Dorado

(Coryphaena hippurus)

Dolphinfish, Mahi mahi, Dolfynvis

1. What is it?

Dorado (Coryphaena hippurus) are fast-growing, widely distributed fish that display nomadic movement behaviour. This makes them fairly resilient to high fishing pressures. Currently, the stocks are rated as data deficient as no recent stock assessments have been conducted for the Pacific and Indian Oceans.

2. How was it caught or farmed?

Linefishing

Dorado is caught using the rod-and-reel or handline method of the traditional linefish sector. Linefishing does not harm the surrounding habitat and bycatch of vulnerable, overfished or endangered species is minimal as this type of fishing methods is selective.

Pelagic longline

Dorado mainly caught as bycatch in the South African pelagic longline fishery for tuna and swordfish. Pelagic longlines consists of a double-line system suspended at different depths covered in baited hooks and which are several kilometers long. Bycatches are a significant issue in the fishery. There are bycatches of seabirds, fish, sharks and turtles, many of which are listed as vulnerable and the fishing pressure may affect their population rates significantly. While recent reports showed that observed bycatch and discard rates in the tuna sector is low, little is known regarding bycatch and discard rates in the swordfish sector.

Imported - pelagic longline

Dorado is mainly caught using pelagic longlines. Pelagic longlines consist of a double-line system suspended at different depths covered in baited hooks and which are several kilometers long. Bycatch is a significant issue in the fishery as catches of non-target species sometimes exceed that of the target species. Bycatch of endangered, threatened or vulnerable seabirds, fish, sharks and turtles is considered to be an issue as even a small number of catches could significantly affect their population sizes.

Imported - gill nets

Dorado are also caught using surface set gill nets which consists of a wall of netting suspended in the water column. Gillnets have high levels of bycatch and a low survival rate, which results in high discard rates. Bycatch often consists of a number of endangered, threatened or protected (ETP) sharks, turtles, marine mammals and birds. As the nets do not come into contact with the seafloor; there is little damage to benthic habitats.

3. Where is it from?

Linefishing

Dorado is caught all along the coast of South Africa. Management is considered partly effective through the use of a total allowable effort (TAE) limitation. There is some concern over the impact of the small-scale fishery rights allocation beyond the recommended TAE and the continuously growing recreational sector.

Pelagic longline

Dorado are found all along the coast of southern Africa. Management in this fishery is considered only partly effective largely due to insufficient monitoring of impacts to threatened species and a comprehensive plan to manage these impacts. In particular, the sector still permits directed shark fishing through various permit exemptions although intentions have been made to phase this out.

Imported - pelagic longline

Dorado are cosmopolitan fish found throughout the Indian and Pacific Oceans and imported into South Africa. As dorado are often caught alongside tuna, it is managed as part of the Inter-American Tropical Tuna Commission ( IATTC ). Management in this fishery is considered to be marginally effective, due to insufficient monitoring of impacts to threatened species and a comprehensive plan to manage these impacts. In addition, data collected is not always accurate and IUU fishing still takes place due to poor levels of enforcement.

Imported - gill nets

Dorado are cosmopolitan fish found throughout the Indian and Pacific Oceans and imported into South Africa. Management for the gill net fishery is different to the pelagic longlines as it is largely the responsibility of each country in the region to regulate usage. Management by each country is considered to be poor as very little effort has been made to reduce bycatch or regulate catches.