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Ecological Issues and the Trades in Live Reef Fishes
Abstract
This chapter focuses on the various ecological issues that are related to the trade of live reef fishes. Well-managed live reef fish fisheries offer an excellent chance for high-value and relatively low-volume trades that could employ many fishers without damaging wild populations, with the income providing strong local incentives to care for marine resources. Similarly, well-considered and cautious mariculture has the potential to help support local people, but then all mariculture operations and proposals should be very carefully scrutinized for ecological integrity, economic viability, and social implications. Currently, mariculture proposals are often viewed as intrinsically positive without considering their potential impacts. Mariculture, like the import of exotic fishes, could threaten local fish fauna because of the potential for releases and escapes, as well as the spread of disease. Infact, the World Conservation Union (IUCN) actively discourages releases unless they are a part of a well-conceived and long-term international program. Moreover, the polluting and resource-expensive (for feed) demands of the larger carnivorous species being cultured pose a range of problems that are have yet not been addressed. Successful management of live fish fisheries for sustainability requires a creative and interdisciplinary mix of management measures, well supported by government, local fishing communities, traders, and consumers. Ecosystem-level approaches, such as MPAs, offer considerable hope as they help conserve habitat and biodiversity simultaneously. Pre-emptively established no-take zones can become increasingly critical as the live fish trades and associated abusive fishing practices spread into new regions. The direct loss of populations through capture and associated disruption, the damage to other species, and the degradation of reefs from illegal capture methods are all very costly in terms of future fishing income and alternative income-earning opportunities, such as tourism.
... Besides the physiological effects of cyanide and reported population declines associated with destructive fishing in reef fish (Sadovy and Vincent, 2002), exposure of reef structuring organisms like corals to cyanide poisoning leads to outbreaks of bleaching and mortality (Cervino et al., 2003). Moreover, dissociation of the symbiotic relation with zooxanthellae, photosynthesis inhibition, lowered calcification rates via inhibition of carbonic anhydrase and long-term cellular impairments were reported in several coral species after exposure to cyanide (Cervino et al., 2003). ...
... As loss of coral reef habitat and consequent secondary loss of species and biodiversity proceeds (Don McAllister et al., 1999), fishers move to more pristine areas continuing habitat destruction (Cervino et al., 2003). These practices coupled to the targeting of spawning aggregations of reef fish for capture (Sadovy and Vincent, 2002) will undoubtedly lead to loss of reef communities and magnify environmental and societal impacts under global change scenarios, as southeast Asian populations mostly depend on fisheries for food and source of income (FAO, 2014). Despite growing evidence that coral reef fisheries cannot sustain commercial exports without cautious controls (Sadovy and Vincent, 2002), governmental agencies have failed to eradicate destructive fishing from the Indo-Pacific region (National Intelligence Council, 2016). ...
... These practices coupled to the targeting of spawning aggregations of reef fish for capture (Sadovy and Vincent, 2002) will undoubtedly lead to loss of reef communities and magnify environmental and societal impacts under global change scenarios, as southeast Asian populations mostly depend on fisheries for food and source of income (FAO, 2014). Despite growing evidence that coral reef fisheries cannot sustain commercial exports without cautious controls (Sadovy and Vincent, 2002), governmental agencies have failed to eradicate destructive fishing from the Indo-Pacific region (National Intelligence Council, 2016). Under this framework, we conclude that if CO 2 emissions follow business-as-usual trends, destructive fishing practices such as the use of cyanide poisoning will become even deadlier and depict a major problem in tropical coral reef ecosystems. ...
An array of anthropogenic pressures is affecting tropical ecosystems, posing major conservation challenges for scientists, stakeholders and populations. Illegal cyanide fishing is one of the major threats to Indo-Pacific coral reefs, targeting a multitude of colorful species for the marine aquarium trade as well as large-sized groupers and wrasses for the food fish trade. Ultimately, the continued use of this destructive practice as oceans warm may overload tropical ecosystems and result in irreversible ecological damage. Here we show that the impact of cyanide poisoning in an ornamental tropical marine fish is magnified under increased temperatures. A sole pulse exposure of 60 s to 50 mg L–1 of cyanide under current temperature (26°C) caused substantial mortality (50–100%) in eight species of Pomacentridae. The clownfish Amphiprion ocellaris was the most resistant, especially medium-sized fish [average total length and weight of 38 mm and 1.12 g; LC50 (95% CI) = 50.00 (46.76 − 53.24) mg L–1] that showed shorter recovery times and higher survival rates (%) when compared to small-sized ones [average total length and weight of 25 mm and 0.30 g; LC50 (95% CI) = 28.45 (20.17 − 36.72) mg L–1]. However, when the most resistant size-class was concomitantly exposed to a sub-lethal dosage of cyanide (25 mg L–1 instead of 50 mg L–1) and ocean warming scenarios for 2100 (+3°C and heat wave +6°C), survival rates (%) decreased to 60 and 20%, respectively, and recovery times increased in the worst case scenario. Mortality outbreaks, as well as vulnerability to predation, will likely expand in fish inhabiting coral reefs exposed to cyanide fishing unless stronger conservation measures are taken in tropical reefs to limit this destructive practice now and in the oceans of tomorrow.
... Most reef-based fisheries tend to target large piscivorous species (mostly Serranidae, Lutjanidae, and Lethrinidae), which are the predominant target of extensive hook-and-line fisheries (Russ, 1991) and are preferred food fishes, at least in most industrialised countries (Sadovy and Vincent, 2002). However, many other families of coral reef fishes, including butterflyfishes (Chaetodontidae) may be subject to fishing-pressure from relatively nonselective artisanal fisheries (Mangi and Roberts, 2006) or highly specific fisheries that service extensive aquarium or curio markets (Grey et a1., 2005). ...
... Modernisation and globalisation are also increasing the efficiency and diversity of fishes that are harvested within coral reef ecosystems (Berkeset ai., 2006). For example, the rapid growth of international markets for marine aquarium fishes (mostly since the 1970's), combined with improved transport routes, has created entirely new fisheries in relatively isolated developing countries (e.g., Philippines), based on species that were not otherwise harvested because they were not regarded as an important food source (Wood, 2001;Bruckner, 2005;Sadovy and Vincent, 2002). ...
... The world-wide trade in ornamental reef fishes was estimated to be worth between U5$24 million (Wood, 2001) and up to U5$300 million (Wabnitz et aI., 2003), with annual sales of between 14 million to 30 million fishes. The actual number of marine aquarium fishes caught on coral reefs is also likely to be well above the numbers actually reported and traded when taking account of mortality of fishes during capture and transport to international markets (5adovy and Vincent, 2002). Marine aquarium fishes are currently harvested from coral reefs in more than 80 countries around the world, and largely represent species that would not otherwise be caught for food (5adovy and Vincent, 2002). ...
Direct harvesting of fishes and other coral reef organisms represents the most significant and pervasive anthropogenic impact on coral reef ecosystems (e.g., Roberts, 1995; Jackson et al., 2001; Myers and Worm, 2003), causing a range of direct and indirect effects on populations, communities, and ecosystems. Extensive harvesting of very large and previously abundant reef-associated organisms has caused massive changes in coral reef ecosystems throughout the last two centuries (Jackson et al., 2001), and contemporary fisheries continue to overexploit many reef species (e.g., Morris et al., 2000). Coral reef fisheries account for a relatively small proportion of global fisheries yield (<1%), but are fundamental in providing food and livelihoods in many tropical nations (e.g., Bell et al., 2009). Also, coral reef fishes are probably more vulnerable to exploitation compared to many other fisheries stocks (Russ, 1991), and overfishing of reef fishes with critical functional roles, such as herbivorous fishes, has contributed to extensive and accelerating degradation of coral reef habitats (e.g., Hughes, 1994, 1996) and greatly increases vulnerability to subsequent disturbances (Bellwood et al., 2003; Hughes et al., 2007).
... Many of the fish populations in the region are (too) heavily fished, and concerns that fishing effort have exceeded optimum levels for most species are now receiving some attention from local communities (Grandcourt et al. 2005). Fisheries that remove large individuals can easily erase all sexually mature fish and/or create a highly skewed sex ratio with the likelihood of reproductive failure (Sadovy and Vincent 2002). There is a strong need for conservation and management measures in this region, as well as more research in this field. ...
... Involving local people in the surveys and explaining results, such as the relationship between high coral coverage and high species diversity, might be enough for the empiric understanding of a healthy ecosystem and control the pressure level of artisanal fisheries in Musandam. To understand the full impact of fishing in this region, studies on size classes, colour phases and social structure in the target population, such as groupers and sweetlips, should be conducted (Sadovy and Vincent 2002). ...
Abstract
The Musandam Peninsula, in the Strait of Hormuz, is the only waterway between the Persian Gulf and the Arabian Sea. Corals from this region, where sea temperatures and salinity are high, are more resilient to those environmental parameters than corals in other parts of the world. Nevertheless recent studies suggest that any additional stress may lead to coral die-off.
Biosphere Expeditions has been conducting surveys, using the internationally recognised Reef Check methodology, around the Musandam Peninsula since 2009, studying benthic and fish communities, and anthropogenic impacts. In October 2012, five different sites in north Musandam were surveyed. Survey results are compiled and compared to previous surveys in this report.
Results show a promising, stable reef habitat in north Musandam since surveys began. Slight increases in hard and soft coral cover, as well as high average coral coverage of 60%, well above the Indo-Pacific average of 22%, illustrate the presence in north Musandam of what can nowadays be considered atypically healthy reefs. However, results also show low numbers of some fish and invertebrate populations, most likely due to overexploitation. The stability of Musandam reefs is therefore not secure.
North Musandam doubtless harbours some of the best reefs of the region, but reefs with such high coral coverage are normally able to support fish populations greater than those observed. Musandam reefs, with the right protection, are able to support such healthy fish populations with appropriate age structures, and thus a source-sink systems for fisheries. Healthy reefs with stable fish and invertebrate populations improve the local economy, not only by supporting local artisan fisheries, but also other economies, such as tourism.
We therefore continue to recommend that a marine protected area (MPA), or a network of MPAs, is created in north Musandam. We also urge rapid action before what is at the moment still a unique natural treasure for Oman is degraded and lost.
المخلص العربي
تعتبر شبه جزيرة مسندم والتى تقع مباشرة عل مضيق هرمز الممر والمنفذ المائى الوحيد بين الخليج العربى وبحر العرب، تتميز الشعاب المرجانية فى تلك المنطقة بالتكيف الكامل مع درجات الحرارة المرتفعة للمياه وكذلك الملوحة العالية مقارنة بأنواع الشعاب المرجانية فى أى منطقة أخرى، بالرغم من ذلك هناك العديد من التحذيرات التى أطلقتها بعض الدراسات الحديثة حيث أشارت أن حالة الشعاب المرجانية بتلك المنطقة حرجة وقد لا تتحمل أى إرتفاع فى درجة حرارة المياه أو الزيادة فى درجات الملوحة مما قد يستتبع ذلك تدهور حالة الشعاب المرجانية وقد تنتهى بإختفائها من المنطقة.
منذ العام 2009م قامت منظمة بعثات المحيط الحيوى (بيوسفير أكسبيديشن) بالعديد من الدراسات البحثية فى المنطقة وذلك بإستخدام أحدث المعايير الدولية لقياس حالة الشعاب المرجانية حول شبه جزيرة مسندم بالإضافة إلى دراسة الأسماك والكائنات البحرية الأخرى المتواجدة بالمنطقة، وبتاريخ أكتوبر 2012م تم الإنتهاء من دراسة خمسة مواقع مختلفة بشبه الجزيرة وتمت مقارنة البيانات بالإبحاث والدراسات السابقة وعرضها بالتفصيل فى التقرير المرفق.
