Ecology of Fish Communities in Coral Habitats Along the Coast of Pakistan: Potential Threats and Conservation Strategies

Amjad Ali1*, Pirzada Jamal Ahmad Siddiqui1, Naveed Ahmad2, Shabir Ali Amir3, Rafaqat Masroor3, Seema Shafique1 and Zaib-un-Nisa Burhan1

1Center of Excellence in Marine Biology, University of Karachi, Karachi 75270

2Aquatic Diagnostic Laboratories, Bahria University, Karachi Campus, Karachi

3Zoological Sciences Division, Pakistan Museum of Natural History, Garden Avenue, Shakarparian, Islamabad

ABSTRACT

Reef ecosystem is an important source of recreation and fish diversity. Present study aimed to record the distribution and diversity of fishes from different coral habitats along the coast of Pakistan. Additionally, potential threats and conservation strategies were also discussed. SCUBA diving was conducted at 10 different dive sites along the coastline. Relative abundance of the fishes was determined using visual techniques. Sea water physiochemical parameters were determined. A total of 58 fish species in 33 genera and 24 families were recorded at 10 different dive sites. High diversity occurred at Churna Island following Mubarak Village and Astola Island. Majority of the recorded fishes were planktivorous. Compare to Churna and Mubarak Village, physico-chemical parameters at Astola Island were found in limits as preferred by fish and coral communities for their proper growth. Fish accumulation appeared to be link with coral cover, diversity and growth forms. Low diversity at Astola Island was mainly due to habitat destruction caused by increasing anthropogenic activities (coral mining, careless SCUBA and skin diving, entangling of corals by fishing nets and mechanical damage by deployment of lobster pots). Conservation efforts should focus on the establishment of effective marine protected areas, involvement of different stakeholder (well reputed research institutes, universities, dive centers, tour operators, local community), making tourism laws and their implementation, rehabilitation of microhabitats for fish communities through the involvement of local community and creating awareness in general public on the significance (ecological, commercial) of these natural resources via print and electronic media for a sustainable ecotourism. Further, to better understand the effects, regular monitoring monitoring and scientific research (environmental, biological parameters) is recommended.

Article Information

Received 02 June 2018

Revised 20 June 2019

Accepted 13 April 2020

Available online 14 May 2021

Authors’ Contribution

AA collected data and wrote the manuscript. PJAS critically analyzed the manuscript. NA helped in collecting data. SAA helped in fish identification. RM helped in statistical analyses of the data. SS and ZNB helped in nutrient analysis.

Key words

Anthropogenic impacts, Reef fish, Churna island, Astola island, Pakistan coast, Coastal area, Conservation

DOI: https://dx.doi.org/10.17582/journal.pjz/20180602100601

* Corresponding author: [email protected]

0030-9923/2021/0004-1341 $ 9.00/0

Copyright 2021 Zoological Society of Pakistan

INTRODUCTION

Reef ecosystem is important source of recreation and fish diversity. World third of marine fish species exist in reef environment (Maragos et al., 1996; Veron et al., 2009; Plaisance et al., 2011). Reef provides 25% of the total fish, consumed by humans. Several millions of people living in at least 99 countries (having coast line with reefs) depend on corals for their food requirements (Teh and Sumaila, 2013). Fishes play a diverse and central role in marine ecosystems. During recent decades, as a result of increasing sea surface temperature and anthropogenic activities (tourism effects, increase in nutrient and sediments load, release of toxic material etc.), reefs degradation has occurred globally. Changes in reef habitats have inserted remarkable effects on the abundance and distribution of reef associated fishes. Future changes can alter ecosystem functions and fish productivity (Pastorok and Bilyard, 1985; Naim, 1993; Maragos et al., 1996; Riegl, 2002; Chittaro, 2004; Loya, 2007; Hay and Rasher, 2010; Gladstone et al., 2013; Hernández-Delgado et al., 2014; Pratchett et al., 2014; Heron et al., 2016).

