Side gilled sea slugs are a delight to find during night diving in Gorontalo.
Nocturnal Sea Slugs
Nudibranchs usually have their gills exposed on the top of their bodies. But side gilled sea slugs have large plume-like gills tucked between the mantle and the foot. The gills are usually on the right side. They mostly live in shallow waters on sand and rubble bottoms. That makes the perfect location for lucky divers to find them. These slugs crawl the sea floor at night looking for tunicates
, anemones and invertibrates. They have a pair of rolled rhinophores that sense chemicals and water current. They have strong jaws and wide mouths and can even eat a sleeping fish! This type of sea slug secretes sulfuric acid when disturbed.
Grand Side Gilled Sea Slugs
The most commonly seen side gilled slug is Pleurobranchus grandis. It can grow up to 21 cm, the size of a dinner plate! Its color pattern varies. However, this slug has three red bands that contrast with its other colors. See Alain Guillard’s photo taken at Sand Bowl dive site in Gorontalo.
Forskal’s Side Gilled Sea Slugs
The beautiful Pleurobrachus forskali is named after a Finnish naturalist. Pehr Forskal was a student of Linnaeus, who recommended that King Frederick V of Denmark appoint the young Forskal to join an expedition to Arabia. While he was busy writing his book on the Flora of Egypt & Arabia, he contracted malaria. He died in 1763 in present-day Yemen. This sea slug is one of three life forms named after him.
Its color varies widely from dark plum red to peach to brown. The only consistent element of its pattern is the white semicircles that outline bumps on its mantle. Both P. grandis and P. forskali arch their mantles when moving. This forms a spout towards the rear of the slug, clearly visible in Albert Hartono’s photo of a young Forskal sea slug taken at Old Port dive site. This spout channels water and feces away from the slug as it travels.
Moon-headed Side Gilled Sea Slugs
The most unusual Euselenops luniceps is rarely seen because it buries itself in the sand during the day. Its long mantle forms a siphon that brings sea water to the slug’s gills while it is buried. Notice the siphon towards the rear of the slug in Wisnu Purwanto’s photo from Sand Bowl dive site. Mr. Purwanto shares other Gorontalo underwater photos on his Flickr page. Its most notable feature is its large, wide oral veil that covers its mouth. The veil is fringed with many sensory hairs called papillae. The slug basically feels for prey along the sand with its mouth. Moon-headed ones are the only side gilled sea slugs that can swim for some distance. To swim, it flaps the sides of its body. It only grows to 7 cm.
Although night dives are not included in dive packages that Miguel’s Diving offers, oftentimes night diving is available. Please ask when you make a booking with us.
That tumbling mass is really sea hare mating! Imagine the surprise of divers looking for critters at Sand Castle, one of Gorontalo’s muck diving sites. On the sand in shallow water were masses that looked like sea weeds, rocking back and forth in the gentle surge. In fact, there were patches of algae on the sea floor. That added to the confusion. But a closer inspection revealed a rarely witnessed event, sea hare mating.
Slugs Looking Like Rabbits
Sea hares are members an opisthobranch order of sea slugs. More colorful opisthobranchs are famously called nudibranchs. Their sensing organs are called rhinophores. In sea hares, these and their oral tentacles are rolled. Many sea hare species have an internal shell, giving them a pudgy appearance. These characteristics make the slug look like a rabbit, hence the name. Sea hares can grow to enormous sizes and weigh five kilograms or more.
Lined Sea Hares
The sea slugs discovered by guests of Miguel’s Diving in the midst of sea hare mating were not of the large variety. Instead, they were Lined Sea Hares (Stylocheilus striatus).
Notice the fine dark lines in the photo by Senior Aldo Galante of Buenos Aires. Some light spots are also visible. This color pattern makes for great camouflage. Lined Sea Hares are usually quite small, such as the ones found in Gorontalo that day. But they can grow to up to 65 mm in length. Like other sea hares, Lined ones eat blue-green algae. When disturbed, most sea hares will secret purple ink. This purple secretion actually comes from toxins found in the blue-green algae eaten by sea hares.
Sea Hare Mating Video
To witness sea hare mating is a rare event. Watch the video shot in Gorontalo that day.
