Common Smooth-hound Shark

(Mustelus mustelus)

Spottie, Gummie, Gummy shark, Spier haai, Dusky smooth-hound shark

1. What is it?

Common smooth-hound sharks (Mustelus mustelus) are slow-growing, long-lived, low-fecundity fish maturing between 7 to 12 years of age. Their life history traits make them vulnerable to over fishing and a recent increase in exploitation of these species (target and bycatch) has left stock levels as unknown. Common smooth-hound sharks are classified as Vulnerable on IUCN’s red list of threatened species.

2. How was it caught or farmed?

Linefishing

Common smooth-hound sharks may be directly targeted in the linefishery sector or indirectly caught as bycatch. Linefishing is a relatively selective fishing method which targets a large number of species many of which are reef-associated but also includes a few pelagic species. When targeting pelagic linefish species, the linefishery is not likely to cause significant damage to overfished, vulnerable or ETP species, which are nearly all reef-associated. The reverse is true when targeting for reef-associated linefish species like common smooth-hound sharks. The fishery has few discards and there are very few “non-target” species landed in the sector.

Inshore demersal trawl

Common smooth-hound sharks are caught as bycatch in inshore trawl fishery for hake (MSC certified) and sole using trawl nets. In the inshore zone, trawl nets are dragged along the sea bed at depths in the area from the coast to the 110 m isobath or to 20 nautical miles from the coast, whichever is the greater distance. Demersal trawling is known to damage the seabed; the extent and impact of this damage remains unknown. This methodology is not selective, however, and a number of other benthic species are often caught in the nets as well. Seabird bycatch was highlighted as an issue and the subsequent introduction of tori lines (lines covered in coloured streamers making attachment lines more visible to birds) has led to a decrease in bird mortalities.

Shark demersal longline

Common smooth-hound sharks are caught in shark demersal longline line which consists of a bottom set double-line system. There is limited information available of the current ecosystem impacts of the fishing, such as discards, bycatch and impact on endangered, threatened or vulnerable (ETP) species due to the lack of an effective observer programme. Historically, there has been concern regarding the impact of the fishery on vulnerable seabirds and sharks.

3. Where is it from?

Linefishery

Common smooth-hound sharks are caught within the inshore zone south of Durban to Namibia. Management for the sector is considered partly effective. In South Africa, this sector is principally managed through a total allowable effort (TAE) limitation and there are additional restrictions to protect overfished species such as bag limits (1) for recreational fishers. There is some concern over the impact of the small-scale fishery rights allocation beyond the recommended TAE and the continuously growing recreational sector.

Inshore demersal trawl

Common smooth-hound sharks are caught between Cape Agulhas and the Great Kei River at depth shallower that 110 m. Management is considered to be partly effective. Management is mainly directed at the target species hake (MSC certified) and sole in the form of Total Allowable Catch (TAC) and permit limitations. Some ecosystem-based management measures have been implemented, such as the use of tori lines to minimize seabird interactions and limited fishing areas. A fishery conservation project (FCP) was developed to test a co-management approach for 10 non-target species in the sector. Other concerns include the lack of information on impacts to sensitive shark, skates and ray populations as well as impacts to the seabed. Efforts are underway to improve the scientific observer coverage at sea for this sector to better understand ecosystem impacts.

Shark demersal longline

Common smooth-hound sharks are caught within the inshore zone south of Durban to Namibia. Management for the sector is considered partly effective. This sector is principally managed through a total allowable effort (TAE) limitation as well as area and bycatch limitations. Recreational fishers are subject to a bag limit of 1 pp/pd. There is no formal scientific or management working group for this fishery and therefore it is currently managed as part of the linefish working group.