News
Untreated sewage and fertilizer runoff threaten the Florida manatee’s main food source, contributing to malnutrition
Aarin-Conrad Allen, Florida International University
The gentle, slow-moving Florida manatee has no natural predators.
And yet, these charismatic mammals face numerous threats.
Manatees are struck by vessels in busy waterways across the state, and a majority bear scars from these collisions.
Harmful algal blooms – characterized by the rapid growth of algae that degrades water quality – can impair their nervous systems.
With less blubber, or fat, compared with other marine mammals like whales, dolphins, seals and sea lions, manatees are vulnerable to cold-stress syndrome during winter months.
And they can ingest or get entangled in marine debris like derelict fishing gear and drown or be crushed by floodgate and water control structures.
I am a doctoral candidate in marine biology at Florida International University’s Institute of Environment. Over the past 15 years, I have gained extensive experience working with marine mammals, particularly manatees.
Recently, my colleagues at the United States Geological Survey, Florida Department of Environmental Protection and I documented a change in the dietary pattern of manatees. We found that manatees are eating less seagrass – traditionally their primary food source – and more algae than in decades past. This change occurred along Florida’s Atlantic coast during a period of extensive seagrass decline.
We believe this represents an emerging threat to the species’ survival.
Protected species
Manatees were listed as an endangered species under the Endangered Species Act of 1973. By the early 1990s, the manatee population in Florida had dwindled to less than 1,300.
Researchers believe that federal protection, along with additional state measures such as slow-speed zones and no-entry refuges, has contributed to the growth of the manatee population in Florida.
In 2017, manatees were reclassified from endangered to threatened. Surveyors counted 5,733 individual manatees during a statewide aerial survey conducted in 2019.
Florida manatees average 9-12 feet (2.7-3.7 meters) in length and typically weigh about 1,000 pounds (450 kilograms), but they can grow as large as 3,500 pounds (1,600 kilograms). As the largest fully aquatic herbivore, they consume 5% to 10% of their body weight in vegetation each day.
While manatees eat a broad diet of over 60 different plants, they most commonly feed on species of seagrass. Seagrasses are marine plants that, like land plants, have leaves, flowers, roots and seeds, and make their food through photosynthesis.
So what happens when these seagrasses are no longer available?
A changing estuary
The Indian River Lagoon is an estuary along Florida’s east coast that covers roughly 350 square miles (560 square kilometers) between the mainland and barrier islands, from Ponce Inlet to Jupiter Inlet.
It is a critical habitat for manatees, which feed on native seagrass meadows in the lagoon during their seasonal migrations.
Seagrasses are vital to the health of marine ecosystems. They are a habitat for juvenile fish and other marine organisms, provide food for aquatic herbivores, reduce carbon in the atmosphere and improve water quality. They also protect coastal habitats by stabilizing sediments and reducing wave energy that can erode shorelines and damage coastal infrastructure, especially during hurricanes.
For more than a decade, the Indian River Lagoon has experienced extensive loss of seagrass meadows, due to a series of algae blooms associated with nutrient runoff and degraded water quality from septic overflow leaching into the environment.
When untreated sewage and fertilizers flow into the estuary, they add nitrogen, phosphorus and other nutrients that drive excessive algal growth. These harmful algal blooms deplete oxygen levels and block sunlight, which seagrass needs for photosynthesis.
Between 2011 and 2019, over 50% of all seagrass in the lagoon was lost. This led to an increase in macroalgae and even led to a change in the animal communities that live in the lagoon. For example, among finfish, sheepshead populations declined, while seabream numbers increased. Invertebrate communities were also affected, with bryozoans colonizing areas previously dominated by barnacles.
Manatees along the Atlantic coast have suffered two unusual mortality events since the seagrass decline, including one that is ongoing. Researchers attribute the increase in manatee deaths to malnutrition due to a shortage of seagrasses in the Indian River Lagoon.
A shift in manatees’ diet
In our study, we examined 193 manatee stomach samples collected from carcasses recovered from the Indian River Lagoon during two time periods – one before and one after the onset of the seagrass loss in 2011.
