Record breaking kelps off Cape Point

The winner (© 2015. AJ Smit).
The winner (© 2015. AJ Smit).

Last week Friday we went diving off the tip of the Cape of Good Hope. It was a dive we had been planning for months, only generally being accessible when the ocean swell is completely down. It was the perfect day: False Bay was flat as a pond, and after the deeper dive off the Point (~14 m) we spent the rest of the day in the Bay doing various bits of kelp research.

But the point of this piece is to talk about the giant specimen of Ecklonia maxima that the divers (Thomas Wernberg, Robert Schlegel and Eric van Onselen) found. In a previous post I mentioned that there were unconfirmed reports of E. maxima specimens of up to 15 m in length – I don’t know where from. As far as I was concerned these were legendary – almost mythical – kelps as I don’t know anyone who has ever actually seen one, of if they think they did, really measured one.

Underwater view of the Cape Point Ecklonia maxima forest (© 2015. Thomas Wernberg).
Underwater view of the Cape Point Ecklonia maxima forest (© 2015. Thomas Wernberg).
Taking kelp off the boat at Buffels Bay, Cape Point (© 2015. AJ Smit).
Taking kelp off the boat at Buffels Bay, Cape Point (© 2015. AJ Smit).

We measured them. Thirteen of them. The maximum length is 16.91 m, and the average is 13.41 m. There are some interesting morphometric relationships between these kelps and those from other populations, but more of this in forthcoming publications.

 

We also sampled Laminaria pallida from the same deep site, and these are equally impressive. Generally Laminaria is a smaller kelp in stature. On average they are around 2.38 m in length, but the average length of the population at the deep site is 3.53 m. Interestingly, Stegenga, Bolton and Anderson’s 1997 red book mentions specimens to 10 m long in the northern portion of South Africa and into Namibia. I am not convinced, but we will certainly search for them.

 

 

 

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