OPINION · SEE-THE-SEA.COM
What I’ve Seen Change in 30 Years Underwater
A diver’s witness account — from the Philippines in 1990 to Bonaire today
By Denny Frazier · June 2026
On the left is a healthy staghorn coral at Lac Bay, which was transplanted from the Reef Renewal of Bonaire nursery eight years ago. Right: the coral barren that dominates most of Bonaire’s west coast sandy shoals from 7 feet to 30 feet of depth. Losses occurred in the 1990’s and have not natural recovered Source: Denny Frazier
San Fernando, La Unión — 1990
I was thirty-something and newly certified, slipping into the warm blue water off San Fernando, La Union in the northern Philippines for one of my first open-water dives. The reef was extraordinary — chaotic and alive in the way reefs were before I had a baseline for comparison. I didn’t know yet what I was supposed to be looking at. I only knew I had never seen anything like it.
Then I felt it.
A pressure wave moved through the water — not a current, not a surge. A concussion. Somewhere above the surface, out of sight, fishermen were using dynamite. The shockwave reached me at depth before any sound did. I felt it move through my chest. I looked at my dive buddy. We both knew what it was.
Blast fishing — illegal, widespread, devastatingly effective. A single charge kills everything in a radius of hundreds of feet: the target fish that float to the surface, and everything else that doesn’t. The coral, the invertebrates, the juveniles, the nursery habitat. Gone in a fraction of a second. What takes centuries to build can be unmade before you finish exhaling.
I came up from that dive changed. Not dramatically — I didn’t give a speech or start an organization. I just understood, for the first time, that what I was looking at was fragile in ways I hadn’t imagined. That it required protection.
“A pressure wave moved through the water — not a current, not a surge. A concussion. I felt it in my chest before I heard it.”
What the Ocean Has Lost Since Then
I’ve been diving off and on for 35 years now. The Philippines. The Caribbean. The Indo-Pacific. Bonaire more times than I can count. And the single most consistent observation across every ocean I’ve entered is this: there is less. Less coral. Fewer fish. Smaller fish. Less color. Less noise — and a healthy reef is loud, the constant crackle of shrimp and parrotfish a kind of underwater static that tells you everything is working.
The Caribbean has been hit from every direction at once, and the cumulative toll is staggering.
In the 1980s, a mysterious pathogen wiped out the long-spined sea urchin — Diadema antillarum — across virtually the entire Caribbean. It was the largest mass mortality of a marine animal ever recorded. Diadema are the reef’s lawnmowers; they graze the algae that would otherwise smother coral. With them gone, algae won. Four decades later, populations have still not recovered. The reef, denied its natural grazer, has been fighting algae overgrowth ever since.
White band disease followed, targeting the two coral species that built the shallow-water architecture of Caribbean reefs — Acropora palmata, the elkhorn, and Acropora cervicornis, the staghorn. These branching corals once formed dense thickets in water shallow enough to snorkel. By the time scientists understood what was killing them, populations had collapsed by more than 90 percent in many areas. Both species are now listed as threatened under the Endangered Species Act.
Then came stony coral tissue loss disease — SCTLD — first documented off Miami in 2014, spreading through the Florida Keys, across the Mesoamerican Reef of Mexico and Belize, reaching Bonaire by 2024. It kills fast, affects more than 20 coral species, and has no confirmed treatment. Scientists are working against a disease that moves faster than the research.
90%+
Decline in elkhorn & staghorn coral populations across the Caribbean since the 1980s
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OPINION · SEE-THE-SEA.COM
What I’ve Seen Change in 30 Years Underwater
A diver’s witness account — from the Philippines in 1990 to Bonaire today
By Denny Frazier · June 2026
San Fernando, La Unión — 1990
I was thirty-something and newly certified, slipping into the warm blue water off San Fernando, La Union in the northern Philippines for one of my first open-water dives. The reef was extraordinary — chaotic and alive in the way reefs were before I had a baseline for comparison. I didn’t know yet what I was supposed to be looking at. I only knew I had never seen anything like it.
Then I felt it.
A pressure wave moved through the water — not a current, not a surge. A concussion. Somewhere above the surface, out of sight, fishermen were using dynamite. The shockwave reached me at depth before any sound did. I felt it move through my chest. I looked at my dive buddy. We both knew what it was.
Blast fishing — illegal, widespread, devastatingly effective. A single charge kills everything in a radius of hundreds of feet: the target fish that float to the surface, and everything else that doesn’t. The coral, the invertebrates, the juveniles, the nursery habitat. Gone in a fraction of a second. What takes centuries to build can be unmade before you finish exhaling.
I came up from that dive changed. Not dramatically — I didn’t give a speech or start an organization. I just understood, for the first time, that what I was looking at was fragile in ways I hadn’t imagined. That it required protection.
“A pressure wave moved through the water — not a current, not a surge. A concussion. I felt it in my chest before I heard it.”
