Zoantharian abundance in coral reef benthic communities at Terengganu Islands, Malaysia

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Abstract

Zooxanthellate zoantharians of the genera Zoanthus and Palythoa are increasingly being studied in baseline work such as confirming distributions and long-term monitoring studies in shallow subtropical and tropical waters. There is some evidence that suggests that these genera increase in abundance as an ecological ‘phase shift’ response to ecological degradation. However, such studies have been limited to a few regions, including the Greater Caribbean, Brazil, and Japan, with little work performed in the waters of Southeast Asia and the central Indo-Pacific (CIP). We investigated changes in zoantharian cover within coral reef benthic communities around Terengganu, Malaysia, between July 2013 and September 2014, utilizing the Coral Video Transect method to survey the benthic communities of nine coral reefs. Zoantharian abundance was observed to be inversely proportionate to other major benthic groups (algae, dead corals, hard corals). Overall, zoantharians thrived in reefs with lower biological diversity of reef-building corals. Additionally, at one site (Pasir Akar) we documented a very sudden and large increase of zoantharian cover over two months from March to May 2014. This increase occurred after the reef was heavily damaged during monsoon season. Our results demonstrate that zoantharians are an understudied yet common major component of reefs in Southeast Asia, and that large changes in their abundance can occur very rapidly. Further research investigating longer-term trends of zoantharian abundance in Southeast Asia and the CIP are needed to ascertain if dramatic increases are part of a ‘normal’ recovery process or represent phase shifts in the benthic community structure of coral reefs.

Introduction

Zooxanthellate zoantharians (Anthozoa: Hexacorallia: Zoantharia) are an order of globally distributed marine organisms. The most common genera are Zoanthus and Palythoa, which are found in shallow tropical and subtropical waters of the Atlantic and Indo-Pacific oceans (Reimer et al., 2008, Reimer et al., 2015, Cruz et al., 2016). Quantitative studies of the distribution of Zoanthus and Palythoa mostly focused on shallow warm temperate and subtropical coral reefs and rocky shores of the Caribbean (Sebens, 1982, Karlson, 1988, Belford and Phillip, 2012), Brazil (Cruz et al., 2016), and Japan (Irei et al., 2011). However, despite being an important part of many coral reef ecosystems, only limited studies have been performed in the biodiversity rich Southeast Asia and Central Indo-Pacific (CIP) regions (Wee et al., 2015, Reimer et al., 2014, Reimer et al., 2015).

Previous studies have shown that many Zoanthus and Palythoa species survive better in shallow waters with some physical disturbances (i.e. waves and currents), such as reef crests, shallow reefs, and intertidal areas (Cooke, 1976, Belford and Phillip, 2011, Irei et al., 2011, Reimer et al., 2011). Furthermore, zoantharians have been reported to be dominant in physically harsh and degraded environments where it may be hard for other benthic organisms to survive (Kumari et al., 2015, Cruz et al., 2016). This dominance is often from a single species and has been designated as the ‘zoantharian zone’ (Karlson, 1983, Cruz et al., 2014, Kumari et al., 2015). Even though coral reef resilience and degradation research has been long established (e.g. Colgan, 1987, Diaz-Pulido et al., 2009, Golbuu, 2007, van Woesik, 2011), there have only been limited studies examining the role of zoantharians in this process (e.g. Yang et al., 2013; Cruz et al., 2014), and more research is needed to fully understand the role they play in coral reef ecosystems.

Malaysia is located at the edge of the Coral Triangle (Hoeksema, 2007, Veron et al., 2009, Tan and Heron, 2011). Monitoring of coral reefs in this region is common due to their value in the eco-tourism industry (Hyde et al., 2013; Mohamad and Nik, 2014; Waheed et al., 2015). Recently, Wee et al. (2015) quantitatively documented the presence of large numbers of zoantharians in shallow Malaysian reefs. However, no research has yet shown how increases in zoantharian abundance affect the composition of reef benthos

In this study, the distribution and abundance of Zoanthus and Palythoa spp. were surveyed from 2013 to 2014 at two islands in Malaysia: Pulau Redang and Pulau Bidong in Terengganu State. Reefs surrounding the two islands have experienced notably different levels of human impacts. Pulau Redang is a tourist destination due to its diverse coral reefs and turtle nesting sites, while Pulau Bidong has been uninhabited since the departure of Vietnamese refugees in the late 1980s (Fisher et al., 2008, Grismer et al., 2014). Previous studies (Reimer et al., 2015, Wee et al., 2015) have documented zoantharians on the reefs of both islands, especially in shallow waters (<6 m). Here, in order to determine the extent of zoantharian cover (abundance), we surveyed reefs around both islands for two years (2013 and 2014) at selected reef sites utilizing the Coral Video Transect method (Safuan et al., 2015).

