Status and changing trends of coral reefs in Lakshadweep archipelago after 1998 mass bleaching ...

13 Pages·2016·3.73 MB·English

Status and changing trends of coral reefs in Lakshadweep archipelago after 1998
mass bleaching event - long term monitoring survey
Idrees babu K.K1 and S. Suresh kumar2
1Coral Reef Research Centre, Department of Science and Technology, Kavaratti- 682555, Union Territory of
Lakshadweep, India,
2School of Ocean Science and Technology, Kerala University of Fisheries and Ocean Studies, Panangad,
Kochi 682506, Kerala, India

Abstract

The status of coral health and trends of the coral reef of Lakshadweep islands were not known
before the mass bleaching event of 1998. Moreover, the status of the coral reef of Lakshadweep
Islands is restricted toqualitative descriptions. Quantitative description on the percentage cover
and abundance of the coral species and the benthic substrate composition status of the
Lakshadweep reefs are essential for the assessments of reef health and inevitable to create
accurate baselines for long-term monitoring.As a preliminary attempt, the status of the coral reefs
in 12 atolls of this Archipelago incorporating generic composition and percentage occurrence of
different coral species and other benthic substrate types in different atolls have been documented.
This baseline information will be of much importance to assess the effect of the natural and
anthropogenic alterations in the coral reef ecosystem of these atolls in a long term perspective.

Keywords- status; coral; health; trends; Lakshadweep; islands

I. INTRODUCTION

The status of coral health and trends of the coral reef of Lakshadweep islands were not known
before the mass bleaching event of 1998 as reported [2][25] and [26]. However, the attempts on the
status of the coral reef of Lakshadweep Islands were restricted to qualitative descriptions.
Quantitative description on the percentage cover and abundance of the coral species and the benthic
substrate composition status of the reefsystem is essential for the assessments of reef health and
inevitable to create accurate baselines for long-term monitoring. [5] provided a snapshot of condition
of the reefs of Lakshadweep four year after the 1998 bleaching event and highlighted the absence of
a comparative base line for long term monitoring.
The present investigation was carried out to establish a broader geographic descriptionin
benthic composition and to create a comparative baseline data to assess the potential weather related
consequencesto the reefs of Lakshadweep atolls. Forecasts of climate data suggest that the 1997–98
El Niño signify on environment where sea surface temperature (SST) anomalies will increase in
intensity and frequency, resulting in recurrent and widespread coral bleaching and mortality events,
possibly every year [17][18]. In this juncture, a preliminary attempthas been made to assess the status
of thecoral reefs, of 12 atolls of Lakshadweep Archipelago. Benthic substrate composition,
quantitative description on the percentage cover of the coral species and relative abundance and
distribution of corals in these atolls were documented.

II. MATERIALS AND METHOD
2.1 Study area
Lakshadweep is an archipelago in the Arabian Sea (8° and 12°30' N, 71° and 74° E) off the West
Coast of India with 20,000 km2 territorial water, and 4,00,000 km2 of Exclusive Economic Zone.
Lakshadweep Archipelago consists of 15 atolls and 5 submerged sand banks. Lakshadweep islands
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are composed entirely of coral reefs, and are the only atoll formation among the oceanic coral reefs
in India. These atolls constitute 11 inhabited, 16 uninhabited islands and 3 submerged reefs. The total
lagoon area for these atolls is 4200 km2. Lakshadweep forms the northern most segment of the
Chagos – Maldive – Laccadive oceanic ridge. The study was carried out in 12 atolls of Lakshadweep
archipelago (Table 1).

2.2 Survey
Data on benthic community were collected using line intercept transects (LIT) in water depths from 1
m to 21 m to obtain the reef profile and coral percentage cover [20][37]. Transect were laid
horizontally along the substratum and data collected along each transect. The projected length of
each substrate category or coral species beneath the 20 m line was recorded to the nearest centimetre.
Among the substrate category the live corals were identified up to genus/species level and the
position of every change in substrate type was recorded as suggested by Global Coral Reef
Monitoring Network (GCRMN) manual [16]. Underwater photography and video documentation
was also conducted to refine the quality of the data collected manually by further observation and
discussion. A total of 296 LIT of 20 m long transects line were laid parallel to the reefs of the
selected atolls. All the LIT were laid at randomly selected locations covering lagoon, inner reef
slope and outer reef slope which were marked using permanent submerged markers and GPS
location during April to December 2005. Number of transect for each island was decided based on
the area of the atolls and the lagoon area (Table 1). All these transect were monitored on yearly basis
for the continuous recording of data; however an additional survey was conducted soon after the
2010 bleaching. Percentage cover of coral was observed from 1 m to 21 m in different atolls with
the help of snorkelling and SCUBA diving to collect the information on broader geographic variation
of coral species distributed in different geomorphologic zones. Genus and species level data on the
corals was collected by using the Indo Pacific Coral Finder robust underwater plastic book [35].
Data on interval of occurrence of coral species and other mixed benthic substratum were recorded on
a PVC slate. From the base data the quantitative description on the percentage cover of the coral
species and benthic substrate composition status were worked out. Photographic and video
documentation was also carried out to find different type to anthropogenic and other natural threats
to the corals. Reference data on the live coral cover during 2001-2004 was collected from
Lakshadweep Coral Reef Monitoring Network [33].

