Seabird researchers and marine scientists are watching anxiously to see whether the mass death of sardines along the Cape coastline may have a ripple effect on the already critically endangered African Penguin population.

📰 Here's What Happened

The researchers say it is too early to draw any firm conclusions, but there have been worrying findings so far of weight loss in birds at three of the seven penguin breeding colonies - Dyer Island, Stony Point (Betty's Bay) and Robben Island - that coincides with the sardine die-offs of recent weeks. However, the data has also shown some subsequent recovery from this weight loss.

The current sardine die-off in South African waters could be partly the result of a viral infection caused by the pilchard herpesvirus pathogen, although this is still to be fully confirmed by laboratory studies. (The terms sardines and pilchards are used interchangeably for the same species.)

This is the first time that this virus has been reported in South African sardines.

📌 Key Details

Researchers are particularly concerned because two similar mass sardine die-offs in Australian waters in the 1990s associated with the virus coincided with large mortalities in the Little Penguin population and significantly reduced its breeding success in the following years.

The African Penguin is listed as "critically endangered" and the species is being intensively monitored at its breeding sites. Current estimates put the population at about 19,800 mature individual birds and only 8,750 to 9,900 breeding pairs.

Monitoring includes the use of small weighbridges - automatic scales - that are part of a larger Automated Penguin Monitoring System that weighs birds and tracks the direction of their movement along well-established pathways in the breeding colonies without disturbing them.

Currently there are weighbridges at five of the seven African Penguin breeding colonies (one is currently out of commission), and there are plans to install two more.

Weight is one of the critical indicators of a penguin's health. These birds weigh 2.2-3.5kg, or as much as 4kg in some populations or before moulting.

Dr Alistair McInnes, Seabird Conservation Programme Manager for bird conservation group BirdLife South Africa, a key partner in the monitoring programme, said they were still analysing recent data from the weighbridges that coincided with the sardine die-off.

📰 Source: AllAfrica Global