In future, major threats for reef fishes will be increasing sea surface temperature and atmospheric carbon dioxide concentration across the globe. These changes will affect food chain, population connectivity, recruitment dynamics and decrease in fish diversity. Many of the reef fishes are living close to thermal optimal condition and an adequate increase in temperature will reduce aerobic space, habitat destruction and effect on behavior and physiological performance of reef fishes (Munday et al., 2008; ). Moreover, it is evident that change in water temperature and carbon dioxide concentration due to climate change can alter fish fitness by altering their behavior, reduction in acclimation ability, response to environmental changes, reduction in hypoxia forbearance capacity of reef fish, reduction in respiratory performance and damage of chemosensory responses to predators (; ; ; ; ). Beside climate change effects, sewage pollution is a major threat for reef associated communities. Increase in nutrient level will enhance the growth of algae and filter feeders in water column. This increase (algae and filter feeders) will decreases oxygen level and reduce coral cover (; ).

Many researchers conducted studies on the ecology of reef fishes on global (e.g. Reese, 1975; Thompson and Munro, 1978; Williams and Hatcher, 1983; Shulman, 1985; Pet-Soede et al., 2001; Graham et al., 2003; Marshall et al., 2003) and regional scale (e.g. Downing, 1985; Smith et al., 1987; Coles and Tarr, 1990; Krupp and Miiller, 1994; Fouda et al., 1998; Kemp, 1998; Rezai and Savari, 2004).

Locating on the northern part of the Arabian Sea, Pakistan covers a major portion of the Arabian Sea with a coast line of 1050 km, distributed between Sindh (250 km) and Balochistan provinces (800 km). The major portion of the coast (Balochistan coast) is still tectonically active. The coast is under the influence of reversal monsoons. Up-sloping brings up nutrient that support macroalgal growth (Haq, 1988; Shameel and Tanaka, 1992; Ali and Memon, 1995; Wiggert et al., 2000; Ali et al., 2017). Corals along the coast are mainly confined to offshore waters (Churna and Astola Islands) while in coastal areas at some locations are mostly patchily distributed (Ali et al., 2014). Studies on reef associated fishes from the coastal waters of Pakistan are lacking though a considerable information are available on their taxonomy (i.e. Bianchi, 1985; Hoda, 1988; Amir et al., 2013, 2014, 2016). These studies were mainly based on samples collected either from fish harbors or even captured using different nets without knowledge of their ecology. The current study displays the outcomes of surveys undertaken in coral habitats along the coast of Pakistan and an overview of the features of the visited sites and fish communities. Additionally, potential threats to fish communities and conservation strategies were also discussed.

MATERIALS AND METHODS

Study sites

Study was conducted at 3 sites, 2 along the Sindh coast (Mubarak Village (MV) and Churna Island (CI)) and 1 along the Balochistan coast at Astola Island (AI) (Fig. 1). The locations were selected on the basis of coral cover. Mubarak Village is located at 24o 51’ N, 66o 39’E and approximately 45 km towards west from Karachi. The substratum is rocky. It is a sport fishing site and people also come for snorkeling and diving. Churna is a small Island off the coast of Karachi and is located at 24o 53’N and 66o 36’E, about 50 km west of Karachi. The substratum is rocky. The Island is well known fishing and recreational site. Recreational fishermen frequently visit the Island where there is enough sea life to attract anglers for big game fishing from all over Pakistan. Astola Island is comparatively larger than Churna Island, located at 25o 07’ N, 63o 50’ E and about 30 km south of the Balochistan coast. The Island has an area of about 4 km2, being 4 km long, 1 km wide and typically 60 m high. There are numerous sandy beaches on the northern side of the Island. These beaches are essential nesting sites for different species of turtles (green and leather back). Recently the Island is declared as a Marine Protected area (Dawn, 2017). The substratum at the Island is mostly rocky, composed of sandstone and calcareous sandstone (Shah, 2009). The Island is also considered as a hot coral spot in offshore waters along the coast (Ali et al., 2014).