منذ بدء الدراسات الحقلية أظهرت النتائج حالة مستقرة وواعدة للشعاب المرجانية فى شمال شبه جزيرة مسندم، لوحظ أن هناك زيادات بسيطة فى الغطاء المرجانى المرن والصلب وكذلك إرتفاع متوسط التغطية المرجانية إلى 60% أعلى من22% المعدل المسجل فى المحيطين الهادى والهندى ويوضح ذلك حالة الشعاب المرجانية الجيدة فى الوقت الحاضر بمنطقة شبه جزيرة مسندم. بالرغم من ذلك، أظهرت النتائج إنخفاض أعداد بعض أنواع الأسماك واللافقاريات بنفس المنطقة وذلك على الأرجح نتيجة للأستغلال المفرط لتلك الموارد الحية وهذا ما يعد مؤشراً وإنذاراً بأن مازال هناك العديد من المخاطر التى تهدد تلك البيئة الحيوية.
... Many of the fish populations in the Persian Gulf have been heavily exploited and concerns that fishing effort may already have exceeded optimum levels for most species are now receiving some attention from local communities (Grandcourt et al. 2005). Fisheries that remove large individuals can easily eradicate all sexually mature fish and/or create a highly skewed sex ratio with the possibility of reproductive failure (Sadovy and Vincent 2002). ...
... Involving local people in the surveys and explaining results, such as the relationship between high coral coverage and high species diversity, might be enough for the empiric understanding of a healthy ecosystem and control the pressure level of artisanal fisheries in Musandam. In order to understand the full impact of fishing in this region, the impacts of selective mortality on specific size classes, colour phases or morphs, and social structure in target population, such as groupers, should be studied (Sadovy and Vincent 2002). ...
Abstract
Coral reefs are globally important hotspots for biodiversity. They also provide human populations with important goods and services, such as food and coastal protection. Despite this, coral reefs are under threat worldwide from direct or indirect anthropogenic impacts such as pollution, overexploitation, coastal development and unmanaged tourist activities. Today reefs face additional pressure from thermal stress and emergent diseases that are closely linked to climate change. Due to the thermal sensitivity of most scleractinian corals, there has been a substantial increase in mass coral bleaching events and subsequent mortality of reefs with rapid changes in global sea-surface temperatures.
The coral reefs of the Musandam Peninsula, situated on the Arabian Peninsula in the Strait of Hormuz, endure very harsh conditions such as high salinity and temperatures, existing in what would be considered marginal and challenging environments for corals in other parts of the world. Surprisingly, reefs in this area are thriving and high mean percentages of coral cover of well over 50% were recorded by Biosphere Expeditions in 2010. Although resilience seems to exist among the Musandam corals, there is increasing concern that any additional stress, for example from natural disasters and/or anthropogenic impacts, may accelerate coral die-off.
Between 9 and 15 October 2011, Biosphere Expeditions, in collaboration with the Emirates Diving Association, ran for the third year a research project along the North Musandam peninsula coastline during which a coral reef survey using the Reef Check methodology was carried out at five sites. The main objectives of this study are to (1) monitor the health of and the impacts on the Musandam Peninsula’s coral reefs and (2) use and disseminate these findings for management, educational and conservation purposes by local government and NGOs.
Data obtained in the past three years of expeditions have revealed some improvements in the system. Besides the high mean coral coverage of 58% observed in North Musandam in 2011, the increase in the number of parrotfish observed during this expedition, as well as the decrease in the mean substrate coverage of nutrient indicator algae and silt, are encouraging signs of a largely intact reef habitat, which nonetheless remains threatened and in need of further conservation action.
The results of the 2009 to 2011 expeditions show clearly that Oman, in the North of Musandam, has in its stewardship (1) arguably the best reefs of the region and (2) a unique area of (a) natural beauty as well as (b) commercial importance, not just for fishermen, but also for the local economy as a generator of income from tourism.
The continuation of this research project is important for the constant monitoring of the valuable coral reefs of the Musandam peninsula; a habitat that not only guarantees high biodiversity in the area, but also provides local communities with essential goods, services and resources. However, without additional actions, Biosphere Expeditions’ annual Reef Check surveys are likely simply to document a continuing decline of yet another reef habitat in the Middle East. We therefore recommend that the following additional projects are instigated by local government and NGOs: (1) fisheries landings studies, (2) patrolling and new legislation for the diving and fishing communities, (3) creation of a Marine Protected Area (MPA) or a network of MPAs, including the installation and monitoring of fixed and marked mooring buoys (4) actions to declare the Musandam peninsula a UNESCO Biosphere Reserve and eventually a UNESCO World Heritage Site and (5) policy and enforcement action for any protected areas created.
ملخص
تحتل الشعاب المرجانية مكانة هامة على الصعيد العالمي للتنوع البيولوجي ؛حيث أنها ترفد المجموعات السكانية البشرية بالعديد من السلع الغذائية الهامة والخدمات ، إضافة إلى دورها الهام في حماية السواحل . ولكن ،وبالرغم من أهميتها القصوى ، فإن الشعاب المرجانية في جميع أنحاء العالم مهددة باستمرار؛ وذلك بتأثير الممارسات البشرية المباشرة أو غير المباشرة: كالتلوث، والاستغلال المفرط، بالإضافة إلى الأضرار الناجمة عن الحركة العمرانية على السواحل ،والأنشطة السياحية غير النظامية. تواجه الشعاب المرجانية في الوقت الحاضر ضغوطًا إضافية ناتجة عن الإجهاد الحراري والأمراض المستجدة التي ترتبط ارتباطًا وثيقًا بتغيّر المناخ. ونظراً للحساسية الحرارية لدى معظم الشعاب المرجانية الحجرية فقد ارتفعت معدلات إصابتها بالابيضاض الجماعي الذي يؤدي إلى وفيات لاحقة في الشعاب نتيجة التغيّر السريع في درجات حرارة سطح البحر في العالم.
لقد تحملت الشعاب المرجانية في شبه جزيرة مسندم الواقعة على مضيق هرمز في شبه الجزيرة العربية ، ظروفاً بيئيةً قاسية للغاية : كارتفاع درجات الحرارة والملوحة العالية التي تتركز في ما يمكن اعتباره أحد البيئات الهامشية التي تشكل تحدياً صعباً للشعاب المرجانية في أجزاء أخرى من العالم . ومن المثير للاستغراب أن تزدهر الشعاب في هذه المنطقة بالذات ،مسجِّلةً نسبة مرتفعة من متوسط الغطاء المرجاني الذي يغطي ما يزيد عن 50 % (وفقًا لسجلات بعثات بايوسفير الاستكشافية في عام 2010) .ولكن، على الرغم من المرونة التي تبديها الشعاب المرجانية في منطقة مسندم، فإن القلق يتزايد حول قدرة هذه الشعاب على تحمّل أي ضغوط إضافية : كالكوارث الطبيعية أو الممارسات البشرية ، أو كليهما معاً ، مما يؤدي إلى التعجيل في هلاك الشعاب المرجانية وفنائها.
وفي الفترة الواقعة بين 9 و 15 أكتوبر 2011 ، قام فريق "بعثات بايوسفير الاستكشافية" بالتعاون مع "جمعية الإمارات للغوص" بإجراء مشروع بحثي على امتداد الساحل الشمالي لشبه جزيرة مسندم، للسنة الثالثة على التوالي . تم خلال المشروع مسح الشعاب المرجانية في خمسة مواقع باستخدام " منهجية مراقبة الشعاب المرجانية " . وتتمثل الأهداف الرئيسة لهذه الدراسة في :
أولا : مراقبة الحالة الصحية للشعاب المرجانية في شبه جزيرة مسندم ، ورصد الآثار المترتبة عليها .
ثانيا: استخدام هذه النتائج ونشرها لغايات إدارية وتعليمية، ولأغراض حفظ البيانات من قِبل الحكومة المحلية والمنظمات غير الحكومية .
البيانات التي تم الحصول عليها في السنوات الثلاث الماضية للحملة أظهرت أن هناك بعض التحسن في النظام. إلى جانب ارتفاع الغطاء المرجاني بنسبة 58% في شمال منطقة مسندم عام 2011. كما لُوحظ أيضاً تزايد في عدد أسماك الببغاء أثناء هذه الحملة ، فضلاً عن مؤشرات النقص في متوسط التغطية السفلية للمغذيات الطحلبية والطمي . هذا ما تم ملاحظته خلال الحملة الاستكشافية لعام 2011. وهي بوادر مشجعة تشير إلى سلامة الشعاب المرجانية كموئل، إلا أن ذلك لا ينفي وجود التهديد ، مما يستدعي اتخاذ المزيد من الإجراءات.
أظهرت نتائج البعثات من عام 2009 إلى 2011 أن المنطقة الواقعة في الشمال من مسندم في سلطنة عمان تمتاز بكونها :
(1) تتوفر على أفضل الشعاب المرجانية في المنطقة .
(2) تتفرّد بالجمال الطبيعي فضلاً عن الأهمية التجارية ، ليس للصيادين فقط ولكن للاقتصاد المحلي أيضًا ،وذلك بوصفها مصدر هام للدخل في القطاع السياحي.
إن استمرار هذا المشروع البحثي له أهمية قصوى لإبقاء الشعاب المرجانية القيّمة في شبه جزيرة مسندم تحت المراقبة المتواصلة ، لكونها الموئل الذي يضمن بقاء التنوع البيولوجي في المنطقة، إضافة لما توفره للمجتمع المحلي من سلع أساسية وخدمات وموارد. إن الدراسات المسحية التي تجريها منظمة "بعثات بايوسفير الاستكشافية" لمراقبة الشعاب سنوياً– ودون مزيد من الإجراءات الإضافية- تعمل على توثيق التدهور المستمر في موطنٍ محتمل آخر للشعاب المرجانية في منطقة الشرق الأوسط.لذا ،فإننا نتقدم بالتوصية بأن تتولى الحكومة المحلية والمنظمات غير الحكومية مسؤولية المشاريع الإضافية التالية:
1- إجراء دراسات حول إنزال مصائد الاسماك.
2- تعيين دوريات خفر سواحل ،وإصدار تشريعات جديدة ، في مناطق الغوص ومجتمعات صيد الأسماك .
3- إنشاء منطقة بحرية محمية (MPA) أو شبكة من المحميات البحرية ، بما في ذلك تركيب عوّامات ثابتة وظاهرة للعيان تقوم بتحديد المنطقة.
4- اتخاذ الإجراءات الرامية إلى إعلان شبه جزيرة مسندم محمية ضمن مجموعة اليونسكو العالمية لمعازل المحيط الحيوي ، ليصار في نهاية المطاف إلى إعلانها كأحد مواقع اليونسكو للتراث العالمي.
5- وضع سياسات وإجرءات لحماية المناطق المحمية التي يتم انشاؤها.
... Many of the fish populations in the Persian Gulf have been heavily exploited and concerns that fishing effort may already have exceeded optimum levels for most species are now receiving some attention from local communities (Grandcourt et al. 2005). Fisheries that remove large individuals can easily eradicate all sexually mature fish and/or create a highly skewed sex ratio with the possibility of reproductive failure (Sadovy and Vincent 2002). ...
... Involving local people in the surveys and explaining results, such as the relationship between high coral coverage and high species diversity, might be enough for the empiric understanding of a healthy ecosystem and control the pressure level of artisanal fisheries in Musandam. In order to understand the full impact of fishing in this region, the impacts of selective mortality on specific size classes, colour phases or morphs, and social structure in target population, such as groupers, should be studied (Sadovy and Vincent 2002). ...
Abstract
Coral reefs are important biodiversity hotspots that not only function as an crucial habitat for a multitude of organisms, but also provide human populations with an array of goods and services, such as food and coastal protection. Despite this, coral reefs are under threat worldwide from direct or indirect anthropogenic impacts, such as pollution, overexploitation and climate change. The coral reefs of the Musandam peninsula (Oman), situated on the Arabian peninsula in the Strait of Hormuz, endure very harsh conditions such as high salinity and temperatures, existing in what would be considered marginal and highly challenging environments for corals in other parts of the world,.