, there are several still photos. Can you make out the individual sea hares? Notice how the mass of sea hares resembles the clump of algae growing on a nearby rock. Do you see individual sea hares crawling from the upper left screen towards the sea hare mating frenzy? Notice the dark portion inside the body of a sea hare. This is the internal shell.
For your chance to witness a rare marine event, please make a dive booking with us at email@example.com
A whale shark encounter was in store for two American divers. On their way to the Togian Islands, they made a last minute decision to make two dives in Gorontalo. That decision made memories to last a lifetime.
World Class Diving in Gorontalo
Sadly, many travelers miss diving in Gorontalo on their way to its more famous neighbors, the Togian Islands, Bunaken Marine Park and Lembeh Straits. But world class diving is easily available here. After touch down at the airport, the ocean is only an hour away. Eight different dive sites are only fifteen minutes from the private dock of Miguel’s Diving. Over 30 named sites are available.
The whale shark encounter captured in the video was at one of those close dive sites. It is named Swirling Steps because of a series of short drops and ledges that push into the current. Staff of Miguel’s Diving have forgotten the number of times we have seen whale sharks at this site. There have been too many over the years! In addition, this site has hard coral below 40 meters, which indicates the vibrant health of Gorontalo reefs. Only in Gorontalo can diver see Salvador Dali sponges with their surreal, carved surfaces.
Whale Shark Encounter Video
[svpVideo v=1]Watch the video shot to see the whale shark passing by. The whale shark enounters in Gorontalo are in a natural environment. They are swimming around looking for schools of small fish. Days with a higher plankton count will also bring in the whale sharks. That is what happened the day this video was shot.
Miguel’s Diving staff tell guests that if a shadow appears overhead, look up! It maybe a whale shark or a manta ray. It seems that the whale sharks are not only curious about divers but also they like the bubbles. They also like the dive boat, which has had numerous whale shark encounters of its own. Perhaps they think it is a long lost relative floating on the surface! A fantastic photo of one is available on our home page. These large pelagics can grow up to 15 meters in length. They can live up to 100 years. Judging by its small size of merely six meters, this one was probably in his early twenties.
On March 27, a Minke Whale breached the perfectly flat sea off Traffic Jam dive site in Gorontalo. Our boat captain watched the 10-meter long whale jump into the air. It hit the water with the belly-flop style characteristic of this whale. The Minke jumped four times and also blew water into the air. Divers that day had already descended. We heard several loud bangs but did not realize a whale was breaching less than 400 meters away. Miguel’s Diving has reported this exciting encounter to the APEX Environmental’s Coral Triangle Oceanic Cetacean Program. We have reported whale sightings to APEX for about ten years.
The Life of a Minke Whale
Minke Whales (Balaenoptera acutorostrata) are the smallest type of rorqual whale. Rorquals have numerous, distinct pleats of skin under their chin. These can expand to hold tons of water when the whale opens its mouth to feed. They eat krill, fish and squid. A Minke Whale uses the baleen of its upper mouth to filter food out of the water held in its mouth. They can be found in all oceans and live up to 60 years. A Minke Whale can weigh up to 10 tons. With populations numbering over 500,000 the Minke Whale is not considered to be endangered.
Good News from the International Court of Justice
Four days after Miguel’s Diving staff sighted the breaching Minke Whale
, whales living in the southern oceans received good news. The International Court of Justice in the Hague sided with Australia in a suite against the Japanese whaling industry. The Court determined that the annual hunt was not for scientific purposes as claimed. The Court ordered a halt to any more whaling in the southern oceans. Japanese demand for eating whale meat has declined drastically over the last decade. According to news.com.au, the meat of more than 2,300 Minke Whales is sitting unsold in freezers in Japan. Whalers had planned to take 1,300 whales annually, despite plunging sales. Minke whales are also hunted in Iceland and Norway.
Everyone here is happy that the Minke Whale we saw will not end up in a freezer! For your chance to dive the blue waters of Gorontalo, please take a look at our dive packages and send an email to firstname.lastname@example.org.
Viable marine protected areas are a crucial need worldwide. At Miguel’s Diving, our business model is based on ecological sustainability and community development.
