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American Journal of  
Environment and Climate (AJEC)

Seagrass Diversity and Distribution in Maribojoc Bay, Bohol, Philippines
Honey Jane C. Mascariñas1*, Julie B. Otadoy2

Volume 1 Issue 1, Year 2022
ISSN: 2832-403X (Online)

DOI: https://doi.org/10.54536/ajec.v1i1.217
https://journals.e-palli.com/home/index.php/ajec

Article Information ABSTRACT

Received: April 19, 2022

Accepted: April 24, 2022

Published: May 3, 2022

Seagrasses are major parts of  coastal and marine biodiversity. Unfortunately, these aquat-
ic plants and their ecological values are virtually unknown to many Filipinos. This study 
assessed the seagrasses in Maribojoc Bay, particularly in the coastal areas of  the three mu-
nicipalities, namely Maribojoc, Dauis, Panglao, and the City of  Tagbilaran. Ecological as-
sessments were conducted to determine the species composition, abundance, distribution, 
percent cover, diversity, dominance, and evenness of  seagrass species. Eight sampling sites 
were surveyed from October to December 2020. Seven seagrass species were identified, 
with Thalassia hemprichii as the most abundant (52.79%). There was a significant difference 
(p>0.05) in seagrass species relative abundance. The Shannon diversity index implies low 
diversity (H’=1.40) of  seagrass species. High dominance (2.98) and low evenness (0.72) were 
attributed to the high abundance of  T. hemprichii in the seagrass beds. The seagrass coverage 
was characterized by patchy and continuous meadows, with percentage cover ranging from 
17.45% (poor) – 60% (good). Maribojoc Bay had a seagrass percentage cover of  38.65%, 
which can be classified under “fair” condition. Seagrass community structure implies sparse 
coverage and low diversity, probably due to the deterioration of  once-continuous meadows. 
However, further studies concerning seagrass communities are recommended in order to 
implement rehabilitation program or improve current management in Maribojoc Bay.

Keywords
Seagrass, Relative abundance, 
percentage cover, Biodiversity, 
Maribojoc Bay

1 College of  Technology and Allied Sciences, Bohol Island State University, Calape, Bohol, Philippines
2 Department of  Biology, School of  Arts and Sciences, University of  San Carlos, Talamban, Cebu, Philippines
* Corresponding author’s email: hjmascarinas@yahoo.com

INTRODUCTION
Seagrass meadows are among the most productive 
ecosystems (McRoy & McMillan, 1997; Duarte & 
Chiscano, 1999) and support a whole range of  highly 
valuable ecosystem services that rival those well-known 
ecosystems such as coral reefs and mangrove forests 
(Phillips & Milchakova, 2003; Nordlund et al., 2016). 
About 72 species of  seagrasses are found worldwide 
(Saenger et al., 2013). Western Australia has more than 30 
seagrass species recorded. While the Philippines has 16 
species of  seagrasses widely distributed throughout the 
country (Meñez et al., 1983; Fortes, 1989; Calumpong & 
Meñez, 1997). Although unknown to many, seagrasses are 
beneficial in the province as the majority of  Boholanos 
are directly dependent on the coastal resources for food 
and livelihood. Unfortunately, seagrass beds are faced 
with serious threats from construction and reclamation 
activities in some parts of  Bohol (Green et al., 2002). 
In Maribojoc Bay, human pressure on its coastal area 
increases as the coastline is fringing a fast-growing city 
and urbanized municipalities.  As observed, the shallow 
coastal habitats colonized by most seagrass meadows 
are often either dug up or covered to allow coastal 
development. Multiple environmental stressors, often 
attributable to human activities have caused seagrass 
reductions such as water eutrophication, coastal salinity 
changes, water turbidity in relationship to sediment 
management, and alien species (Orth et al., 2006; Waycott 
et al., 2009). Land-based activities also put pressure such 
as wastewater pollution and run-off  from deforestation, 
mining, and agriculture (Hemming & Duarte, 2000; 
Short et al., 2011). Likewise, climate change is a large-

scale pressure that affects seagrass ecosystems. Hence, 
resources productivity might be affected in the coming 
future (McKenzie et al., 2007). If  these problems are not 
addressed, seagrass ecosystems may be threatened by 
stresses causing the natural productivity and ecosystem 
values to be compromised and degraded. Besides, seagrass 
degradation will not only cause scarcity in resource 
availability but affecting as well the ecological integrity 
of  Maribojoc Bay. This study assessed the composition, 
abundance, distribution, diversity, and percentage cover 
of  seagrasses in Maribojoc Bay. The result of  this study 
would help support seagrass conservation so that coastal 
biodiversity values and services will be optimized and 
sustained. 