Although Musandam corals exhibit resilience there is increasing concern that any additional stress, as a result of natural disasters and/or anthropogenic impacts for example, may accelerate coral die-off. For the past decade, reefs in the Arabian Gulf have been devastated by major coral bleaching events, cyclones, harmful algal blooms and extensive coastal developments.
Between 10 and 23 October 2010, and for the second consecutive year, Biosphere Expeditions, in collaboration with the Emirates Diving Association, conducted a research project whereby a coral reef survey using Reef Check methodology was carried out in 18 different dive sites along the Musandam peninsula coastline. The main objectives of the expedition were to (1) monitor the health of and impacts on the Musandam peninsula’s coral reefs and (2) use and disseminate these findings for the purposes of management, education and conservation by local government and non-governmental organizations (NGOs).
The main objectives of the expedition were to (1) monitor the health of and the impacts on the Musandam peninsula’s coral reefs and (2) use and disseminate these findings for management, educational and conservation purposes by local government and NGOs.
A comparison of findings from the 2009 and 2010 expeditions found no significant changes in the mean average of indicator species or substrate categories. However, there were significant changes of concern in the type and amount of impacts such as an increase in (1) invertebrates harvested for food, (2) tourist diving and snorkelling pressure and (3) artisanal and recreational fishing. There were also other clearly negative trends: although changes in the mean average of indicator species or in the percentage substrate coverage were not alarming, there was a clear trend suggesting that if the increase in pressure and impacts is maintained at its current rate, then future significant and highly detrimental effects for the Musandam peninsula marine life are inevitable.
The continuation of this research project is important for the regular monitoring of the invaluable coral reefs of the Musandam peninsula; a habitat that not only guarantees high biodiversity in the area, but also provides local communities with essential goods and resources. However, without additional actions, Biosphere Expeditions’ annual Reef Check surveys are likely simply to document a continuing decline of a reef habitat already near the brink of collapse. We therefore recommend that the following additional projects are instigated by local government and NGOs: (1) fisheries landings studies, (2) patrolling of and new legislation for the diving and fishing communities, (3) creation of a Marine Protected Area (MPA) or a network of MPAs, including the installation and monitoring of fixed and marked mooring buoys and (4) actions to declare the Musandam peninsula a UNESCO Biosphere Reserve and ultimately a UNESCO World Heritage Site.
ملخص
تعتبر الشعاب المرجانية أحد أهم النقاط الساخنة في مسألة التنوع البيولوجي، ليس فقط بوصفها الموئل الذي لا مثيل له للعديد من الكائنات الحية ، ولكن لكونها مصدرا هاما للكثير من السلع الغذائية ، ولدورها الحيوي في حماية السواحل . ولكن وبالرغم من هذه الأهمية القصوى للشعاب المرجانية ، فإن هذا الموئل الحساس يتعرض وباستمرار لشتى أنواع التهديد بتأثير من الممارسات البشرية المباشرة أو غير المباشرة ، كتغير المناخ ،على سبيل المثال.
ويبدو أن الشعاب المرجانية في شبه جزيرة مسندم ، التي تقع على مضيق هرمز في شبه الجزيرة العربية ، قد أصبحت بيئة محفوفة بالمخاطر كغيرها من الشعاب المرجانية في أجزاء أخرى من العالم ، حيث تعاني من ظروف قاسية للغاية تتمثل في ارتفاع نسبة الملوحة ودرجة الحرارة.
على الرغم من قدرة الشعاب المرجانية على التعايش مع العديد من المؤثرات ، فإن العلماء يعربون عن قلقهم المتزايد عن مدى قدرة هذه الشعاب لتحمل أي ضغط اضافي قد ينتج عن الكوارث الطبيعية و / أو الممارسات البشرية التي قد تعجل في هلاك ودمار الشعاب المرجانية المتواجدة قبالة الخليج العربي . على امتداد العقد الماضي ، تعرضت الشعاب المرجانية الرئيسية للدمار بتأثير من ابيضاض الشعاب المرجانية ، و الطحالب الضارة ، والأعاصير ، بالإضافة إلى أعمال التطوير الساحلي والإنشاء التي تتم وعلى نطاق واسع .
في الفترة ما بين بين 10 و 23 أكتوبر 2010 ، أجرى فريق "بعثات بايوسفير الاستكشافية" و بالتعاون مع جمعية الامارات للغوص مشروعه البحثي للسنة الثانية وذلك على امتداد ساحل شبه جزيرة مسندم . تم خلال المشروع مسح الشعاب المرجانية باستخدام " منهجية مراقبة الشعاب المرجانية " و هو بروتوكول دولي لرصد الشعاب المرجانية ، تم تطبيقه في 18 موقعا للغوص.
تتمحمور الأهداف الرئيسية للبعثة حول متابعة الحالة الصحية للشعاب ، ورصد تأثير الأرصفة المرجانية في شبه جزيرة مسندم ، واستخدام هذه النتائج لاتخاذ القرارات الإدارية والتعليمية ولغايات جمع بيانات علمية موثقة يمكن استخدامها من قبل المنظمات غير الحكومية والحكومات المحلية مستقبلا .
بمقارنة النتائج التي تم الحصول عليها خلال البعثة في 2009 عام مقابل نتائج البعثة لعام 2010 ، لم يتم رصد أي تغيرات بارزة على متوسط مؤشر الأنواع البحرية أو الفئات الئيسية. ولكن تم ملاحظة ورصد تغيرات خطيرة وبالغة السوء في دراسة الآثار المسحية ، حيث لوحظت زيادة في معدلات البحث عن الغذاء لدى اللافقاريات ، كما تم تسجيل ارتفاع ملحوظ في أنشطة الغوص السياحية الحرفية منها والترفيهية و الغطس وصيد الأسماك. وبالرغم من أن التغيرات في متوسط معدل مؤشر الأنواع أو في تغطية نسبة من الفئات المختلفة الرئيسية لم تكن مثيرة للقلق ، إلا أن تغييرات مروعة ستشهدها الحياة البحرية في شبه جزيرة مسندم مستقبلا ،إذا ، اذا تزايد معدل الضغوط والتأثيرات عن معدلها الحالي.
إن استمرار هذا المشروع البحثي في شبه جزيرة مسندم ،هام جدا لإبقاء هذه الشعاب المرجانية القيمة تحت المراقبة المتواصلة ، ليس لكونها الموئل الذي يضمن بقاء التنوع البيولوجي في المنطقة بل لما توفره من موارد أساسية للمجتمع المحلي . كما ينبغي أن تتضافر الجهود من قبل كافة الجهات المعنية في مجتمع الغوص المحلي ، بحيث يتم اصدار تشريعات جديدة وتنفيذ دوريات خفر سواحل في جميع أنحاء شبه جزيرة مسندم ، تقوم بعملها جنبا إلى جنب مع الدراسات الاستقصائية حول الشعاب المرجانية ومصائد الأسماك وذلك من أجل التصدي و بمزيد من التفصيل للآثار الرئيسية التي تم كشفها خلال البعثة . إن تطبيق برتوكول " محمية بحرية" (MPA) أو (مناطق بحرية محمية ) من شأنه أن يساعد أيضا في التغلب على جميع هذه المشاكل فضلا عن قلة البيانات المتاحة عن الموارد الطبيعية وعدم وجود عوامات ثابتة وظاهرة للعيان لتحديد المنطقة.
إن مسألة ضم شبه جزيرة مسندم إلى مجموعة اليونسكو العالمية لمحميات المحيط الحيوي، وبالتالي إعلانها في نهاية المطاف كأحد مواقع اليونسكو للتراث العالمي ، أمرٌ ينبغي أن يتم تفعيله على المستوى الحكومي .
... Marine ornamental fish trade around the world supports an international trade worth USD 90-300 million in annual retail sales (Sadovy & Vincent 2002). One thousand species from 50 families are targeted for this trade (Wood 2001), and are exported from approximately 80 supplying countries (Sadovy & Vincent 2002). ...
... Marine ornamental fish trade around the world supports an international trade worth USD 90-300 million in annual retail sales (Sadovy & Vincent 2002). One thousand species from 50 families are targeted for this trade (Wood 2001), and are exported from approximately 80 supplying countries (Sadovy & Vincent 2002). The biological, socio-economic, scientific and aesthetic value of coral reefs and their associated fauna are widely recognised (e.g., Smith 1978;Salm & Kenchington 1984;Munro & Williams 1985;Clark et al. 1989;Spurgeon 1992) and the utilisation of this resource in a sustainable and environmentally friendly manner should be promoted. ...
... Although rarely targeted in Mediterranean fisheries, chondrichthyans are often caught as bycatch [121,122]. According to [119], in the Eastern and Southern Mediterranean countries some chondrichthyan bycatch species provide an important source of cheap fishmeal. ...
... The number of reported species drastically increased from 119 to 176 along the past decade (Figure 1), which corresponds to a total number increase of 36%, or 63% in numeric terms of skates and rays and 16% of sharks [17,18,36]. This recent biological diversity boom is certainly related to the REVIZEE scientific surveys in the recent past (1996-2007) and its ongoing influence, which resulted in the most extensive effort in order to evaluate possible promising marine fishery resources in Brazil [52,75,122]. However, even these scientific surveys need to be properly designed to catch and better evaluate the elasmobranch biodiversity. ...
Chondrichthyes are a group of cartilaginous fish, where we have sharks, rays, and chimeras as members. This group plays an important role in aquatic ecology, as they act as predators throughout the food chain (e.g., sharks). However, many populations of Chondrichthyes are threatened by several factors (increased direct fishing, high mortality rate as accompanying fauna, marine pollution, habitat destruction, etc.). These declines are evident in many parts of the world and have come to the attention of scientists, conservation organizations, the media, and the general public. Fisheries legislation regulating international fisheries markets has been amended to provide greater protection for this group along with other species of fish. However, little is known about these species, which reinforces the importance of studies in order to have a better understanding of the elasmobranch stocks, as well as to identify the influences of the anthropic action of fishing. In response to knowledge on the low sustainability of cartilaginous fish fisheries on a global scale, FAO has developed an international plan of action for the management and conservation of these fish, with the aim of developing and implementing national plans of action to ensure management and conservation of these stocks, having as main recommendation the collection of information about the Chondrichthyes, especially the sharks. Even so, this group is little known in terms of biodiversity, ecology, behavior, and a host of other characteristics relevant to this taxon, which is very worrying. Chondrichthyes - Multidisciplinary Approach attempts to portray to the readers up-to-date information on Chondrichthyes to promote an overview of the current taxon, serving as an indispensable source of access to more accurate and detailed information on shark rays and chimeras.
... Additional fishery harvests consist of the live animal aquarium trade where corals, small fishes, and invertebrates are collected from reefs. The aquarium trade has reached an estimated $90-300 million year À1 (Sadovy and Vincent, 2002). The export and sale of shells and jewelry also makes up a substantial portion of fisheries on reefs; giant clams, conch shells, coral, and pearls are all among the many heavily harvested organisms. ...
... Therefore, the status of grouper fishing in the Alas Strait is in an over-exploited condition [26]. Grouper fishing and a heavy exploitation is due to increased global market demand, due to both in alive and frozen conditions, high selling prices, and good tastes for consumption [24,27,28]. ...
Grouper are demersal fishes that can be found in tropical and subtropical waters. In Indonesia, one of the areas where grouper production takes place in Saleh Bay, a semi-enclosed water with small islands, coral reefs and a high diversity. Information’s about the population and abundance of grouper species in Saleh Bay are currently limited. The benefits of this research are to enhance the availability of information on grouper diversity and the area as grouper fishing ground for future improvement on grouper fisheries management in Saleh Bay. Therefore, the study aimed to analyse the diversity, equitability, species richness and dominance index of different grouper species and the grouper fishing ground in this area. The data were obtained from field observations and fish landing data. Grouper caught have been calculated for each fishing gear based on the following parameters: diversity index (Shannon-Wiener), species richness, equitability, and dominance index. The results showed that grouper fishing grounds are spread over Saleh Bay. Fishers caught grouper around small islands with coral reefs. The diversity of grouper for each fishing gear ranged in a moderate category. We found that the bottom longline caught the highest species richness of grouper compare to other fishing gears. The dominance index showed no dominance using each examined fishing gear, or it can be said that grouper species are evenly caught with each fishing gear based on the calculation of the equitability index.