Table 1. Lagoon area and location of the Islands of Lakshadweep Archipelago selected for the present investigation.
No. of transects
Name of the Island Latitude Longitude Lagoon area used
17.5 km2
Agatti 10° 51.347'N 72° 10.530'E 25
1.5 km2
Amini 11° 07.359'N 72° 43.151'E 17
0
Andrott 10° 48.953'N 73° 40.305'E 6
45.6 km2
Bitra 11° 35.000'N 72° 10.031'E 29
46.2 km2
Bangaram 10° 56.932'N 72° 17.384'E 28
1.6 km2
Chetlat 11° 41.651'N 72° 42.401'E 21
4.9 km2
Kavaratti 10° 34.057'N 72° 38.353'E 25
1.7 km2
Kiltan 11° 29.012'N 73° 00.039'E 22
37.5 km2
Kadmat 11° 13.296'N 72° 45.888'E 27
25.6 km2
Kalpeni 10° 05.513'N 73° 37.849'E 27
78.6 km2
Suheli 10° 04.453'N 72° 16.552'E 38
30.6 km2
Minicoy 08° 17.963'N 73° 02.179'E 27

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The length of each substrate type directly underneath the tape measure of each line intercept
transect (LIT) was averaged over the replicates separately for lagoon and outer reef slope of each
atoll. Calculation of the percentage of benthic substrate composition type was based on the
contribution of each substratum to the total length of projection. Mean percentage occurrence of
coral species in the different sites were estimated directly from their densities in transects. The
average percentage covers estimated were compared between the islands to determine variation in
benthic substratum. Microsoft Excel for Windows was used for tabulation and descriptive statistical
analysis. Primer 6 software [36] was used for diversity analysis. Bray-Curtis similarity method was
used to evaluate the distance or similarities between the coral reef area of different atolls and
similarities in mixed picture of the benthic status and percentage of coral species coverage in
different reefs of the studied atolls. Non metric multidimensional scaling was also adopted to
configure the points in Euclidean space between the coral reef area based on the mixed picture of the
benthic status and percentage of coral species coverage in different reefs of various atolls [36]

