The Manta Rays of Milne Bay

By Don Silcock

From a distance there is little to distinguish the small island of Gonu Bara Bara from the myriad of others in this part of southern Milne Bay Province.

Few would guess that just off its northern beach is possibly the best place in the whole of Papua New Guinea to see Mobula alfredi — the magnificent reef manta ray.

Manta rays had been known to patrol that beach for many years, but all attempts to try and interact with them were random at best — maybe you would see one or more, maybe you wouldn’t…

Then back in 2002, almost by accident, Craig de Wit discovered why the mantas were there.

Craig is the skipper of the liveaboard Golden Dawn, which had been charted to search for mantas and he had gone to all the best-known Milne Bay locations but did not find a single animal. Finally, in an act of inspired desperation he responded to the pleas of James, the boat’s engineer, to check out his home island where there were “lots of mantas just off the beach”.

Here is how Craig described finding them:

“I discovered the cleaning station when we went to Gonu Bara Bara, James my engineer kept insisting that there were lots of mantas at his island so we went in search of them.

On arriving we saw them around the place on the surface so most of the group went for a snorkel in hope of getting close to them.

I decided to go for a dive along the beach hoping to get close and while drifting along in the current came across the cleaning station and I guess the rest is now history.”

Craig christened the cleaning station Giants@Home and I was fortunate to experience it first-hand just two weeks after that initial discovery.

Manta Cleaning Stations

Manta rays are filter-feeding planktonivores that use their mouths and modified gill plates to strain plankton and small fishes from the water.

They have teeth, which are tiny and peg-like, about the size of a pin-head, but they are not used for feeding — rather they are utilized during breeding so that the mating mantas can hold on to each other.

While manta rays pose no real danger, they are big animals with the wingspan of reef mantas reaching up to 5.5m, while the larger oceanic manta (Mobula birostris) getting to at least 7m.

They are truly intriguing creatures that are both intelligent and curious, having brains that are significantly larger by proportion to their body size than other fish. Being in their presence is, in my opinion, an absolute joy and cleaning stations are a great way to maximize that interaction time.

Open water encounters with reef mantas are typically fleeting in nature — they will check you out, but that’s usually it and they move on, whereas with a cleaning station there are more mantas plus they stay longer as they take turns being serviced.

Usually a cleaning station will be close to an area with a strong current that brings the rich plankton which mantas feed on — which explains the early reports of mantas near Guna Bara. Because close by is the China Strait that connects the Coral Sea to the South with Milne Bay and the Solomon Sea to the North.

Giants@Home is a particularly good station as it is shallow at about 9 m so bottom time is not an issue, it is literally just off the beach which makes it very safe and water clarity is usually (but not always…) pretty good.

But the exceptional thing about its location at Gunu Bara Bara is that it can only really be dived from a liveaboard. Therefore the total number of divers in the area is the number on the boat and shifts can be organized to minimize the number in the water at any point in time.

At other locations this is rarely the case and your interaction can often be spoiled by the sheer number of other divers…

Manta Ray Protocol

We have all seen those old images of “intrepid divers” riding on the backs of manta rays by holding on to a couple of resident remoras — so 1970s… but at least the offenders could claim ignorance!

Today we know much more about these wonderful creatures and they truly are an incredible mix of grace and symmetry combined with intelligence and curiosity.

Both oceanic and reef mantas are on the IUCN Red List as “Vulnerable,” which means they are likely to become “Endangered” unless the circumstances threatening their survival and reproduction improve.

There are many reasons for that status, which are way beyond the scope of this article but as divers we are privileged to experience such creatures and therefore it is our responsibility to behave properly when we do.

We should never, ever, try to ride a manta like those guys from the 1970s and we should never chase or harass them in any way!

What we should do, and in my personal experience this is by far the best way to get the best interactions, is to position ourselves around the cleaning station so that the mantas have a clear entry and exit.

Don’t get too close as you will be in the way and the mantas simply won’t come in, as they appear to feel vulnerable when hovering to be cleaned and are easily spooked.

Once they have made a few passes and got used to you they will often come close to really check you out, which is the best type of encounter as it is on the manta’s terms and they are in control…

Basically, if you behave you will be amply rewarded!

Where is Gunu Bara Bara?

The island is in southern Milne Bay Province, about 8km to the south-east of the former provincial capital of Samarai Island, at the bottom of the China Straits.

Roughly 2 km wide and 7 km long, the China Strait is the passage between the Southeast tip of the Papua New Guinea mainland and the China Straits group of islands.

It connects the Coral Sea to the South with Milne Bay and the Solomon Sea to the North and was named by Captain John Moresby, who surveyed the region and claimed the Southeast part of New Guinea for Britain in 1873.

How to dive Gunu Bara Bara?

There only way to dive at Gunu Bara Bara is from a liveaboard and there are two ones that service the area.

Top of the list is the MV Chertan which is owned and operated by Rob van der Loos.

Chertan is based in Alotau, the capital of Milne Bay Province and operates year-round in Milne Bay, with regular visits to the China Straits, Samarai Island and of course Gonu Bara Bara.

Rob has been running dive trips in Milne Bay since 1986 and, simply stated, knows the area better than anybody else.

MV Golden Dawn also dives Gonu Bara Bara but it is based from Madang and operates throughout Papua New Guinea depending on the seasons.

March, June and October are when the boat visits Milne Bay and as its skipper Craig de Wit discovered Giants @ Home – so he clearly owns the bragging rights about the site!

Don Silcock

Don Silcock is from Bali in Indonesia. He has dived extensively in Papua New Guinea, Indonesia and many other countries in the Indo-Pacific region and his website is full of information on those locations.

Also check out Don’s Complete Guide to Diving Milne Bay for more information on this very special part of Papua New Guinea.