LITERATURE REVIEW
Seagrasses are angiosperms which grow in marine 
environments. Seagrasses are not true grasses. They are 
called “seagrass” because most species have long green, 
grass-like leaves. Like terrestrial plants, seagrasses have 
leaves, roots and veins, and produce flowers and seeds 
(McKenzie, 2008). Sea grasses are one of  the groups 
of  flowering plants capable of  completing their life 
cycle in a marine environment (Kuo & McComb, 1989). 
Seagrass meadows have evolved important physiological, 
morphological and ecological adaptations to cope with 
the range of  coastal marine environments they inhabit. 
The spatial distribution of  seagrass meadows heavily 
influenced by environmental factors such as light, 
temperature, salinity, nutrient availability, and wave action 
(Orth et al., 2006; Hemming & Duarte, 2000). Being 
plants, they need light for photosynthesis. Light availability 

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is the most important factor determining seagrass growth 
and distribution (Hall et al., 1999; Bach et al., 1998; 
Dennison et al., 1993). Likewise, temperature and salinity 
affect the growth and distribution of  seagrasses (Masini 
& Manning, 1997; Koch & Dawes, 1991; Bulthuis, 1987) 
while sheltered conditions (reduced wave action and 
current velocity) are also often necessary for seagrasses 
to become established (Van Katwijk & Hermus, 2000; 
Dan et al., 1998; Lee Long et al., 1993). Conversely, 
seagrass beds affect these physical parameters. They 
reduce current velocity (Koch & Gust, 1999; Gambi et 
al., 1990; Fonseca & Fisher, 1986; Fonseca et al., 1982), 
attenuate wave energy (Verduin & Backhaus, 2000; Koch, 
1996; Fonseca & Cahalan, 1992), change the level of  
turbulence in the water (Koch & Gust, 1999; Worcester, 
1995; Ackerman & Okubo, 1993; Gambi et al., 1990), and 
enhance light availability by promoting the deposition of  
suspended sediments (Kemp et al., 1984, Short & Short, 
1984). 
Seagrass are mainly found in clear shallow inshore areas 
between mean sea-level and 25 meters depth. The depth 
range of  seagrass is most likely to be controlled at its 
deepest edge by the availability of  light for photosynthesis 
(McKenzie, 2008). Seagrass abundance typically shows 
a parabolic pattern with increasing depth, with low 
abundance towards its shallow limit, increasing to 
maximal abundance at intermediate depths, and declining 
exponentially thereafter (Duarte, 1991). Seagrasses survive 
in the intertidal zone with most extensive meadows 
occurring on soft substrates like sand and mud. Exposure 
at low tide, wave action and associated turbidity and 
low salinity from fresh water inflow determine seagrass 
species survival at the shallow edge. Seagrass plants 
form small patches that develop into large continuous 
meadows. These meadows may consist of  one or many 
species, sometimes up to 12 species present within one 
location (McKenzie, 2008).
Seagrasses evolved from terrestrial plants which migrated 
back into the ocean about 75 to 100 million years ago 
(Papenbrock, 2012; Orth et al., 2006). Seagrasses 
returned to the sea in a least three separate lineages or 
families (Les et al., 1997). Thus, seagrasses are not a 
taxonomically unified group but a biological or ecological 
group. The evolutionary adaptations required for survival 
in the marine environment have led to convergence 
in morphology (Olsen et al., 2016; McKenzie, 2008). 
Seagrasses are a polyphyletic assemblage of  basal 
monocots belonging to four families in the Alismatales 
(Larkum et al., 2006; Les et al., 1997) namely Zosteraceae, 
Hydrocharitaceae, Posidoniaceae and Cymodoceaceae (Tomlinson 
& Vargo, 1966). Their common names, like eelgrass, turtle 
grass, tape grass, shoal grass, and spoon grass, reflect their 
many shapes and sizes and roles in marine ecosystems 
(McKenzie, 2008). Seagrasses represent a diverse and 
globally distributed group with up to 76 species occurring 
in boreal, temperate, and tropical waters (Green & Short, 
2003). While most coastal regions are dominated by one 
or a few seagrass species, regions in the tropical waters of  

the Indian and western Pacific oceans have the highest 
seagrass diversity with as many as 14 species growing 
together. Antarctica is the only continent without 
seagrasses. Over 30 species can be found within Australian 
waters. The most diverse seagrass communities are in the 
waters of  north-eastern Queensland (McKenzie, 2008). 
The global distribution of  seagrass genera is remarkably 
consistent north and south of  the equator. The northern 
and southern hemispheres share ten seagrass genera 
and only have one unique genus each. Some genera are 
much more speciose than others, with the genus Halophila 
having the most seagrass species. There are roughly the 
same number of  temperate and tropical seagrass genera 
as well as species (Short et al., 2007). 

