Not all good news for the threatened Black Cod of the Solitary Islands
The recently published Scientific study by Drs David Harasti and Hamish Malcolm has proven what we have suspected with the many years that we have dived the Solitary Islands Marine Park.
The Black Rockcod (Epinephelus daemelii) or what we call Black Cod are a regular sighting at South Solitary islands, however we should consider ourselves very lucky because it is probably the largest population of the threatened fish. We find these magnificent large fish mainly in the sanctuary zones of South Solitary Island. In fact we know where they are usually sitting either in gutters or around rocks that they blend in with. They change their colour as they move from caves, where they are all black, to a motley stripped effect and even all grey, when they are out in the water column. They vary in size with the largest around 1.2 metres. They can be very timid, but if divers are slow and careful on their approach, they can get quite close to the large fish and catch a good picture or video.
Are the Sanctuary Zones big enough?
After reading the findings of the Scientific paper, we feel that why the numbers are not increasing is because of accidental hook-up of the species, which can lead to injury and death. Over 28 years, and thousands of dives in the area, we have seen that Black Cod grow and then disappear. On the northern side of South Solitary island, where we see the largest number of Black Cod, we see a high percentage of Black Cod with hooks hanging from their mouths. We have also seen a large dead black cod with a spear hole and on a number of occasions helped swim Black cod down to depths to save them, as their swim bladders have blown up due to rapid rise to the surface on a fishing line. Without our help, those fish would have died, floundering on the surface.
The Back Cod doesn’t appear to go far from their hiding spots, but unfortunately for them, they wander out beyond the boundaries of the sanctuary zones designed to protect them. We see them in the water column and in deeper water over the 100 metres zone from the island. However we don’t see them out any further. We believe that for the Sanctuary zones to be effective, they need to extend beyond 100 metres to a point where the depth of water is beyond 30 metres. maybe then, we will see an increase in the threatened Black Cod numbers.
