biochemical, and biophysical tools to understand how cells achieve membrane homeostasis in changing environments. At PBA, Dr. Melchionna integrates this research into her upper-level Molecular and Microbiology laboratory courses, providing undergraduates with unique opportunities in experimental design, critical thinking, and scientific inquiry.
ABOUT SARAH MARMION
Sarah Marmion is the executive director of Friends of Manatee Lagoon, an independent nonprofit that raises resources to advance environmental education, conservation, and community engagement. FOML funds exhibits, events, research programs, and outreach -- both at Manatee Lagoon, An FPL Eco-Discovery Center and throughout the region. The nonprofit’s initiatives are designed to protect manatees and their habitats, restore critical seagrass ecosystems, and inspire public action for Lake Worth Lagoon's marine life. Sarah recently retired from FPL where she led the company’s education programs throughout the state, focusing on K-12 STEM and workforce development. She also helped design and open FPL’s Manatee Lagoon center, running it for the first six years of its operation, and she has watched it become one of the most popular environmental education centers in SE Florida.
October SPEAKER: WRECK DIVER EXTRAORDINAIRE
JOHN CHATTERTON
Discovery of 17th century pirate ship - the Golden FLeece
JOHN CHATTERTON
Bring a friend and join SFDI for an unforgettable evening of discovery beneath the waves!
Join SFDI Wednesday, October 7th for an exciting Evening!
Come and join South Florida Divers on Wednesday October 7th, as we meet and hear from wreck diver, technical diving instructor, commercial diver, explorer, and television host John Chatterton, who will discuss wreck salvage work in the Dominican Republic and the discovery of the 17th century pirate ship The Golden Fleece. He will also focus on some of the highlights of his amazing career. This presentation will be in person.
ABOUT JOHN CHATTERTON
ABOUT JOHN CHATTERTON
bio from johnchatterton.comJohn Chatterton has been teaching divers since 1986 and currently offers TDI/SDI training in advanced wreck, decompression, trimix, and technical diving. His background includes twenty years as a commercial diver in and around New York City, extensive deep wreck exploration, cave diving, rebreather diving, and trimix diving to depths deeper than 500 feet. He is also certified to pilot the Kittredge K250 submarine.
In 1991, John was part of the discovery and identification of the German submarine U-869 off the coast of New Jersey. The story was featured in the NOVA documentary Hitler’s Lost Sub and later became the subject of Rob Kurson’s bestselling book Shadow Divers.
John co-hosted 57 episodes of the History Channel’s Deep Sea Detectivesand has worked as a consultant for major film and television studios. More recently, he appeared on the History Channel’s The Curse of Oak Island, participating in multiple episodes involving complex underwater search and investigation work.
In 2005, John and his partners organized an expedition to Titanic, diving the wreck to approximately 12,500 feet in MIR submersibles from the Russian Research Ship Keldysh. Their work was featured in History Channel specials including Titanic’s Final Moments – Missing Pieces and Titanic’s Achilles Heel.
Today, John lives in Brandon, Florida and trains technical divers in several locations, including Pompano Beach, Florida. His courses draw directly from decades of exploration, commercial diving, and expedition experience, giving students a practical foundation for advanced wreck and technical diving.
September SPEAKER: Sharks of the Great White North
Dr. Chris Harvey-Clark, B.Sc., DVM
Why Are Great White Sharks Thriving in Maritime Canada?
Dr. Chris Harvey-Clark, B.Sc., DVM
Bring a friend and join SFDI for an unforgettable evening of discovery beneath the waves!
Join SFDI Wednesday, September 2nd for an exciting Evening!
SFDI is honored to welcome internationally recognized shark researcher, scientific diver, filmmaker, and educator Dr. Chris Harvey-Clark to our September 2 club meeting.
Great white sharks are making an extraordinary comeback in the cold waters of Atlantic Canada—but why? Drawing upon decades of scientific diving, cutting-edge telemetry, and firsthand underwater observations, Dr. Harvey-Clark will explain the remarkable recovery of these apex predators and what it means for divers, marine ecosystems, and future conservation efforts.