 

Methods

SCUBA diving was conducted at 10 dive sites, 6 along the Sindh coast (1 each at MV1, MV2 and 4 at CI) and 4 at northern sheltered site of Astola Island along the Balochistan coast (Fig. 1). Surveys along the Sindh coast were conducted between January to March 2014 while along the Balochistan coast, during February 2018. In situ observations, GPS coordinates and depth at each site was noted (Table I). Fish abundance at each site was determined visually using 1 to 6 mathematical scale (6 (dominant)= up to300 individuals; 5 (abundant)= up to 200 individuals; 4 (common)= up to 50 individuals; 3 (frequent)= up to 20 individuals; 2 (occasional)= up to 10 individuals, 1(rare)= up to 5 individuals). Considerable numbers of species were identified in situ while for others, relayed on underwater photographs, taken using a digital camera (Fine Pix F660EXR) in an underwater housing. Following Froese and Pauly (2018), fishes were further classified on the basis of their feeding level. Fishes were identified using available literature (Kuiter and Debelius, 2007; Bianchi, 1985; Carpenter et al., 1997).

Seawater physico-chemical parameters

Seawater physico-chemical parameters along the Sindh coast were not determined but relayed on previous study, conducted by Ali et al. (2017) while physical parameters (temperature, salinity, dissolved oxygen, pH), inorganic nutrients (nitrate, nitrite, phosphate, ammonia) and organic content (chlorophyll a) along the Balochistan coast were determined in triplicate. Temperature (°C) and dissolved oxygen (mg/L) were determined using Dissolved Oxygen/Temp. Waterproof Tester (EZDO 7031). Salinity was determined using refractometer (ATAGO 0161633 Japan) while pH was determined using pH meter (Hanna HI98107). Water samples for inorganic and organic contents were collected in lid covered plastic bottles, stored in ice box and brought to laboratory. Analyzes of the samples were performed following Strickland and Parsons (1972).

Data analysis

Cluster techniques were used to examine relations between sites based on root square transformation of data and Bray-Curtis similarity index (Bray and Curtis, 1957; Clarke and Warwick, 2001; Clarke, 1993). Frequency distribution of species at 10 diving sites was perceived using K. dominance curve (Lambshead et al., 1983). Multivariate analysis was piloted using PRIMER v.6 software package (Clarke and Gorely, 2006).

RESULTS

Fish communities

A total of 58 fish species in 33 genera and 24 families were recorded at 10 different dive sites. Among these, 51 were identified at species level whereas 5 up to genus level. Relative abundance and diversity of fishes at each site is shown in Table II. High fish diversity occurred at northern sheltered sites of CI following MV and AI. Fish habitat (coral) degradation was observed at AI and MV. Also, diseased corals were seen at Astola Island. Out of 58 species 7 (Chromis flavaxilla, Pseudochromis aldabraensis, Pseudochromis omanensis, Pseudochromis springeri, Scarus arabicus, scarus zufar, Scorpaenopsis barbatus) have a confined distribution, mostly limited to Arabian Sea and Red Sea region. Two species (Diplodus capensis, Abudefduf vaigiensis) were also reported from the Atlantic including western Indian Ocean, whereas 49 had a wide distribution range i.e. Indian Ocean, western Indian Ocean or western Pacific.

Based on feeding level, most of the recorded fishes were planktivorous (18 species) followed by invertivorous (16 species), carnivores (12 species), herbivorous (8 species), invertivorous and carnivorous (2) and omnivorous (2 species). A cluster analysis for fish communities at 10 dive sites showed that the northern sheltered sites of the Astola Island, Churna Island and MV1 (AI1 and AI4, AI2 and AI3, CI1 and CI3 and CI4 and MV1) formed well defined clusters at similarity levels of 80%, 75%, 67% and 57% whereas MV2 and CI2, formed separate clusters at similarity levels of 35% and 60% approximately (Fig. 2). The K dominance curve showed that species-frequency distribution is high at CI 2 trailed by CI 1, CI 4, CI 3, MV1, AI 2, AI3, MV 2, AI 4 and AI 1 (Fig. 3).

 

 

Table I. GPS positions, depths and general observations recorded at each dive site.