MATERIALS AND METHODS
Sampling and Data Collection
Maribojoc Bay is situated in the southwestern part of  
the island province of  Bohol covering the coastal areas 
of  the four municipalities of  Maribojoc, Cortes, Dauis, 
Panglao, and the City of  Tagbilaran. It has a total of  73.4 
kilometers of  coastline and covers an area of  145 square 
kilometers. Four sampling stations were established in 
the three municipalities of  Maribojoc, Dauis, Panglao, 
and the City of  Tagbilaran (Figure 1). At each station, 
two sampling sites were established, for a total of  eight 
sites surveyed. This study followed a standardized field 
sampling design consisting of  three fixed, parallel, 50m 
transects (Short et al., 2006; McKenzie et al., 2008). 
At each sampling site, three transect lines were laid 
perpendicular to the shoreline, each separated from the 
other by a distance of  100 meters. For each transect line, 
a quadrat measuring 50cm x 50cm was laid at five-meter 
intervals along each transect. A total of  11 quadrats 
were sampled. Within each quadrat, biotic variables 
were measured such as species composition, abundance, 
distribution, diversity, and percentage cover (McKenzie 
et al., 2003; Short et al., 2006). Identification of  seagrass 
species was based on the identification keys by McKenzie et 
al (2003) and the classification system used by Fortes (2013). 
Ecological Assessments

Figure 1. Location map of  transect lines in eight study 
sites of  Maribojoc Bay, Bohol.

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Calculation of  Diversity Index
Relative abundance was calculated to determine the 
species abundance and its distribution.
Relative Abundance = (n/N)*100
Where n = individual species count N=total species 
count
Shannon Diversity Index and Simpson Index Dominance 
were computed to determine the diversity index, 
dominance, and evenness of  seagrass species among 
sampling stations.
Whittaker plot or rank-abundance curve was created 

using Tinn-R version 6.01 and R for windows version 
4.0.1.
Calculation of  Seagrass Coverage 
Estimation of  the percent cover for each seagrass species 
found in each quadrat was done through ocular estimates 
based on the seagrass percentage cover photo guide 
(McKenzie et al., 2007). Calculations for the cover (C) of  
each species in each 50cm x 50cm quadrat are as follows 
(English et al. 1997):
The seagrass coverage for each transect was determined 

by dividing the sum of  the average cover for each quadrat 
by the number of  quadrats utilized. The corresponding 
percent cover per sampling site was determined by 
getting the total percent cover of  transects divided by 
the number of  transects used for each sampling site. The 
percentage of  seagrass cover of  each sampling site was 
then categorized using the categories used by Jackson 
and Nemeth (2007), where poor = 0-25%, fair =26-50%, 
good = 51-75%, and excellent = 76-100%.  
Data Analysis
One-way analysis of  variance (ANOVA) was used to test 
for significant differences at the alpha (α=0.05) level of  
confidence. The post-hoc test was used in defining the 
subsets of  variance that contribute to differences among 
sampling stations and between sampling sites. The data 
was analyzed using SPSS.

RESULTS AND DISCUSSION
Species Composition, Abundance, and Distribution 
Seven species of  seagrass were identified in Maribojoc 
Bay, namely Cymodocea rotundata, Enhalus acoroides, Halodule 
pinifolia, Halodule uninervis, Halophila ovalis, Syringodium 
isoetifolium, and Thalassia hemprichii (Table 1). Compared to 
the 16 species that are present in the Philippines (Meñez 
et al., 1983; Fortes, 1989; Calumpong & Meñez, 1997), 
the seagrass in Maribojoc Bay is about 44% of  the total 
seagrass found in the country. In Region 7, about 78% of  
the total seagrass species were found in 8 surveyed sites 
that included four municipalities (Calape, Getafe, Mabini, 
and Talibon) in Bohol (Alcaria et al., 1999). The seagrass 
species composition in Maribojoc Bay is comparable to 
other seagrass beds surveyed in Palawan (Terrados et al., 

1998), Pangasinan (Vermaat et al., 1995), Guimaras Island 
(Babaran & Ingles, 1996), Davao del Sur (Jumawan et al., 
2015), and Tawi-Tawi (Abubakar et al., 2018). There were 
more seagrass species compared to some surveyed areas 
in Mindanao (Orbita & Gumban, 2013; Redondo et al., 
2017) and even southwestern Thailand and South Sulawesi, 
Indonesia (Terrados, et al., 1998; Vonk et al., 2008). 
Among the surveyed stations, Dauis had all seven 
seagrass species. The higher number of  seagrass species 
in the area can be due to its landscape, which is a cliff-
rocky shore. Thus, seagrasses are sheltered from direct 
impact from sediment burial and human disturbances 
like the construction of  tourism facilities, pollution, and 
human settlements. Other stations recorded six or five 
of  the species, and the lowest was in Tagbilaran, with 
only four species found. Tagbilaran is located in a high-
use bayside that serves as a docking port, tourism, fishing 
area, and human settlements. The difference in the 
number of  species identified in the four stations could be 
one factor in the deterioration of  the seagrass ecosystem 
in Maribojoc Bay.
The occurrence of  seagrass species ranged from Thalassia 
– Enhalus bed to a maximum of  seven species in mixed 
Table 1: Species composition and distribution of  
seagrass species among four sampling stations in 
Maribojoc Bay, Bohol.
Species Maribojoc Tagbilaran Dauis Panglao
Cymodocea 
rotundata