Featured on Discovery Channel's Shark Week in 2024 and 2025, Dr. Harvey-Clark combines compelling storytelling, world-class photography, and groundbreaking science into a presentation that is both educational and entertaining. Whether you're passionate about sharks, underwater photography, marine biology, or simply enjoy hearing from leading explorers, this is a program you won't want to miss.
Great White North
Dr. Chris Harvey-Clark, B.Sc., DVM
ABOUT Dr. Chris Harvey-Clark, B.Sc., DVM
Dr. Chris Harvey-Clark is Professor Emeritus and former University Director of Animal Care at Dalhousie University in Halifax, Nova Scotia. For more than thirty years he has conducted pioneering research on Greenland sharks, great white sharks, Atlantic torpedo rays, and other marine wildlife, authoring more than 40 scientific publications and book chapters.
An accomplished scientific diver with over 3,000 dives since 1976, he has achieved numerous underwater firsts in Canada, including documenting basking shark mating behavior, filming mako sharks underwater, pioneering underwater studies of Greenland sharks, and documenting great white sharks underwater in Canadian waters.
Beyond science, Dr. Harvey-Clark is an award-winning underwater filmmaker and photographer whose work has appeared in more than 50 marine documentaries, including Sharkwater, River Monsters, Discovery Channel Shark Week, BBC, CBC, History Channel, and the National Film Board of Canada. He is also the author of the respected marine life guides Eastern Tidepool and Reef and Maritime Marine Life.
His unique blend of scientific expertise, exploration, and visual storytelling has made him one of Canada's most respected voices in shark research and marine conservation.
AUGUST SPEAKER: A Deep Dive into Diving Fatalities
Dr. Craig nelson - science behind diving fatality investigations
Dr. Craig Nelson
This program offers a rare behind-the-scenes look at the science of diving fatality investigations and provides valuable knowledge for every diver committed to making the sport safer.
Join SFDI Wednesday, August 5 for an Extraordinary Evening with Dr. Craig Nelson.
What really happens when a diving fatality is investigated? When news of a diving accident spreads, online discussion forums quickly fill with rumors, speculation, and theories—but they rarely provide the facts.
Our club is honored to welcome Dr. Craig Nelson, a long-time diver and forensic pathologist in Raleigh, North Carolina. He will take us beyond the rumors and into the science behind diving fatality investigations.
In this presentation, Dr. Craig Nelson will explain how diving fatalities are investigated, how forensic pathologists determine the cause and contributing factors of a fatal dive, and how those findings are used to improve diver safety. Drawing on his unique background as both an accomplished diver and practicing forensic pathologist, he will share real-world insights into accident investigation, the role of the medical examiner, and how lessons learned from these tragedies contribute to safer diving through the work of Divers Alert Network (DAN).
Dr. Craig Nelson - Deep Dive on accident investigation
Dr. Craig Nelson
ABOUT Dr. Craig Nelson
Dr. Craig Nelson is a practicing forensic pathologist with the North Carolina Office of the Chief Medical Examiner in Raleigh. His career represents a rare combination of elite diving experience and forensic medical expertise, making him uniquely qualified to interpret the circumstances surrounding diving fatalities and the lessons they hold for improving diver safety.
A lifelong diver, Dr. Nelson was first certified in 1989 and became a diving instructor in 1996. That same year, he earned the prestigious Rolex Our World-Underwater Scholarship, spending the following year traveling the world exploring professional careers in diving. His work with Lifeguard Systems in New York teaching underwater body recovery and water rescue ultimately inspired his pursuit of forensic pathology.
After earning his medical degree from Wake Forest University School of Medicine, Dr. Nelson completed his pathology residency at the University of Arizona and a fellowship in forensic pathology at the San Diego County Medical Examiner's Office. Following more than five years as a Deputy Medical Examiner in San Diego, he returned to North Carolina in 2014, where he continues to serve as a forensic pathologist.
Throughout his medical career, Dr. Nelson has remained active in the diving community as a member of public safety dive teams, combining his passion for diving with his forensic expertise. His work has also included conducting diving fatality reviews for Divers Alert Network (DAN), helping advance diver safety through careful scientific investigation and analysis.