Spatial and temporal distribution dataset of benthic macroalgae during 2015-2016 tropical monsoonal cycle in Malaysia

Study Extent

Sampling activity was conducted in four locations in the eastern Johor coastline: Pantai Pasir Lanun, Pulau Mawar, Telok Gorek and Tanjung Lompat. Pantai Pasir Lanun is located at the tip of a foreland with a relatively straight coastline, predominantly featuring hard substrates composed of large areas of coral rubble and boulders. Pulau Mawar is characterized by a shallow-elevated sandy terrain with small patches of mangrove trees and coral rubble. Telok Gorek is located within an indented bay, covered with mangrove trees and sheltered from the foreland. Tanjung Lompat consists of a foreland and an extensive bay, characterized by boulder-pebbles on the foreland and a shallow sandy bay.

Sampling

Sampling was done from January 2015 until February 2016 during the lowest tide of the month. Transects were placed randomly, taken to represent the macroalgae cover and frequency at each site. The quadrats were placed alternately at every 1 meter of the 25-meter transect line. Initially, the macroalgae that were found inside the quadrat were recorded, identified and inventoried according to the type of species, percentage of cover and percentage of frequency. The types of substratum attached by macroalgae were noted as representing the habitat specificity of the macroalgae. The raw data of cover and frequency were calculated by multiplying the vertical count of every species to the five levels of multiplier and the total number of sub-quadrat from the 9 transect lines with a total of 234 quadrats. The cover of every species of macroalgae was then analyzed by summing the percentage cover value of prostrate and erect parts of the macroalgae in each sub-quadrat (10cm × 10cm) after Saito and Atobe (1970). The percentage frequency of macroalgae was obtained by calculating the total number of squares (qn) in which the species occurred, divided by the total number of small squares in the quadrat (= 25), and multiplied by 100.

Quality Control

All scientific names were morphologically identified according to Ismail (1995), Trono and Ganzon-Fortes (1988), Zainee et al. (2018), and Zainee et al. (2019), and were further standardized according to AlgaeBase and The World Register of Marine Species (WoRMS).

Method steps

1. In-situ identification of species and destructive collection for first-time observed samples and preservation in formaldehyde.
2. Non-destructive sampling (except for filamentous algae that need microscopic observation in the laboratory) at four study sites.
3. Photography, sorting, cleaning, and preparation of herbarium specimens.
4. Conversion of paper-based records from the field and laboratory into an electronic data format (Excel spreadsheets).
5. Organizing the datasets into a standardized format.
6. Standardization of taxonomy using the World Register of Marine Species and AlgaeBase.
7. Export of data as a DarwinCore Archive.
8. Generation of dataset-level metadata.

We report identification of species belonging to family Rhodomelaceae, Lithophyllaceae, Corallinaceae, Pterocladiaceae, Gigartinaceae, Galaxauraceae, Gracilariaceae, Cystocloniaceae, Lomentariaceae, Dictyotaceae, Sargassaceae, Polyphysaceae, Caulerpaceae, Cladophoraceae, Boodleaceae, Ulvaceae and Valoniaceae.

1. Ulvophyceae
   rank: class
2. Phaeophyceae
   rank: class
3. Florideophyceae
   rank: class
4. Bryopsidales
   rank: order
5. Cladophorales
   rank: order
6. Dasycladales
   rank: order
7. Ulvales
   rank: order
8. Dictyotales
   rank: order
9. Fucales
   rank: order
10. Ceramiales
    rank: order
11. Corallinales
    rank: order
12. Gelidiales
    rank: order
13. Gigartinales
    rank: order
14. Gracilariales
    rank: order
15. Nemaliales
    rank: order
16. Rhodymeniales
    rank: order

Sampling was done along four major shore stretches of the entire coast of east Johor, covering approximately 180 km from Desaru to Mersing. The eastern coast of Johor extends approximately 175 km from Teluk Lipat (i.e. Lipat Bay) to the north and Teluk Ramunia to the south. Coordinates: Pantai Pasir Lanun (N 02⁰ 38' 52'', E 103⁰ 45' 29''), Pulau Mawar (N 02⁰ 37' 08'', E 103⁰ 47' 01''), Telok Gorek (N 02⁰ 18' 37'', E 103⁰ 57' 31''), Tanjung Lompat (N 01⁰ 36' 10'', E 104⁰ 15' 17'').