III. RESULTS
A sharp decline in the percentage live coral cover was observed after the 2010 bleaching event
in all the 12 atolls of Lakshadweep archipelago selected for the study (Fig. 1 and 2). The benthic
status of reef, before the 2010 bleaching event, showed that coral cover was above35% which
indicates a good health status of the reef of this archipelago. Outer reef slope up to 20 m depth of
Agatti, Kavaratti, Kadmat, Kalpeni, Minicoy, Bangaram, Amini, Bitra and Kiltan have 58.0%,
55.5%, 46.0%, 44.5%, 43.5%, 42.0%, 41.5%, 41.5% and 41.0% live coral cover respectively. Live
coral cover varied considerably in reef across the atolls of Lakshadweep, with Andrott, Chetlat and
Suheli having relatively low live coral cover with a record of only 22.0%, 34.1% and 31.0%
respectively (Fig. 2). Clear difference in benthic composition was apparent between the lagoon and
outer reef slop. Lagoons in the Lakshadweep archipelago with a depth range of 1m to 6m had
comparatively higher live coral cover. Benthic status worked out for the twelve atolls are given in
the Table 2.
Table 2. Percentage Mixed picture of the benthic status of reef of Lakshadweep Island 2011
Atolls Live Coral Dead Coral Rubbles Rock Sand Algae Others
Agatti 42.80± 0.06 38.50± 0.09 1.00± 0.11 2.00± 0.11 5.50± 0.21 9.00± 0.04 2.00± 0.63
Amini 30.50± 0.26 38.00± 0.06 7.00± 0.91 2.00± 0.26 9.50± 0.28 8.50± 0.09 5.00± 0.63
Andrott 11.50± 0.66 31.00± 0.19 6.50± 0.91 1.50± 0.61 8.00± 0.19 34.50± 0.06 7.00± 0.33
Bangaram 31.00± 0.06 32.00± 0.09 11.00± 0.11 9.00± 0.21 7.00± 0.16 3.00± 0.23 6.50± 0.63
Bitra 30.10± 0.06 38.50± 0.09 6.00± 0.11 3.00± 0.21 5.50± 0.16 9.00± 0.06 8.00± 0.73
Chetlat 25.00± 0.32 41.80± 0.21 3.50± 0.61 5.60± 0.91 5.50± 0.36 12.00± 0.16 6.00± 0.63
Kadmat 34.80± 0.06 35.00± 0.09 10.00± 0.11 4.80± 0.21 3.50± 0.16 5.60± 0.16 6.30± 0.35
Kalpeni 35.00± 0.08 29.00± 0.09 5.60± 0.13 20.00± 0.21 2.40±0.16 5.00±0.16 3.00± 0.63
Kavaratti 39.00± 0.06 40.00± 0.09 4.00± 0.21 8.00± 0.21 3.50±0.16 3.00±0.26 2.50± 0.63
Kiltan 29.03± 0.16 38.00± 0.19 8.00± 0.21 2.00± 0.23 6.00±0.17 13.00±0.04 4.00± 0.61
Minicoy 33.00± 0.06 34.50± 0.09 6.50± 0.11 3.00± 0.21 5.00±0.16 3.50±0.26 4.00± 0.73
Suheli 30.07± 0.06 45.00± 0.09 1.50± 0.11 2.50± 0.21 5.50±0.16 7.30±0.06 8.00± 0.61

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80
2010 % live coral 2010% Coral bleaching 2011% live coral
70
60
50
er
v
o
% C40
30
20
10
0
KVT MCY AGT BNG AND KLP AMN KDM CHT BTR KLT SUH
12 atolls of lakshadweep
Figure 1. Percentage cover of live corals in various lagoons of Lakshadweep archipelago during 2010-2011. KVT-
Kavaratti, MCY- Minicoy, AGT-Agatti, BNG-Bangaram, AND- Andrott, KLP-Kalpeni, AMN-Amini, KDM- Kadmat,
CHT-Chetlat, BTR-Bitra, KLT-Kiltan and SUH-Suheli
70
2010 % live coral 2010% Coral bleaching 2011% live coral
60
50
er40
v
o
C
%
30
20
10
0
KVT MCY AGT BNG AND KLP AMN KDM CHT BTR KLT SUH
12 atolls of lakshadweep

Figure 2. Percentage cover of live corals in the outer reef slope of various islands of Lakshadweep archipelago
during 2010-2011. KVT-Kavaratti, MCY- Minicoy, AGT-Agatti, BNG-Bangaram, AND- Andrott, KLP-Kalpeni, AMN-
Amini, KDM- Kadmat, CHT-Chetlat, BTR-Bitra, KLT-Kiltan and SUH-Suheli

The extent of bleaching came about in 2010, as evidenced from the pooled data from various
islands, severely affected the total live coral cover of the islands with a decline from 36% to 26% in
live coral coverage (Fig. 3). Bleaching was prominent in shallow water in depth less than 10 m.
Nearly 65% of the corals in the reef flats of the lagoons of Lakshadweep archipelago were bleached
(Fig. 1 and 2). Majority of hermatypic corals including fast growing Acropora and slower growing
massive Porites, were bleached severely, due to the increased sea surface temperatures as the
maximum temperature recorded was 33.8°C. Bleaching affected all the reefs of 12 atolls and the live
coral cover declined to the status of live coral cover in 2005 (Fig. 3). Results showed that 25% of the
live coral was beached when taking the average across all the LIT sampled across the atolls from
different depths. Live coral bleaching was severe in Agatti (35%) while Andrott (10%) showed
moderate beaching. Live coral beaching in the outer reef slope up to a depth of 10 m showed an
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average of 35%, however, the corals below 10 m showed only 10.2% bleaching. Thus the bleaching
was more seriously affected to live coral at the lagoon rather than the live coral in the deeper regions
of outer reef slope. The result also suggests that depth plays an important role in the extent of
bleaching and influencing resilience across the atoll of this Archipelago.

