Tag Archives: WATER YEARS.

A Tough Year for Everglades’ Nesting Birds

Abandoned stork nests, Jetport S colony, WCA 3A, as presented 5-11-23 SFWMD GB

Today I am going to put aside the St. Lucie Canal to discuss another very important subject, the birds of the Everglades. Since the late 1800s drainage, farming, and development  has drastically altered the avian environment. As we try to restore what we can, each year the SFWMD reports on nesting outcomes in SFER or the “South Florida Environmental Report.” This is done in “Water Years” that run from May 1 of one year to April 30th of the next.

At the May 11th, 2023 meeting of the South Florida Water Management District, I asked a question to presenter Lawrence Glenn about the “Ecological Conditions Update.” Mr. Glenn was explaining sensitivity to water/food levels and why it had been observed that hundreds to thousands of wood storks and white ibis in Water Conservation Area 3-A of the Everglades had evacuated their nests abandoning their young.

Mr. Glenn’s chart specifically focused on wood storks (WOST) and white ibis (WHIB).  I inquired about other birds nesting in the Everglades. Mr. Glenn explained that for purposes of this scientific report wood storks and white ibis were the sentinel species.

~Note the decline of these species nests below below.

On May 24, 2023, about two weeks after the governing board meeting, I received an email in response to my question from SFWMD avian expert Dr. Mark Cook.  I had had the pleasure of meeting and flying with Dr. Cook in a rare banner-nesting year, in 2021. Dr. Cook who oversees the SFER nesting bird reports gave an in depth explanation to my question about “other birds,” and how the science works. Thank you to the SFWMD and Dr. Cook for allowing me to reprint below. I wanted to share it with you!

Wood storks, roseate spoonbills, white ibis, courtesy SFWMD

 

Subject: Following up on your question about nesting in the Everglades (May GB)

 

Good morning, Ms. Thurlow-Lippisch.  At the May Governing Board Meeting you asked Lawrence Glenn if there were other types of birds nesting in the Everglades aside from white ibis and wood storks.  Dr. Mark Cook has responded to your question (below).

 

Yes, we have about 14 species of wading birds nesting in the Everglades, all of which are monitored to some degree for the wading bird report.

 

However, there are four species that are used specifically as indicator species to gage restoration success of the freshwater Everglades and to help guide water management: white ibis, wood storks, snowy egrets and great egrets. Multiple aspects of their reproduction are monitored including nesting effort, timing of nesting, location of nesting and reproductive success (numbers of offspring produced per nest). Of these four species, the stork and ibis are particularly useful for understanding the health of the everglades because they are tactile foragers (feed by touch) meaning they need higher densities of prey to feed effectively compared to the visually feeding egrets and in turn their nesting patterns are highly dependent on getting the water right – the right amount of water at the right time and place. Historical hydrological conditions were particularly conducive to successful nesting of these two species. A good example of this was the relatively wetter conditions on the coastal marshes and western prairie marshes in Everglades National Park that promoted good prey production and allow for early nesting of storks and massive super colonies of white ibis in the coastal colonies.

 

For Florida Bay we have a single indicator species, the roseate spoonbill. This pink beauty is also a tactile forager and as such is highly sensitive to hydrological conditions within the coastal marshes of eastern Florida Bay. This species was almost exclusively restricted to nesting and foraging in Florida Bay but within the past decade it has moved inland to the freshwater Everglades probably because sea level rise has increased water levels in the coastal foraging areas. This species is generally doing poorly in the bay but relatively well in the freshwater Everglades.

 

As predicted given the relatively dry antecedent conditions, this nesting season has not been a great year for the five indicator species. Nesting effort (numbers of nests) was about average but nest success has ben very low for all species except perhaps the snowy egret. White Ibis and great Egrets started abandoning nests in March-April probably because prey was limited in the Everglades after last year’s extensive drying of WCA-3A. In addition, extensive rain-driven reversals (loss of concentrated prey) in April finished off many of the remaining ibis and egret nests and led to the complete abandonment of wood stork nests in WCA-3A and significantly reduced their nests in ENP. Surprisingly, snowy egrets seem to be doing quite well, possibly because they are feeding in the STAs or elsewhere. My colleagues from University of Florida, who monitor nesting on the ground, have reported very poor growth rates of nestling and high levels of starvation in all species except snowy egrets. Nesting data are currently being processed and will be available as soon as possible.