+ + + +

Enhalus 
acoroides

+ + + +

Halodule 
pinifolia

+ - + -

Halodule 
uninervis

+ - + +

Halophila 
ovalis

+ + + +

Syringodium 
isoetifolium

- - + +

Thalassia 
hemprichii

+ + + +

Total species 6 4 7 6
+presence, - absence

communities. In the Philippines, seagrass bed is often a 
mixed of  T. hemprichii, E. acoroides, C. rotundata, H. pinifolia, 
H. uninervis, and H. ovalis (Meñez et al., 1983). Notably, 
this study shows that some species are site restricted, for 
example, S. isoetifolium is restricted in Panglao Island. Of  
the seven seagrass species, T. hemprichii was observed to 
be the most ubiquitous. In similar studies, T. hemprichii 
was also found to be the most proliferate in Negros 
(Meñez, et al., 1983), Bolinao (Vermaat et al., 1995), 
Guimaras (Babaran & Ingles, 1996), Pto Galera (Terrados 
et al., 1998), Calape, Bohol (Alcaria et al., 1999), Tawi-
Tawi (Abubakar et al., 2018) and some surveyed areas 
in Mindanao (Orbita & Gumban, 2014; Redondo et 
al., 2017). The ubiquitous presence of  T. hemprichii is 
probably an indication of  their morphological advantage 

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in thriving without significant interference from the other 
seagrass species (Genito et al., 2010). 
In terms of  relative abundance, Thalassia hemprichii had 
the highest across sampling stations (Figure 2; Table 2). 
More than half  of  the overall relative abundance was 
obtained by T. hemprichii (52.79%) when all stations were 
combined. The remaining seagrass relative abundance 
were Enhalus acoroides (18.85%), Cymodocea rotundata 
(9.55%), Halodule uninervis (7.48%), Halophila ovalis 
(7.20%), Syringodium isoetifolium (3.96%) and Halodule 
pinifolia (0.18%) respectively. ANOVA analysis showed a 
significant difference (p>0.05) in seagrass species relative 
abundance (F (6, 21) = 19.77, p= 0.00). The highest 
relative abundance of  T. hemprichii was recorded in the 
municipality of  Dauis (59.36%), followed by Maribojoc 
(56.73%), Panglao (53.85%), and Tagbilaran City 
(41.22%) respectively. One-way ANOVA analysis showed 
no significant difference (p>0.05) in T. hemprichii relative 

abundance among sampling stations (F (3, 20) = 1.56, 
p= 0.23). The result suggests that T. hemprichii is highly 
tolerant of  various environmental conditions. Considered 
a climax species (den Hartog, 1970; Lacap et al., 2002; 
Short et al., 2010), T. hemprichii usually dominates over 
the other seagrass species (Meñez et al., 1983). It can 
occupy more space permanently, and accumulate and 
retain resources for longer periods of  time (Vermaat 
et al., 1995). T. hemprichii thrives on mud-coral-sand or 
coarse coral-sand substrates in sheltered habitats (Meñez 
et al., 1983).  Also, a study found that T. hemprichii can 
grow even under algal blooms and develop optimally, 
so it can successfully colonize seagrass beds with other 
species. One factor for its resilience is its root system and 
its adaptability to the low concentration of  light during 
algal blooms (Liu et al., 2005; Jiang et al., 2010). 
This species Enhalus acoroides was next to T. hemprichii 
in terms of  its abundance (Table 3).  E. acoroides 

Table 2. Analysis of  variance (ANOVA) to test seagrass relative abundance between seagrass species (p<0.05).

Sum of  Squares Df Mean Square F P-value

Relative 
Abundance

Between 
Groups

7712.362 6 1285.394 19.76762 0.00

Within Groups 1365.529 21 65.02521

Total 9077.891 27

abounds on the shore of  Tagbilaran. Likewise, its 
relative abundance was highest in Tagbilaran (41.47%), it 
was slightly higher than T. hemprichii. One-way ANOVA 
analysis showed a significant difference (p<0.05) in E. 
acoroides relative abundance among sampling stations (F 
(3, 20) = 3.89, p= 0.02). A Tukey post hoc test revealed 
a significant difference between Tagbilaran and Panglao 
(p = 0.02). The abundance of  E. acoroides in Tagbilaran 
sites could be due to the effect of  muddy-sandy substrate 
(Calumpong & Meñez, 1997; Fortes, 2013). The large, 
slow-growing E. acoroides is also a climax species 
(Duarte, 1991) that has been demonstrated to be resilient 
to light reduction and enhanced sedimentation (Vermaat 
et al., 1995). 
The relative abundance of  C. rotundata was higher in 
Dauis (12.82%), while H. uninervis was higher in Panglao 
(15.03%). One-way ANOVA analysis showed a significant 
difference (p>0.05) in H. uninervis relative abundance 
among sampling stations (F (3, 20) = 3.17, p= 0.05). 
A Tukey post hoc test revealed a significant difference 
between Tagbilaran and Panglao (p = 0.05). Pioneering 
seagrass species such as C. rotundata and H. uninervis were 
observed to be abundant in the sandy-rocky substrate. 
Pioneering seagrass species are best equipped to colonize 
new areas through rhizome expansion or to wander 
from gap to gap within established beds. These are best-
adapted nearshore, as a result of  their lower elongation 
rates (Vermaat et al., 1995). Relative abundance of  H. 
ovalis was higher in Panglao (9.78%). This pioneering 
species is produced throughout the year in tropical waters 
and are known to be primary colonizers, being the first 
to enter areas of  bare sand or disturbed seagrass beds 