Gorontalo Marine Protected Areas
During our early years of operation, Miguel’s Diving staff conducted a series of coral awareness campaigns. These took place in local schools, village halls and government buildings. We even used the front porch of a house! Gorontalo Province Fisheries Department, the Nature Lovers club at the local university and law enforcement took part. The basic message was “no coral, no fish, your choice.” The culmination of these educational efforts was the establishment of the Olele Village Marine Park in 2007. Miguel’s Diving pays a fee directly to the village for our guests to dive in designated sites. In this marine protected area, fishing is not allowed.
During regular diving season, Miguel’s Diving staff are in the water almost daily. Diving season is November to April. We take time during each dive to clean up a bit of trash or fishing line. Any Crown-of-Thorns starfish are taken immediately from the dive sites. In other marine protected areas in the world, Crown-of-Thorn outbreaks severely threaten the coral reef. Divers will immediately notice the dense and healthy hard corals of Gorontalo.
Vast Tomini Bay
Miguel’s Diving offers diving along the northern shore of Tomini Bay. Other operators provide diving in the Togian Islands. They are located in southern part of Tomini Bay. Tomini Bay is one of the largest in the world. It plunges over four kilometers in depth near Gorontalo dive sites. It takes eight hours by metal ferry boat to cross from Gorontalo to the Togian Islands.
Togian Islands Marine Protected Areas
There is no dynamite fishing in the areas where Miguel’s Diving operates. This is because of environmentally-friendly local fishing practices and community education efforts. Gorontalo Fisheries Department also patrols the coastline. No so fortunate are our neighbors to the south. Although the Togian Islands is one of Indonesia’s official marine protected areas
Not a fictional cartoon super villain, but a real Black Manta Ray caused quite a stir in Gorontalo.
A Curious Black Manta Ray Visits Divers
Divers were enjoying a day of brilliant visibility when the dive master turned around and pointed. Behind us came the distinct flying motion of a manta ray. But this was no ordinary one. It was a rare Black Manta Ray. Usually, mantas are dark on the top and white on the bottom. The underside also has various marking that are unique to the individual manta. However, a genetic morph known as the Black Manta Ray is black both on the top and the bottom. The one we saw was gliding off the wall at Traffic Circle dive site in the Olele Village Marine Park. It was quite curious about the divers. It came within a couple of meters of the enthralled humans. This Black Manta Ray circled and swayed for about fifteen minutes. The video does not last that long.
Ridwan Monoarfa’s borrowed GoPro ran out of batteries! Diving in Gorontalo is notoriously draining on batteries. There is too much to shoot!
A Division of Species
Humans have known about mantas for millennia. However
, the actual species name has undergone much revision. In fact, only in the current millennium has genetic science confirmed two separate species. The official studies were done by Kashiwagi et al (2008), Marshal et al (2009) along with Ito and Kashiwagi (2010). Researchers analyzed difference among numerous mantas. This included color, spines, the mantas’ tooth-like scales and teeth. As a result, there are now two recognized species. One is Manta birostris. This manta is the largest and grows to up to seven meters wide. It lives in many oceans worldwide and migrates. The other is Manta alfredi. It is named after Prince Alfred of England. This manta is smaller and grows to only 5.5 meters wide. It lives in Indo-Pacific waters and tropical areas of the eastern Atlantic Ocean. The Black Manta seen in Gorontalo is most probably M. alfredi. The separation of species has been confirmed by consistent morphological and genetic differences. Ironically, authorities have long debated about the rare Black Manta Ray. However, genetic research confirms that it is a morph. Both manta species can occasionally produce the Black Manta.
Pelagic Rays of Gorontalo
To see a Black Manta Ray is quite rare. The most common large ray seen is Gorontalo is the White-spotted eagle ray. Occasionally, numerous Mobula rays glide by divers. For your chance to see a pelagic ray, please make a dive booking with us at email@example.com
, Miguel’s Diving boat crew spotted a jumping sailfish. It jumped a total of three times. The crew carefully moved the boat closer and discovered three sailfish swimming together just under the surface. Their dark forms were clearly visible in the calm blue water.
