The Case of the Disappearing Sea Cucumbers

by John MacMahon

One of the projects that Blue Ventures has got involved with in order to empower the local people, and give a sustainable alternative to traditional fishing is that of sea cucumber farming. Approximately 2 weeks prior to this trip Georgie had brought about 1400 juvenile sea cucumbers from Toliara up to Andavadoaka and then on to Ambolimoke in the north of Velondriake, where 4 purpose built pens have been built to house the cucumbers and allow them to grow. The beauty of the project is that although farmed, the cucumbers require little attention except to ensure there are no natural  predators in the pens and moreover that no one steals them!

So the trip in question was that a status update was required as to how the project was progressing, and the ideal time to do this is at low tide.  With spring tide occurring 2 weeks following their arrival the timing was perfect so Romney, Axelle and a dozen enthusiastic volunteers boarded our pirogues after a days diving for the two day mini expedition. So the thing that probably needs that mentioning at this stage, in case the reader did not realise it – as the writer did not – is that the cucumbers only come out at night; residing in the sand during daylight hours. With low tide at circa 12am (midnight!) this in turn meant surveying at 10pm! i.e. 2 hours after our some of our usual bed times.

To sum up what the monitoring involved, basically 4 of us got into a 12x12m square pen, at about 50cm (max!) depth with a dive torch and floated about trying to spot cucumbers in sea grass with about 30cm visibility! Not as easy as it sounds!!! We hoped to find approximately 300 cucumber in each pen, a total of 1200. Unfortunately though after over 2 hours searching in each pen over the two nights a total of only 500 cucumbers were found. The reasons why this is have yet to be determined, however there were certainly more than a few predators – along with a few unidentified species of sea slug (aliens according to our resident marine scientist Romney), a few cow fish, crocodile fish, eels and many others that gave a few of us more than a mild scare when reaching down into the unknown…

On both nights we stayed on the beach and the day was spent reading, playing cards, or for the more adventurous amongst us an attempted trip to the mangroves that was somewhat thwarted by first, an overloaded sinking pirogue, then by the spring tide, then by zero visibility and finally by a swarm of blood thirsty mosquitoes. In the evenings we had food courtesy of the village president’s wife, which was very much appreciated by one and all, with many of us having octopus for the first time in the form of a gorgeous stew on the second night. A few rums may also have been had around the expertly constructed Russian camp fire post snorkeling and the sun woke one and all early the next morning for our return trip back to base – a very tired but adventure laden bunch.

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