|Scientific Name:||Actinopyga mauritiana|
|Species Authority:||(Quoy & Gaimard, 1833)|
Muelleria mauritiana (Quoy & Gaimard)
Muelleria varians Selenka, 1867
There are a few different morphs in the Africa and Indian Ocean region (Conand 2008) which may make correct identification of the species difficult.
|Red List Category & Criteria:||Vulnerable A2bd ver 3.1|
|Assessor/s:||Conand, C., Purcell, S. & Gamboa, R.|
|Reviewer/s:||Polidoro, B., Harwell, H. & Carpenter, K.E.|
This species is commercially exploited throughout its range, and is a medium value species that is somewhat difficult to collect (as it can hide in crevices and is found on the reef crest). It is a common species that is becoming increasingly rare, but has relatively high fecundity. Based on a number of quantitative and qualitative studies, populations are estimated to be depleted and have declined by more than 60-90% in at least 60% of its range over the past 50 years, and is considered overexploited in at least 25% of it range although exact declines are difficult to estimate. The status of populations in East Africa are unknown, but it is known to be collected. Declines and over-exploitation have occurred primarily since the 1960s, and although generation length is not known, echinoderms are not considered to go through senescence and therefore may be greater than several decades. At present, global declines are therefore estimated to be between 30%-40% based on estimates of depletion and overexploitation across its range. This species is therefore listed as Vulnerable.
However, better and more quantitative data are needed to better estimate the impact of fishing on this species. If other shallow water species are continued to be fished out, effort for this species will probably increase even further.
|Range Description:||This species is found throughout the central Pacific and Indian Oceans. It occurs from eastern Africa and the Red Sea in the west, to Hawaii, and the Solomon Islands in the southeast. In Madagascar, this species is observed on the west coast from the south of Toliara to Nosy-be. It is common on the west coast of Madagascar from Fort-Dauphin to Nosy-be and in the northeast coast (Antongil Bay).|
Native:American Samoa (American Samoa); Australia; Brunei Darussalam; Cambodia; China; Comoros; Cook Islands; Djibouti; Egypt; Eritrea; Fiji; Guam; India; Indonesia; Kenya; Kiribati; Madagascar; Malaysia; Mayotte; Micronesia, Federated States of ; Mozambique; Myanmar; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Réunion; Samoa; Seychelles; Singapore; Solomon Islands; Somalia; Sri Lanka; Sudan; Tanzania, United Republic of; Thailand; Tonga; United States (Hawaiian Is.); United States Minor Outlying Islands; Vanuatu; Viet Nam; Wallis and Futuna
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – northeast; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
This species used to be common in many areas of its range, but is increasingly rare. This species has been depleted in at least 60% of its range (e.g. South Pacific, Philippines, Indonesia, Papua New Guinea). This species is considered overexploited in at least another 25% of its range (e.g India, Torres Strait) and the fishery has been closed in these regions. The status of populations that are fished in East Africa and the Red Sea are unknown and some statistics are unreliable. Depletion refers to commercially un-viable, and is estimated to represent an approximately 60 to 90% loss over the past 50 years (since the 1960s). In areas where it is considered overexploited, the population is difficult to estimate based on differences in regional and local fishing effort, but harvests have declined and based on traditional fisheries definitions overexploited is estimated to be 30% above maximum sustainable yield.
Several population surveys in the Western Central Pacific Region showed this species to be moderately common (Kinch et al. 2008), but later it was considered at low abundance in the same area. Similar findings are reported for Fakaofo and Atafu (Kinch et al. 2008). In the Cook Islands, most species of sea cucumbers were at low abundance, with the exception of Actinopyga mauritiana (Kinch et al. 2008). In the Solomon Islands, it was considered rare. In New Caledonia, populations of this species appear low and will need to be managed prudently to safeguard stocks from dwindling to levels where they cannot easily be repopulated naturally (Purcell et al. 2009).
In the Commonwealth of the Northern Mariana Islands (CNMI) a sea cucumber fishery started in 1995 mainly because of the relative abundance of Actinopyga mauritiana (and Stichopus chloronotus), and continued until 1996 when the fishery moved to Saipan due to a drop in harvest because of overexploitation. A. mauritiana made up ca. 99% of exports. Population surveys estimated that the population of this species was between 10-22% of its initial population size. In the Federated States of Micronesia (FSM), only A. mauritiana and S. choloronotus were believed to be abundant enough to support a commercial fishery, with A. mauritiana being the principal commercial species. In Nauru, the species seems to be the only commercially viable species. In Kiribati, it is part of a multispecies fishery that is considered overexploited after a short exploitation period between 2000-2002. On Wallis, there is a small but growing sea cucumber multispecies fishery targeting A. mauritiana. In Samoa, the bêche-de-mer fishery consists of ca. 30% A. mauritiana (Kinch et al. 2008).In Papua New Guinea, densities went from 12 individuals per hectare in 1992 to less than 2 individuals per hectare in 2006 (Kaly et al. 2007), representing an 85% decline. In the Torres Strait, this species was considered overexploited and the fishery was closed in 2003, with an indication of modest recovery in 2009 (Skewes et al. 2010). But the species here is still found in very low density, and a 90% decline is based on survey data in the 1980s (Conand 1989) and 2007-2008 (Purcell et al. 2009).
