Abstract: Species composition of seaweed and distribution were investigated in the coastal waters of Bintulu, Sarawak. The seaweed samples were collected during low tide between May 2011 and May 2012 from the six different stations. In total 54 species of seaweeds were identified from study areas of Bintulu coastal waters. Among them, 23 species were from Rhodophyta with 11 families, 15 species were from Phaeophyta with 2 families and 16 species were from Chlorophyta with 10 families. Seventeen species of seaweeds were recorded from the Tanjung Batu, while 23 species from Pantai Telekom, 14 species from Golden Beach, 26 species from Kuala Similajau, 12 species from Kuala Nyalau and 21 species from Batu Mandi. Seaweeds abundance was high in rocky substrate and Rhodophyta (11 families and 23 species) was the common and highest group of seaweeds in this coastal areas. Present study recorded high diversified seaweed species at the rocky shore area compare to reef area.
INTRODUCTION
Marine macro algae or (seaweeds) are taxonomically can be classified under main group namely green algae (Chlorophyta), brown algae (Phaeophyta) and red algae (Rhodophyta). Malaysia has extensively total coastline 4675 km where Sarawak covered approximately 1035 km length at the Borneo Island east of Malaysia. As Sarawak coastline surrounded by coral reefs, rocky shores, sandy area, mudflats and mangroves with high humidity and rich of organic matter tends to seaweeds growth and inhabits a variety of these substratum along the coastline. Most seaweeds tend to growth well at the protected area and some are limited distribute depends on the ability of adaptation in the different marine coastline environment, high temperature, heavy rainfall, large tidal range and high wave-exposed along coastlines (FRC, 2000).
As Malaysia, earlier report for seaweed status was in 1991 and been updated 1998. From the earlier report until recent survey on Malaysian marine algae (1991-2006) recorded the tally of 373 species (Phang, 2006). Nurridan (2004) recorded 19 species of seaweed from Pulau Layang Layang, Sabah and a total of 66 taxa of marine algae checklist from Phang et al. (2008) at Perak Island, Jarak Island and the Sembilan Group of Island in the Straits of Malacca. Phang et al. (2005) also reported a total 84 taxa of seaweed from the Langkawi Island. In recent years, studies on the distribution and biology of seaweed in Sarawak especially at Bintulu coastal areas have been discovered by few studies (FRC, 2000; Harah et al., 2006, 2007; Wong et al., 2008) and the recent recorded is 35 species of seaweed. Most of the publications on the seaweed around Bintulu coastal water come from rocky shore study areas and not included reef areas. Hence, the present study was conducted from both location of rocky beaches and reef area for checklist the current update of seaweed species around Bintulu coastal water and there might be more seaweed species that have not been reported.
MATERIALS AND METHODS
Sampling areas: Sampling was conducted at rocky shore areas of Pantai Tanjung Batu (N 03°12.705 ’E 113°02.832’), Pantai Telekom (N 03°18.914 ’ E 113°06.934’), Kuala Similajau (N 03°32.451’ E 113°17.783’), Kuala Nyalau (N 03°37.990’ E 113°22.298’) and Golden Beach, Similajau National Park (N 03°25.075’ E 113°11.797’) with one fringing reef area of Batu Mandi, Similajau National Park (N 03°21.941’ E 113°07.952’) which located at Bintulu coastal regions (Fig. 1).
| Fig. 1: | Map of the sampling sites, TB: Tanjung Batu, PT: Pantai Telekom, BM: Batu Mandi, Similajau National Park, GB: Golden Beach, Similajau National Park, KS: Kuala Similajau and KN: Kuala Nyalau |
Sampling technique: Samples were collected during low tide between May 2011 and May 2012 and sampling time based on the tide schedule as described by Rigby et al. (2007a, b). Transect line with 30 m long was laid on the rocky shore from the low tide to the high tide area except for Batu Mandi area, which scuba technique has been used to collect the sample during high tide. The 50x50 cm quadrat has been placed at each 10 m on the rocky shore contour for further measurement at the field. Three replicates for transect are chosen randomly along the rocky shore contour. A total of 15 min have been spending for each quadrat for species coverage assessment on the rocky shore area and 30 min for underwater assessment.
Morphological identification: All samples were collected, recorded and kept in zip lock bag for samples identification in the laboratory. All samples collected entire thallus (fronds, stems and holdfasts) and transport to the laboratory for further identification based on the physical morphological characteristic and microscopic structure. The work and identification of seaweed by Ismail (1995), Coppejans et al. (1997), Trono (1998), Nurridan (2004) and Tsutsui et al. (2005) were followed. Samples were label, photos and preserved with 10% of formalin for further identification and collection of fresh samples.
RESULTS AND DISCUSSION
A total number of 54 species of seaweed was identified from six different study areas of Bintulu coastal water (Fig. 2); in which 23 species were from Rhodophyta with 11 families, 15 species were from Phaeophyta with 2 families, 16 species were from Chlorophyta with 10 families (Table 1). In this present study, 17 species of seaweed were recorded from Tanjung Batu, 23 species from Pantai Telekom, 14 species from Golden Beach, 26 species from Kuala Similajau, 12 species from Kuala Nyalau and 21 species from Batu Mandi. Rhodophyta division is the largest species can be found compare from Chlorophyta and Phaeophyta.
