Reef Foraminifera As Bioindicator of Coral Reef Health in Pulau Tioman, Pahang, Malaysia
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Reef Foraminifera As Bioindicator Of Coral Reef Health in Pulau Tioman, Pahang, Malaysia Aishah Norashikin Abdul A’ziz Universiti Malaysia Terengganu Fatin Izzati Minhat ( [email protected] ) Universiti Malaysia Terengganu https://orcid.org/0000-0001-8153-3500 Pan Hui-Juan National Taiwan Ocean University Hasrizal Shaari Universiti Malaysia Terengganu Wan Nurzalia Wan Saelan Universiti Malaysia Terengganu Nazihah Azmi Universiti Malaysia Terengganu Omar Abdul Rahman Abdul Manaf Universiti Malaysia Terengganu Md Nizam Ismail Fisheries Research Institute Malaysia Research article Keywords: Foraminifera, Coral Reef, FORAM Index, Coastal development, Reef recovery Posted Date: August 26th, 2020 DOI: https://doi.org/10.21203/rs.3.rs-51033/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/18 Abstract Pulau Tioman is one of the famous tourism islands in Peninsular Malaysia due to the beautiful terrestrial and coral reefs ecosystem. This study aims to assess and monitor the health of coral reef sites surrounding Pulau Tioman based on the application of Foraminifera in Reef Assessment and Monitoring (FORAM) Index. A total of ten selected sampling sites from west and east side of Pulau Tioman were setup in front of the major beach areas around Pulau Tioman. At each site, 100 m transect was laid out from shore towards the reef slope and surface sediment samples were collected at 50 m intervals. Eight orders, 41 families, 80 genera and 161 species of benthic foraminifera were identied around Pulau Tioman. Amphistegina lessonii found to be the most dominant species and the least dominant species (< 4%) are Bolivina vadescens, Elphidium neosimplex, Heterolepa dutemplei, Heterolepa subhaidingerii, Mikrobelodontos bradyi, Milliolinella suborbicularis, Operculina discoidalis, Parahourinoides fragillissimus, Quinqueloculina incisa, Quinqueloculina sulcate, Triloculinella bertheliniana and Triloculinella parisa. The highest and lowest numbers of species was recorded at station J3 and station F3. The agglutinated type of foraminifera contributed between 2–8% of the total assemblages. Meanwhile, calcareous hyaline and porcelaneous group represent 79% and 19% of total assemblages respectively. Based on the functional groups, symbiont-bearing taxa were the most common foraminiferal found in most of the stations. The present study indicates that majority of sampling sites around Pulau Tioman are conducive for coral reef growth and could recover from any future bleaching events or temporary damage in the ecosystem. However, several areas with higher coastal development and tourism activities has reduced water quality (FI < 4) and chances of better reef recovery. Thus, the number of visitors and tourists should be revised in order to produce a better condition for coral reefs to grow. This assumption is based on the established results of the FORAM index. Thus, we suppose that FORAM index could be used together with coral reef health index in other reef ecosystems around Malaysia to determine the condition and status of coral reef area. Introduction Coral reef ecosystem is among the most biologically diverse ecosystem in the world which play a vital role in shaping the ecosystems over the past 200 million years (Hoegh-Guldberg, 1999). Coral reef provides goods and services to marine tropical and subtropical regions (Moberg and Folke, 1999). Globally, coral reef ecosystem has been threatened and many have already been lost due to climate change and human intervention (Shahbudin et al., 2017). On a larger scale, elevated sea temperature and ocean acidication due to climate change has challenged the natural resilient of tropical reef (Anthony et al., 2015). Meanwhile the local stressors which ranged from human activities such as coastal development and pollution, reef predatory and diseases usually reduce the potential of reef recovery to climate change (Bruno and Selig, 2007; Anthony et al., 2015; Cowburn et al., 2018). Since coral reef ecosystems provide various natural environmental services, their ability to survive the global climate anomaly is very important. Consequently, understanding the health status of local individual reefs is important in order to make sure the coral reef survive and recover from any next mass mortality event in near future (Anthony et al., 2015). Pulau Tioman which is situated in the Southern South China Sea (SSCS) is surrounded by extensive coral covers that host various marine species (Harborne et al., 2000). Recognizing the importance of coral ecosystem, part of Pulau Tioman has been gazetted as National Marine Park by Malaysian government (Department of Marine Park, 2012). Concurrently the beauty