Environmental Services

Invertebrate sampling

Marine invertebrates caught by bottom trawl activities have not featured much in the sampling strategies of the South African marine research and commercial trawling systems and only in more recent times has the data been sufficiently detailed to be confidentially useful for management.

As part of the sustainable use and management of the marine ecosystems and to continue to remain certified by the Marine Stewardship Council, the avoidance of VMEs (Vulnerable Marine Ecosystems) by the hake trawl fleet is important and are now managed by implementing a commonly accepted protocol and move on rules (MOR). Within the South African bottom trawl footprint some of the vulnerable areas have already been identified and partially protected by the recent promulgation of the offshore MPAs. However, there are potential areas not yet identified as vulnerable and the observing of commercial trawls for invertebrate species will help to identify such areas.

The sampling protocol requires that the observers collect all the invertebrates (excluding squids and octopuses) from one, randomly selected, trawl per day. These were counted and the VME indicator species were retained (bagged and tagged) for weighing ashore. Indicator species are listed in the VME Move-On Rule protocol circulated to all companies and vessels in the fishery.

The invertebrate sampling strategy was initiated in April 2020. Since then, the observers have sampled 255 trawls for invertebrates over 31 trips. Approximately, 8028 invertebrate specimens and 251 VME indicator species were identified and counted and the VME weighed.