A Jumping Sailfish Video
After they passed within a few meters of the boat, dive staff encouraged the guests to make a video. The results of the combined effort are available to watch in a brief video. In the first segment, notice the dark shape in front of the dive boat. That is one of the jumping sailfish. Next a dive master jumps in the water with a camera and swims after the fish. In the original video, two distinct sailfish are visible, stripes and all. Then the camera emerges to the surface in time to catch the jumping sailfish. The final sequence was shot with a smart phone from the dive boat. Hear everyone scream and cheer for the jumping sailfish.
Marine Life in Gorontalo’s Deep Waters
Gorontalo dive sites are scattered along the continental wall of Sulawesi. Ocean depths near Buffalo Head Point dive site plunge to over four kilometers. That is where the jumping sailfish were. This same group of divers had close encounters with a spotted eagle ray, blacktip shark and schooling jacks. Just after everyone descended for a third dive, the boat crew watched a whale jump from the water and blow a spray of water into the air. Divers below heard the noise and wondered what was going on.
The trio of jumping sailfish are actually Indo-Pacific sailfish (Istiophorus platypterus), a type of marlin. They are native to the deep Indian and Pacific Oceans. The color is dark blue on the top, brownish to blue on the sides and with sliver belly. They also have a series of dark bars on their sides. These bars were clearly visible to the watching divers and the dive master in the water. The distinctive sail-like dorsal fin was not raised the day divers saw the jumping sailfish. However, the large pointed bill was clearly visible. These sailfish grow up to three and a half meters long. The world tackle record is over 100 kilos. Indo-Pacific sailfish are perhaps the fastest swimmers in the ocean. They have been clocked at speeds of over 100 kilometers an hour. A sailfish feeds by blasting through a school of fish and thrashing its head back and forth. In this way, it uses it bill as a weapon to kill or wound other fish. The sailfish then eats the fish as they sink in the water column.
Drift diving can be a delightful experience for scuba divers. Sometimes this type of diving is called current diving. Here are some tips from Miguel’s Diving.
General Drift Diving Tips
When diving in a current, the most important thing is to maintain neutral buoyancy and depth. You want to avoid contact with the coral reef while drift diving. Relax and ride the current. In other words, go with the flow!
To detect a change in current up ahead, look at the fish. Fish will always face into a current. Do you notice the school of Purple Anthias in Digant Desai’s photo? They are all facing into the current. In fact, the stronger the current the more fish will gather along the reef. They are waiting for passing food, such as plankton. One of the keys for safe drift diving is good surface support. An experienced boat crew is essential. Miguel’s Diving has been operating safely since 2003. At certain sites where currents are expected, the dive boat will wait in blue water off the reef edge, so that spotting the divers is easy.
Accessories for Safe Drift Diving
Sometimes divers bring a dive sausage in areas of strong currents. The tube is inflated by using an alternate air source, like an octopus. The tube is attached to a line that the diver holds while drifting with the current. Since the tube is inflated with air, it bobs along the surface of the water and marks the position of the diver. This helps the surface crew keep track of divers. This is particularly useful in Komodo where currents are strong.
In certain areas in Indonesia, like Raja Ampat, divers bring dive hooks. This is basically a metal hook on a line and attached to your BCD. Divers descend into a strong current, hook into the coral and watch the fish go by.
Miguel’s Diving encourages divers not to use dive sausages or reef hooks here. They are not needed here. Instead, your dive guide will use a dive whistle attached to his inflator hose to signal the boat crew for picking up divers.
Currents in Gorontalo
Gorontalo has long shore currents that run to the right or to the left along the shore. It is not possible to be towed out to sea by a current in Gorontalo. Currents here are also quite gentle. That is why Gorontalo is suitable for newer divers
, as well as serious underwater photographers. Currents here also tend to reverse every 20 to 30 minutes. We have named one dive site “Traffic Circle” because divers often can ride the lower current to several underwater points and then ride the upper current back to the mooring buoy where the dive boat waits.
When diving submerged points in Gorontalo, like at White Point or Buffalo Head Point, the current pushes divers around the point. This is the time to look into the deep water for the schools of fish that pass by. Once around the point, there is no longer a current. Now is a good time to enjoy the coral wall. Sometimes divers encounter reverse currents that are too strong to fin against. In that case, the dive guide will signal everyone to turn around and drift with the new current.
For more tips on diving in Gorontalo, check out our Advice page on our web site. To arrange your dive trip to Gorontalo, please make a booking with us at firstname.lastname@example.org