Mola Mola: Where and when to dive with them

Encountering a *Mola mola* is an unforgettable experience, and respectful observation is paramount. These fish can be shy and easily spooked despite their size. Maintain a calm demeanor and avoid sudden movements. Keep a respectful distance, generally at least 5-10 meters, and never attempt to touch, chase, or harass them; this can stress the animal and is often illegal in protected areas. Pay attention to your dive guide, as they can often spot the subtle cues of a sunfish, such as their distinctive dorsal fin breaking the surface or their large, paddle-like appearance in the blue. When encountered at cleaning stations, such as those found around Nusa Penida, Indonesia, divers should position themselves quietly and observe from a distance, allowing the cleaner fish to do their work undisturbed. Buoyancy control is crucial to avoid disturbing any potential cleaning stations or stirring up sediment. Mola mola often ascend during daylight hours for thermoregulation or cleaning, so divers should be attentive to the water column above them and in the deeper blue. Remember to ascend slowly and safety-first, especially in areas with potential strong currents where these pelagic species are found.

Encounters with *Mola mola* are often tied to upwelling events and seasonal changes that bring their gelatinous prey closer to the surface or coastal areas. In Monterey, California, the best time for sightings is typically from late summer to fall, particularly from August to November, when the upwelling brings cold, nutrient-rich water and abundant food. For the Azores, the peak season is generally June to October, coinciding with warmer surface waters and increased plankton blooms. In Bali, Indonesia, particularly around Nusa Penida's Crystal Bay, July to October is the prime season, as cooler currents from the deep bring these magnificent fish closer to cleaning stations. Around the Galapagos Islands, while possible year-round, they are more frequently observed during the cooler, dry season from June to December, when cold currents are strongest and plankton is plentiful. Visibility can be a factor, often being clearer in the dry season in tropical locations, enhancing the chances of spotting these pelagic wanderers.

The ocean sunfish, *Mola mola*, is a fascinating pelagic species, typically found in temperate and tropical oceans worldwide. While often seen drifting at the surface, they can dive to impressive depths, sometimes exceeding 600 meters, to hunt. They prefer waters with a temperature range of 10°C to 20°C. Known hotspots for encounters include the Pacific Ocean off California near Monterey, the waters around the Azores in the Atlantic, and the eastern Pacific surrounding Bali, Indonesia. Around Galapagos, Ecuador, they are frequently observed in the nutrient-rich currents, particularly near oceanic upwellings. These fish often ascend to sunbathe near the surface after deep foraging dives, which is believed to aid in thermoregulation and parasite removal by seabirds. They are not restricted to specific reef structures but are more commonly sighted in open ocean environments, occasionally drifting closer to shorelines where deep water is accessible.

The diet of the *Mola mola* primarily consists of gelatinous zooplankton. Their main prey items include jellyfish, siphonophores, and salps, although they are opportunistic feeders and will consume other slow-moving organisms. Despite their large size, their mouths are relatively small, which necessitates a diet of soft-bodied prey. They are not active pursuit predators but rather forage by slowly swimming through the water column, engulfing their prey. Studies have shown they also consume small crustaceans, squid, and even some small fish larvae, suggesting a more varied diet than previously thought. Their feeding strategy involves cruising with an open mouth, acting as a living filter to ingest their gelatinous meals. They are thought to be significant predators of jellyfish populations, playing a role in marine food webs.