Dive sites	GPS positions	Depth (m)	Habitat features
Churna Islan 1 (CI 1)	24° 54'.053'’ N, 66° 36'.436'’ E	7	The habitat at the 4 sites of CI was almost same. The substrate consisted of undulating rocks, boulders, mounds, gullies, fractures and ridges covered with thick algal turf. The corals were diverse with diverse growth forms (massive, encrusting, and submassive). The coral cover was approximately 55%. High coral cover was at site 2 following 1, 3 and 4. Fishes were abundant compare to any other site. The commonest species including Neopomacentrus sindensis, Neopomacentrus cyanomos, Neopomacentrus bankieri, Abudefduf vaigiensis and Sphyraena obtusata. Overall the community was dominated by damselfishes.
Churna Island 2 (CI 2)	24° 53'.982'’ N, 66° 36'.464'’ E	7
Churna Island 3 (CI 3)	24° 53'.939'’ N, 66° 36'.486'’ E	7
Churna Island 4 (CI 4)	24° 53'.878'’ N, 66° 36'.547'’ E	7
Mubarak Village 1 (MV1)	24° 51'.625'’ N, 66° 39'.780'’ E	2-5	Located approximately 15 to 20 m offshore. The substrate consisted of uplifted rocks, ridges and occasional boulders on sandy bottom. Hard coral cover was approximately 20%. The dominant genus was Porites with massive and encrusting growth forms. Coralline algae were dominant with approximately 60 % cover. Fishes were moderately abundant and the community was dominated by Neopomacentrus sindensis, Pristiapogon fraenatus, Pempheris malabarica and Pomacentrus caeruleus.
Mubarak Village 2 (MV2)	24° 51'.602'’ N, 66° 39'.751'’ E	3	Located approximately 15 m offshore. The habitat was characterized by uneven but smooth rocks and boulders. Rocks were covered with algal turf. Coral cover was approximately 5%. Fish diversity was low and the community was dominated by Neopomacentrus sindensis following Neopomacentrus bankieri and Abudefduf vaigiensis. Corals degradation at both sites of Mubarak Village was observed.
Astola Island (AI1)	25° 7'.445'’ N, 63° 50'.391	3	Rocky habitat with few uplifted boulders. Dominent corals were massive Porites species. Fish diversity was quite low
Astola Island (AI2)	25° 7'.463'’ N, 63° 50'.444 E	3	Rocky bed, with few sandy pockets and boulders. Low coral cover, consited of branching as well as massive and encrusting growth forms. Fish diversity was high compare to site 1.
Astola Island (AI3)	25° 7'.494'’ N, 63° 50'.480	3	Similar habitat as in site 2. Fish diversity was quite well at this site.
Astola Island (AI 4)	25° 7’.560’’ N, 63° 50’.558’’	3	Rocky habitat. Corals were consisted of massive Porites. Neopomacentrus sindensis was recorded as dominant.

 

Physical parameters of seawater

No significant variations were recorded in seawater physical parameters. Maximum temperature was noted 27.07 °C (±0.2+1) while minimum 26.05 °C. High salinity value was 35.01‰ while minimum 34.10 ‰. High pH value was noted as 8.30 (±0.1) whereas minimum 8.0 (±0.1). High dissolved oxygen concentration was recorded as 6.36 mg/L (±0.2+1). List of physical parameters recorded at each diving site are shown in Table III.

Inorganic and organic contents of seawater

High nitrate concentration was noted as 0.11 μM/L while minimum 0.06 0.11 μM/L. High ammonia concentration was noted as 1.68 μM/L while minimum 1.16 μM/L. Details about the concentrations of inorganic and organic parameters noted at each diving sites are included in Table IV.