What the Ocean Has Lost Since Then
I’ve been diving off and on for 35 years now. The Philippines. The Caribbean. The Indo-Pacific. Bonaire more times than I can count. And the single most consistent observation across every ocean I’ve entered is this: there is less. Less coral. Fewer fish. Smaller fish. Less color. Less noise — and a healthy reef is loud, the constant crackle of shrimp and parrotfish a kind of underwater static that tells you everything is working.
The Caribbean has been hit from every direction at once, and the cumulative toll is staggering.
In the 1980s, a mysterious pathogen wiped out the long-spined sea urchin — Diadema antillarum — across virtually the entire Caribbean. It was the largest mass mortality of a marine animal ever recorded. Diadema are the reef’s lawnmowers; they graze the algae that would otherwise smother coral. With them gone, algae won. Four decades later, populations have still not recovered. The reef, denied its natural grazer, has been fighting algae overgrowth ever since.
White band disease followed, targeting the two coral species that built the shallow-water architecture of Caribbean reefs — Acropora palmata, the elkhorn, and Acropora cervicornis, the staghorn. These branching corals once formed dense thickets in water shallow enough to snorkel. By the time scientists understood what was killing them, populations had collapsed by more than 90 percent in many areas. Both species are now listed as threatened under the Endangered Species Act.
Then came stony coral tissue loss disease — SCTLD — first documented off Miami in 2014, spreading through the Florida Keys, across the Mesoamerican Reef of Mexico and Belize, reaching Bonaire by 2024. It kills fast, affects more than 20 coral species, and has no confirmed treatment. Scientists are working against a disease that moves faster than the research.
90%+
Decline in elkhorn & staghorn coral populations across the Caribbean since the 1980s
And over all of it, accelerating every other threat, are the marine heat waves.
Oil Slick Leap, Bonaire — October 2025
Bonaire has long been considered one of the healthiest reefs in the Caribbean. It earned that reputation through strict marine park regulations, no-take zones, and a dive community that genuinely cares. I’ve been returning for years. I know the dive sites the way you know a neighborhood — where the green moray lives under the overhang, octopus hunt crabs, which direction the current runs at Oil Slick Leap in the morning.
Last October, my wife and I dropped into Oil Slick for what would be our last dive of the trip. At 70 feet, I checked my dive computer out of habit. The water temperature read 80 degrees Fahrenheit.
I stopped finning.
At that depth, fed by the upwelling cold water from the Bonaire Trench, Oil Slick normally runs 72 to 74 degrees. That upwelling is part of what makes Bonaire’s reef so resilient — the cool water moderates heat stress on the coral. At 80 degrees, the upwelling had failed. The thermal buffer was gone.
I turned to my wife and signaled — we’d talk about it on the surface. When we climbed the ladder back onto the deck, I told her what I was thinking: with that much thermal energy that deep in the water column, if a tropical disturbance entered the Caribbean, it would have everything it needed to intensify rapidly. The ocean was loaded.
“At 70 feet, I checked my dive computer. The temperature read 80°F. Where it should have been 72. The thermal buffer that protects Bonaire’s reef was gone.”
Two weeks later, Hurricane Melissa made landfall in Jamaica as a Category 5 — the most powerful hurricane ever recorded to strike the island. The same thermal energy I’d felt underwater had fed a monster.
I’m a diver, not a climatologist. But a diver’s body is a kind of instrument. You feel temperature change immediately, viscerally. You notice when water that should be 72 degrees is 80. You notice when a reef that should be loud is quiet. When species that should be everywhere are nowhere. These are not data points I read in a report. They are things I experienced, over decades, in my own body, underwater.
What Gives Me Reason to Keep Diving
I don’t want to leave you here, in 80-degree water at Oil Slick, with nothing but grief. That’s not the whole story. And if it were, I’m not sure I’d keep getting in the water.
The blast fishing I witnessed in the Philippines in 1990 has declined significantly in that region. Ecotourism gave coastal communities an economic reason to protect the reef rather than detonate it. That’s a genuine, measurable win driven by human decision-making. It proves the direction of travel is not fixed.
Bonaire’s marine park — one of the oldest in the world — demonstrates that active, enforced protection produces measurably healthier reefs than unprotected alternatives. The fish are bigger. The coral cover is higher. Even now, even stressed, the reef at Bonaire is alive in a way that reefs without protection are not. However, three years of back-to-back marine heat waves and an infestation of SCTLD caused by climate change have caused many of Bonaire’s coral reefs to fall silent, lose their color, and their diversity of life. However, some life has found refuge in the gorgonian soft corals, which give me hope, as well as the efforts of the Reef Renewal of Bonaire.
The global 30×30 movement — the commitment to protect 30 percent of the ocean by 2030 — represents a scale of political will that would have been unimaginable when I was getting my certification paperwork processed at a dive shop in the Philippines. It’s not enough. But it’s real, and it’s growing.