70.00%
Live coral Algae
60.00%
50.00%
r 40.00%
e
v
o
c
% 30.00%
20.00%
10.00%
0.00%
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Year
LCRMN data

Figure 3. Mean percentage cover of live coral and algal turf during 2001-2011

The plot with the help of reference data from 2001 to 2004 showed that, after the 1998
bleaching event, there was a stress on the live coral cover during 2002 and 2003 manifested by
slower growth in these atolls (Fig. 3). Recovery of the live coral cover was observed from 2005
onwards and reached 35.25% by 2010. Algal turf was found to be the dominant benthic component
in the reefs of Lakshadweep atolls subsequent to the bleaching event, which reached 32%of the total
area in 2010 (Fig. 3). Significant variability was observed in the cover of turf algae between the
atolls. Similar increase in the algal turf cover was also observed in the reefs of Lakshadweep after
the 2010 bleaching event.
Composition and percentage occurrence of different coral genus/species in different atolls
showed significant variations. Percentage cover of live coral species in the reefs of Agatti,
Bangaram, Kavaratti, Suheli and Bitra islands showed 83% similarity among them. Kalpeni and
Minicoy (85%) and Chetlat and Kiltan (92%) showed greater similarity in their percentage live coral
cover, while Kadmat and Amini showed only 63.5% similarity. Andrott Island showed only 40%
similarity with all other atolls based on percentage cover of live coral species in the reef (Fig. 4). The
most common genera projected in the line intercept transect include Acropora, Pocillopora, Porites,
Platygyra, Favites, Favia, Hyndnopora and Pavona. Echinopora, Goniopora, Stylophora and
Montipora, establishedaweak geographic trends in the composition of coral species across the atolls
(Table 3). Similarly, atolls of Kavaratti, Kalpeni, Kadamat, Bangaram and Minikoy formed a group,
while, Agatti, Amini, Bitra, Chetlat, Kiltan and Suheli atolls form another group and Andrott is very
distinct in the case of benthic substrate composition (Fig. 5).
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Table 3. Generic composition of live coral cover in various islands of Lakshadweep
KVT MCY AGT BNG AND KLP AMN KDM CHT BTR KLT SUH
Acroporaformosa 1.8 0.8 2.4 3.4 0 0 0.25 0 0 2.4 2.02 0.9
Acroporahyacinthus 2.8 0.3 5 0.4 0.4 0.3 0 4.02 0.2 0.8 0.2 0.6
Acroporahumilis 1.08 2.2 2.8 0.17 0.1 2.2 0 3.3 0.12 0.12 0 0.12
Acropora digitifera 2.4 2.5 3.08 2 0 0.4 0 3.3 0.13 0.6 0 0.6
Pocilloporadamicornis 5 1.02 7 1.03 0.7 0.6 0.1 0.3 0.3 1.6 0.3 1.6
Poritessolida 8.6 8.9 6.8 3.1 2.3 9.6 6.2 8.5 6.3 9.2 6.3 10.02
Poriteslutia 5.2 3.8 3.2 2.01 1.4 3.8 2.05 6.6 3.2 5.3 3.2 7.3
Poritessp. 3.04 4.02 4 4 4.3 3.01 1.4 1.2 0.2 3.5 0.7 3.5
Platygyrasp. 1.3 0.5 1.3 1.3 0.02 0.5 0.5 4.2 0.4 1.04 0.4 3.2
Favitessp. 0.8 0.3 1 1 0.3 0.3 0.2 3 0.6 3.2 0.6 0.08
Faviasp. 0.6 0.4 0.6 0.6 0.02 0.3 0.1 1 0.3 3.1 0.3 0.6
Hyndnoporasp. 0.2 0.8 2.1 2.1 0 0.8 0 0 1.2 0.32 1.2 0.32
Pavonasp. 3.6 0.19 1.1 1.1 0 2.8 0 2 0 2.2 0 0.8
Echinoporasp. 3.1 0.08 4 4 0.2 3.8 4 3 0.38 4.8 0.38 2.5
Gonioporasp. 2.2 1.63 0.8 0.8 0.7 1.63 0.2 1.3 0.3 1.03 0.3 1.03
Stylophora sp. 1.3 1.43 2.5 2.5 0.1 4 0.3 0.7 4.2 3.6 4.2 3.6
Montipora sp. 0.9 1.6 1.8 1.8 0.8 2.1 3 1.3 9.8 2.3 9.8 2.3
soft corals 2 0.6 4 3.01 0 0.6 0 0 0.13 2.01 0.13 3.29
KVT-Kavaratti, MCY- Minicoy, AGT-Agatti, BNG-Bangaram, AND- Andrott, KLP-Kalpeni, AMN-Amini, KDM- Kadmat, CHT-Chetlat, BTR-Bitra, KLT-Kiltan and SUH-Suheli
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Figure 4. Clustering of the reefs of Lakshadweep based on the percentage cover of live coral cover