DISCUSSION

Habitats structured by corals with topographic complications (rocky outcrops) are to be considered as ideal places for fish accumulation. Several studies (Bell and Galzin, 1984; Sale and Douglas, 1984; Roberts and Ormond, 1987; Chabanet et al., 1997; Friedlander and Parrish, 1998; Ferreira et al., 2001; Almany, 2004; Sandin et al., 2008; Graham and Nash, 2013) have been undertaken in this regard. High fish diversity at CI might be due to the presence of complex habitat, structured by diverse forms of corals (e.g. encrusting, massive,

 

Table II. Fish abundance and diversity documented at 10 dive sites. 6 (D)= up to300 individuals; 5 (Abundant)= up to 200 individuals; 4(common)= up to 50 individuals; 3(frequent)= up to 20 individuals; 2 (occasional)= up to 10 individuals; 1(rare)= up to 5 individuals. CI 1-CI4: Churna Island dive sites 1-4; MV1-MV2: Mubarak Village dive sites 1-2; AI 1-AI 4: Astola Island dive sites 1-4.

Fish species	Family	Feeding level	Sindh coast						Balochistan coast
			Churna island				Mubarak village		Astola island
			CI 1	CI 2	CI 3	CI 4	MV1	MV2	AI 1	AI 2	AI 3	AI 4
Abudefduf bengalensis	Pomacentridae	Planktivorous	2	2	2	2	1
Abudefduf sexfasciatus	Pomacentridae	Planktivorous	1	1
Abudefduf vaigiensis	Pomacentridae	Planktivorous	4	4	4	4	3	3	2	2	2	1
Amphiprion sandaracinos	Pomacentridae	Omnivorous	1	1
Chromis flavaxilla	Pomacentridae	Planktivorous	2		1
Chromis sp.	Pomacentridae	Planktivorous	2		2
Neopomacentrus bankieri	Pomacentridae	Planktivorous	4	4	4	4	3	4
Neopomacentrus cyanomos	Pomacentridae	Planktivorous	4	4	4	4
Neopomacentrus sindensis	Pomacentridae	Planktivorous	6	6	6	6	6	6	3	3	3	3
Neopomacentrus miryae	Pomacentridae	Planktivorous	3	2	2	2
Pomacentrus caeruleus	Pomacentridae	Planktivorous				5	5
Pristiapogon fraenatus	Apogonidae	Planktivorous					5
Archamia bleekeri	Apogonidae	Planktivorous		3	3				2	3	3	2
Apogonichthyoides pseudotaeniatus	Apogonidae	Planktivorous		1		1
Apogonichthyoides sialis	Apogonidae	Planktivorous				1				1	1
Ostorhinchus cookii	Apogonidae	Invertivorous				2
Ostorhinchus flagelliferus	Apogonidae	Invertivorous				2
Chlorurus bowersi	Scaridae	Herbivorous		2		2	2	2
Chlorurus capistratoides	Scaridae	Herbivorous		2		2	2
Chlorurus sordidus	Scaridae	Herbivorous		2			2
Scarus arabicus	Scaridae	Herbivorous				2	2
Scarus zufar	Scaridae	Herbivorous		2			2
Labroides dimidiatus	Labridae	Invertivorous						1
Halichoeres dussumieri	Labridae	Invertivorous	1	1	1			1
Halichoeres nigrescens	Labridae	Invertivorous							1	2	2	2
Halichoeres scapularis	Labridae	Invertivorous	1	1
Pseudochromis aldabraensis	Pseudochromidae	Invertivorous	1	1	1	1				1
Pseudochromis nigrovittatus	Pseudochromidae	Invertivorous	1
Pseudochromis omanensis	Pseudochromidae	Invertivorous		1	1
Pseudochromis springeri	Pseudochromidae	Invertivorous	1	1	1	1	1
Plectorhinchus gattuerinus	Haemulidae	Invertivorous				1
Plectorhinchus sordidus	Haemulidae	Invertivorous				1	1
Pomadasys stridens	Haemulidae	Carnivorous				1		1
Signanus javus	Siganidae	Herbivorous		1	1	1					2	1
Siganus luridus	Siganidae	Herbivorous	1	1	1
Signanus sp.	Siganidae	Herbivorous	2
Heniochus acuminatus	Chaetodontidae	Planktivorous					2
Heniochus diphreutes	Chaetodontidae	Planktivorous					2
Lutjanus lutjanus	Lutjanidae	Invertevorous & Carnivorous		1
Lutjanus vitta	Lutjanidae	Invertevorous & Carnivorous		1		1			2	3	2	1
Epinephelus malabaricus	Serranidae	Carnivorous			1						1
Epinephelus diacanthus	Serranidae	Carnivorous									3	2
Acanthopagurs catenula	Sparidae	Invertivorous	1
Diplodus capensis	Sparidae	Invertivorous	2					1	1	2		1
Ctenochaetus striatus	Acanthuridae	Invertivorous	1	1	1	1
Abalistes stellatus	Balistidae	Invertivorous			1
Sardenella sp.	Clupeidae	Planktivorous?				3	3
Platax teira	Ephippidae	Omnivorous	1	1
Karalla daura	Leiognathidae	Invertivorous	3				3	2
Scolopsis vosmeri	Nemipteridae	Invertivorous		1		1	1			1
Pempheris malabarica	Pempheridae	Planktivorous		3			5
Coeroichthys brachysoma	Scombridae	Carnivorous?		1	1
Scorpaenopsis barbatus	Scorpaenidae	Carnivorous			1
Sphyraena obtusata	Sphyraenidae	Carnivorous		5						4	4
Pseudosynanceia sp.	Synanceiidae	Carnivorous			1
Lagocephalus sp.	Tetraodontidae	Carnivorous	1	1	1
Torpedo fuscomaculata	Torpedinidae	Carnivorous	1
Torpedo sinuspersici	Torpedinidae	Carnivorous	1		1
Total species			25	29	22	24	19	9	6	10	10	8

