Oceans & Blue Carbon · Field Notes
10 Things to Know About Biodiversity in the Strait of Hormuz
March 2026 · 6 min read
While the world's gaze is fixed on the Strait of Hormuz through the lens of periscopes and fuel prices, there is a far older, more intricate drama unfolding beneath the calm blue water. This 21-mile wide "chokepoint" is a biological motorway of staggering importance.
Here are 10 things you ought to know about biodiversity in the Strait of Hormuz.
The Lungs of the Gulf
The Persian Gulf is essentially a giant, salty puddle with very little fresh water coming in. The Strait of Hormuz acts as its primary life-support system. Every drop of oxygenated, nutrient-rich water from the Indian Ocean must squeeze through this narrow gap. Without this constant 'inhalation' of fresh seawater, the inner Gulf would become too saline for almost any form of life.
Heat Resistant Corals
The coral reefs around Qeshm and Larak Islands are, quite frankly, over-achievers. While reefs elsewhere in the world are bleaching at the mere mention of a heatwave, the corals here are 'extremophiles.' They regularly survive temperatures of 35°C and high salinity levels. You could call them 'climate change pioneers'. If we want to save the world's oceans, the genetic secrets held in these waters might hold the key.
What Can the Dolphins Hear?
The Strait is home to the Indo-Pacific humpback dolphin and the bottlenose dolphin. Since the military escalations began in February 2026, the underwater world has become deafening. Between the Cobra-V8 jamming signals and the constant hum of naval sonar, these sensitive creatures are navigating through a thick fog of noise — and it's blocking their ability to hunt and communicate.
The Dugongs in the Crossfire
Hidden in the seagrass meadows near the coastal shallows are the elusive dugongs. Often called a 'sea cow' because it's a herbivore, these gentle mammals are incredibly shy. With the increase in fast-attack craft patrols this month, the risk of boat strikes has skyrocketed. Losing the dugongs would mean losing the gardeners of the Gulf's seabed.
Blue Carbon and the Hara Forests
The Iranian side of the Strait boasts the Hara Forests, vast tracts of Avicennia marina mangroves. These are not just pretty trees; they are 'blue carbon' powerhouses, locking away carbon dioxide far more efficiently than tropical rainforests. Today, protecting these mangroves is as much about global survival as it is about local ecology.
The Whale Shark Highway
Despite the heavy industrial traffic, the Strait remains a vital migratory corridor for the whale shark. Some, the size of a double-decker bus, pass through these waters to reach feeding grounds in the Gulf of Oman. Imagine a 12-metre shark navigating between a fleet of 'dark' tankers and a naval blockade — it's a precarious journey.
The Accidental Nature Reserves
Ironically, the heavy military presence on islands like Greater Tunb and Larak has created 'accidental' nature reserves. Because civilians and builders alike have been kept away for decades, some of the most pristine hawksbill turtle nesting beaches are found on these islands that are technically off-limits. The tragedy is that these very sanctuaries are now the primary targets of military strikes.
The 2026 'Dark Fleet' Risk
As of this week, there are dozens of tankers idling in and around the Strait, many part of the so-called 'dark fleet' with questionable maintenance records. A single collision or strike wouldn't just be a headline on the Financial Times; it would be a death sentence for the intertidal mudflats that support hundreds of species of migratory birds flying between Siberia and Africa.
Marine Data Deficiency
One of the most sobering facts is that we don't actually know the full extent of what lives here. Over 60% of the species in the Strait are classified as 'data deficient.' We are currently engaged in a conflict that could wipe out species we haven't even had the chance to properly name or study.
A Shared Heritage
Biodiversity knows nothing of maritime borders or lines of control. The Arabian carpetshark and the green sea turtle don't carry passports. The Strait of Hormuz is a shared ecological heritage that belongs to no single nation, yet its slow destruction would be a loss for the entire planet.
In March 2026, as the "Epic Fury" strikes continue to dominate the news, we must remember that the true value of the strait isn't measured in barrels of Brent crude, but in the resilience of its reefs and the survival of its seas.