Roseate spoonbills, courtesy SFWMD
Group shot, SFWMD
Great Egret, SFWMD
Snowy egret, Audubon

 

 

 

Color-coded Nutrient Pollution Maps Shine the Light! LakeO/SLE

I have been wanting to write about these water quality maps for months. Now that I am at home, social distancing, due to the coronavirus pandemic, I have no excuse. So today, we begin.

Some history: about six months ago my brother, Todd Thurlow and Dr Gary Goforth started collaborating to create nutrient pollution color coded maps. The data is compiled by Dr Gary Goforth via South Florida Water Management District’s DBHydro water quality database; and the graphics are generated by Todd. All of these computer generated images can be found on my brother’s website, eyeonlakeo. This is a site you are probably familiar with as it led the charge on Harmful Algal Bloom Lake O satellite imagery before that went public in 2018. My goal is to do the same with these maps. In time, have them “go public.” The form this data exists in the District’s reports today is very sophisticated and thus confusing for the general public. With help from Gary, Todd, and a former eighth grade teacher, (me) it doesn’t have to be!

So let’s start with overview color. Basically, any color other than green is a flashing light, especially orange-red, or dark russet! 

When looking at these maps, one must keep in mind that the map is in WATER YEARS. A water year begins on May 1 of a year and goes through the following year ending April 30th. The above map labeled “Lake Okeechobee Watershed Total Phosphorus Concentrations,” is Water Year 2019. (May1, 2018 – April30, 2019.)

Next, one must learn to think in terms of SUBWATERSHEDS and BASINS. The image above is for the entire 3.4-million acre watershed of Lake Okeechobee, and is broken into sub-watersheds and basins from large to small based on the way the water “flows” or used to. The sub watersheds are identified in bold in the table to the left and the basins are listed below.

The colors on the map are shown by scale at the bottom from green to dark red. You don’t have to be a genius to see that for instance S-154 Basin is one of the darkest color reds with a concentration of 857 “µg/L” (microgram per liter, commonly expressed as “parts per billion”, or “ppb”). In 2001, the State of Florida established a Target for the average phosphorus concentration in water entering Lake Okeechobee of about 40 ppb, so this basin’s concentration of 857 ppb is 21.4 times the Target concentration for the Lake; hence this basin has a “Target Multiple” shown in the table of 21.4.  

The color coding gives you a quick and easy way to identify which basins are close to the target (green basins) and which basins need a lot of improvement in their non-point source controls (red basins).  For a more quantitative assessment, you can check out the  “” values in the table for each basin.  It’s important to remember that while concentrations are very important to identify which basins need additional non-point source controls, such as farming or urban best management practices (BMPs), the “load” entering the lake from each basin is also important.  We’ll talk about loads in a future blog. Now let’s take a look above at map number two, the “St Lucie Estuary and Watershed Total Nitrogen Concentrations” map.   Nitrogen is the other important nutrient besides phosphorus that affects our water quality, including algae blooms.  Since we already know now how to interpret the color coding, we can easily see that the Tidal Basins – the largely urban areas around the estuary – has the lowest nitrogen concentration, i.e., the Tidal Basins has the best nitrogen water quality.  The Tidal Basin had a concentration of 824 ppb, and with a Target Multiple of 1.1 this concentration is still about 10% higher than the Target set by the State of 720 ppb.  So while this basin has the best nitrogen levels in the watershed, it still has some improvements to make in order to meet the nitrogen Target.  By contrast, Lake Okeechobee discharges, and runoff from the C-23 and C-24 basins are the darkest red and therefore have the poorest water quality, with nitrogen concentrations about 2 times the Target.    The orange to red colors for these and the C-44 and Ten Mile Creek basins indicate these basins need to implement considerably more effective source controls in order to meet the Target for the Estuary.

Todd’s website and Gary’s (http://garygoforth.net/Other%20projects.htm) show phosphorus and nitrogen maps for the Lake and St. Lucie Estuary watersheds.  They are working on maps for the Caloosahatchee River and Estuary Watershed.

In closing, these powerful visual maps give us the ability to easily “see” where the greatest problems of nutrient runoff are located; the nutrients come from many sources, including urban and agricultural activities, e.g., fertilizer application. And although the numbers and colors don’t tell us exactly where this pollution is coming from, we can determine it is problematic in the designated basins.

That’s enough for our first day. Hope it was a good one!