 

Table III. Seawater physical parameters (n=3) ± SE recorded from coral habitats along the northern sheltered side of Astola Island (Balochistan), Pakistan. AI 1- AI4= Astola Island dive sites 1-4.

Diving sites	Temperature (◦C)		Salinity (‰)		pH		Dissolved oxygen (mg/L)
	Mean	± SE	Mean	± SE	Mean	± SE	Mean	± SE
AI 1	26.05	0.15	34.86	0.17	8.30	0.11	6.26	0.08
AI 2	26.06	0.11	35.46	0.14	8.06	0.12	6.10	0.11
AI 3	27.07	0.11	34.10	0.05	8.13	0.08	5.73	0.08
AI 4	27.05	0.05	34.16	0.08	8.00	0.05	6.36	0.08

 

submassive) and maximum coral cover that provided sheltered from predators and abundant food supply. Depth gradient could also be another factor for high diversity as high fish diversity was also reported from Arabian Gulf in offshore habitats at deeper depth (Coles and Tarr, 1990).Literature survey indicated the dominance of fishes in coral habitats with maximum branching growth forms and live coral cover (Sutton, 1985; Wilson et al., 2008). Further, the dominance of the damselfishes at CI compared to MV and AI also supported the relationship between coral cover and fish abundance as damselfishes are highly dependent on live coral cover (Sutton, 1985; Patton, 1994; Gratwicke and Speight, 2005; Wilson et al., 2008; Komyakova et al., 2013). Comparatively low fish diversity at MV might be due to

 

Table IV. Average (n= 3) concentrations M±SE of dissolved organic and inorganic nutrient noted from 4 dive sites at Astola Island along the Balochistan coast of Pakistan. Abbreviations are same as in Table III.

Diving sites	Nitrate (μM/L)		Nitrite (μM/L)		Ammonia (μM/L)		Phosphate (μM/L)		Chlorophyll (μg/L)
	Mean	± SE	Mean	± SE	Mean	± SE	Mean	± SE	Mean	± SE
AI 1	0.11	0.00	-0.07	0.00	1.68	0.32	0.24	0.01	0.00	0.00
AI 2	0.11	0.00	-0.07	0.00	1.16	0.15	0.27	0.00	0.00	0.00
AI 3	0.11	0.00	-0.08	0.00	1.28	0.30	0.32	0.06	0.00	0.00
AI 4	0.06	0.00	0.03	0.01	1.57	0.26	0.02	0.00	0.00	0.00

 

less coral cover, lack of branching growth forms and excessive macroalgal growth. Macroalgae certainly decrease the growth rates of corals (McCook, 1999; Jompa and McCook, 2003; Box and Mumbay, 2007).