... Groupers (Serranidae: Epinephelinae) are one of the main targets for commercial and artisanal fishing (Heemstra & Randall 1993;Sadovy and Vincent 2002;Craig et al. 2011). ...
Groupers are commercially important fish for the local population of Palau. For this reason, they have been harvested for years causing a decrease in their numbers over time. The establishment of MPAs, such as Ngerumekaol Spawning Area and Ebiil Conservation Area which are closed to extractive activities, and implementation of periodic fishing bans, were meant to help their populations recover. Grouper spawning aggregations are hard to monitor because they are highly variable over space and time and require financial and human resources. Following the need for a convenient and standardized methodology to successfully monitor their populations, the aim of this study was to investigate a new technique that could estimate grouper aggregation size and the effects of fishing closure. Parallel and perpendicular transects were performed crossing each other over aggregation areas in order to estimate spawning aggregation size across sites with different protection status. Results reported that April 2020 had the biggest aggregations compared to the other survey months for all sites. Both fishing closures and bans appear to be effective in enhancing spawning aggregation sizes, but daily and inter-annual variability in grouper numbers were not considered during this study. In several instances, transects shape and size were causing aggregation size overestimation, and these results have to be interpreted with caution.
... The common name "surgeonfish" refers to the peculiar scalpellike modified scales on both sides of the caudal peduncle that is used in inter-and intraspecific aggressive interactions (Randall, 2001). Due to their attractive colors and shapes, surgeonfishes dominate aquarium trade in several areas (Sadovy and Vincent, 2002;Papavlasopoulou et al., 2014). ...
Fishes of the genus Acanthurus (Acanthuridae) are strongly related to reef environments, in a broad biogeographic context worldwide. Although their biological aspects are well known, cytogenetic information related to this genus remains incipient. In this study, Acanthurus species from populations inhabiting coastal regions of the Southwest Atlantic (SWA), South Atlantic oceanic islands (Fernando de Noronha Archipelago and Trindade Island), Greater Caribbean (GC), and Indo-Pacific Ocean (the center of the origin of the group) were analyzed to investigate their evolutionary differentiation. For this purpose, we employed conventional cytogenetic procedures and fluorescence in situ hybridization of 18S rDNA, 5S rDNA, and H3 and H2B-H2A histone sequences. The Atlantic species (A. coeruleus, A. chirurgus, and A. bahianus) did not show variations among them, despite their vast continental and insular distribution. In contrast, A. coeruleus from SWA and GC diverged from each other in the number of 18S rDNA sites, a condition likely associated with the barrier created by the outflows of the Amazonas/Orinoco rivers. The geminate species A. tractus had a cytogenetic profile similar to that of A. bahianus. However, the chromosomal macrostructures and the distribution of rDNA and hisDNA sequences revealed moderate to higher rates of diversification when Acanthurus species from recently colonized areas (Atlantic Ocean) were compared to A. triostegus, a representative species from the Indian Ocean. Our cytogenetic data covered all Acanthurus species from the Western Atlantic, tracked phylogenetic diversification throughout the dispersive process of the genus, and highlighted the probable diversifying role of ocean barriers in this process.
... The live reef food fish (LRFF) trade is particularly unsustainable: it targets long-lived and large-bodied fishes that are easy to overexploit and can take generations to recover. Further, it is largely unregulated, demand-driven, and geographically broad and therefore untethered from local supply, and it incentivizes overexploitation because the value of a species increases with rarity (Sadovy and Vincent, 2002;Sale, 2008). The LRFF trade has caused the near extirpation of several of the largest reef fishes such as Napoleon wrasse, bumphead parrotfish, and several groupers (Blackmore et al., 2015;Sadovy de Mitcheson and Yin, 2015). ...
The overexploitation of coral reef fisheries threatens the persistence of reef ecosystems and the livelihoods and food security of millions of people. Market-based initiatives to increase fisheries sustainability have been widely implemented in industrialized commodity fisheries, but the suitability of these initiatives for coral reef fisheries has not been systematically investigated. Here, we present a typology of market-based interventions and coral reef fisheries sectors and identity promising approaches for each fishery archetype. For high value, export-oriented reef fisheries that are highly unsustainable (live reef food fish and dried sea cucumbers), traditional regulatory efforts including trade restrictions will be most effective. For high-value, export-oriented fisheries for highly fecund invertebrates (lobsters and mollusks), certification and ratings efforts, fishery improvement projects, and sustainable purchasing commitments can improve fishing practices and increase fisher market access and revenue. For lower-value fisheries targeting species for domestic or regional consumption, sustainable purchasing commitments among local buyers, consumer awareness campaigns, and local certification and ratings schemes hold promise for shifting attitudes toward sustainability and increasing food security for local communities. Finally, fisher empowerment efforts including direct access to local markets and market information, training on improved post-harvest methods, and formation of fisher associations hold promise for increasing fisher incomes, reducing wasteful catch, increasing food security, and de-incentivizing unsustainable practices. Despite the potential of market-based interventions, specific approaches must be carefully tailored to the ecological and social reality of these systems, including the inherent unsustainability of commercial coral reef fisheries, the limited capacity for fisheries governance, the limited financial support of market-based initiatives, and the threatened status of coral reef ecosystems globally.
... Many of the fish populations in the Arabian Gulf have been heavily exploited and concerns that fishing effort may already have exceeded optimum levels for most species are now receiving some attention from local communities (Grandcourt et al. 2005). Fisheries that remove large individuals can easily eradicate all sexually mature fish and/or create a highly skewed sex ratio with the possibility of reproductive failure (Sadovy and Vincent 2002). ...
Abstract
Coral reefs are important biodiversity hotspots that not only function as a crucial habitat for a multitude of organisms, but also provide human populations with an array of goods and services, such as food and coastal protection. Despite this, coral reefs are under threat worldwide from direct or indirect anthropogenic impacts, such as pollution, overexploitation and climate change. The coral reefs of the Musandam peninsula (Oman), situated on the Arabian Peninsula in the Strait of Hormuz, endure extreme conditions such as high salinity and temperatures, existing – indeed thriving – in what would be considered marginal and highly challenging environments for corals in other parts of the world.
Although Musandam corals exhibit extraordinary resilience, there is concern that any additional stress, as a result of natural disasters and/or anthropogenic impacts, for example, may induce coral die-off. For the past decade, reefs within the Arabian Gulf have been devastated by major coral bleaching events, cyclones, harmful algal blooms and extensive coastal developments. Fisheries of the area have also declined, with longlining significantly reducing shark numbers, whilst targeted hammour (grouper) fisheries in the region are in decline in many regions.
Between 6 and 12 October 2013, Biosphere Expeditions conducted its fifth annual coral reef survey (2009 – 2013) using the Reef Check methodology in 8 different dive sites along the northern Musandam peninsula coastline. The main objectives of the 2013 expedition were to (1) monitor the health of and impacts on the Musandam peninsula’s coral reefs, (2) train local scholars in the Reef Check methodology and involve these individuals in surveys, and (3) use and disseminate these findings for the purposes of management, education and conservation by local government and non-governmental organisations (NGOs).
This particular expedition saw coral cover of around 55% for most of the dives at shallow (<12 m) depths. Perhaps more significantly, there was little evidence of any coral disease, bleaching or predation. All corals were in a healthy climax state on many of the shallow reefs, with many sites hosting very large Porites colonies, indicating no significant damaging events to corals over the past 400 years.
The grouper populations were healthier this year than in previous years’ expeditions; however, this does not necessarily indicate a recovery as the sites visited in 2013 are not necessarily exactly the same as those in previous years. However, the fact that the numbers are about double (of animals greater than 30 cm size) of previous expedition surveys (comparisons are made here with 2010 in particular, but also apply to surveys of 2011, 2012 and before) indicates that there may be something of a recovery in the population. Snapper populations are considerable at most shallow sites, and are joined deeper down by populations of medium to large emperor and bream. The latter two families were seen at almost every site.
Invertebrate populations (as recorded by Reef Check) were dominated by Diadema urchins – from the shallowest reef flats, within Pocillopora colony framework, and in the deeper waters where the more open water Echinothrix diadema feeds out on sand flats, particularly during nighttime foraging. Pencil urchins were common in shallow waters. Giant clam remain absent from the region. Large commercially important molluscs are dominated by Murex spp. that were observed during the expedition being harvested by fishermen using snorkeling gear. Commercially important lobsters were observed at low densities, with a total of 5 recorded on all surveys combined. However, this is a reasonably high density compared to many surveys from around the Indo-Pacific.
In 2013, the Omani government (Ministry of Agriculture and Fisheries) announced a Marine Protected Area (MPA) for the southeast of the Musandam peninsula in the area of two inlets (Khor Najd and Khor Hablain). The management measures introduced were to restrict fishing to handline only for the entirety of these areas. All net, longline and trap fishing were banned. This is a significant step for the conservation of the fisheries of the area, whilst allowing local artisanal fishing to persist – a sensible management measure given the need for local communities to fish.
The peninsula itself, with so many clear natural waypoints, bays, inlets and geological features, lends itself to very effective MPA conservation measures at a discrete scale. It is recommended that these natural features are used to their maximum potential to zone areas for different protection measures around the rest of the Musandam peninsula beyond the Khor Najd and Hablain inlets.
We therefore recommend that the following additional projects are instigated by local government and NGOs: (1) fisheries landings studies, (2) patrolling of and new legislation for the diving and fishing communities beyond the Khor Najd and Hablain inlets, (3) extension of Marine Protected Area (MPA) measures or a network of MPAs, including the installation and monitoring of fixed and marked mooring buoys, and (4) actions to declare the Musandam peninsula a UNESCO Biosphere Reserve and ultimately a UNESCO World Heritage Site.
ملخص
تعتبر الشعاب المرجانية من أحد أهم مكونات النظم البيئية الحيوية والتى تساهم بصورة إيجابية فى التنوع البيولوجى، ليس فقط بكونها الموئل الذي لا يمكن الإستغناء عنه للعديد من الكائنات الحية، ولكن لكونها مصدرا هاما للكثير من المكونات الغذائية ، ولدورها الحيوي في حماية السواحل . ولكن وبالرغم من تلك الأهمية القصوى للشعاب المرجانية ، فإن هذا الموئل الحساس يتعرض وباستمرار لشتى أنواع التهديدات بتأثير من الممارسات البشرية المباشرة أو غير المباشرة ، كتغير المناخ والتلوث البيئى والأستخدام الجائر للمصادر الشحيحة بالأضافة إلى التغير المناخى. إن الشعاب المرجانية في شبه جزيرة مسندم والتابعة لسلطنة عمان والتي تقع على مضيق هرمز في شبه الجزيرة العربية ، قد أصبحت بيئة محفوفة بالمخاطر كغيرها من الشعاب المرجانية في أجزاء أخرى من العالم ، حيث تعاني من ظروف قاسية للغاية تتمثل في ارتفاع نسبة الملوحة ودرجة الحرارة وبالرغم من ذلك فإن تلك الشعاب المرجانية مازالت موجودة ومزدهرة فى المنطقة بالرغم من التحديات والتهديدات المحيطة والتى تواجها العديد من مناطق الشعاب المرجانية حول العالم.