(Waycott et al., 2002). On the other hand, S. isoetifolium 
was only encountered in Panglao Island: Panglao (9.84%) 
and Dauis (6.01%). According to Green and Short (2003), 
S. isoetifolium can be found in clear waters and prefers 
sandy substrates. Of  the surveyed sites, Panglao Island 
had the highest horizontal visibility, and the substrate 
type is generally a combination of  both sand and rock. 
Sufficient light and suitable substratum are therefore 
important physical factors determining seagrass presence 
and distribution (McKenzie, 2008). The species that 
occurs least frequently was H. pinifolia, with the lowest 
relative abundance found in Dauis (0.58%) and Maribojoc 
(0.13%). The rarity of  H. pinifolia indicates that it is less 
tolerant of  prevailing hydrographic parameters compared 
to other seagrass species (Meñez et al., 1983). Seagrass 
species such as H. pinifolia, H. ovalis, and S. isoetifolium 
are able to inhabit relatively deeper waters by having low 
light requirements, and faster and continuous rhizome 
growth (Vermaat et al., 1995). Meanwhile, T. hemprichii 
and E. acoroides are indiscriminate species in relation to 
depth (Genito et al., 2010). Certainly, the growth and 
distribution of  seagrasses are controlled by the physical, 
chemical, and biological properties of  the environment 
they live in (Greve & Binzer, 2004; Borum et al., 2006). 
Diversity Index
The diversity of  seagrass species was higher in Panglao 
(H’=1.33), followed by Dauis (H’=1.31), Maribojoc 
(H’=1.21), and Tagbilaran (H’=1.15) respectively (Figure 
3). Dominance was also higher in Panglao (D=2.9), 
followed by Tagbilaran (D=2.8), Maribojoc (D=2.59), 
and Dauis (2.55). Meanwhile, evenness was higher in 
Tagbilaran (E=0.83), followed by Panglao (E=0.74), 

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Figure 2. Relative abundance of  seagrass species in four sampling stations (error bars are standard deviation). 

Figure 3. Whittaker plot on seagrass species among 
four sampling stations in Maribojoc Bay, Bohol.

Table 3. One-way ANOVA analysis showing difference on seagrass relative abundance among four sampling 
stations and Tukey post hoc test showing a significant difference between sampling stations (p<0.05).  

One-way ANOVA Test Tukey’s Multiple Comparisons
Seagrass sp. N Sum of  

squares
F P-value 1-2 1-3 1-4 2-3 2-4 3-4

E. acoroides 24 19550.01 3.89 0.02* 0.40 0.90 0.34 0.14 0.02* 0.73

C. rotundata 24 2256.49 0.62 0.61 0.87 0.60 0.70 0.96 0.99 1.00

H. ovalis 24 867.13 0.48 0.70 0.99 0.99 0.84 0.92 0.95 0.66

H. pinifolia 24 4.27 2.75 0.07 0.95 0.25 0.95 0.10 1.00 0.10

H.uninervis 24 2509.38 3.17 0.05* 0.21 0.49 0.90 0.93 0.05* 0.18

S. isoetifolium 24 587.90 12.81 0.00* 1.00 0.02* 0.00* 0.02* 0.00* 0.27

T. hemprichii 24 9912.87 1.56 0.23 0.45 0.97 1.00 0.24 0.34 1.00

Maribojoc (E=0.68), and Dauis (E=0.67). The overall 
biodiversity index values of  the seagrass ecosystem in 
Maribojoc bay were diversity (H’=1.40), dominance (2.98), 
and evenness (0.72). The Shannon diversity index implies 
low diversity as the value is less than 2 (H’<2.0) based on 
the biodiversity index category by Odum (1983). Higher 
dominance and lower evenness were attributed to the 
extensive distribution of  Thalassia hemprichii. The presence 
of  dominating species means that the community is less 
diverse and indicates low stability. Hence, the seagrass 
ecosystem in Maribojoc Bay is under threat from losses 
and degradation. Coastal development, sedimentation, 
eutrophication, destructive fishing, and waste disposal 
are some of  the anthropogenic activities that pose the 
greatest threats to seagrass ecosystems in the Philippines 
(Fortes 1995, 2013; Fortes & Santos, 2004).
The Whittaker plot, or Rank-abundance Curves (Figure 
3), showed the patterns of  species diversity among 
sampling stations. It shows Thalassia hemprichii as the 
most abundant species, and the slope indicates low 
evenness as T. hemprichii has a much higher abundance, 
thus a steeper gradient than the other species. The species 
richness showed the following order: Dauis > Panglao = 

Maribojoc > Tagbilaran. In terms of  species evenness, a 
steep gradient indicates low evenness in Dauis, followed 
by Maribojoc and Panglao. In contrast, high evenness 
was observed in Tagbilaran, which could be due to the 
ubiquitous co-occurrence of  Thalassia hemprichii and 
Enhalus acoroides. Moreover, abundance was higher in 
Maribojoc, followed by Panglao, Dauis, and Tagbilaran, 
respectively. 
Cover percentage
The seagrass coverage in Maribojoc Bay was characterized 
by both patchy and continuous meadows, with a percentage 

Sites: 1-Maribojoc, 2-Tagbilaran, 3-Dauis, 4-Panglao
* The mean difference is significant at the 0.05 level.