We compared stomach sample contents from carcasses collected between 1977 and 1989 with samples collected between 2013 and 2015.
Our findings indicate that manatees consumed 45% less seagrass and 74% more algae after the seagrass decline.
Recently, in a study supported by FIU’s Center for Aquatic Chemistry and Environment, I investigated differences in the nutritional composition – like protein, fat, carbohydrate and fiber – of items identified in manatee stomach samples. My preliminary results show notable differences in the nutritional composition of seagrass and algae.
Marine mammals are particularly vulnerable to dietary shifts due to their large size and high energy demands. Such changes can worsen their physical health and increase the likelihood of starvation.
Depleted oxygen levels are having a similar impact on aquatic vegetation and seagrass meadows in other regions of Florida, like Biscayne Bay and the Caloosahatchee River and Estuary. This suggests that the ecological challenges seen in the Indian River Lagoon could become more widespread.
What is the solution?
Remediation efforts within the lagoon have incorporated the restoration of seagrass through aquaculture and replanting strategies, similar to efforts to restore coral reefs.
While the lagoon’s seagrass has recently shown signs of regrowth, the rehabilitation of the ecosystem must begin with improving and maintaining water quality.
Counties along the lagoon have enacted fertilizer bans that aim to reduce the levels of nitrogen and phosphorus in the water that drive algal blooms.
New research, however, indicates that these restrictions alone will not fix the problem, as residential septic systems are the primary source of nutrient pollution in the lagoon.
Furthermore, many of the factors contributing to harmful algal blooms are intensified by global warming and changing climate, which could accelerate the decline of seagrass in Florida and elsewhere.
Given the multiple, synergistic threats facing manatees, I believe that improving water quality, protecting their food sources, and further research – coupled with community outreach and education – are critical to ensure the long-term survival of this iconic Florida species.
Aarin-Conrad Allen, Ph.D. Candidate in Marine Sciences, Florida International University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Last Updated on November 13, 2026 by Daily News Staff
STM Daily News | November 12, 2026
Graffiti Cleanup Transforms Oceanwide Plaza
LOS ANGELES — The unfinished skyscrapers known as downtown Los Angeles’ “Graffiti Towers” have reached a visible milestone: most of the exterior tagging has been removed, although completing the long-stalled Oceanwide Plaza development remains a separate challenge.
City officials celebrated the cleanup November 12. According to the mayor’s office, crews cleared graffiti from roughly 250 balconies across the three-tower complex opposite Crypto.com Arena and near the Los Angeles Convention Center. Remaining work has included touch-ups on windows and other exterior areas.
Oceanwide Plaza was envisioned as a mixed-use destination with residences, a luxury hotel, shops and restaurants. Construction stopped in 2019 after Beijing-based developer Oceanwide Holdings could no longer finance the project.
In early 2024, trespassers covered the unfinished towers with graffiti, turning them into an internationally recognized sight. The property also attracted dangerous stunts and heightened concerns about security.
The development entered bankruptcy in February 2024. This July, a bankruptcy court approved a purchase arrangement involving KPC Square, a joint venture between KPC Group and Lendlease. Graffiti removal began while the acquisition was still pending.
What Comes Next for LA’s Graffiti Towers?
The partnership is targeting a January 2027 closing, according to the Los Angeles Business Journal. Financing, a construction contract and required approvals remain important steps before the development can be completed.
For downtown residents and businesses, the cleanup marks tangible progress at a prominent property. However, it does not mean the towers are ready to open, and no firm opening date has been announced.
Sources
- Los Angeles Mayor’s Office, November 12, 2026: https://mayor.lacity.gov/news/mayor-bass-celebrates-graffiti-removal-oceanwide-plaza-clearing-way-full-restoration-and
- Los Angeles Business Journal, November 9, 2026: https://labusinessjournal.com/real-estate/cleaning-up-oceanwide/
- City News Service / MyNewsLA, November 12, 2026: https://mynewsla.com/life/2026/11/12/graffiti-cleanup-milestone-marked-at-oceanwide-plaza-in-downtown-la/
Forgotten Genius Fridays
David Crosthwait: The Engineer Behind Indoor Comfort
David Crosthwait helped solve the challenges of heating large buildings, including Radio City Music Hall. Explore his inventions and lasting engineering legacy.