بالرغم من المرونة الشديدة والتأقلم على البيئة المحيطة والتى تظهرها الشعاب المرجانية بمنطقة شبه جزيرة مسندم فإن الدراسات الحديثة أعربت عن تخوفها وقلقها الزائد على مدى قدرة تلك الشعاب المرجانية على تحمل أى ضغوط ومؤثرات سلبية إضافية والتى قد تنتج عن طريق الكوارث الطبيعية المحتملة بالمنطقة أو عن طريق المؤثرات البشرية السلبية الواقعة على تلك البيئات الهشة والتى قد تعجل فى هلاك ودمار البيئة المرجانية بالمنطقة. على امتداد العقد الماضي ، تعرضت الشعاب المرجانية الرئيسية بمنطقة الخليج العربى للدمار من خلال مايعرف بإبيضاض الشعاب المرجانية ، و الطحالب الضارة ، والأعاصير ، بالإضافة إلى أعمال التطوير الساحلي والإنشاءات والتي تتم على نطاق واسع، وقد لوحظ أيضاً من خلال الدراسات التى تمت على بيئة تلك المنطقة انه هناك أنهيار فى أعداد الأسماك من خلال الصيد الجائر لأنواع محددة من الأسماك مثال أسماك الهامور مما أدى إلى تقلص سريع لأعداد أسماك القرش بالخليج.
في الفترة ما بين بين 6 و 12 أكتوبر 2013 ، أجرى فريق "بعثات بايوسفير الاستكشافية" مشروعه البحثي للسنة الخامسة على التوالى (2009 – 2013) وذلك على امتداد ساحل شبه جزيرة مسندم . تم خلال المشروع مسح الشعاب المرجانية باستخدام " منهجية مراقبة الشعاب المرجانية " و هو بروتوكول دولي لرصد الشعاب المرجانية ، تم تطبيقه في ثمانية مواقع للغوص. إن الأهداف الرئيسية للبعثة هى 1) متابعة الحالة الصحية للشعاب، 2) تعليم وتدريب شباب الباحثين المحليين على أحدث طرق رصد وتقييم الشعاب المرجانية، 3) إستخدام تلك النتائج لاتخاذ القرارات الإدارية والتعليمية ولغايات جمع بيانات علمية موثقة يمكن استخدامها من قبل المنظمات غير الحكومية والحكومات المحلية مستقبلاً .
فى تلك الدراسة تم ملاحظة وتسجيل تجمعات شعاب مرجانية بنسبة حوالى 55% فى معظم مناطق الدراسة وذلك فى المناطق الضحلة والتى يبلغ فيها العمق لحوالى 12 متر، لم يوجد أى دليل ظاهرى على وجود شعاب مرجانية مريضة أو مبيضة أو أى مظاهر لأفتراس تلك الشعاب المرجانية، كل التجمعات المرجانية كانت بحالة جيدة مما أعطى دليلاً على أنه لايوجد أضرار كبيرة تعرضت لها الشعاب المرجانية بالمنطقة لزمن يعود إلى 400 عام مضى.
لوحظ من خلال الدراسة الاخيرة أن أسماك الهامور أصبحت فى أفضل حالتها مقارنة بأعدادها فى السنوات السابقة. وبالرغم من ذلك، لا يعتبر هذا التقدم فى الأعداد فى سنة 2013 ومقارنته بالسنوات السابقة مقبولا بصورة نهائية لإختلاف مواقع الرصد فى كل سنة عن السنوات السابقة. ومع ذلك، فإن تضاعف أعداد الإسماك (التى حجمها أكبر من 30سم) مقارنة بالمواسم السابقة (حيث تمت مقارنة دراسة عام 2013 بعام 2010 تحديداً وإجمالاً مع عامى 2011 و 2012) أثبت أن هناك تحسناً ملحوظاً فى الثروة السمكية فى منطقة الدراسة حيث زادت أعداد أسماك النهاش بصورة مقبولة فى المناطق الضحلة وشارك أسماك النهاش فى المناطق العميقة من الدراسة أسماك الأمبراطور وأسماك الدنيس والتى تمت مشاهدتهما فى معظم المواقع التى تم دراستها.
وبالنسبة لحصر وتسجيل الأنواع اللافقارية فقد تم تسجيل نوع من أنواع قنافذ البحر الشوكية (Diadema urchins) وذلك فى المناطق الضحلة المستوية داخل مستعمرات المرجان البحرى الحجرى (Pocillopora colony)، وبدراسة المناطق العميقة تم تسجيل قنفذ البحر من نوع (Echinothrix diadema) ويتغذى فى المناطق الرملية المستوية فى قاع الخليج العربى وبالأخص فى فترات الليل، وكذلك تم تسجيل نوع (Pencil urchins) فى المناطق الضحلة مع غياب حيوان البطليموس فى تلك المناطق.
تعتبر الرخويات والمتمثلة فى القواقع البحرية هيا الأهم من الناحية الإقتصادية التجارية من نوع (Murex spp.) والتى تم تسجيلها وملاحظتها أثناء فترات الدراسة حيث يتم تجميعها بواسطة الصيادين بإستخدام عدة الطفو البسيطة، تم أيضاً ملاحظة وتسجيل حيوان سرطان البحر ولكن بإعداد قليلة جداً بإجمالى خمس أفراد فقط فى كل مناطق الدراسة وإجمالا لكل السنوات الماضية ولكن بالرغم من ذلك تعتبر تلك المشاهدات كبيرة مقارنة بالعديد من الدراسات الأخرى فى مناطق المحيطين الهادى والهندى.
قامت الحكومة العمانية فى العام 2013 والممثلة فى وزارة الزراعة والثروة السمكية بإعلان منطقة جنوب شرق شبه جزيرة مسندم كمنطقة محمية بحرية وتتكون من خور النجد وخور الحبلين، وتم تفعيل خطط إدارة للمنطقة بتقييد الصيد الجائر لكل المنطقة والسماح فقط بإستخدام السنارة البسيطة ومنع كافة أشكال الصيد الأخرى مثل الصيد بالشباك ووضع مصائد للأسماك حيث أعتبر هذا القرار كخطوة هامة فى مجال الصون والحفاظ على الثروة السمكية بالمنطقة مع إستمرار السماح للمجتمعات المحلية البسيطة والتى تقيم بتلك المنطقة بالصيد لسد إحتياجتهم الغذائية من الموارد المتاحة.
تحتوى شبه جزيرة مسندم على العديد من المناطق الطبيعية الخلابة من الخلجان والخور وكذلك التشكيلات والتكوينات الجيولوجية المتنوعة والفريدة من نوعها، تم إقتراح ان يتم إدارة المنطقة عن طريق فرض نطاقات حماية محددة للحفاظ عليها وأن تشمل مستويات إدارة مختلفة لكل شبه جزيرة مسندم.
إجمالاً وتلخيصاً لما سبق فإننا نقترح البرامج والمشاريع التالية أن توضع فى الإعتبار بواسطة الحكومة المحلية ومنظمات المجتمع المدنى:
1) دراسات متخصصة عن مصائد الأسماك.
2) تنظيم عمليات التقييم والدوريات على أنشطة الغوص والصيد فى جميع مناطق شبه الجزيرة بخلاف خور النجد وخور الحبلين.
3) توسيع المحميات القائمة أو إنشاء محميات جديدة ويشمل ذلك إنشاء وتركيب ومتابعة عوامات المراسى الثابتة منها وكذلك المتحركة.
4) وضع خطة عمل فعالة لإعلان منطقة مسندم منطقة محمية من محميات المحيط الحيوى والتابعة لمنظمة اليونسكو وكذلك محاولة إعلانها منطقة تراث طبيعى عالمى.
... Grandcourt et al. 2005). Fisheries that remove large individuals can easily eradicate all sexually mature fish and/or create a highly skewed sex ratio with the possibility of reproductive failure (Sadovy and Vincent 2002). ...
Abstract
Coral reefs are important biodiversity hotspots that not only function as a crucial habitat for a multitude of organisms, but also provide human populations with an array of goods and services, such as food and coastal protection. Despite this, coral reefs are under threat worldwide from direct or indirect anthropogenic impacts, such as pollution, overexploitation and climate change. The coral reefs of the Musandam peninsula (Oman), situated on the Arabian Peninsula in the Strait of Hormuz, endure extreme conditions such as high salinity and temperatures, existing – indeed thriving – in what would be considered marginal and highly challenging environments for corals in other parts of the world.
Although Musandam corals exhibit extraordinary resilience, there is concern that any additional stress, as a result of natural disasters and/or anthropogenic impacts, for example, may induce coral die-off. For the past decade, reefs within the Arabian Gulf have been devastated by major coral bleaching events, cyclones, harmful algal blooms and extensive coastal developments. Fisheries of the area have also declined, with longlining significantly reducing shark numbers, whilst targeted hammour (grouper) fisheries in the region are in decline in many regions.
Between 26 October and 1 November 2014, Biosphere Expeditions conducted its sixth annual coral reef survey using the Reef Check methodology in five different dive sites along the eastern Musandam peninsula coastline. Surveys were undertaken in a significant ‘khor’ (or embayment) called Khor Hablain. This large bay measures about 20 km from east (open sea) at the mouth, to west (enclosed coastline). There are no built-up areas in the entire area, with only sporadic observations of handline use by fishing boats, and only a single incident of a line of fish traps being set. The area was said to have been declared a Marine Protected Area, but there is no such evidence either in official documents, conversations with government or management or enforcement procedures in place.
The main objectives of the expedition were to (1) monitor the health of and impacts on the Musandam peninsula’s coral reefs, (2) train local scholars in the Reef Check methodology and involve these individuals in surveys, and (3) use and disseminate these findings for the purposes of management, education and conservation by local government and non-governmental organisations (NGOs).
Coral cover generally increased towards the mouth of the bay (khor) where there was greater wave action ‘True coral reefs’ could be seen at the survey/dive sites of Osprey point, Paradise Point and Gargoyle Cliffs, with the diversity of reefs increasing the further west the surveys occurred. Osprey Point has many reefs similar to those outlined in the 2013 annual survey - Pocilliopora-dominated in shallow waters, with deeper areas Porites dominated with very high coral cover (88%). Reefs at Gargoyle Cliffs resembled communities heavily influenced by sediments, but remaining stable over hundreds of years. Here large (>3 m tall) blocks of Porites lobata dominated the seabed. At Paradise Point, the most exposed site, reefs were the most diverse with both scleractinian corals, but also large areas of soft corals in slightly deeper waters. Inner areas of the khor were heavily dominated by sedimentary communities with few ‘true’ reefs (only isolated coral colonies occurred separated by sand). Indeed sites over 20 km from the ‘open’ sea had coral cover of only 3% (Urchin Heaven). There was little evidence of any coral disease, bleaching or predation.
The grouper populations were relatively low with usually fewer than 5 animals (>30 cm) seen at each transect replicate (5 per 100 m2). Numbers were higher at the more exposed condition at the mouth of the bay at Paradise Point, where numbers reached five individuals per 100 m2. Snapper populations were large at two sites – Gargoyle Cliff (105 individuals per 100 m2 and Pharaoh’s Cliff (24 individuals per 100 m2).
Invertebrate populations were dominated by Diadema urchins as is the case for all Musandam sites. These animals are ubiquitous from the shallowest reef flats, within Pocillopora colony framework, and in the deeper waters where the more open water Echinothrix diadema feeds out on sand flats, particularly during night-time foraging. There were very few other invertebrates recorded, although large Pinna bivalves were recorded in the very sheltered waters of Urchin Heaven, well within the khor.
The entire Musandam peninsula itself, with so many clear natural waypoints, bays, inlets and geological features, lends itself to very effective marine protected area conservation measures at a discrete scale. It is recommended that these natural features are used to their maximum potential to zone areas for different protection measures for habitat protection (limited damage to corals) and to protect fish (with restrictive fish management).