Figure 5. Clustering of the reefs of Lakshadweep based on the status of benthic substrate.
IV. DISCUSSION
The present investigation was aimed to develop baseline information on the health status of the
reef and to establish the geographic response of the live coral. This data is requiredto assess the
impact of threat, if any,happened to the coral reef in future due to natural or anthropogenic drivers.
Benthic substrate composition in all the 12 atolls of this archipelago was worked out to provide
information on geographic peculiarities and faunal composition of the reef. The quantification of the
impact of earlier bleaching events were not possible due to the lack of baseline information prior to
the 1998 and 2001 mass bleaching event. Percentage cover of live coral estimated from the data
collected through quick surveys in Kavaratti and Kadmat lagoon was available only after 1998
bleaching events [26]. After 1998 bleaching event, studies were concentrated on the assessment of
live coral recovery in the reefs for the four subsequent years. Arthur (2005) pointed out that, without
a comparative base line a rapid survey can only give a snapshot. A long-term study of coral reef
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ecology will be a good opportunity to examine the temporal variation on the impact of mass coral
bleaching at those reef sites [27].
Mass coral bleaching was clearly observed in the atolls of Lakshadweep archipelago in 2010
with a sharp decline in live coral coverage. Increased sea surface temperatures may be the prime
reason for the bleaching as the maximum temperature recorded was 33.8°C. High seawater
temperature consequent to high levels of solar irradiation leads to severe coral bleaching [18]. The
higher percentage of coral bleaching recorded in Agatti can be attributed to the occurrence of live
coral at shallow areas, which may exposed to higher temperature. However, Andrott, with live coral
occurrence in its deeper outer reef slope area, where elevated sea surface temperature seldom affects,
registered lowest beaching. Live coral beaching in the outer reef slope up to a depth of 10 meters
showed an average of 35%, however, the corals below 10m showed only 10.2% bleaching. On an
average, 65% of the live corals in the reef flats were bleached during 2010 bleaching event.
Bleaching may be influenced by the depth for light to penetrate and reduced intensity of light which
corals could withstand. This suggests that reduced light penetration site exhibited little or no
bleaching. The present findings are in line with earlier reports of [21]. Majority of hermatypic corals
where bleached severely, due to the increased sea surface temperatures. Several studies showed that
these coral taxa as the most susceptible to sudden stress [8][13][15]and [19]. These findings clearly
reveal that depth plays an important role in influencing coral resilience across this atoll chain.
As long-term data on coral reef ecosystem provide good opportunity to examine and explain
the temporal variation in the impact of various stressors on the coral reef health and trends [27]. The
graph, plotted with the reference data from 2001 to 2004, provided a long time trend in status and
impact of the corals and its structural changes in the Lakshadweep atolls. The result of the finding
showed that after the 1998 bleaching event, there was a stress on the live coral cover during 2002 and
2003 manifested by slower growth in these atolls. Annual mean sea surface temperature (SST) trend
showed that the reef areas of Lakshadweep become warmer from 28.50°C in 1985 to 28.92°C in
2005, at a rate of 0.21°C per decade [28]. Such temperature rises affect the Indian coral reefs, which
have experienced widespread bleaching events in 1989, 1998 and 2002 [2][23][24]. mass mortality
of coral in the Arabian Sea consequent to El Niño.Anomalously high seawater temperature, which is
an upshot of high levels of irradiation, normally resulted in coral bleaching [2][5][18]. The
observation showed that atolls of Lakshadweep archipelago experienced a series of coral bleaching
after 1998 El Niño in 2002 and 2010. It is further observed that the 2010 coral bleaching
phenomenon was more severe than the 2002 bleaching event evident by drastic decline in the
percentage live coral cover. The impact of earlier experience on coral bleaching susceptibility may
become increasingly significant in shaping coral responses to temperature and solar radiation stresses
in the future [7].
Reduction in live coral cover could bring in major shift in the benthic status with the luxurious
growth of macroalgae in elevated temperature using dead coral as substratum. On an average 36% of
the total benthic substratum was occupied by algal turf in the reefs of Lakshadweep atolls after 2002
bleaching event (Fig 3). The loss of live coral benefitted opportunistic species like fleshy
macroalgae, which often rapidly dominate benthic substrate, drastically shifting functional position,
and potentially hinder the re-colonisation of corals in these areas [4][6]. Present findings point
towards the structural changes in the benthic status of coral reef ecosystem with the loss of live coral
cover. Reduction in live coral cover eventually leads to change in ecosystem structure, which
indicating their significance in maintaining functional element in coral reef ecosystem.
Andrott Island showed 5.72 points in Euclidean space of variability with the benthic mixture
substrate compared to other atolls of the archipelago (Fig. 5). In plain sight observation, the sighting
frequencies of the shoal of herbivore fishes in Andrott reef were comparatively low, when compared
to the other reef of the archipelago. Fishes of the family Acanthuridae and Scaridae play important
role in controlling algal biomass on Lakshadweep Island [5][31]. This may be the reason for the low
percentage cover of live coral in Andrott Island among the atoll chain. Result also brought out that
live coral percentage covers were 11.50% which was considerably low, as algal coverage was
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dominated and restricted the projection of live coral. Loss of live hard coral either by anthropogenic
or natural causes and the consequent shifts in the structure of coral communities will almost
universally have impacted on fish communities [11][30][31]. Dominance of algal turf in benthic
substratum may be due to the less sighting frequency of the shoal of herbivorous fisheswhen
compared to the other reefs of the atolls.Herbivorous fishes potentially provide opportunities for
corals to recover between the disturbance events [12][14]
During the beginning of bleaching event there was a decrease in sighting frequency of
butterflyfishes and other corallivorous fishes, however sighting frequency of Acanthaster planci was
relatively high, generally in all the atolls of the archipelago. Furthermore, zooxanthalae symbiotic
organisms such as giant clams, sea anemones and zoanthids have been found to be affected with the
increase in SST (Plate 1). Change was observed in reef associated fishes and other reef associated
organisms in Agatti during the 2010 bleaching event [1].Besides the effect of SST on coral reef other
natural threats like predation of corals by star fish,Acanthaster planci, coral diseases and other
anthropogenic activities that directly or indirectly stress the island coral reef were also documented
for the discussion (Plate 2.).

