Taxonomic Notes
There are three sub-species: P. homarus homarus found throughout the range; P. homarus megasculpta is known only from the northern Arabian Sea; and P. homarus rubellus is found southern East Africa, from Mozambique to Natal and southeast Madagascar (Holthuis 1991).
Justification
Panulirus homarus has been assessed as Least Concern. This is due to its widespread distribution that covers a number of regions and ocean systems. It is harvested throughout its range, and known to be over-exploited in some regions, which has caused localised depletions; however this is unlikely to have a significant impact on the global population. Monitoring of harvest levels, particularly catch-per-unit-effort data, should be carried out to check for possible increases in fishing, together with stricter enforcement of current management regimes.
Geographic Range Information
This species has a broad geographic range extending from East Africa to Japan including Indonesia, Australia, New Caledonia and the Marquesas Archipelago (Holthuis 1991).
Population Information
The main concentrations of this species are said to be off the coast of East Africa and Indonesia (Pollock 1993).
This species is harvested throughout much of its range, although it most commonly taken in Kenya, South Africa and Indonesia. Despite this species widespread nature, information on harvest rates, and species ecology and biology is lacking (Kulmiye and Mavuti 2005).
Africa
It is the second most important lobster fishery in Kenya (Kulmiye and Mavuti 2005) and accounts for 32% of the catch (Kulmiye et al. 2003). The Kenyan lobster fishery is artisinal with spears constituting the main fishing method (Kulmiye and Mavuti 2005). Annual harvest of Panulirus species (P. homarus, P. longipes, P. ornatus, P. penicillatus and P. versicolor) is approximately 70 tonnes.
In Somalia, the annual landings of Panulirus spp. is approximately 2,100 tonnes, of which this species constitutes the majority of the catch (Phillips and Melville-Smith 2006).
Along the coast of South Africa, this species comprises a significant portion of the intertidal lobster fishery where there is a subsistence and recreational fishery. The recreational fishery is said to harvest approximately 150 tonnes per year (Cockcroft and Payne 1999). Due to poor enforcement, fishing of individuals below the minimum legal size of 65 mm (CL) is common (Fielding et al. 1994).
Asia
This species is the most important lobster fishery off India particularly around Kerala and Tamil Nadu. This is a commercial fishery; gear types include anchor hooks, traps and gill nets (Holthuis 1991) and trammel nets (Radhakrishnan et al. 2005). In the southwest coast fishery (mainly Colachel and Muttom) landings have decreased from a peak of 301 tonnes in 1966 to 4 tonnes in 2002 of which P. homarus comprised 92% of the catch. In the southeast coast fishery (Kanyakumari to Chennai), the gillnet fishery of Kayalpattinam saw increases in catch from 42.2 tonnes (catch per unit effort = 6.5 kg/unit) in 1993, to 50.6 tonnes (catch per unit effort = 5.5 kg/unit) in 1994, however there has been a subsequent decline to only 4.4. tonnes (catch per unit effort = 1.1 kg/unit) in 2002. There was also an observed decline in the average length of caught individuals from 245 mm (TL) in 1978 to 145 mm (TL) in 2002, indicating growth overfishing. The other major gill net fishery in the south-east, Tharuvaikulam, has also seen notable declines from 11 tonnes (catch per unit effort = 1.1 kg/unit) in 1993, to 1.1 tonnes (catch per unit effort = 0.6 kg/unit) in 2002.
This species is also harvested in Taiwan and Thailand (Holthuis 1991) although no data appears to be available on harvest rates or landings.
Habitat and Ecology Information
This species is commonly found in very shallow waters (1 - 15 m), although can be found to depths of 90 m. It utilises rocky reefs for shelter (Holthuis 1991).
In Kenyan waters, functional maturity in females is said to be attained at 5.05 cm (CL) while in males it is 5.75 cm (CL) (Kulmiye, Mavuti and Groeneveld 2006).
Threats Information
Over-exploitation by fisheries is likely to be a localised threat to this species.
Use and Trade Information
This species is harvested throughout its range, ranging from recreational catch through subsistence and artisinal practices to commercial operations. Information shows catches are between ~1.1 tonnes to ~2,100 tonnes per year.
Conservation Actions Information
There are few restrictions on the harvest of this species. The few restrictions that do apply, such as minimum legal size, are poorly adhered to.
Further research on this species ecology is recommended. Management strategies for this species need to be developed and enforced to maintain or rebuild populations to a sustainable level. It is recommended that accurate fisheries data be collected and monitoring of CPUE to create a baseline of data to measure trends into the future.