ملخص
تعتبر الشعاب المرجانية من المكونات الرئيسية الهامة للتنوع البيولوجي مما لها من أهمية شديدة ليس فقط كموائل بالغة الأهمية للعديد من الكائنات الحية، ولكن أيضا لما توفره للبشرية من مجموعة من السلع والخدمات، كمصدر للغذاء وكذلك كحماية للشواطئ. على الرغم من هذا، تعتبر بيئات الشعاب المرجانية مهددة في جميع أنحاء العالم من التأثيرات السلبية البشرية المباشرة والغير مباشرة كمثال التلوث والاستغلال المفرط للموارد الطبيعية والتغير المناخي. تقع الشعاب المرجانية لشبه جزيرة مسندم (عمان) في منطقة شبه الجزيرة العربية على مضيق هرمز، تتحمل الظروف القاسية مثل ارتفاع نسبة الملوحة ودرجة الحرارة، موجودة بالفعل ومزدهرة فيما يمكن اعتباره بيئات هامشية وصعبة للغاية مقارنة ببيئات الشعاب المرجانية في أجزاء أخرى من العالم.
على الرغم من أن الشعاب المرجانية بمنطقة مسندم تبدي مرونة غير عادية للظروف الصعبة التي تواجهها، مازال هناك قلق من أن أي ضغط إضافي، على سبيل المثال نتيجة للكوارث الطبيعية و/أو التأثيرات البشرية يمكن أن يتسبب بالموت الفوري للشعاب المرجانية. على مدى العقد الماضي، دمرت الشعاب المرجانية في الخليج العربي عن طريق ابيضاض المرجان والأعاصير وتكاثر الطحالب الضارة والتطورات الساحلية واسعة النطاق. وتراجعت أيضا الثروة السمكية في المنطقة، لوحظ انخفاض أعداد أسماك القرش بشكل ملحوظ، في حين نتيجة زيادة ضغط الصيد على أسماك الهامور (الوقار) أدى ذلك لانخفاض أعدادها في العديد من المناطق.
أجرت بعثات المحيط الحيوي في الفترة بين (26 أكتوبر -1 نوفمبر)، المسح السنوي السادس للشعاب المرجانية باستخدام منهجية اختيار الشعاب المرجانية في خمسة مواقع غوص مختلفة على طول الساحل الشرقي لشبه جزيرة مسندم. أجريت الدراسة البحثية الاستقصائية في منطقة يطلق عليها خور الحبلين.
هذا الخليج الكبير يقاس بحوالي 20 كيلومترا من الشرق (البحر المفتوح)، إلى الغرب (الساحل المغلق). يخلو الساحل بأكمله من أي مباني او انشاءات، مع بعض المشاهدات المتفرقة للصيد بواسطة الخيط اليدوي بقوارب الصيد البسيطة، مع تسجيل حالة واحدة للصيد بواسطة مصايد الأسماك وقد قيل إن المنطقة أعلنت محمية بحرية، ولكن لا توجد ولكن لم يستدل على ذلك في الوثائق الرسمية، والمحادثة مع الجهات الحكومية حيث لا توجد إجراءات تنفيذية على أرض الواقع.
تمثلت الأهداف الرئيسية للدراسة إلى:
(1) متابعة حالة الشعاب المرجانية والأثار المترتبة على ذلك بشبه جزيرة مسندم.
(2) تدريب الباحثين المحليين عن طرق دراسة الشعاب المرجانية وإشراكهم في الدراسة
(3) استخدام ونشر النتائج لأغراض الادارة والتعليم والحفاظ على الموارد من قبل المنظمات الحكومية والجمعيات الاهلية.
يزداد كثافة الغطاء المرجاني عموما كلما اقتربنا من مصب الخليج (الخور) حيث يتواجد نشاط أكبر من حركة الأمواج ويمكن تسجيل " الشعاب المرجانية الحقيقية" وذلك عند دراسة مواقع مثل منطقة العقاب، والجنة وكذلك منحدرات جارجويل حيث يزداد تنوع الشعاب المرجانية باتجاه الغرب من منطقة الدراسة. يعتبر تنوع الشعاب المرجانية بمنطقة العقاب مشابهة للدراسة السابقة والتي تمت عام 2013، حيث ينتشر النوع Pocillioporaبمنطقة المياه الضحلة وفى المقابل ينتشر النوع Poritesفي منطقة المياه العميقة بنسب عالية تصل الى (88%). تشبه الشعاب المرجانية بمنطقة منحدرات جارجويل تلك الشعاب المتأثرة بشدة جراء الترسيبات، ولكن ظلت ثابتة على مدار مئات السنين. هناك يتواجد بكميات كبيرة النوع Porites lobataوالذى يبلغ طوله اكثر من ثلاثة أمتار ويسود قاع البحر. تعتبر منطقة الجنة من أكتر المناطق تعرضا ونجد أن الشعاب المرجانية بتلك المنطقة أكثر تنوعا ولكن هناك أيضا مجموعات وفيرة من الشعاب المرجان الرخوة في المياه المتوسطة العمق. ولقد ظهرت سيادة مجتمعات الشعاب المرجانية الرسوبية في المناطق الداخلية للخور وع بعض أنواع من الشعاب المرجانية الحقيقية حيث يتواجد تلك المجموعات منفصلة عن بعضها بواسطة الرمال. تغطى الشعاب المرجانية حوالي 3% من مساحة الموقع المقدرة بحوالي 20 كم ومع ذلك لم يسجل أي عرض سلبي على الشعاب المرجانية كوجود اى أمراض أو تبييض للشعاب أو أي أثر من أثار الافتراس واقع عليها.
سجلت أعداد منخفضة من تجمعات أسماك الهامور أقل من خمس أفراد في كل تكرار للمقاطع العرضية من مناطق الدراسة (خمس لكل 100متر مربع). وكانت الأعداد أكبر كلما كانت المنطقة مفتوحة أكثر عند مصب الخليج حيث بلغ أكثر من خمسة أفراد لكل مائة متر مربع. كانت أعداد أسماك النهاش كبيرة في موقعين أثنين حيث سجل مائة فرد لكل مائة متر مربع في موقع والموقع الاخر تم تسجيل عدد 24 فرد لكل مائة متر مربع.
بالنسبة للافقاريات سادت أعداد القنافذ البحرية في كل مواقع الدراسة بشبه جزيرة مسندم. توجد تلك الأنواع اللافقارية في كل مكان من المناطق الضحلة للشعاب المرجانية والمناطق العميقة حيث تتغذى في الأعماق الرملية المستوية وبالأخص في الليل. تم تسجيل بعض الأنواع اللافقارية الأخرى ولكن بصورة اقل بكثير من القنافذ البحرية.
تعتبر منطقة شبه جزيرة مسندم وما تمثله من مناطق طبيعية وخلجان وأخوار وخصائص جيولوجية من أكتر المناطق البحرية صلاحية لإنشاء وتفعيل تدابير حفاظ وحماية فعالة لتلك البيئات في نطاقات منفصلة. من المستحسن ان يتم استخدام تلك المميزات الطبيعية لأقصى إمكانياتها في تفعيل إجراءات حماية لتلك الموائل مع تقليل الأضرار الواقعة على الشعاب المرجانية للحد الأدنى وحماية الأسماك وإدارة مستدامة للمصايد السمكية.
... Involving local people in the surveys and explaining results, such as the relationship between high coral coverage and high species diversity, might be enough for the empiric understanding of a healthy ecosystem. In order to understand the full impact of fishing in this region, the impacts of selective mortality on specific size classes, colour phases or morphs, and social structure in target population, such as groupers, should be studied (Sadovy & Vincent 2002). Actual concern needs to be created around the two sites with the highest impacts: Lobster's Demise (D1) and Death Valley (D27) and more studies need to be conducted regarding groupers, a species known to be in high demand due to its value. ...
Abstract
The Musandam peninsula, situated on the Arabian peninsula in the Strait of Hormuz, comprise of coral reefs that appear to endure extremely harsh conditions when compared to corals in other parts of the world. Although resilience seems to exist among corals, scientists are increasingly concerned that any additional stress, imposed by global climate change or regional coastal development may accelerate coral die-off. In the past decade reefs in the Arabian Gulf have been devastated by major coral bleaching events and recently by extensive coastal developments.
Between 18 and 31 October, 2009, Biosphere Expeditions ran a research project along the Musandam peninsula coastline during which a coral reef survey using the Reef Check methodology was conducted in 18 dive sites, at two different depths. The main objective of the expedition was to provide data on reef health and current threats.
In accordance with what is encountered elsewhere in the Indo-Pacific, the Musandam also shows higher abundance of fish from the families Chaeodontidae (butterflyfish) and Lutjanidae (snappers) than Haemulidae (sweetlips) and Scaridae (parrotfish). However, the number of snappers in Musandam is substantially higher than the average for the Indo-Pacific. Serranidea (groupers) were found to be low in abundance due to the known fishing value of this family in the region. Curio collection and aquarium trading, as well as blast fishing and destructive fishing appear not to be a threat around the Musandam peninsula. In the invertebrates surveys the number of Diadema urchins was found to be significantly above the average number observed in the Indo-Pacific. This high density population is a concern, since it increases bioerosion activity in the area, making new coral recruitment difficult. The mean hard coral coverage of 34% found is slightly above the worldwide calculated average of 30%.
Further Reef Check surveys and fisheries landings studies should be done around the Musandam peninsula in order to address in more detail the main impacts found during the expedition. The application of a Marine Protected Area (MPA), or a network of MPAs, would also help to overcome the principal problems encountered, such as the lack of available data on natural resources, the absence of proper fixed and marked mooring buoys and the low public awareness. Declaring the Musandam peninsula a UNESCO Biosphere Reserve and eventually a UNESCO World Heritage Site is also something that should be considered at government level.
ملخص
شبه جزيرة مسندم ، التي تقع في شبه الجزيرة العربية في مضيق هرمز ، تتألف من الشعاب المرجانية التي يبدو أنها تتحمل ظروف قاسية للغاية بالمقارنة مع الشعاب المرجانية في أجزاء أخرى من العالم. على الرغم من المرونة بين الشعب المرجانية فأن العلماء قلقون على نحو متزايد أن أي ضغط إضافي على هذه البيئة الهشة ، والتي يفرضها تغير المناخ العالمي أو الإقليمي و التنمية العمرانية الساحلية قد تسارع بموت هذه الشعاب المرجانية.
في العقد الماضي الشعاب المرجانية في منطقة الخليج العربي تعرضت للعديد من الكوارث الطبيعية و الانسانية مثل ابيضاض الشعاب المرجانية ، ومؤخرا التطورات الساحلية واسعة النطاق.
ما بين 18 و31 تشرين الأول 2009 ، قامت حملة البيوسفير بحملة دراسة الشعاب المرجانية في شبه جزيرة مسندم حيث تم جمع المعلومات من اكثر 18 موقع غوص ، على اثنين من الأعماق المختلفة. وكان الهدف الرئيسي للبعثة توفير بيانات عن صحة الشعاب المرجانية في شبه جزيرة مسندم والتهديدات الحالية القائمة على النظام البيئي في هذه المنطقة.
و كما هو موجود في المحيطين الهندي والهادئ ، ففي شبه جزيرة مسندم وأعلى أيضا وفرة الأسماك من عائلات Chaeodontidae ، Lutjanidae ، sweetlips ،Haemulidae وScaridae ، على الرغم من أن عددا من النهاش في مسندم هي كبيرة أعلى من المتوسط بالنسبة للالمحيطين الهندي والهادئ. على الجانب الآخر Serranidea (الهامور) تم العثور عليها في وفرة منخفضة نظرا لقيمة الصيد المعروفة من هذه العائلة في المنطقة.
الغريب أن الصيد وتجارة احواض الاسماك ، فضلا عن الانفجار والصيد المدمرة لا يبدو أن يكون التهديد الرئيسي في شبه جزيرة مسندم ، من خلال المسوحات في اللافقاريات وجد أن عدد القنافذ البحرية (دياديما) وجد أن للغاية أعلى من متوسط العدد في المحيطين الهندي والهادئ. هذه الكثافة السكانية العالية تشكل مصدر قلق لأنه يزيد نشاط bioerosion في المنطقة ، مما يجعل من الصعب على المرجان بناء الحيود الجديدة.
