Miami-Dade’s annual Biscayne Bay Report Card revealed a bay still in distress, with slight improvements in the bay waters off Coconut Grove.
The results are in: This year’s Biscayne Bay Report Card shows Coconut Grove’s coastal water quality has taken a turn for the better.
With improvements in four of the seven indicators, it may be a small sign of hope for the Grove, despite poor results for many other areas in the bay.
“If the data is reflecting an improvement, then yeah, that’s definitely something to be happy about,” said Adriana González Fernández, science and research director at Miami Waterkeeper.
The 2025 report card, overseen by the Miami-Dade County’s Division of Environmental Resources Management (DERM), evaluates the bay on two main components – water quality and aquatic habitat.
For purposes of the report, the bay is divided into 12 distinct regions. Each receives an overall “stoplight” score – red for “poor,” yellow for “fair,” and green for “good” – as well as a water-quality rating and individual scores for bacteria, algae, nutrients, sea grass and sponges.
For the first time since 2022, the portion of the bay that laps Coconut Grove (described as North Central Inshore or NCI) received a “good” rating for water quality, after being stuck in the middle ground for years.
The positive rating is a reflection of several key changes.
Nitrogen levels in the region dropped to the lowest rate since the report card started. Nitrogen is one of the two nutrients responsible for algae blooms and fish kills, the other being phosphorus. On both fronts, bay waters near the Grove were rated as “good.”
González Fernández said this improvement may reflect the impact of the county’s fertilizer ordinance, which prohibits the use of nutrient-rich fertilizer during South Florida’s rainy season to prevent contaminated runoff.
But with other factors in play – including septic-to-sewer conversions, more green infrastructure to absorb runoff and growing environmental awareness, González Fernández said it’s difficult to pinpoint a single reason for the overall improvement.
“There are so many different little components,” she said.
The results for two other water-quality measurements in the Grove region were mixed. The bay’s water clarity – which describes how turbid or clear the water is – improved to “good” while chlorophyll – an indicator of algae levels – remained “poor.”
On the habitat side, bay waters along the Grove shoreline worsened significantly.
The number of sponges dropped dramatically, while seagrass levels remained stagnant, the report found. These two organisms help to filter the water, provide oxygen, serve as a source of food and create habitat for marine animals.
These habitat setbacks kept the portion of the bay closest to Coconut Grove out of the top spot for the best overall health in the bay.
That honor went to the coastal waters around the mouth of the Miami River and south along the Brickell waterfront. That region was tinted green for “good” while the waters to the south in Coconut Grove and Coral Gables were coded yellow for “fair.”
Although any improvement in water quality is welcome, the results of this year’s report card don’t necessarily reflect a true sign of progress for bay waters in the Grove.
The region’s indicators have fluctuated regularly over the years. Water quality, for instance, previously reached a “good” status, but was “poor” the year before, and “fair” the year after.
And even if the Grove continues in a positive trend, like the neighboring Brickell region, it doesn’t guarantee the rest of the bay is following suit.
“Biscayne Bay is still struggling to improve in water quality, but the Coconut Grove area is seeing slight improvements in several parameters,” Rachel Silverstein, the CEO of Miami Waterkeeper, told the Spotlight.
“However, the real test will be steady improvements over several years. Miami still has a lot of work to do on reducing the main pollution sources affecting the Bay, including septic tanks, sewage leaks, and stormwater runoff,” she added.
Of the bay’s 12 regions – each of which has its own monitoring stations – only three were rated “good” for water quality.
It’s a concerning, but not shocking result. No region of the bay has received an overall rating of “good” since the program began, with the exception of the waters off Brickell’s shoreline.
While the results continue to disappoint, new programs are a source of hope for water-quality activists.
These include the county’s “impervious surface” ordinance that took effect in March 2025 with new rules that seek to minimize runoff by limited hard surfaces such as concrete sidewalks that prevent rainfall from being absorbed into the ground.
The county is also working on the “reasonable assurance plan,” an overarching framework that will set goals for Biscayne Bay and fund projects to meet those goals.
The impacts of this legislation will likely take years to determine.
“We have to be patient, because it will take a long time to actually see that improvement, sometimes reflected in the report card,” González Fernández said.