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cover ranging from 17.45% (poor) – 60% (good). Among 
sampling stations, the seagrass percentage (Figure 4) 
revealed Maribojoc (45.53%), Panglao (43.93%), and 
Dauis (40.53%) with “fair” seagrass conditions, while 
Tagbilaran (24.61%) revealed a seagrass percentage 
cover with “poor” condition. ANOVA analysis showed 
no significant difference (p>0.05) in seagrass percentage 
cover among sampling stations (F (3, 20) = 1.45, p= 0.26). 
The overall seagrass percentage cover for the entire bay 
area is 38.65%, which can be classified as “fair” seagrass 
conditions. The result indicates sparse coverage and 
habitat fragmentation, probably due to the deterioration 
of  a once-continuous meadow. Possible causes are 
anthropogenic activities such as improper shoreline 
development, increased human settlements in coastal 
areas, and the use of  destructive fishing gear. The use 
of  the digging tool “sud-sud” by gleaners was observed 
in the area. In Tagbilaran, it is highly likely a result of  
relatively high sedimentation and siltation brought about 
by inputs from the Abatan River directly to the seagrass 
beds. Also, the introduction of  waterborne pollutants as 
well as nutrient loading along the shores from domestic, 
agricultural, and industrial wastes. As observed, nutrient 
indicator algae, Padina sp. proliferates in Tagbilaran. High 
algal cover denotes high nutrients caused by pollution that 
contributes to the increase in sea nutrient level (Fortes, 
et al., 2004). The seagrass condition in Maribojoc Bay is 
similar to that in Guimaras Island (Babaran and Ingles, 
1996), Lubang Island (Genito et al., 2010), and the coastal 
areas of  Iligan City (Orbita & Gumban, 2013). In the 
Philippines, data from 26 sites reported seagrass cover to 
be generally low, usually not exceeding 20%, indicating 
that most of  the seagrass beds in these areas have sparse 
coverage (BINU, 2005). 

Figure 4. Percentage cover of  seagrass species among 
sampling stations in Maribojoc Bay, Bohol (error bars 
are standard deviation).

respectively. The overall seagrass percentage cover 
revealed “fair” seagrass conditions, and the community 
structure revealed sparse distribution and low diversity. 
The seagrass ecosystem, as one of  the most important 
coastal ecosystems, requires greater attention for its 
monitoring, management, and conservation. Thus, 
further studies concerning seagrass communities are 
recommended in order to implement rehabilitation 
programs or improve current management in Maribojoc 
Bay.
Acknowledgements
The proponent would like to thank Commission on 
Higher Education (CHED) through its K to 12 Transition 
Scholarship Program, the Community Environment and 
Natural Resources Office of  Tagbilaran, and the Local 
Government Units (LGU) of  Maribojoc, Tagbilaran, 
Dauis, and Panglao.

REFERENCES
Abubakar, F.Z.B. & Echem, R.T. (2018). Distribution 

and Abundance of  Seagrass in Bongao, Tawi Tawi, 
Philippines.

Alcaria, J.F., Padin, J.I., & Padua, J.R. (1999). Survey 
of  seagrass community in the CEP [community 
environmental program] sites of  Region-7, Central 
Visayas, Philippines. Ecosystems Research and 
Development Service. International System for 
Agricultural Science and Technology (AGRIS) 24,181.

Babaran, R.P., & Ingles, J. (1996). The coastal marine 
habitats of  Guimaras Province: a rapid appraisal. 
Institute of  Marine Fisheries and Oceanology. Miagao, 
Iloilo, 161-191.

Biodiversity Indicators for National Use. (2005). Philippine 
Report on Coastal and Marine Ecosystems, Unep-
Gep-Wcmc.Bfar-Pawb Quezon City, Philippines, 75.

Borum, J., Sand-Jensen K., Binzer T., Pedersen O., & 
Greve, T.M. (2006). Chapter 10: Oxygen movements in 
seagrasses. In Biology of  seagrasses. Eds Larkum, Orth 
& Duarte. In press.

Calumpong, H., & Meñez, E. (1997). Field guide to the 
common mangroves, seagrasses and algae of  the 
Philippines. Makati City, Philippines. Bookmark, Inc, 
197.

Den Hartog, C. (1970). The seagrasses of  the word. 
North Holland Publishing Co., Amsterdam, 275. 