These things matter. They’re worth fighting for.
A Witness, Not a Prophet
I began diving because I wanted to see what was down there. I keep diving, in part, because I feel an obligation to keep looking — to not look away from what the ocean is becoming, and to bring back an honest account.
The ocean doesn’t need my grief. It needs my attention, and yours. It needs people who will learn what a healthy reef sounds like, so they can hear when it goes quiet. Who will know what 74-degree water feels like at depth, so they’ll notice when it’s 80.
Thirty-five years in, I’m still getting in the water. The reef is still worth seeing. And what we do next — in policy, in our daily choices, in the conversations we’re willing to have — will determine what’s left to see.
“What does it take for you to really pay attention to something? And when did you last let the ocean — or any wild place — ask something of you?”
By Denny Frazier · see-the-sea.com · Impacts
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And over all of it, accelerating every other threat, are the marine heat waves.
Oil Slick Leap, Bonaire — October 2025
Bonaire has long been considered one of the healthiest reefs in the Caribbean. It earned that reputation through strict marine park regulations, no-take zones, and a dive community that genuinely cares. I’ve been returning for years. I know the dive sites the way you know a neighborhood — where the green moray lives under the overhang, octopus hunt crabs, which direction the current runs at Oil Slick Leap in the morning.
Last October, my wife and I dropped into Oil Slick for what would be our last dive of the trip. At 70 feet, I checked my dive computer out of habit. The water temperature read 80 degrees Fahrenheit.
I stopped finning.
At that depth, fed by the upwelling cold water from the Bonaire Trench, Oil Slick normally runs 72 to 74 degrees. That upwelling is part of what makes Bonaire’s reef so resilient — the cool water moderates heat stress on the coral. At 80 degrees, the upwelling had failed. The thermal buffer was gone.
I turned to my wife and signaled — we’d talk about it on the surface. When we climbed the ladder back onto the deck, I told her what I was thinking: with that much thermal energy that deep in the water column, if a tropical disturbance entered the Caribbean, it would have everything it needed to intensify rapidly. The ocean was loaded.
“At 70 feet, I checked my dive computer. The temperature read 80°F. Where it should have been 72. The thermal buffer that protects Bonaire’s reef was gone.”
Two weeks later, Hurricane Melissa made landfall in Jamaica as a Category 5 — the most powerful hurricane ever recorded to strike the island. The same thermal energy I’d felt underwater had fed a monster.
I’m a diver, not a climatologist. But a diver’s body is a kind of instrument. You feel temperature change immediately, viscerally. You notice when water that should be 72 degrees is 80. You notice when a reef that should be loud is quiet. When species that should be everywhere are nowhere. These are not data points I read in a report. They are things I experienced, over decades, in my own body, underwater.
What Gives Me Reason to Keep Diving
I don’t want to leave you here, in 80-degree water at Oil Slick, with nothing but grief. That’s not the whole story. And if it were, I’m not sure I’d keep getting in the water.
The blast fishing I witnessed in the Philippines in 1990 has declined significantly in that region. Ecotourism gave coastal communities an economic reason to protect the reef rather than detonate it. That’s a genuine, measurable win driven by human decision-making. It proves the direction of travel is not fixed.
Bonaire’s marine park — one of the oldest in the world — demonstrates that active, enforced protection produces measurably healthier reefs than unprotected alternatives. The fish are bigger. The coral cover is higher. Even now, even stressed, the reef at Bonaire is alive in a way that reefs without protection are not. However, three years of back-to-back marine heat waves and an infestation of SCTLD caused by climate change have caused many of Bonaire’s coral reefs to fall silent, lose their color, and their diversity of life. However, some life has found refuge in the gorgonian soft corals, which give me hope, as well as the efforts of the Reef Renewal of Bonaire.
The global 30×30 movement — the commitment to protect 30 percent of the ocean by 2030 — represents a scale of political will that would have been unimaginable when I was getting my certification paperwork processed at a dive shop in the Philippines. It’s not enough. But it’s real, and it’s growing.
These things matter. They’re worth fighting for.
A Witness, Not a Prophet
I began diving because I wanted to see what was down there. I keep diving, in part, because I feel an obligation to keep looking — to not look away from what the ocean is becoming, and to bring back an honest account.
The ocean doesn’t need my grief. It needs my attention, and yours. It needs people who will learn what a healthy reef sounds like, so they can hear when it goes quiet. Who will know what 74-degree water feels like at depth, so they’ll notice when it’s 80.
Thirty-five years in, I’m still getting in the water. The reef is still worth seeing. And what we do next — in policy, in our daily choices, in the conversations we’re willing to have — will determine what’s left to see.
What does it take for you to really pay attention to something? And when did you last let the ocean — or any wild place — ask something of you?
By Denny Frazier · see-the-sea.com · Impacts