Jellyfish on Bonaire: what divers and swimmers should know

Jellyfish on Bonaire rarely make the headlines, and for good reason. On most days you will snorkel and dive our reefs without seeing a single one. Still, guests regularly ask us about them, especially now that international dive media report that researchers have identified two new box jellyfish species around the island. So we put together the practical guide we give our own friends and family.

At Sunwise we live and dive here year-round. Below, we explain which jellyfish on Bonaire you might meet, why timing matters more than location and exactly what to do if one brushes your arm.

Which jellyfish you can meet on Bonaire

Bonaire sits in warm, clear Caribbean water with relatively few nutrients, so the massive jellyfish blooms you see along some European coasts are uncommon here. Several species do live around the island, and a few are worth recognizing.

• Caribbean box jellyfish (Alatina alata): small, transparent, with a cube-shaped bell and four long tentacles. Divers often call it a ‘sea wasp’. Its sting hurts, but in our waters it is mainly a nighttime visitor.
• Bonaire banded box jelly (Tamoya ohboya): a species with striped tentacles. Scientists described it in 2011 after divers photographed it here, and its name came from a public naming contest. Sightings are rare.
• Upside-down jellyfish (Cassiopea): rests bell-down on sheltered sandy bottoms, for example in parts of Lac Bay. It hardly moves, yet the mucus around it can cause mild itching.
• Moon jellyfish (Aurelia): drifts by now and then. Its sting is weak and most people feel nothing.
• Portuguese man o’ war: strictly speaking not a true jellyfish but a colonial organism. After strong easterly winds, one may wash up on the rugged windward coast. Never touch the blue float, even on the beach.

For a small island, Bonaire gets a lot of attention from jellyfish researchers. Knowing a little about these animals and their habits helps you plan your dives.

When jellyfish on Bonaire peak: the full moon rhythm

Here is the local detail most visitors don’t know. The Caribbean box jellyfish follows the moon. Roughly eight to ten days after each full moon, these jellies gather in shallow water along the leeward coast to spawn. They do this after dark, usually starting about an hour after sunset.

Light attracts box jellies. That is why divers on a night dive suddenly see them circling their torch, and why they cluster near lit piers. During the day you will almost never encounter them.

Check a moon calendar before you plan any night dives. A simple rule of thumb:

• Count eight to ten days after full moon and mark those evenings.
• Plan night dives and evening snorkels outside that window whenever possible.
• If you dive inside the window anyway, cover up fully and point your torch down or dim it during safety stops.
• Daytime dives and snorkels are generally unaffected.

For current marine park information, including the rules for night diving in the Bonaire National Marine Park, visit STINAPA Bonaire. STINAPA manages the park and asks every diver and snorkeler to pay the nature fee.

How to avoid stings while diving and snorkeling

Avoiding jellyfish on Bonaire mostly comes down to habits. The marine park does not allow gloves for recreational divers, so your protection comes from what you wear and how you behave.

• Wear a full-length wetsuit or a thin dive skin, even though the water is 27 to 29 °C.
• Add a hood or neck protection for night dives; your face and neck are the most exposed areas.
• Keep surface time short after dark, because box jellies swim just below the surface.
• Look before you grab a line or ladder, since tentacles can tangle around ropes.
• Rinse your gear with fresh water, away from your skin, as loose tentacle pieces can still sting.
• On the windward coast, check the tideline for blue floats before you walk barefoot.

Shore diving makes it easy to adjust your plans. If you stay on the water with your own entry point, you can shift a night dive by a few days without losing a boat booking. That is one reason guests choose our oceanfront apartment at Belmar with diving facilities: the reef is a few steps away, rinse tanks and storage are on site and you choose the timing.

What to do if you get stung

Even with good preparation, a sting can happen. Most stings from jellyfish on Bonaire cause sharp, burning pain and red lines on the skin, which fade within hours to a few days. Stay calm and follow these steps:

1. Leave the water calmly. If you are diving, end the dive with a normal, safe ascent and don’t rush to the surface.
2. Rinse the area generously with vinegar for at least 30 seconds if you suspect a box jellyfish. Many dive shops on the island keep a bottle ready.
3. Remove any remaining tentacles with tweezers or the edge of a card, never with bare fingers.
4. Soak the area in hot water (as hot as feels comfortable, around 45 °C) for about 20 minutes to ease the pain.
5. Don’t rub, don’t pour fresh water on fresh tentacles and skip home remedies such as urine.

For a Portuguese man o’ war, rinse with seawater, remove the tentacles and then use hot water. Advice on vinegar differs for that species, so stick to removal and heat.

Seek medical help right away if you notice difficulty breathing, chest pain, severe muscle cramps, nausea or a sting covering a large area. Call 911 and go to Fundashon Mariadal, the hospital in Kralendijk. Also tell your buddy and your dive operator, so they can warn others.

Jellyfish are no reason to skip the reef

Jellyfish on Bonaire belong to a healthy reef. Box jellies follow a predictable lunar schedule, most other species are harmless or rare, and a dive skin plus a bottle of vinegar covers almost every situation.

Some divers use the timing the other way round. They plan a well-protected night dive inside the window, just to watch these small translucent animals glow in their torch beam. Keep your distance and leave them where they are.

Planning your trip? Send us an email and we will help you find a base next to the reef, so you can dive on your own schedule.