Duarte, C.M. (1991). Allometric scaling of  seagrass form 
and productivity. Marine Ecololgy Progress Series. 77, 
289-300.

Duarte, C.M., & Chiscano, C.L. (1999). Seagrass biomass 
and production: a reassessment. Aquat. Bot. 65, 159.

English, S., Wilkinson C., & Baker, V. (1997). Survey 
Manual for Tropical Marine Resources. Townsville, 
Australia, Australian Institute of  Marine Science, 
Townsville Australia, 378.

Fortes, M.D. (1989). Seagrasses: a resource unknown in 
the ASEAN region. ICLARM education series, 
International Centre for Living Aquatic Resources 
Management, Manila, Philippines, 46. 

CONCLUSIONS
Seven species of  seagrass were identified in Maribojoc 
Bay, Bohol. The most abundant seagrass species was 
Thalassia hemprichii, which obtained the highest relative 
abundance. Species richness showed the following order: 
Dauis > Panglao = Maribojoc > Tagbilaran. Seagrass 
relative abundance and percentage cover were higher in 
Maribojoc, followed by Panglao, Dauis, and Tagbilaran 

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Pa
ge

 
18

 https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 1(1) 12-19, 2022

Fortes, M.D. (1995). Seagrasses of  East Asia: 
Environmental and Management Perspectives. United 
Nations Environment Programme, Bangkok. RCU/
EAS Technical Report Series No. 6.

Fortes, M.D., & Santos, K.F. (2004). Seagrass ecosystem 
of  the Philippines: Status, problems and management 
directions. 90-95. In DA-BFAR (Department 
of  Agriculture-Bureau of  Fisheries and Aquatic 
Resources). In Turbulent seas: The status of  Philippine 
marine fisheries. Coastal Resource Management Project, 
Cebu City, Philippines, 378.

Fortes, M.D. (2013). A review: biodiversity, distribution, 
and conservation of  Philippine seagrasses. Philippine. 
J. Sci. 142, 95–111.

Genito, G.E., Nabuab, F.M., Acabado, C.S., Belle, 
S.A., & Beldia II, P.(2010). Baseline Assessment of  
Seagrass Communities of  Lubang and Looc Islands, 
Occidental Mindoro, Philippines. Publications of  the 
Seto Marine Biological Laboratory. Special Publication 
Series, 10, 53-64.

Green, S., Monreal, R., White, A., & Bayer T. (2002). 
Coastal Environmental Profile of     Northwestern 
Bohol, Philippines. Coastal Resource Management 
Project, Cebu City, Philippines, 113.

Green, E.P., & Short, F.T. (2003). World Atlas of  
Seagrass. Prepared by the UNEP World Conservation 
Monitoring Centre. University of  California Press, 
Berkley, USA, 298.

Jumawan, J., Bitalas, M., Ramos, J.J., Garcia, A.R., Landero, 
R., Cordero, J., Matela, M.N., Apostol, M.A., and 
Cataluña, R. (2005). Seagrass diversity and structure 
along the coastal area in Paligue, Hagonoy Davao del 
Sur, Philippines. AES Bioflux, Volume 7, Issue 3. 351-
356.

Lacap, C.D.A., Vermaat, J.E., Rollon, R.N., & Nacorda, 
H.M. (2002). Propagule dispersal of  the SE Asian 
seagrasses Enhalus acoroides and Thalassia hemprichii. 
Marine Ecology Progress. Ser. 235, 75-80.

Liu, S.L., Wang, W.L., Dy, T.D. & FU, C.C. (2005). 
The effect of  ulvoid macroalgae on the inorganic 
carbon utilization by an intertidal seagrass Thalassia 
hemprichii.Botanical Bulletin- Academia Sinica Taipei 46, 
3.

Hemming, M.A., & Duarte, C.M. (2000). Seagrass Ecology. 
Cambridge University Press.

Jackson, J.B., & Nemeth D.J. (2007). A new method to 
describe seagrass habitat sampled during fisheries-
independent monitoring. Estuaries and Coasts 30, 171–
178.

Jiang, Z.J., Huang, X.P., & Zhang, J.P. (2010). Effects 
of  CO2 Enrichment on Photosynthesis, Growth, 
and Biochemical Composition of  Seagrass Thalassia 
hemprichii (Ehrenb.) Aschers. Journal of  Integrative 
Plant Biology. 52 (10), 904–913. 

Meñez, E.G., Phillips, R.C., & Calumpong, H. (1983). 
Seagrasses from the Philippines. Smithsonian    contriib. 
Marine Science 21, 40.

McKenzie, L.J. (2003). Guidelines for the rapid 

assessment of  seagrass habitats in the western pacific, 
Department of  Primary Industries Queensland, 
Northern Fisheries Centre PO Box 5396.

McKenzie, L.J., & Mellors, J.E. (2007). Seagrass-Watch: 
Guidelines for Monitoring Seagrass Habitats in the 
Burdekin Dry Tropics Region. Proceedings of  a 
training workshop, Arcadian Junior Surf  Life Saving 
Club Townsville, 18th March 2007 (DPI&F, Cairns), 
24.