Poor fish diversity at AI was mainly due to the degradation of fish habitat (corals) especially branching and submassive forms (Pocillopora damicornis and Porites nodifera) on a large scale. The corals were uprooted either for sale or as ornaments. Other possible causes of habitat destruction observed were entangling of fishing nets, coral diseases, sediment load, deployment of lobster pots in shallow water and careless skin and scuba diving. Physical parameters especially temperature and high nutrient concentrations along with other factors such as decrease in coral grazing fishes and sediment load are major cause of reef degradation (Brown, 1997; Fitt et al., 2001; Szmant, 2002). But in this study, physiochemical parameters along the Balochistan coast (Astola Island) were found in limits as coral and fish prefer for their proper growth (Vine, 1986; Furnas, 1991; Precht and Aronson, 2004; Martin and Wuenschel, 2006; Munday et al., 2009; Trotter et al., 2011; Nowicki et al., 2012) compare to Sindh coast (Ali et al., 2017). According to Ali et al. (2014), Astola Island was a hot coral spot in offshore waters of Pakistan. Pocillopora damicornis and Porites nodifera were main reef builders at the Island with up to approximately 80% cover, but now are not prevalent and only few colonies were observed. Similarly, diverse fish communities were also observed. Appearance of different coral diseases could be the outcomes of habitat destruction. Emerging of coral diseases as a result of habitat destruction have been reported from Eilat coral reefs, Red Sea (Loya, 2007). Habitat destruction as a result of increasing human activities and diseases eliminated the fishes due to food shortage and lack of hiding spaces.

Large number of planktivorous (18 species) and invertivorous (16 species) fishes indicated that nutrient rich water start a food chain from phytoplankton to zooplankton to planktivorous that ultimately consumed by predators. Comparing coral associated fishes with reef fishes in the region i.e. 511 fish species from Oman (Fouda et al., 1998), 187 species from northern Arabian Gulf (Krupp and Miiller, 1994), 71 species from Bahrain (Smith et al., 1987), 101 species from Arabian Gulf (Coles and Tarr, 1990) and 43 species from Iranian off waters (Rezai and Savari, 2004) showed that reef associated fish diversity in coastal waters of Pakistan seemed to be much lower but comparable to Bahrain and better than Persian Gulf but in Persian Gulf environmental stressors and shallow depth also responsible for poor fish diversity (Coles, 1988; Randall, 1995) . However, compare to volume of above mentioned studies, our study is conducted on a small scale. As the coast of Pakistan is quite large, it is expected that further studies will help in finding new coral habitats with maximum number of fishes and also to understand the relationships between coral and fish association in terms of physiological and environmental context.

CONCLUSIONS

As the coral associated fish communities of Pakistan are living in a threatened environment, the conservation efforts should focus on the establishment of MPAs (Marine Protected Areas) as better management of environment and ecosystems is possible through MPAs (Siddiqui et al., 2008). Although, Astola Island has already been declared as a marine protected area (Dawn, 2017) but MPA should not be confined to uplifted boundaries of the Island. According to Grimsditch and Salm (2006), there should be inclusion of all parameters necessary for the design of effective MPA i.e. have abilities to cope with environmental and anthropogenic changes and provide maximum habits for fish growth and by increasing microhabitats for fish communities through Low-tech coral rehabilitation and forming by the involvement of community (Hernández-Delgado et al., 2018). Further, involvement of different stakeholders (well reputed research institutes, universities, dive centers, tour operators and local communities), making tourism laws and implantation on laws and to create awareness on the significance (ecological, commercial) of these precious natural resources in general public via print and electronic media for a sustainable ecotourism. Moreover, to better understand, monitoring and scientific research on different aspects is recommended.

ACKNOWLEDGEMENTS

The authors are thankful to the Director CEMB for providing research facilities.

Statement of conflict of interest

The authors have declared no conflict of interest.

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