Tuesday, February 2, 2016

Nudibranch and octopus

The title sounds a bit like a recipe for a none too appetising seafood platter but it actually best describes my dive off the Tutukaka coast at the weekend.

I was attending a farewell gathering held in Tutukaka for Phil Bendle and his amazing wife Faye before they returned to Taranaki to enjoy their retirement. Prior to his retirement two years ago, Phil had been the skipper of the outstanding charter boat ‘Norseman’ for two decades, taking underwater photographers and divers to the world famous ‘Poor Knights Marine Reserve’. Just from seeing those who attended, it was very apparent to see how much Phil and the Norseman contributed to the development of diving in New Zealand.

My dive started with a drive around the local coastline. There was not even a hint of swell on the ocean, so my surfboard stayed stowed in its bag (every time I take the surfboard the sea is flat, but when I don’t take the surfboard the surf breaks are absolutely pumping… go figure!). Luckily I'd packed my dive gear in addition to the surfing gear, so I eventually settled on a dive site near the mouth of the Tutukaka Harbour. Having scrambled down to the rocky beach in my dive gear, I eagerly entered the water. At 20C the east coast water was considerably warmer than in Taranaki, and the visibility was verging on 20m.

About 30 minutes into my dive, I pulled myself through a tight swim-through in the lava rock formations making up the fish infested reef and something caught my attention. It was a sharp bright green colour on a slightly darker patch of green algae. The contrast was only really possible because of the clear water and having the midday sun directly overhead, but it certainly stood out even to me and I’m colour blind! Upon closer inspection, I saw what looked like a green butterfly with vibrant little blue spots dashed about it’s “wings” and body. The head had the most beautiful graduated blue coloured rhinophore (stalk like organs used to smell odours in the water). I got the surprise of my life when I put my gloved finger next to it to get a sense of its size… it was tiny compared to my finger’s width weighing in at about 16mm in length. This was a perfect illustration of how objects appear 25% larger in water than on the surface. I stayed watching the rarely seen nudibranch (later identified as Elysia Sp. 4) for over 10 minutes as it grazed away on the algae. I finally said my goodbyes and left it merrily chomping away.

I had only moved about 1m away from the nudibranch when I looked up into the piercing gaze of an octopus’s eye. A rush of excitement gripped me and I soon manoeuvred myself to within 80cm of its head. The tentacles were all rolled up in the small hole it was hiding in except for one. This tentacle, I presumed, was the one it was using to catch anything that walked/swam close enough to be grabbed and digested. The octopus had matched the surrounding rocks, sponges, and seaweeds with its perfect camouflage colouration, but it also remarkably pulled its flesh to form little spikes to better match the texture of the background reef. It took ages before the octopus accepted that I was no threat to it and slowly rolled out its free tentacle towards me. Just before the tentacle touched my dive suit the octopus started to pulse the colour pigments in its eye in a rapid rolling black to light grey pattern and then it stopped short of touching me, gently retracting the tentacle. I took this to mean it might have been a bit stressed by my presence so I backed off and gave it some space.

Finding lots of swim-throughs and dark undercuts in the reef, I played about with the smaller fish that were taking refuge in there. Shoals of juvenile fish like bigeye and two spot demoiselles peered out from the sanctuary of their hiding places. It was not long before I discovered another much bigger octopus. In no time at all, it was time to be returning to shore and I took a bearing for the beach. Swimming around the large pinnacles and lava rock outcrops, I snaked my way back at full steam. Taking a break from the swimming in 6m of water I stopped, but something took my attention from the corner of my eye. Looking right, I saw the familiar shape of an octopus, but this was no ordinary octopus because it was bloody huge in size and was spanning the entrance to a cave with it tentacles fully stretched out effectively blocking the entrance. I could hear rock lobsters cracking away from within and it looked like they were about to become dinner for the octopus!

The dive was soon over as I approached the abruptly sloping beach. Suddenly I saw a panicked motion in front of me. I had no idea what it was that was trashing about in the shallows trying to escape the water so I surfaced the last metre popping my head out of the water to hear screams of terror! Through my mask I could make out a family with young children retreating quickly up the beach. Apparently my sudden unidentified appearance in the water had startled the children who were paddling at the waters edge and they had bolted for the safety of dry land! :o)