Occurrence and Distribution of an Invasive Octocoral, Carijoa riisei in Malaysia s Marine Park of Pulau Payar

Research Article

Austin Environ Sci. 2021; 6(2): 1060.

Occurrence and Distribution of an Invasive Octocoral, Carijoa riisei in Malaysia’s Marine Park of Pulau Payar

Normah S¹, Ismail MS²*, Md. Nizam I², Zaidnuddin I² and Goeden GB³

¹Department of Fisheries, Putrajaya, Malaysia

²Fisheries Research Institute, Pulau Pinang, Malaysia

³Blue Planet Environment PLT, Pulau Pinang, Malaysia

*Corresponding author: Mohamad Saupi Ismail, Fisheries Research Institute, Batu Maung, 11960 Pulau Pinang, Malaysia

Received: May 27, 2021; Accepted: July 07, 2021; Published: July 14, 2021


The occurrence of the invasive snowflake coral, Carijoa riisei (Duchassaing & Michelotti, 1860) in Malaysian waters was reported after the species was first detected at Pulau Payar Marine Park in 2014. Its recent appearance in Pulau Payar highlights the need for baseline data concerning the distribution pattern and diversity of C. riisei within the Pulau Payar Marine Park and may enable effective remedial actions in controlling the overgrowth of this octocoral. The snowflake coral and other substrates were quantified over quadrats located randomly on a 50 m transects in three study sites, i.e. Coral Garden, Kaca Reef and Lembu Rock. The percent cover of each substrate category and diversity were determined using the Coral Point Count with Excel extensions (CPCe) software. The snowflake coral was most frequently observed at the depths of 10 to 20 m at each of the study sites. The area with highest coverage of this octocoral was in Kaca Reef at the depth of 20m. About one-third of the benthos and abiotic substrate at all sites was populated by C. riisei. Statistically, no significant differences were found between the distributions of C. riisei by sites. Using diversity indices, we were able to demonstrate the ability of this species to exploit a wide range of differing environments. This ability has allowed it to spread within this marine protected area. Based on this study, we suggested monitoring programs should be regularly conducted within Pulau Payar Marine Park, other reefs should be surveyed for its presence, and an effective mitigation program should be developed for the conservation of the marine ecosystems affected by this invasive species.

Keywords: Invasive species; Snowflake coral; Octocorallia; Marine protected area; Peninsular malaysia


Invasive Alien Species (IAS) are one of the main threats to biodiversity, often adversely affecting ecosystems on a large scale. The spread of invasive alien species can have negative impacts on the environment, human health, animals and plants, and the economy [1]. However, information regarding the existence and impact of marine IAS from Malaysian waters is lacking. Recently, there have been 10 marine IAS documented from Malaysian waters. Of these, a single report of invasive coral species was recorded in Peninsular Malaysia [2].

Carijoa riisei (Duchassaing & Michelotti, 1860), globally known as snowflake coral, is a non-photosynthetic colonial octocoral native to the Indo-Pacific [3-6], although its original native distribution is still unknown [7]. Being a shade-loving species, this coral is commonly found on hard substrates, away from direct sunlight. It has been observed growing on rocks, on substrates covered with sediment and even on other organisms such as sponges, corals, and bivalves [5,8]. It also grows well on artificial hard surfaces such as concrete, metal, and plastic [9]. It has been reported on sunken ships, pier pilings [10] and artificial reefs visited by SCUBA divers [6].

The snowflake coral is a fast growing species with its linear branch growth rate exceeding one cm per week and its axial polyp extension reaching between 0.5 to 2.0 cm per week [8,10]. This species can reach sexual maturity in a few months once its branches reach 2.5 cm, and then it appears to reproduce continuously [11]. This species was observed to overgrow and successfully compete with black coral and other native invertebrate forms [8]. Because of its ability to dominate space and crowd out other marine organisms, snowflake coral is considered as a wide-spread invasive fouling species [7] and is listed in the database of invasive species of IUCN [6].

The first invasion of C. riisei was documented in Hawaii in 1972 [11]. Since then, it has invaded many countries in the Caribbean- Atlantic Ocean as well as the Indo-Pacific [3]. In South East Asia, C. riisei has reportedly spread to Indonesia [12], Vietnam [13], and allegedly, Thailand and the Philippines [8]. This highly invasive species was discovered for the first time in Malaysia in 2014, at a depth of more than 10m, in Pulau Payar [14]. Unfortunately, detailed data on the degree of its impact is lacking. The means of the snowflake coral’s invasion of Pulau Payar is still unknown. Since this marine park is in close proximity to Indonesia and Thailand, there is a likelihood of its larvae were transported by water currents from these neighboring countries.

Baseline data concerning the status of C. riisei in Pulau Payar Marine Park is necessary to enable effective remedial actions in controlling the spread of this invasive species. It is vital to know its distribution, its impact on native species, and its ecological preferences (depth, substrates, etc.). Therefore, the aim of this study was to assess the current distribution and quantify the density of the invasive C. riisei within this marine park waters.

Materials and Methods

Study area

Payar Archipelago is located about 28km off the coast of Kedah state, on the west coast of Peninsular Malaysia. It consists of four islands, the largest being Pulau Payar, and the other three islands being Pulau Kacha, Pulau Lembu and an offshore island, Pulau Segantang. Since 1994, it has been gazetted as the Pulau Payar Marine Park (PPMP) under the Malaysia’s Fisheries Act 1985 (Amended 1991). This archipelago is the only marine park situated in the west coast of Peninsular Malaysia and is the most biodiverse coral reef in the Straits of Malacca. The waters surrounding the islands support 38 genera of coral [15] and 48 species of coral reef fish [16]. This present study focused on the C. riisei population at three representative sites i.e. Coral Garden (CG) of Pulau Payar, Kaca Reef (KR) of Pulau Kacha, and Lembu Rock (LR) of Pulau Lembu (Figure 1).