McKenzie, L.J. (2008). Seagrass-Watch: Proceedings of  
a Workshop for Mapping and Monitoring Seagrass 
Habitats in North East Arnhem Land, Northern 
Territory, 18–20 October 2008. (Seagrass-Watch HQ, 
Cairns), 49.

McRoy, C.P., & McMillan, C. (1997). Production 
ecology and physiology of  seagrass. In: McRoy, C.P., 
Helfferich, C. (Eds.), Seagrass Ecosystems: a Scientific 
Persective. Dekker, New York, e81, 53.

Nordlund, L.M., Koch, E.W., Barbier, E.B., & Creed, 
J.C. (2016). Seagrass ecosystem services and their 
variability across genera and geographical regions. 
PLoS One. 

Orbita, M.L.S., & Gumban, N.B. (2013). Investigation of  
the community structure of  seagrasses in the coastal 
areas of  Iligan City, Mindanao, Philippines. Advances 
in Agriculture & Botanics-International Journal of  Biological 
Sciences, 5(3), 140–151. 

Orth, R.J., Carruthers, T.J.B., Dennison, W.C., Duarte, 
C.M., Four-qurean, J.W., Heck, Jr K.L., Hughes, A.R., 
Kendrick, G.A., Kenworthy, W.J., Olyarnik, S., Short, 
F.T., Waycott, M., & Williams, S.L. (2006). A global 
contemporary crisis for seagrass ecosystems.

Phillips, R.C., & Milchakova, N.A. (2003). Seagrass 
ecosystems. Mar. Ecol. J. 2(2): 29-39 Prog Ser 29, 
15–22.

Redondo, A.F., Dagoc, K.M., Ignacio, M.T., Sanchez, 
R.R., & Tampus, A. (2017). Seagrass mapping and 
assessment using remote sensing in the Municipality 
of  Kauswagan, Lanao del Norte, Philippine. Journal 
of  Biodiversity and Environmental Sciences (JBES) ISSN: 
2220-6663 (Print) 2222-3045 (Online) Vol. 11, No. 4, 
74-88.

Saenger, P., Gartside, D., & Funge-Smith S. (2013). A 
Review of  Mangrove and Seagrass Ecosystems and 
their Linkage to Fisheries and Fisheries Management. 
Bangkok: RAP Publication, FAO.

Short, F.T., Koch, E., Creed, J.C., Magalhaes, K.M., 
Fernandez, E., & Gaeckle, J.L. (2006). SeagrassNet 
monitoring across the Americas: case studies of  
seagrass decline. Marine Ecology 27, 277–289. 

Short, F.T., Carruthers, T.J.R., Waycott, M., Kendrick, 
G.A., Fourqurean, J.W., Callabine, A., Kenworthy, 
W.J., & Dennison, W.C. (2010). Thalassia hemprichii. 
The IUCN Red List of  Threatened Species 2010: 
eT173364A7000000.

Short, F.T., Polidoro, B., Livingstone, S.R., Carpenter, 
K.E., & Bandeira, S. (2011). Extinction risk assessment 
of  the world’s seagrass species. Biol, Conserv. 144 (7), 

 https://journals.e-palli.com/home/index.php/ajec


Pa
ge

 
19

 https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 1(1) 12-19, 2022

1961-1971.
Terrados, J., Duarte, C.M., Fortes, M.D., Agawin, 

N.S.R., Bach, S., Thampanya, U., Kamp-Nielsen, L., 
Kenworthy, W.J., Geertz-Hansen, O., & Vermaat, J. 
(1998). Changes in community structure and biomass 
of  seagrass communities along gradients of  siltation 
in SE Asia. Estuarine, Coastal and Shelf  Science, 46, 
757- 768.

Vermaat, J.E., Agawin, N.S.R., Duarte, C.M., Fortes, M.D., 
Marba, N., & Uri, J.S. (1995). Meadow maintenance, 
growth and productivity of  a mixed Philippine 
seagrass bed. Marine Ecology Progress Series, 124, 215-
225.

Vermaat, J.E., Rollon, R.N., Day, C., Lacap, A., Billot, 

C., Alberto, F., & Terrados, J. (2004). Meadow 
fragmentation and reproductive output of  the SE 
Asian seagrass Enhalus acoroides, 52, 321–328. 
http://doi.org/10.1016/j.seares.2004.04.002.

Vonk, J.A., Christianen, M.J.A., & Stapel, J., (2008). 
Redefining the trophic importance of  seagrasses for 
fauna in tropical Indo-Pacific meadows. Estuarine, 
Coastal and Shelf  Science 79 (4), 653–660

Waycott, M., Duarte, C.M., Carruthers, T.J.B., Orth, R. J., 
Dennison, W.C., & Olyarnik, S. (2009). Accelerating 
loss of  seagrasses across the globe threatens coastal 
ecosystems. Proc. Natl. Acad. Sci. U.S.A. 106, 12377–
12381. doi: 10.1073/pnas.0905620106.

 https://journals.e-palli.com/home/index.php/ajec