تغطي الحيود المرجانية الصلبة 34 ٪ من شبه جزيرة مسندم ويتفق مع المتوسط المحسوب في جميع أنحاء العالم بنسبة 30 ٪. مزيد من التحقق من الدراسات الاستقصائية للشعاب المرجانية والدراسات الإنزال السمكية وينبغي أن تتم في شبه جزيرة مسندم من أجل معالجة الآثار الرئيسية التي عثر عليها أثناء الرحلة.
ومن شأن تطبيق خطة ادارة المناطق المحمية البحرية ، أو شبكة من المناطق البحرية المحمية ، يساعد أيضا على التغلب على المشاكل الرئيسية التي واجهتها ، مثل الافتقار إلى البيانات المتاحة عن الموارد الطبيعية ، وعدم وجود حدود ثابتة وسليمة ملحوظ والجمهور الواعي بيئيا .
... Therefore, this industry heavily relies on the millions of wild-caught specimens traded annually, and as a consequence there is significant overexploitation (Cato & Brown, 2003;Moorhead & Zeng, 2010;Olivotto, Piccinetti, Avella, Rubio, & Carnevali, 2010;Palmtag, 2017). In addition, organisms sourced from the wild often present high levels of postcollection mortality along the distribution chain, mostly due to collection stress, poor husbandry, diseases, and inadequate shipping procedures (Palmtag, 2017;Sadovy & Vincent, 2002;Wabnitz et al., 2003). ...
The marine aquarium industry has grown significantly and so has marine ornamental fish aquaculture. The main species targeted by commercial aquaculture are clownfish, dottybacks, gobies, and blennies. However, the limited knowledge available for the reproductive biology of several fish species hinders production, especially for blennies. Therefore, this study investigated whether two mass‐produced blenniids, Meiacanthus nigrolineatus and Meiacanthus smithi, are gonochorists and display caudal fin sexual dimorphism. For this purpose, gonadal samples and morphometric data were collected from specimens of both species kept in captivity for 6 months. Histological preparations of the whole individuals or their gonads were performed and analyzed. Results show that sex ratio does not differ from 1:1 and that gonadal development was similar to other blenniids. No evidence of sexual reversion or simultaneous hermaphroditism was found in the first 8 months of development, suggesting that both species are gonochoric. Differences in the length of upper and lower rays in the caudal fin were not detected for M. smithi, but M. nigrolineatus male individuals displayed significantly longer upper and lower rays, confirming it as a dimorphic trait for this species. The identification of the sexual pattern and sexually dimorphic traits may aid in broodstock pairing for M. nigrolineatus blennies, improving its aquaculture production and perhaps reducing some of the pressure on wild stocks.
... Groupers have significant economic value because they are widely consumed in the seafood restaurant around the world (Mous et al. 2000;Sadovy and Vincent 2002). Wild-caught grouper generally fetch a higher price than the cultured fish. ...
Stock enhancement and sea-ranching of groupers are a potential solution to overfishing of wild grouper catches. Hence, it is vital to understand the costs and benefits of stock enhancement and sea-ranching. A simulation was conducted to estimate the cost and benefits of using brown marbled grouper Epinephelus fuscoguttatus (Forsskål, 1775) for stock enhancement in the Karimunjawa Islands, Indonesia. The major costs for stock enhancement were the purchase of fish and transportation to the release site. Overall, the calculations of a theoretical benefit of 1.27-1.69 USD per released fish were estimated based on 1000 released fish of 10 and 15 cm length at release. The theoretical benefit decreased to 0.83 USD per released fish under extreme climate conditions exemplified by El Niño. Although releasing 15 cm E. fuscoguttatus was more costly and generated less economic benefit, the likelihood of predation for the larger fish was much lower. When the economic benefit of grouper mariculture is compared with stock enhancement, the former provides an additional advantage, which is conservatively estimated at 0.62 USD per individual. Besides, the annual benefit from the stock enhancement was estimated to be of 550,000 USD per year from related tourism activities in Karimunjawa Islands.
... The harvesting of marine organisms for aquarium and ornamental art crafts is a very common and worldly widespread activity (Sadovy & Vincent, 2002;Rhyne et al., 2012). However, this practice has been shown to be a threat of very high potential (Lecchini et al., 2006), and, consequently, many harvested species are endangered and under risk of extinction (Gasparini et al., 2005). ...
The harvesting of marine organisms for aquarium and ornamental art crafts is a very common and widespread activity, threatening a number of coral reef species. The goal of this manuscript is to report the intensive harvesting of two marine invertebrate species, the starfish Oreaster reticulatus and the gorgonian Phyllogorgia dilatata, in reef environments of a national priority area for the creation of a Marine Protected Area (MPA) in the Espírito Santo State, central coast of Brazil. These species were present on the 2003 Brazilian Red List of Endangered species as threatened of extinction, but P. dilatata was removed from the most recent 2014 Brazilian Red List, while O. reticulatus is currently considered vulnerable. Neither species have been assessed by IUCN. The harvest of these invertebrates was registered in 17% of the 51 days of monitoring (ten expeditions between March 2005 and February 2006), with catches of up to 24 starfishes and 1000 gorgonians in a single day. Starfishes used to be sold to local traders for US 0.15. This starfish is already in decline on a regional scale, and the actual harvesting rate of the gorgonian could lead to the extinction of the local population in about 17 years of exploitation. Due to the ecological importance of these two endangered species, their harvest threatens the entire local rocky reef ecosystem. Further ecological and fisheries studies on these species should be conducted, and the definition and creation of the MPA could help to manage all the unsustainable activities conducted and expected in the region.
... Introduction. The humphead wrasse (HHW) (Cheilinus undulatus Rüppell, 1835) is traded as live reef fish food (LRFF) where Indonesia is among the principal producers that exports this fish species to Hong Kong and China (main markets), beside Taiwan and Singapore (Sadovy & Vincent 2002;Greenpeace 2004;Suharti 2009;Wu & Sadovy de Mitcheson 2016). An excessive demand and in the following of climbing price is the root for the highly exploitation of this species. ...
The aim the present study was to investigate the natural abundance and size of the humphead wrasse (HHW), Cheilinus undulatus, in Raja Ampat waters. Density surveys was done using a modified Underwater Visual Census (UVC) with Global Positioning System (GPS) performed at 4 sub-districts and 1 marine protected area. The results were combined and compared with the previous studies. The abundance of C. undulatus in North Salawati Sub-District was 6.61 individuals ha⁻¹, of which density is moderately correlated with area surveyed rather than distance elapsed. Fish size was dominated by juvenile and pre-adults phase, putting higher risk of population decreased caused by fishing. The accumulation abundance in C. undulatus based on survey data in 2012-2016 was 3.36 individuals ha⁻¹ with a total surveyed area along 105.105 km with covering an area of 953107 m². Both previous and present studies were in agreement that habitat protection by avoiding destructive fishing is the most appropriate management measure to recover C. undulatus population.
... The number of reported species drastically increased from 119 to 176 along the past decade (Figure 1), which corresponds to a total number increase of 36%, or 63% in numeric terms of skates and rays and 16% of sharks [17,18,36]. This recent biological diversity boom is certainly related to the REVIZEE scientific surveys in the recent past (1996-2007) and its ongoing influence, which resulted in the most extensive effort in order to evaluate possible promising marine fishery resources in Brazil [52,75,122]. However, even these scientific surveys need to be properly designed to catch and better evaluate the elasmobranch biodiversity. ...
The deep-water shery in Brazil is currently in expansion due to depletion of most neritic economic species. This increasing deep-water e ort brings concern on the bycatch impact, its speci c composition, the need for capture’s evaluation and development of bycatch reduction devices. The impact is particularly aggressive on deep-water elasmobranchs, which have an extreme ecological k-strategy due to their reproductive constraints (lower fecundity and late rst maturity age). Scienti c deep- water surveys and intensive research programs (REVIZEE) along the past decade indicate that Brazilian elasmobranch diversity is higher than previously imagined. However, the deep-water shery threatens this poorly known community of sharks and rays on the Brazilian continental slope as they become bycatch of a fast-growing and uncontrolled shery. The recent study case of the monk sh (Lophius gastrophy- sus) shery dynamics, well presented and discussed by the Brazilian scienti c com- munity, provided evidence of the need of bycatch-speci c monitoring programs and fast-response shery regulations. The present work discusses the Brazilian deep-water elasmobranch bycatch problem under the light of its biological diversity and com- pletely unknown population status. Suggestions and management considerations are presented in order to coordinate and manage the establishment and growth of this deep-water shery in Brazil.
... The number of reported species drastically increased from 119 to 176 along the past decade (Figure 1), which corresponds to a total number increase of 36%, or 63% in numeric terms of skates and rays and 16% of sharks [17,18,36]. This recent biological diversity boom is certainly related to the REVIZEE scientific surveys in the recent past (1996-2007) and its ongoing influence, which resulted in the most extensive effort in order to evaluate possible promising marine fishery resources in Brazil [52,75,122]. However, even these scientific surveys need to be properly designed to catch and better evaluate the elasmobranch biodiversity. ...
... Past research has demonstrated that the collection of marine ornamental reef fish for the aquarium fish trade can have detrimental effects upon targeted populations (Lubbock and Polunin 1975, Edwards and Shepherd 1992, Wood 2001, Sadovy and Vincent 2002, Kolm and Berglund 2003, Tissot and Hallacher 2003, Shuman et al. 2005, Jones et al. 2008). In Costa Rica, approximately 40 species of marine fishes are taken by the aquarium fish industry, which has been regionally ...
Costa Rica hosts an active industry for the collection of marine ornamental reef fish that are supplied to the international aquarium fish trade. Little is known about the effects that collection activities may be having upon target species in Costa Rica, although research elsewhere gives reason for concern. Thalassoma lucasanum (Cortez rainbow wrasse) is an important species in this fishery. Costa Rican collectors prize the vibrantly colored terminal phase T. lucasanum individuals, but also collect the less dramatic initial phase T. lucasanum. We measured the density of T. lucasanum and the length of terminal phase individuals on highly collected reefs close to a fishing village and on nearby less-collected reefs located within the Guanacaste Conservation Area. Our findings show that densities of T. lucasanum were significantly lower and that terminal phase individuals were significantly smaller on the reefs near the fishing village where collection pressure was high. These findings indicate that even moderate amounts of relatively non-destructive aquarium fish extraction can negatively affect targeted populations. We present some suggestions for the reform of the aquarium reef fish industry in Costa Rica, which we believe would improve the long-term sustainability of this fishery.
Fish are among the most threatened vertebrates worldwide. In freshwater, dangers are posed by water pollution, straightening, weirs and dams, introduced species (neozoa), as well as the introduction of chemicals from agriculture, industry, and cities. Despite the seemingly infinite expanse of the oceans, marine fish are threatened by commercial fishing, sport fishing, wastewater from fish farms, settlements, industry, and agriculture, as well as neozoa. Coral reefs and thus all fish living on or in the reef also suffer from global warming, international trade in coral fish, and tourism.
The Napoleon wrasse – Cheilinus undulatus, locally known as “mameng” – was assessed as “endangered” in 2004 under the International Union for Conservation of Nature (IUCN) Red List assessment and is also listed under the Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Although there are numerous reports of Napoleon wrasse sightings by tourists and researchers in the two atolls within the Tubbataha Reefs Natural Park (TRNP), its density and size-frequency distribution have not been formally documented. A thorough survey was conducted in TRNP in May 2017 employing the fish visual census (FVC) technique but with a much broader swath width. A total reef area of 103 hectares not frequently visited by tourists was surveyed in the North and South Atolls, where a total of 641 individuals was recorded with an average density of 6.83 individuals/ha. Density comparison between atolls showed a significant difference (Welch’s two-sample t-test (t5.42 = –3.28, p < 0.05). South Atoll has a higher density (8.13 individuals/ha ± 1.11 se) than the North Atoll (4.20 individuals/ha ± 0.46 se). However, by size class, the North Atoll was significantly larger (n = 398; median = 65 cm) than in the South Atoll (n = 243; median = 60 cm) based on Wilcoxon Rank Sum test (W = 55,674, p < 0.05). A comparison of density and size class between the NW and SE coastline in the North Atoll showed no significant difference. Juveniles were also found at a site at the North Atoll. Taken together, these findings suggest that TRNP may serve as a source and a sink at the same time. This implies that TRNP is a key habitat for the Napoleon wrasse in the Sulu Sea and possibly in the adjacent seas through its pelagic larvae.
