The purpose of this post is to continue to share the slides of the late Fred van Vonno. I presented charts and aerials yesterday in Loxahatchee Lesson 4. Tomorrow, or later today, I will add structures and people. Today we share my favorite, Loxahatchee Flora and Fauna as well as River Scenes. If you recognize anything interesting let us know! My mother noticed what appears to be old world climbing fern slide #7. A terrible invasive plant that costs millions of dollars for the State of Florida to manage.
Thank you to my mother for archiving these photos that were once slides in Mr van Vonno’s 1980s slide shows. Thank you to our friend, Nicki van Vonno for sharing her husband’s work.
SLIDES RELATING TO THE LOXAHATCHEE RIVER
Removed from a slide carousel used by Fred van Vonno who was a Planner (GS-11) from June 1978 until 1982 for the Department of Interior National Park Service, Regional Office in Atlanta, Ga. His work involved assessing the “recreational potential of rivers and trails.” The slides were used for presentations when van Vanno was the Study Coordinator for the Loxahatchee and Myakka Wild and Scenic River studies. It is a good idea to make sure these photographs are documented because some of the photos are more than 40 years old. I would think they would have been taken around 1980.
Recently a gigantic swath of dead mangroves, east of the Indian River Lagoon on Hutchinson Island in Jensen Beach was brought to my attention. About a year ago, I had noticed the dead forest of trees; however, with my full attention on toxic-algae, water-quality, or lack thereof, I had put this graveyard of walking trees out of my mind. Until I got a phone call a couple of days ago…
My contact, as many others, proposes fundamental changes, such as culverts or another small inlet between the barrier island and the IRL to allow more flushing and increase salinity, pointed out that the primary reason the mangrove forest died, post Hurricane Irma, was too much fresh water. He also noted that the toxic-algae, as bad as it is, is not the worst killer for our St Lucie River. The worst killer is an old enemy: too much fresh water from Lake Okeechobee and area canals. The fluorescent toxic algae has just “put a face” on the carrier, the real enemy, too much fresh water.
The St Lucie is an estuary (https://oceanservice.noaa.gov/facts/estuary.html) and needs salt water to exist, also the microcystin toxin cannot survive in a brackish system. The constant discharges, from Lake Okeechobee especially, continually push fresh water through a once brackish system, poisoning it, and toxic algae is along for the ride…
I found this message a powerful tool in visualizing what has happened to our St Lucie River. The dead mangroves are indeed a metaphor for the entire St Lucie River/Indian River Lagoon system: our lush seagrass beds have died and the water quality is terrible, leaving little or no wildlife.
We must remember, below our waters, too much fresh water has caused a dead forest too.
Below, I am including Martin County’s response to my inquiry about the dead mangrove forest as a matter of public interest and education.
This loss of mangroves at the JBI site prompted a serious investigation by the Mosquito Control and Environmental Resources Divisions. Given the large-scale mortality event, testing was conducted to rule out site contamination. Water quality testing was also conducted to determine dissolved oxygen, pH, salinity, and hydrogen sulfide levels. The Florida Department of Environmental Protection, St. Johns Water Management District, Smithsonian, a local mangrove arborist and Ecological Associates Inc. were all consulted regarding concerns over the mangroves. The majority opinion was that heavy late season rain and high water levels were the primary cause of the mangrove mortality with hurricane stress and suspended solids associated with storm surge as secondary causes. Additionally, lack of species and age structure diversity contributed to the loss, more diverse communities are associated with greater resiliency. Areas in close proximity to the JBI show evidence of mortality caused by ‘ponding’ in which high freshwater levels result in the loss of vegetation.
Recommendations going forward are to improve hydrological connectivity through the installation of additional culverts, clear out channel sedimentation, and install spillways. These actions will improve water quality by allowing for more exchange with the IRL and also increase the discharge capacity of the south cell to prevent high water levels associated with heavy rain and storm surge. In order to accomplish these actions, a capital improvement plan for the site was tentatively approved by the board on April 10th, 2018. Additional funding opportunities will be sought for site improvements and the board granted permission on July 24th, 2018 for staff to pursue State Wildlife Grant funding from the Florida Fish and Wildlife Commission.
While funding opportunities are being sought, in-house activities have been pursued. Specifically, staff gauges have been installed to monitor natural tide conditions to allow for careful water level monitoring. The Project Engineer from Field Operations has put together a conceptual plan. A failed culvert is in the process of being replaced. Blockages along the perimeter have been identified and several have been cleared. Transects are being put in for vegetative monitoring. New growth can be seen within the JBI site, however, this is primarily restricted to the areas in closest proximity to the IRL. Culverts are currently opened to allow for natural recruitment and mosquito control is being accomplished through alternative means to allow the area to reseed.
Let me know if you would like to meet to discuss this.
Terry B. Rauth, P.E., Public Works Director, Martin County Board of County Commissioners
One of the first things I learned about the Indian River Lagoon and St Lucie River as a kid at the Environmental Studies Center and later at Florida Oceanographic was mangroves. Red mangroves had cool arch like roots; white mangrove had a notch on the leaf and a salty back; and black mangrove had weird breathing sucker roots coming out of the ground around the tree and were sometimes very large. http://www.floridaocean.org/uploads/docs/blocks/22/irl-mangroves.pdf
I also remember walking with my parents along the beach of Jupiter Island and there were gigantic halloween like remnants of a black mangrove forest coming out of the eroding sands. I also remember the closed off mosquito impoundments around today’s Marriott, Indian River Plantation, and A1A, along the ocean, drowning the mangroves, many white, and black, that looked like giant dead sentinels, somehow still alive, watching us over-kill our environment and all the little misquitoes.
And today, yes, it seems the red mangrove, more than the others, flourishes. Interestingly enough, before the St Lucie Inlet was opened by hand in 1892, there were not many mangroves along the St Lucie River as it was fresh. But close to the ocean, along parts of the Indian River Lagoon, there was brackish water and there were mangroves.
My historian mother recently told me she attended a lecture of fish scientist, Dr. Grant Gilmore, and he was of the opinion we needed to create, restore more wetlands and fewer mangroves (as they were destroyed by mosquito impoundments) as the wading birds and many fish rely on this habitat, not just mangrove habitat.
In closing this short reminiscent piece, one other thing I remember about being a kid growing up in Martin County is the mosquitos! They were brutal at certain times of the year. We would run in place at the bus stop so they couldn’t get us, and my little legs were always full of bites and scars. I also remember riding our bikes behind the mosquito fogger truck for entertainment…(so that’s what happened!)
Remembering it all, I can empathize why we went to war with the mosquitos, but if we went too far, let’s take a clear-headed walk through the mangroves, and see what we can do…