Plate 1. Effect of bleaching on different zooxanthelle symbiotic organisms in Agatti and Kavaratti Atolls. A. Coral,
before bleaching, January 2010. B. Coral after bleaching, April 2010, Outer reef slope Kavaratti. C. Amenone,
before bleaching February 2010, D. After bleaching April, 2010, in the lagoon of Kavaratti, E. Giant Clam,
Tridacna maxima before bleaching, January 2010, F. After bealching, Inner reef of Agatti. (Not intended for
publication, included for the verification of reviewers; if the reviewers permit, the same may be included in the
paper).
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Plate 2. Natual and anthropogenic threat to the Reefs of Lakshadweep. A.Coral bleached inside the lagoon of Kavaratti
during 2010 bleaching event, B. Algae dominated on coral subsequent to the bleaching event at Kavaratti inner
reef, C.Pink band coral diseases observed during the study at Agatti reef, D.predation of corals by
Acanthasterplanci in Kavaratti reef, E. Acanthurustriostegus, ConvictSurgeonfish one of the predominant
herbivore fish, harvested from the reefs at more than sustainable levels, will lead to various degrees of stress to
the reefs and F.Distraction of habitat and impart stress, increase negative pressure on the corals. Octopus-
fishing at Kavaratti reef.(Not intended for publication, included for the verification of reviewers; if the reviewers
permit, the same may be included in the paper).
The anthropogenic activities are also increased the stress of the coral reef. The people of
Lakshadweep Islands have traditionally been dependent on fishing for livelihood for centuries and
for their socioeconomic benefits. Coral reefs are very important to Lakshadweep island economy.
Coral reefs, which are economically important resources to most tropical countries, are declared as
the critically threatened ecosystems on the globe [27]. Unmanaged harvesting of coral associated
fishes as live bait for tuna pole and line fishing and unsustainable harvesting of herbivorous fishes
like Surgeon fishes and parrot fishes also cause distraction of habitat and impart stress to
Lakshadweep coral reef system, these local stresses directly or indirectly pressure the island coral
reef. Approximately 75% of the world's coral reefs are categorized as being threatened when local
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