Conservationists concerned over cob spawning migration

Conservationists concerned over cob spawning migration

Urges anglers not to injure the fish whilst removing hooks or releasing the fish back into the water….

Floris Steenkamp

Anglers and conservationists discovered an alarming number of dead cob on the beaches south of Walvis Bay. That is since the annual cob spawning migration reached this area. There is only one explanation for the large numbers of dead cob: anglers don’t know the correct procedure to follow when they release the fish into the sea and the wrong type of hook is used on the tackle.

It is illegal to catch and keep cob between Pelican Point and the border line with Sandwich Harbour between 1 January and 31 March of each year. Many anglers continue to flout this angling regulation, but in recent days fisheries inspectors renewed their efforts to catch and fine the culprits.
Releasing cob is the only option to anglers fishing in the area. However, anglers fail to adopt the proper techniques to release the fish safely into the water. They injure the fish and the fish dies shortly after being released. In other instances, anglers using the wrong hook-type which also leads to injuring the fish and death shortly after being placed back into the water.
Conservationists and fisheries inspectors are urging anglers to use only “Circular-shape” fishing hooks, as these hooks can only capture the fish by the lip or parts of the mouth where it does not harm the fish.
The “J-shape” hook is easily swallowed by the fish and in removing it damages the fish’s gill’s, oesophagus and stomach. The fish is injured during the process to remove the hook. It dies after release.
An angling expert said this week in this instance it is best to cut the line as close as possible to the hook and allow for the fish’s body to loosen and remove the hook over time.
Furthermore, anglers are also urged not to throw the fish back in the water upon releasing it. Fish have an internal air bladder. If thrown back this bladder can burst and the fish turns upside down, washes ashore and dies. Throwing back the fish can also lead to damage to other internal organs.
It is also important to keep the protective layer of mucus (slime) on the fish’s body intact. If that layer is damaged in any way, the fish is open to disease. The mucus layer is in actual fact part of the fish’s immune system.
It is also not advisable for anglers to carry heavy fish by the gills if the plan is to release it. Gills are vulnerable and the fish’s weight can result in the angler’s fingers or hand damaging the gills. Even the smallest of damage to the gills can result in the fish dying soon after release due to a lack of oxygen.
In areas outside the closed zone: anglers are also warned not to risk going fishing without an angling license and it is important to stick to fish size and bag limits.
An angler can catch a total of ten fish a day, irrespective whether the catch consists of a single species or more than one species.

In the case of cob the fish may not be smaller than 40 cm and only two of the ten fish allowed as a bag limit may exceed 70cm in length.
The life of cob. Cob start their lives as juvenile fish soon after the annual spawning between Sandwich Harbour and Meob (about 180km stretch). Shoals upon shoals of adult fish varying in size between 60cm and 120cm move south from the Skeleton Coast every year to Sandwich Harbour to spawn. The so called spawners vary in size between 70cm and 120cm.
The females release their eggs and male spawners fertilise the eggs. The shoals move deeper into the ocean after the spawning and moves northwards again to the Skeleton Coast.
In an effort to protect the spawner segment of the Cob biomass, only two Cob of 70cm and more in length are allowed per angler.
Furthermore, Sandwich Harbour is permanently closed to allow for the spawning process and the subsequent development of the fish larvae to take place unhindered.
The fish larvae are washed by the sea currents in a northerly direction during which the fish grows to 30cm within the first year and to 40 cm in the second year. Cob would spend several more years off the Namibian coast between Swakopmund and the Ugab-mouth reaching adult size.
As the fish reaches adult size, they too migrate in a northerly direction to join the spawner population off the Skeleton Coast where they eventually too reach spawning age.
And so, the process is repeated each season to migrate to Sandwich Harbour to spawn.

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