The Penguin Debate Continues - Food for thought!

13 Nov 2014
13 Nov 2014


Extract taken from by Michael Cherry, November 13 2014, 07:41 – FINANCIAL MAIL

IN TABLE Bay, 7km west of Cape Town, lies Robben Island, famous as the site where Nelson Mandela was incarcerated for 18 of the 27 years he spent behind bars. It is now a museum, visited by up to half a million tourists each year.

But it is the island’s African penguins that are the new news story among SA’s marine science community. At stake is the fate of the species, which was listed as endangered by the International Union for Conservation of Nature last year; and a model for managing conflict between predators and fisheries in similar marine ecosystems globally.

The African penguin has a restricted distribution and breeds in colonies, mostly on islands, between southern Namibia and Algoa Bay. Numbers fell by 90% during the 20th century and have since declined by a further 64%, from 61 000 breeding pairs in 2001 to 22 000 in 2013. No-one knows exactly why but the multiple possible causes of this decline include oil pollution, fishing and climate change.

One plausible cause is fishing, which may be depriving the penguins of their most important food source, anchovy and sardines.

In an effort to determine the extent to which penguins and fishermen compete with each other, the now defunct department of environmental affairs & tourism initiated an experimental study in 2008 involving four islands: two on the west coast, Robben and Dassen (55km to the north); and St Croix and Bird islands, 50km apart in Algoa Bay.

In each case a 20km zone around one island in each pair was closed to pelagic fishing for a three-year period while the other island remained open as a control, before reversing the situation.

Penguin populations and fish abundance have been monitored, respectively, by the new departments of environmental affairs; and agriculture, forestry & fisheries (Daff).

This is the first time that such an experiment has been conducted anywhere, though the effects of permanent fishing closures on kittiwakes in Scotland, and on Hector’s dolphins in New Zealand have been monitored. Johann Augustyn, secretary of the SA Deep Sea Trawling Industry Association, says the experiment is of broad significance as it is aimed at determining whether creating a no-take fishing zone can provide penguins with sufficient food to raise their chicks without having to forage over long distances.

BirdLife South Africa, which held a workshop last month to evaluate the experiment, would prefer permanent closure of all four islands to purse-seine fishing. Both St Croix and Bird islands will shortly be proclaimed by the SA National Parks Board as part of the Greater Addo marine protected area. A 20km zone around St Croix, and a smaller 7km zone around Bird Island would then be permanently closed to fishing.

But whether the alternate closure of Robben and Dassen islands should continue has become the subject of a fierce debate between two different camps of researchers within the Marine Research Institute at the University of Cape Town. There are those who follow an “ecosystem approach” versus those who have a stock assessment view of fisheries management. The former considers a much wider set of management objectives than the management of a particular targeted resource……..\

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