Previously, FRC (2000) had recorded 31 species (10 Chlorophyta, 5 Phaeophyta and 16 Rhodophyta) of seaweed in Bintulu area, while Harah et al. (2006) reported 35 species of seaweed in the coral fragment and rocky shore of Similajau National Park (10 Chlorophyta, 6 Phaeophyta and 19 Rhodophyta). In addition, a total of 35 species (12 Chlorophyta, 8 Phaeophyta and 15 Rhodophyta) of seaweed was also recorded from the rocky shore of Bintulu, Sarawak by Harah et al. (2007). Whilst Wong et al. (2008) recorded 35 species of seaweed (12 Chlorophyta, 5 Phaeophyta and 18 Rhodophyta) from rocky area of Bintulu. The number of seaweeds recorded was higher in this present study.
Seaweed abundance was high in rocky substrate and Rhodophyta (11 families and 23 species) was the common and highest group of seaweed in this coastal area. In contrast, Wong et al. (2008) recorded 9 common species of seaweed from the coastal area of Bintulu, which are mostly come from the family Rhodomelaceae (Cladophora prolifera, Ulva intestinalis, Padina minor, Sargassum sp., Gracilaria salicornia, Hydropuntia edulis, Acanthophora spicifera, Laurencia papillosa and Laurencia sp.). The highest diversity of Rhodophyta algae was observed from Langkawi Island by Phang et al. (2005) recorded 84 species of seaweed and high abundance from Rhodophyta with 62 species. In addition, Phang et al. (2008) reported most abundance of Rhodophyta with 39 taxa from 66 taxa of marine algae recorded at Perak Island, Jarak Island, Sembilan Group of Island in the the Straits of Malacca where most of the samples collected from rock surface, coral and artificial substrate.
| Fig. 2(a-f): | Percentage of seaweed abundance from the six sampling sites around Bintulu coastal waters, (a) Tanjung Batu, (b) Kuala Nyalau, (c) Kuala Similajau, (d) Pantai Telekom, (e) Golden Beach and (f) Batu Mandi |
| Table 1: | Species of seaweed recorded from Bintulu coastal waters |
Gan et al. (2011) stated the Rhodophyta were most diversified species recorded from the Johor coastal waters where rocky shores resulted the high abundance of marine algae assembles.
| Table 2: | Comparison of seaweed species among the different stations of the Bintulu coastal waters |
| TB: Tanjung Batu, PT: Pantai Telekom, GB: Golden Beach, KS: Kuala Similajau, KN: Kuala Nyalau and BM: Batu Mandi, -: Absent, +: Present | |
Difference recorded from Nurridan (2004) on seaweed communities at coral reef in the lagoon of Pulau Layang Layang, Sabah with 19 species of seaweed recorded and Chlorophyceae was the most abundance species.
Checklists of seaweed species assemble at six different locations are presented in the Table 2. Kuala Similajau area recorded the highest seaweed species compare to other locations and the lowest was recorded at Kuala Nyalau area.
| Fig. 3: | Summary of seaweed species assemble in the tidal zone of rocky shore area in Bintulu coastal waters |
Rhodophyta recorded the higher assemble of seaweed species at Tanjung Batu, Pantai Telekom, Golden Beach and Kuala Nyalau area. There was no Phaeophyta recorded from Kuala Nyalau. In contrast, some Phaeophyta species have been recorded by Wong et al. (2008) at Kuala Nyalau area. Phaeophyta and Rhodophyta were common at Kuala Nyalau area. But it had shown different at Batu Mandi area where Phaeophyta species was recorded the highest. Ulva intestinalis, Padina minor, Gracilaria salicornia and Acanthophora spicifera showed the most common species can be found at five out of six locations of coastal areas.
From this study, it was observed that, the dominance seaweed species was recorded at the intertidal zone with 76% coverage of 29 species, followed by subtidal zone with 16% which cover six species and high intertidal zone with 8% with three species (Fig. 3). It was shown that sea water and sun light plays the important role to the seaweed for photosynthesis and growth in a good condition. Study also recorded the high number of seaweed species existing at Bintulu coastal area ecologically due to the nutrient enrichment and provided suitable hard substrate necessary for seaweed attachment growth. According to Konar (2007), marine communities such macroalgae tends to be high assembling for their biodiversity and hard substrate provided attachment for their growth.
There were different recorded of seaweed species from Bintulu coastal water when compared to previous study by Harah et al. (2007) and Wong et al. (2008) since both previous study focus on rocky shore based area for macroalgae recorded (Table 3). Hence, present study on seaweed recorded includes both rocky shore area and reef area from Bintulu coastal waters. Seasonality pattern of seaweed assemblages is generally recognized to be a factor affected the species recorded from similar area (Guerra-Garcia et al., 2010). Other than environmental factor, temperature tends to be most influenced the seasonal pattern of seaweed communities (Branco et al., 2008).
| Table 3: | Comparison of seaweed recorded from present study with previous recorded in Bintulu coastal waters |
| -: Absent, +: Present | |
According to Prathep (2005), variation and different diversity of macroalgae were affected from seasonal pattern and sites of study areas, hence the percentage of macroalgae assemble highly influence by the degree of wave exposure during wet seasons.
CONCLUSION
The present study revealed that Bintulu coastal areas highly diversified with macroalgae species there might be need to be conserve and monitoring for reliable potential used in some industries seems these seaweeds known as natural bio-renewable sources. However, further observation or knowledge of seaweed assembles due to environmental factor and seasonal pattern need to be monitoring for more information and understand on seaweed diversity.
ACKNOWLEDGMENTS
The authors would like to thank the anonymous reviewers for critical reading of manuscript and comments, Universiti Putra Malaysia for encouragement and research facilities. This sstudy was funded by the Ministry of Higher Education, Malaysia (MoHE) under programme Fundamental Research Grant Scheme (FRGS) 5524038.