In Mozambique, high fluctuation in exports of Holothuria scabra, H. nobilis, H. fuscogilva, H. atra, Actinopyga echinites and A. mauritiana may be due to irregular reporting or to overexploitation. Catch was reported at 500 t in 1990, 700 t in 1993, 6 t in 1995, and 54 t in 1996. In Inhambane Province, holothurian fisheries are closed until stocks rebuild (Bruckner et al. 2003). In Madagascar, the level of exploitation of this species is increasing and there has been an estimated decline of 35% over 12 years for this species (Rasolofonirina pers comm. 2009). In Egypt, this species was second in abundance to Holothuria atra, however a survey four years after the official fishing ban showed no evidence of stock recovery (Conand 2008).
|Habitat and Ecology:||
In the Western Central Pacific Region, Actinopyga mauritiana prefers outer reef flats and fringing reefs, mostly in the surf zone between 0-20 m. This species is characteristic of the outer reef flats, as part of the medio-littoral reef community. Kinch et al. (2008) reports that it is more active during the day when it feeds on the substrate. In the Africa and Indian Oceans, A. mauritiana prefers the outer reef flats with surf influence over sand substrate between 0-5 m. It holds on to the hard bottom when exposed to wave action (Conand 2008). In China, A. mauritiana lives in depths between 10 and 50m (Li 2004). In the Red Sea, it is usually found in subtidal and intertidal sandy areas, as well as sea grass and sand lagoons in the coral reef zone. Members of this species can be found over a wide range of depths, however the majority are found between 5 and 10 m (Gabr et al. 2004). In Solomon Islands, adults are commonly found around solid reef rock and scattered tables of the coral Acropora sp. (Graham and Battaglene 2004).This species has a high fecundity and early sexual maturity. However, many sea cucumbers are broadcast spawners, which can limit the fertilization success of a species in exploited populations.
In Egypt, females reach Size at Maturity (SOM) at 23 cm TL (Gabr et al. 2004). In general, in Guam Actinopyga mauritiana reaches SOM at 158 g (drained weight) (Hooper 1998), whilst in New Caledonia it reaches SOM at 350 g (Conand 1993). In the Africa and Indian Ocean region, this species reaches sexual maturity at 23 cm TL (Conand 2008).
In Guam, the peak reproductive activity is between April and August, whilst in New Caledonia it is in December and January, and in the Solomon Islands from October until January (Kinch et al. 2008). Actinopyga mauritiania presents annual cycles that relates to ambient ocean temperature and photoperiod in Guam (Hopper et al. 1998). In Egypt it reproduces annually between spring and summer, and individuals are mature at 23 cm TL (Gabr et al. 2004, Conand 2008).
The generation length of this species is unknown. Its body size is not a good indicator of age or longevity. There is some indication, however, that many echinoderms do not go through senescence, but simply regenerate. Therefore generation length cannot be estimated, but is assumed to be greater than several decades in a natural, un-disturbed environment.
Although heavily targeted, Actinopyga mauritiana is difficult to fish because it is found on the exposed reef crest, and is somewhat cryptic (found in crevices). Although not one of the most important species (medium value) for fishery purposes, it can be expected that this species may become more popular after the depletion or reduction of other species of higher commercial importance and value. This scenario was seen in Fiji, after the decline of Actinopyga miliaris as well as in Torres Strait (Australia) after the decline of Holothuria scabra (Kinch et al. 2008a).
Excessive commercial harvest of this species is reason for concern in some of its range. Choo (2008) states that Actinopyga mauritiana is of commercial importance in China, Japan, Malaysia, Indonesia and Philippines. In Seychelles, it is one of the most important commercial species, along with five others, where it is considered to be overexploited (Aumeeruddy and Conand 2008). Depletion of wild stock in Egypt has prompted the study and possible development of an aquaculture venture (Gabr et al. 2004).
A 10-year moratorium on the harvest of all sea cucumbers was put in place across the CNMI in 1998. In Torres Strait (Australia), the Actinopyga mauritiana fishery was closed in 2003 due to overexploitation (Uthicke 2004). In Papua New Guinea there are restrictions in place for the harvesting of this sea cucumber such as: minimum landing size (20 cm live, 8 cm dry), a fishing season (between January 16th and September 30th), Total Allowable Catch, gear restrictions and permits for storage and export. This species has been overexploited in some areas, leading to closed fisheries (Skewes et al. 2004). Sea cucumber fishing has been banned in India since 2001. Sea cucumber collection has been banned in the Andaman and Nicobar Islands (Bruckner et al. 2003). In Inhambane Province, Mozambique, holothurian fisheries are closed until stocks rebuild (Bruckner et al. 2003). The distribution of A. mauritiana directly overlaps with several Marine Protected Areas.
|Citation:||Conand, C., Purcell, S. & Gamboa, R. 2013. Actinopyga mauritiana. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 24 April 2014.|