Section snippets

Survey sites

This study was carried out at two islands, Pulau Redang and Pulau Bidong (Fig. 1). Surveys were conducted approximately one year apart, in July 2013 and September 2014. A total of nine survey sites were visited in 2013 survey on the islands, with six located on Pulau Redang, and three on Pulau Bidong (Supplement 1). The number of sites in 2014 survey was reduced to only six due to logistical restraints, with four located on Pulau Redang, and two on Pulau Bidong. Additionally, the site at Pasir

Zoantharian cover

Zoantharian cover greatly varied among the surveyed sites (Table 1), from almost completely absent (0%) to covering more than two-thirds the substrate of the reef (>70%). In 2013, the highest recorded zoantharian cover was at Pulau Karah (72.50 ± 12.66%) followed by Pulau Lima (34.43 ± 23.55%). Zoantharians were the dominant benthic cover at both of these sites. Zoantharians were also present at Pulau Paku (18.69 ± 14.82%), Ekor Tebu (8.85 ± 9.90%), and Terumbu Kili (6.19 ± 6.38%). Low

Discussion

For the first time in Malaysia, we surveyed zoantharian abundance in shallow coral reefs over time. Zoantharian coverage varied widely from almost completely absent to dominant and covering more than two-thirds of the reef (Table 1). At some ‘low coverage’ (<5%) sites, zoantharians were either present with patchy distributions or not present. This may be because zoantharians at low abundance are commonly found growing in hard-to-reach crevices, which makes them relatively cryptic (Reimer

Acknowledgements

This research was conducted in collaboration with the Department of Marine Park Malaysia (DMPM) and Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu (UMT). All equipment was provided by INOS and DMPM, including funding [grant number VOT T66904] for charter boats for the surveys. Specimen collection and surveys of zoantharians within marine parks adhered to rules and regulations set out by DMPM, and were sanctioned officially by the institute. Special thanks to

References (46)

  • I.C.S. Cruz et al.

    Evidence of a phase shift to Epizoanthus gabrieli Carlgreen, 1951 (Order Zoanthidea) and loss of coral cover on reefs in the Southwest Atlantic

    Mar. Ecol.

    (2014)
  • I.C.S. Cruz et al.

    Effect of phase shift from corals to Zoantharia on reef fish assemblages

    PLoS One

    (2015)
  • G. Diaz-Pulido et al.

    Doom and boom on a resilient reef: climate change, algal overgrowth and coral recovery

    PLoS One

    (2009)
  • J.B. Fisher et al.

    Balancing water, religion and tourism on Redang Island, Malaysia

    Environ. Res. Lett.

    (2008)
  • R.B. Francini-filho et al.

    Predation on the toxic zoanthid Palythoa caribaeorum by reef fishes in the Abrolhos bank, Eastern Brazil

    Braz. J. Oceanogr.

    (2010)
  • S. Gall

    The effect of long established marine protected areas on the resilience of Caymanian coral reefs

    (2009)
  • Y. Golbuu et al.

    Palau’s coral reefs show differential habitat recovery following the 1998-bleaching event

    Coral Reefs

    (2007)
  • L.L. Grismer et al.

    A new species of insular Rock Gecko (genus Cnemaspis Strauch, 1887) from the Bidong Archipelago, Terengganu, Peninsular Malaysia

    Zootaxa

    (2014)
  • O. Hoegh-Guldberg et al.

    Coral reefs under rapid climate change and ocean acidification

    Science

    (2007)
  • B.W. Hoeksema

    Delineation of the Indo-Malayan centre of maximum marine biodiversity: the coral triangle

  • J. Hyde et al.

    Five years of reef check monitoring data for Tioman, Perhentian and Redang Island

    Malays. J. Sci.

    (2013)
  • Y. Irei et al.

    Distribution patterns of five zoanthid species at Okinawa Island, Japan

    Zool. Stud.

    (2011)
  • R.H. Karlson

    Disturbance and monopolization of a spatial resource by Zoanthus sociatus

    Bull. Mar. Sci.

    (1983)
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