Forgotten Genius | STM Daily News
When audiences enter New York’s Radio City Music Hall, they notice the stage, the lights, and the sweeping auditorium. The engineering that keeps the building comfortable rarely receives applause.
One of the people behind that comfort was David Nelson Crosthwait Jr., a Black engineer and inventor whose work helped advance heating, ventilation, and temperature control in large buildings.
His career offers a reminder that some of the most useful inventions work quietly around us.
Solving the Problem of Heating Large Buildings
Heating a large building takes more than producing enough heat. Different areas can have different needs: one side may face bitter wind while another receives warming sunlight. Delivering the right amount of heat throughout the building requires careful control.
Crosthwait devoted much of his career to those challenges. A Purdue University engineering graduate, he worked for the C.A. Dunham Company, developing equipment and systems for heating and ventilation.
His inventions included improvements to boilers, thermostat controls, and vacuum pumps. These components helped engineers manage the movement and regulation of heat in larger buildings.
One example appears in U.S. Patent No. 1,727,965, granted in 1929. The patent describes a vacuum steam-heating system designed to serve different sections of a building at different steam pressures. That allowed the system to address varying heating needs while using a shared steam source.
Behind the technical drawing was a practical question: How could one building provide comfortable conditions in spaces that needed different amounts of heat?
His Connection to Radio City Music Hall
Crosthwait’s best-known projects included designing the steam-heating system for Radio City Music Hall at Rockefeller Center.
It was a fitting assignment for an engineer whose expertise centered on the demands of large buildings. While performers entertained audiences, the systems behind the scenes helped make the experience comfortable.
His contributions extended across a substantial body of work. The National Inventors Hall of Fame credits him with 39 U.S. patents and 80 international patents, spanning heating, refrigeration, controls, and other technologies.
Sharing Knowledge and Breaking Barriers
Crosthwait also helped other engineers learn. He wrote technical material, contributed to engineering guides, and later taught steam-heating theory and control systems at Purdue.
In 1971, he became the first Black Fellow of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Purdue awarded him an honorary doctorate in 1975, and the National Inventors Hall of Fame inducted him in 2014.
His legacy rests in the practical details of engineering: controlling pressure, improving equipment, and making complicated systems work together.
The next time you settle into a comfortable auditorium on a cold evening, consider the ingenuity behind that warmth. David Crosthwait helped make indoor comfort an engineering achievement worth remembering.
Discover more inventors and innovators through the Forgotten Genius series in The Knowledge at STM Daily News.
Related Links
- National Inventors Hall of Fame: David Crosthwait — Biography covering his inventions, patent totals, Radio City Music Hall work, teaching, and professional honors.
- Rockefeller Center: A Rock Center Innovator — Highlights his role in designing Radio City Music Hall’s steam-heating system.
- Original 1929 Patent: U.S. Patent No. 1,727,965 — Technical drawings and Crosthwait’s description of a steam-heating system serving different building sections at different pressures.
- Purdue University Libraries: Historical Timeline — Documents his 1913 graduation and contributions to heating, ventilation, and air conditioning.
Sources: National Inventors Hall of Fame, Rockefeller Center, Purdue University Libraries, and U.S. Patent No. 1,727,965.
Family
The House That Hosts: When Your Home Becomes Your Holiday Entertaining Partner
The House That Hosts: There’s a special pleasure in opening your home for the holidays to share the menu you’ve imagined, welcome guests to the glow of a room ready for company and enjoy the anticipation of familiar faces at the door. This year, make sure the house itself can lend a hand.
The House That Hosts: When Your Home Becomes Your Holiday Entertaining Partner
(Feature Impact) There’s a special pleasure in opening your home for the holidays to share the menu you’ve imagined, welcome guests to the glow of a room ready for company and enjoy the anticipation of familiar faces at the door. Every detail is an opportunity to make the loved ones you’ve invited feel especially welcome.