of the island has attracted and promote tourisms activities since 1990 (Chia et al., 2018). Tourisms, recreational diving activities and coastal development may post local threat to the surrounding reef ecosystem by reducing their resilience to climate change (Cowburn et al., 2018). Therefore, the most viable management approach in facing climate change is to reduce and monitor local stressors such as coastal pollution (Game et al., 2014; Anthony et al., 2015). Benthic foraminifera have been proven to be an excellent indicator for sediment quality, heavy metal pollution, organic pollution and water quality (Alve, 1995; Hallock et al., 2003; Sen Gupta, 2003; Carnahan, 2005). This single cell organism is abundant in reef ecosystems with several taxa that possess similar ecological requirements as reef building corals (Hallock et al., 2003). Several studies have successfully monitor the potential recovery of reef environment using benthic foraminifera as indicator (Schueth and Frank, 2008; Uthicke et al., 2010; Natsir and Subkhan, 2012). The development of Foraminifera in Reef Assessment and Monitoring (FORAM) index by Hallock et al. (2003) has allow continuous monitoring of reef health condition. In order to safeguard the coral ecosystems and maintain their ecological importance in Pulau Tioman, monitoring the environmental health surrounding the reef is very important to park management. This study aim to assess and monitor the health of reef environment surrounding the Pulau Tioman based on the application of Foraminifera in Reef Assessment and Monitoring (FORAM) Index. Methods/experimental Study site The study was carried out at Pulau Tioman, Pahang, Malaysia (Fig. 1). Pulau Tioman lies off the southeast coast of Peninsular Malaysia in SCS region. The island is located in tropical region under the inuence of two type of monsoon; the northeast monsoon and southwest monsoon (Akhir et al., 2014). The maximum wave height during the northeast monsoon that occur through November to March is ~ 4 m while during southwest monsoon (April to August), the maximum wave height is < 1 m (Chu et al., 2004; Marghany, 2001). Pulau Tioman is surrounded by numerous coral reefs area with approximately 57–59 genera of hard coral distributed around the island (Shahbudin et al., 2016). Accropora, Montipora and Porites are among the most common coral genera reported from Pulau Tioman (Toda et al., 2007; Shahbudin et al., 2017). The sheltered west coast of Pulau Tioman (Fig. 1) made such area suitable for snorkeling and diving activities compared to the west side of the island. Therefore, the east coast of Pulau Tioman receives more tourist visits and much more developed with numerous resorts and housing area that are distributed along the coast (Shahbudin et al., 2017). Samples Collection In order to assess the marine environmental health of Pulau Tioman, samples were collected from coastal water of both west and east side of the island. A total of 10 sampling sites were selected based on the intensity of human activities and development along the coastal environment around Pulau Tioman. A transect of three sampling points were setup at each sampling site, giving a total of 30 sampling points around Pulau Tioman. At each sampling site, three Page 2/18 samples were collected along the 100 m transect laid perpendicular from the shore towards the reef slope. On each transect, the samples were collected at every 50 m intervals. Bulk sediment samples were collected by SCUBA divers using scoop and kept in labelled plastic bags. The in-situ parameters (i.e., water salinity, temperature and pH) and water depth (m) were obtained at each sampling station using Hydrolab Quanta Multiparameter from a small vessel. All samples collected at eld were brought back to the marine park station to be sorted. Sediment samples that have been collected were divided into two components for future analysis, i.e., foraminiferal and sedimentological analyses. Approximately 30 cm3 sediments were subsampled from the bulk samples for foraminiferal analysis and were xed with 4% buffered formalin (Murray, 2006). The remaining sediment samples were kept in zip-lock plastic bags, labelled and brought back to the laboratory for sediment grain size analysis. Laboratory analysis In the laboratory, the sediment samples for foraminiferal analysis were gently washed under running tap water over a 63 µm mesh sieve (Hallock et al., 2003). The residue on the 63 µm sieve was carefully transferred into pre-labelled weighing boat before being dried in the oven at 40–50 ºC overnight. The dried samples were later kept in plastic bags for analysis. Foraminiferal specimens were handpicked using a ne brush under a stereomicroscope. Approximately 300 optimally preserved foraminifera test were picked from every station