Ocean News

Living by the Tides

17th March 2008
Our life revolves around the tides, high tide, low tide and the severity of the level. If we are on the island and the tide is too low the boat cannot navigate over the reef and if we are on the outside of the reef and the tide drops too low before we return we cannot get back to the island until the tide turns and the water level rises. It takes about six hour on average for a complete turn in the tides, for high tide to become low and visa-versa. Thus, this morning we did not set out until 12h00, on the incoming tide when the water was sufficient for us to glide out without touching any corals, and returned full speed at 17h30 just in time to get back over the reef.
With a low tide the reef is exposed and this morning it was covered in startling white egrets fishing in the shallows. From my room they look like the sails of miniature sail boats floating across a flat bay. Rainer spent the morning stalking them with his 300mm lens, while I photographed the scientific officer’s 3 year old splashing in the shallows with her friends – the black tip reef sharks.
At midday we headed out to dive the bait station number 2 that we fixed to the reef on the Atoll’s outer rim reef yesterday to see what shark species, if any had come in. After drifting over the reef’s edge, where it drops from about 10m to more than 30m, with a baited drum following us we found an area on the reef that looked like a particularly productive spot, with plenty of yellow banded snappers, bohar, humpback snappers, a large assemblage of groupers and many more. One grouper was particularly grumpy today and tried to swallow my flash strobe several times – it has even left teeth marks on it! So you see it is not the sharks that give the problems. I saw four green turtles swimming out over the drop off and into the blue, but our turtle spotting expert, Kim, must have seem about twice as many. It looked like it had potential – in other words we thought that a slick of potent fish oil had a good chance of attracting in some large sharks.
After refilling the bait tube a few black tip sharks, a couple of sicklefin lemon sharks and one tawny nurse shark swam in to investigate. Disappointing results, which mirrored exactly what Dr Ormond and the SOSF team found on the preliminary expedition last year. Are we baiting in the wrong area or are there simply no more large shark species left to find the odor corridor?
Determined to find the answers we continued on to investigate the next site. Venturing up the main channel for the first time it felt like we were traveling up a river in the ocean and only then did I really get a grasp on how large the lagoon itself is. The main channel is the main channel for a reason – approximately 60% of the lagoon’s tidal flow passes through it between our island Picard and Polymnie. Smaller channels branch of the main channel and we spotted one grey reef shark when we hopped in the water to look at the reef drop off along one of these smaller channels.
Further up the main channel we squeezed in a quick snorkel, and it turned out to be the best of the day. I photographed a hawksbill turtle lying amidst the coral and Dan caught a glimpse of a great hammerhead before he turned about in terror at the sight of us, and we couldn’t find him again.
The whole day has been overcast and both this morning and this afternoon we were pelted by a tropical downpour. The tide tells us to head out at 6h00 tomorrow, so we will have a full day. All the more time to see what sharks we can find.
Meanwhile the remotely operated camera is doing a test run overnight in the shallows off the beach and I wonder how many black tip reef sharks are swimming through James and Dr Ormond’s computer screen.

Our life revolves around the tides, high tide, low tide and the severity of the level. If we are on the island and the tide is too low the boat cannot navigate over the reef and if we are on the outside of the reef and the tide drops too low before we return we cannot get back to the island until the tide turns and the water level rises. It takes about six hour on average for a complete turn in the tides, for high tide to become low and visa-versa. Thus, this morning we did not set out until 12h00, on the incoming tide when the water was sufficient for us to glide out without touching any corals, and returned full speed at 17h30 just in time to get back over the reef.

With a low tide the reef is exposed and this morning it was covered in startling white egrets fishing in the shallows. From my room they look like the sails of miniature sail boats floating across a flat bay. Rainer spent the morning stalking them with his 300mm lens, while I photographed the scientific officer’s 3 year old splashing in the shallows with her friends – the black tip reef sharks.

At midday we headed out to dive the bait station number 2 that we fixed to the reef on the Atoll’s outer rim reef yesterday to see what shark species, if any had come in. After drifting over the reef’s edge, where it drops from about 10m to more than 30m, with a baited drum following us we found an area on the reef that looked like a particularly productive spot, with plenty of yellow banded snappers, bohar, humpback snappers, a large assemblage of groupers and many more. One grouper was particularly grumpy today and tried to swallow my flash strobe several times – it has even left teeth marks on it! So you see it is not the sharks that give the problems. I saw four green turtles swimming out over the drop off and into the blue, but our turtle spotting expert, Kim, must have seem about twice as many. It looked like it had potential – in other words we thought that a slick of potent fish oil had a good chance of attracting in some large sharks.

After refilling the bait tube a few black tip sharks, a couple of sicklefin lemon sharks and one tawny nurse shark swam in to investigate. Disappointing results, which mirrored exactly what Dr Ormond and the SOSF team found on the preliminary expedition last year. Are we baiting in the wrong area or are there simply no more large shark species left to find the odor corridor?

Determined to find the answers we continued on to investigate the next site. Venturing up the main channel for the first time it felt like we were traveling up a river in the ocean and only then did I really get a grasp on how large the lagoon itself is. The main channel is the main channel for a reason – approximately 60% of the lagoon’s tidal flow passes through it between our island Picard and Polymnie. Smaller channels branch of the main channel and we spotted one grey reef shark when we hopped in the water to look at the reef drop off along one of these smaller channels.

Further up the main channel we squeezed in a quick snorkel, and it turned out to be the best of the day. I photographed a hawksbill turtle lying amidst the coral and Dan caught a glimpse of a great hammerhead before he turned about in terror at the sight of us, and we couldn’t find him again.

The whole day has been overcast and both this morning and this afternoon we were pelted by a tropical downpour. The tide tells us to head out at 6h00 tomorrow, so we will have a full day. All the more time to see what sharks we can find.

Meanwhile the remotely operated camera is doing a test run overnight in the shallows off the beach and I wonder how many black tip reef sharks are swimming through James and Dr Ormond’s computer screen.