This year, make sure the house itself can lend a hand.
From the kitchen to the living room to the guest bathroom, residential technology offers new ways to turn a host’s imagination into a memorable experience. The best innovations don’t take over the occasion. They help the person bringing everyone together make it extraordinary.
Nor does a home need an elaborate network of connected gadgets. A few well-chosen technologies can make a difference. Explore these ideas from the bathroom design and technology experts at TOTO to level up the different hosting areas of your home as you prepare to gather with family and friends this holiday season.
The Kitchen: Bringing Something Extraordinary to the Table
The holidays invite a little culinary ambition, and today’s kitchens are borrowing a few tricks from professional chefs.
Imagine presenting a beef tenderloin cooked to a perfect rosy pink from edge to edge, thanks to the precision of sous vide cooking. Or bringing a platter of roasted root vegetables to the table, their edges beautifully caramelized and their centers tender, prepared in a steam-convection oven. On an induction cooktop, precise, responsive heat helps turn fresh mushrooms into a golden, savory accompaniment.
These technologies put sophisticated techniques within reach of adventurous home cooks, opening the door to new preparations and dishes worthy of special occasions. Experiment with new flavors and rich cuisines that fill your home with enticing aromas and your guests with awe at the first bite.
Nothing says “happy holidays” quite like watching guests discover what you’ve created for them.
The Living Area: Setting the Stage for Connection
Holiday gatherings have a rhythm all their own. The first arrivals are greeted with excitement, conversations pick up where they left off months (or years) prior, and before long, the room is filled with laughter and the pleasure of being together.
Today’s smart lighting systems allow hosts to create and schedule scenes that shift from the sparkle of a festive welcome to the softer, golden glow of an intimate evening. Multiroom wireless audio systems can bring lively music into the kitchen while keeping it a gentle accompaniment to conversation in the living area. Digital art displays can turn a television screen into a gallery of artwork chosen to complement the celebration, bringing holidays past to life as loved ones mingle in the present.
Successful holiday entertainment engages people not merely as observers, but participants. A short film could start an inspiring conversation, the right music might get people dancing and atmospheric visual-audio experiences, like a crackling fireplace or soft snowstorm, can create a relaxing seasonal backdrop for shared activities.
With the atmosphere changing quietly in the background, no one needs to interrupt a favorite story to adjust the lights or lower the music. The host can simply enjoy the company they’ve brought together.
The Bathroom: The Art of Personal Comfort
The most gracious hosts think beyond the rooms where guests gather. Fresh towels, fragrant soaps and a few unexpected comforts can make the guest bathroom feel every bit as welcoming as the rest of the home.
Technology adds a new dimension to that hospitality. Consider a TOTO WASHLET bidet seat, which offers the welcome warmth of a heated seat, the refreshing pleasure of warm-water cleansing and the soothing comfort of warm-air drying. It’s an unexpected luxury that makes an everyday experience feel special.
Hosts can choose an option that complements their home’s character. The S2 offers inviting simplicity with convenient side-panel controls. The sleek S5 pairs contemporary elegance with a wireless remote. Meanwhile, the S7A adds a touch of theater with a lid that opens automatically, a softly glowing nightlight and personalized cleansing settings.
Even the housekeeping benefits from a little ingenuity through automatic PREMIST and EWATER+: One mists the toilet bowl before use to help keep it cleaner, while the other cleans the cleansing wand and, on select models, the bowl itself with electrolyzed water.
It’s another way a thoughtful host can anticipate guests’ needs and make them feel wonderfully welcome.
Long after the last guest has departed, what lingers isn’t the sophistication of the house. It’s the meal that inspired compliments, the conversations no one wanted to end and the little surprises that made everyone feel at home.
Those are the moments that make holiday entertaining special. Behind each one is a host whose warmth, creativity and attention to detail made it possible, with a little help from the house. Explore more sophisticated bathroom upgrade ideas for the holidays and beyond at TOTOUSA.com.
Photo courtesy of Shutterstock (holiday table)
SOURCE:
TOTO
