The Munsoms (Jejudo, South Korea)
by Alex Boulton
If you keep digging youll get to China (Dad 1976). This observation of my childhood antics was my first moment to consider what the opposite side of the world would be like. Would the world up there be upside down, back to front, would it be similar or would it be strange? When I became a diver, and then an Instructor, I came to realize that my Dads geography was a bit out and that the opposite side of the world from Northland wasnt China.
In fact if you want to know what the Poor Knights or White Islands northern hemisphere cousin looks like you need to make a pilgrimage to South Koreas Hawaii. You need to get yourself to latitude 33 north and dive the volcanic islands of Little and Big Munsom. So in search of the similar and the strange I packed my dive bag and headed for Big Blue 33 the only English speaking dive centre in Sogwipo on the island of Jejudo.
The warm water Tsushima Current that flows off the Chinese coast bathes the south facing coast of Jeju island. This warm water can raise the south coast water temperatures to 28oCelsius. The underwater ecosystem created by the Tsushima Current is distinct from anywhere else on the island or the Korean peninsula. In the winter months this current is deflected to the south and allows the blooming of huge kelp forest, similar to those of Tasmania. The tropical fish disappear and there is a bloom in the population of temperate species that populate the kelp. In early summer the current mixes with the local water creating pockets of warm and cold separated by oily haloclines. At a different latitude this fluctuation could be an ecological disaster but in this environment it is responsible for creating an outstanding local ecology as the south coast shifts from temperate to tropical and then back to temperate every 365 days!
The three kilometre drift dive started at a small rocky outcrop called Little Munsom. The outcrop is separated from Big Munsom by a gulley about 30 metres wide and approximately 10 metres deep. We had dived this gulley the previous day. Today the dive plan was to drift the front side of Little Munsom on a falling tide running east to west. We would follow the submerged face of Little Munsom and rounding the western end of the island gradually ascend the contour across rough terrain. We would pass in front of the separating gulley and continue along the wall created by Big Munsom to the islands western tip and then ascend into a small cove. The dive went to plan and after 71 minutes of bottom time, at an average depth of 15 metres we ascended into west cove.
What astounded me about this dive site was the mix of marine life that I saw. Having worked in the Bay of Islands and the Bay of Plenty Im familiar with the common coastal species like leather jackets, red moki, demoiselles, big eye, flounder, goat fish, spotties, blennies, gobies, toados, squid and octopus. On the first day that I dived I saw all of these species and was completely at home. It was then that I reminded myself that this wasnt the Rurimas or the Cavallis. In fact New Zealand was nowhere in sight. The backdrop to these fish was equally familiar: encrusting sponges; bivalves; tunicates; fan worms; dalia anemones; nudibranchs and crabs. It felt strange to be so at home on the other side of the world.
By the second day it was also becoming clearer that the effect of the Tsushima Current on Jejudo was similar to the effect of the East Auckland current on the Poor Knights and White Island; but none of this prepared me for what I saw next.
Entering the water we descended an overhanging rock wall. Little Munsoms north wall is festooned in multicolored soft coral. Catfish and bar face cardinal fish nestle on the top of the wall but it is the soft coral that holds your gaze. Endless reds, yellows, oranges and blues that easily rival Vanua Levus White Wall. The soft coral dominates this portion of the dive from a depth of 5 metres down to a grotto and a boulder slope at 40 metres.
The sight is overwhelming. Leaving the wall behind and passing the end of Little Munsom we remained at 30m as we crossed the rough ground. Here, out of the fast current we could almost stem the tide to observe the numerous lion and turkey fish comfortable in the tidal flow. Large schools of orange anthias, blue angel fish and sergeant majors danced and turned over the boulders, red wrasse went about their business while scorpion fish surveyed the scene. Once across this slope we were on the wall of Big Munsom island. It was here I saw my first of many frogfish sitting oblivious to my interest while red and white cleaner shrimp debated my presence and quarrelsome tube blennies darted in and out of their tiny holes. Along this wall were red and white gorgonians and black coral trees encrusted in red and orange anemones. We were now almost out of the current following Big Munsoms coast around to the south. These walls run much deeper and the exposure is hypnotic as we began heading into the bay. And it was here that the last marvel was in store.
Now out of the current we headed along the gentle slope that runs from 20 metres to the surface and its here that I saw the soft coral trees. Individually each tree stands at almost a metre! They radiate six branches and the trunks have a diameter of almost 20cm. They are pink or purple and tower above all life around them. Ive never seen soft coral species of this scale before. These trees are Fjordlands sea pens multiplied thousands of times in size and even here seem totally out of scale with their environment. As we headed up the slope for our stops I had time to ponder the incredible variety of this diving: how species that I would usually separate between temperate and tropical coexist in abundance, and how species have adapted and thrived in water temperatures that in other parts of the world mean death and extinction.
I have dived at other sites that Ive enjoyed as much and still reckon that the Poor Knights and White Island are hard to beat. I did notice the absence of many temperate and tropical species on Jejudo. I didnt see urchins, eels, stingrays, crays, sharks, turtles, sharks or Nemo (although I was informed he is usually around). But what I did see is the strongest argument for a continuing and increasing respect for the variety and wonders at work in the worlds oceans. There is humility in understanding that man is one species amongst many. Species whose variety and adaptation never cease to amaze, captivate and teach us more about our spectacular water planet.