This datasheet on Amphiprion covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
The Saleh Bay is one of the bays in West Nusa Tenggara utilized as the grouper fishing ground. However, in the previous spawning potential ratio study, some grouper species have been overexploited in Saleh Bay. This study aimed to estimate the status of grouper utilization with a catch per unit effort (CPUE) approach and the spatio-temporal fishing intensity of grouper in fishing grounds in Saleh Bay. Data were gathered using the fish landing data and geo-reference of fishing ground grouper in Saleh Bay. This study used several methods: descriptive analysis, catch per unit effort, and spatial-temporal analysis. The result showed that the catch unit effort positively impacts production, with the increasing trend of grouper fishing in Saleh Bay waters. The CPUE value in 2016 was 2.82 kg/trip, while in 2020, it increased to 3.99 kg/trip. Spatially and temporally, fishers caught grouper around small islands such as Liang Island, Dempu Island, Lipan Island, Takat Nusa Pudu, and Rakit Island. The highest intensity of grouper fishing around the marine protected area, namely Rakit Island, Liang Island, and Ngali Island.
Keywords: catch per unit effort, fishing ground, grouper, Saleh Bay
Background
The use of ornamental fish as pets has important implications for the conservation of the species used in fish keeping, particularly in relation to overexploitation. Understanding ornamental fish keepers’ relationship with the hobby can provide important information for assessing the potential impacts of the activity. Here, we analyzed the profile of Brazilian ornamental fish keepers and evaluated their preferences and the implications of their choices.
Methods
Information was obtained by applying questionnaires to 906 ornamental fish keepers participating in fish keeping groups in a social network. The questionnaire contained questions about the species of fish kept (freshwater and marine), techniques used, socio-economic aspects, and associated conservation perspectives.
Results
Most ornamental fish keepers were young men (20–40 years old), with higher education and monthly income above US$ 530.00. Participants predominantly kept freshwater fish (86%), but marine fish only (5%) or both marine and freshwater hobbyists (9%) were also recorded. A total of 523 species of ornamental fish were kept, most of which comprised freshwater (76% of the total) and exotic species (73%). About a third of the fish species recorded were under national trade restrictions. In addition, about a third of ornamental fish keepers declared that they also had invertebrates. Marine aquariums require a greater financial investment, especially at the beginning, than freshwater aquariums and are also almost entirely based on exotic species. The aesthetic factor is the main motivation associated with practicing this hobby, being color and behavior key factors in choosing fish. A total of 10% of hobbyists have already released fish into the wild, highlighting concerns about potential biological invasions. There is an urgent need to enforce regulations towards restricting ornamental fish keepers’ access to threatened native species and potentially invasive species, as well as measures aimed at informing and raising hobbyists’ awareness of conservation measures related to the hobby.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
More than three months of cumulative comprehensive studied we conducted to evaluate coral reef fishes composition in Eastern Indonesia Region (Liki Island) and Western Indonesia Region (Natuna Island) of small outer Island (SOI) Indonesia. There is a fundamental problem in the ecological function of the coral reef ecosystem and the potential of economically important reef fishes in small outer Island Indonesia. Several obstructions become an essential problem, including the location of SOI, which is far from the mainland with a lack of surveillance and monitoring; consequently, the coral ecosystem and its coral reef fishes are threatened. Overfishing and destructive fishing are the major problems reported in several locations on the outermost island. Both anthropogenic stressors cause degraded coral ecosystems and give the loss specific species of marine species, especially in economically important coral reef fishes that primary target for fisheries. The latest and continuous time series data is essential as necessary information to arrange the appropriate and sustainable policies in Small outer islands, especially in protected the ecosystem from ecological extinction. The main goal of our study is to evaluate the potential of economic coral reef fishes with analysis of two families of fundamental economic and targeted fisheries: groupers (Serranidae) and snapper (Lutjanidae) in eastern and western small outer island Indonesia. The data were collected in each six site location in both eastern and western region SOI using Underwater Visual Census (UVC) technique. Four parameters, including species richness, abundance, biomass, and indices of economic coral reef fishes (Shannon, Evenness, Simpson, and ENS), were compared between the eastern region (Liki) to the Western region (Natuna) with Kruskal-Wallis non-parametric statistical analysis and internal Pairwise Wilcoxon analysis. The eastern region (Liki) recorded higher fish richness, abundance, and biomass than the western region (Natuna) (p< 0.05). Comparisons with ecological indices shown in the eastern region SOI (Liki) had a more diverse economic important coral reef fishes than western region SOI (Natuna). Understanding the composition of economically important coral reef fish in SOI will reveal more about the condition of the ecological function of the coral ecosystem and their vulnerability to future changes.
The directed harvest and global trade in the gill plates of mantas, and other mobulid rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography in the context of other sharks and rays. Despite the limited availability of data, we use life history theory and comparative analysis to develop plausible ranges of somatic growth rate, annual pup production and age at maturity to estimate risk of extinction (maximum intrinsic rate of population increase rmax) using a variant of the classic Euler-Lotka model. Manta ray rmax is most sensitive to the length of the reproductive cycle, and the median rmax of 0.11 year-1(CI: 0.089-0.137) is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information. In common with other unprotected, unmanaged, high-value large-bodied species with low or very low productivity, manta rays are unlikely to sustain unmonitored, unregulated exploitation and may face increasing local and regional extinction risk.
Marine angelfishes (F: Pomacanthidae) are amongst the most conspicuous reef fish families inhabiting reefs on tropical and subtropical latitudes. While being disproportionately represented in the marine ornamental fish trade, only a handful of taxonomically restricted studies explored their biogeographic history and the evolution body size and trophic guilds. Here, we reconstruct the phylogenetic history for 70 pomacanthid species (85% of nominal species), based on previously published data for three nuclear and four mitochondrial markers. We use the resulting phylogenetic framework to explore the ancestral biogeography and ecological diversification of the family. Divergence times and ancestral range estimation highlight the origins of the family most likely lie in the Central Pacific region. Vicariance among ocean basins reflects the impact of the Terminal Tethyan Event and the closure of the Isthmus of Panama in the historical biogeography of Pomacanthus and Holacanthus genera. The reconstruction also uncovers ancestral colonization pathways via the Pacific Ocean into the western Atlantic waters for Holacanthus. We confirm the Indian Ocean invasion scenario previously proposed for the “acanthops” complex (genus: Centropyge). Finally, interspecific variation in body size among clades appeared to be correlated to some degree with trophic guilds, whereby 15% of variance in body size was explained by trophic modes. This suggests that the higher ecological diversification observed in the Centropyge clade might be promoted by smaller body sizes acting as an ecological novelty allowing the expansion of the genus within available niches.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The commercial important coral reef fishes viable source, re-aggregating, have been exploited coral reef parrot fish in pearl coast of Gulf of Mannar. Its beautifully colour parrot fish reported between ranges 08°53.6’N, 78°16’E and 08°53.8’N, 78°32’E at a depth of 36 m. The parrot fishing of natural mortality (M), fishing mortality (F) and total mortality (Z) was calculated at 0.47, 0.40 and 0.87, respectively. Growth equation based on modified von Bertalanffy’s equation and Ford-Walford graph was arrived. The growth parameters such as L∞ = 104.50 cm and K = 0.23 was estimated combining both sexes. Length and weight frequency data obtained from the growth equation, has been dealing with S. gibbus attains the length of 21.96, 39.21, 51.76, 62.74, 70.58, 77.64 and 83.13 mm during first and seventh year respectively. The spawning peaks one in December and another in April could be observed. The life span of S. gibbus was estimated for seven years. The exploitation ratio of 0.46 indicated that the resource of S. gibbus is currently exploited along the Tuticorin coast. Heavy fishing pressure on the length group 6 to 81 cm revealed that S. gibbus in Tuticorin waters suffer due to recruitment overfishing. The present level of exploitation rate and exploitation ratio (F/Z) is estimated at 0.46 and 0.5 respectively. The average length of parrot fish, the beginning capture (Lc) was calculated as 20.0 cm. The total stock, average annual stock and maximum sustainable yield were estimated as 35.150 tonnes, 9.385 tonnes and 10.206 tonnes respectively. Virtual Population Analysis have been assessing the mortality ranges from 85 cm. The parrot fish study shows that the further stressed that strict management measures need to be undertaken to conserve this species from further to avoid exploitation and to restore the biodiversity of heavybeak parrotfish population of Gulf of Mannar in general and Tuticorin coast in particular.
Keywords Scarus gibbus; Population dynamics; Age and growth; Thoothukudi coast; Recruitment pattern; India
The commercial important coral reef fishes viable source, re-aggregating, have been exploited coral reef parrot fish in pears coast of Gulf of Mannar. Its beautifully colour parrot fish reported between ranges 08° 53.6’N 78° 16’E and 08° 53.8’N 78° 32’E at a depth of 36 m. The parrot fishing of natural mortality (M), fishing mortality (F) and total mortality (Z) was calculated at 0.47, 0.40 and 0.87, respectively. Growth equation based on modified von Bertalanffy’s equation and Ford-Walford graph was arrived. The growth parameters such as L∞ = 104.50 cm and K = 0.23 was estimated combining both sexes. Length and weight frequency data obtained from the growth equation, has been dealing with S. gibbus attains the length of 21.96, 39.21, 51.76, 62.74, 70.58, 77.64 and 83.13 mm during first and seventh year respectively. The spawning peaks one in December and another in April could be observed. The life span of S. gibbus was estimated for seven years. The exploitation ratio of 0.46 indicated that the resource of S. gibbus is currently exploited along the Tuticorin coast. Heavy fishing pressure on the length group 6 to 81 cm revealed that S. gibbus in Tuticorin waters suffer due to recruitment overfishing. The present level of exploitation rate and exploitation ratio (F/Z) is estimated at 0.46 and 0.5 respectively. The average length of parrot fish, the beginning capture (Lc) was calculated as 20.0 cm. The total stock, average annual stock and maximum sustainable yield were estimated as 35.150 tonnes, 9.385 tonnes and 10.206 tonnes respectively. Virtual Population Analysis have been assessing the mortality ranges from 85 cm. The parrot fish study shows that the further stressed that strict management measures need to be undertaken to conserve this species from further to avoid exploitation and to restore the biodiversity of heavybeak parrotfish population of Gulf of Mannar in general and Tuticorin coast in particular.
Keywords Scarus gibbus, Population dynamics, Age and growth, Thoothukudi coast, Recruitment pattern, India
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
The aquariums industry is a trade that is expanding. Although there is no accurate information regarding the figures of the aquarium industry in the international scenario, it is estimated to generate revenues over US 28 to 44 million of this amount is generated by the ornamental marine fish trade. However, the trade in marine species has aroused controversy regarding the extraction of almost all traded marine organisms from wild populations and, in many cases, illegally. This paper presents a review that includes: the ornamental marine fishkeeping history, the species of commercial importance, the international trade scenario, risks of the aquarium industry, conservation strategies, and the current situation of this trade in Mexico. The last section focuses on describing the development and market prospects of the marine aquarium trade. Additionally, some initiatives from academic and private institutions aimed at developing sustainable aquaculture on ornamental marine fish species of commercial importance in Mexico are provided.
The local diversity and global richness of coral reef fishes, along with the diversity manifested in their morphology, behaviour and ecology, provides fascinating and diverse opportunities for study. Reflecting the very latest research in a broad and ever-growing field, this comprehensive guide is a must-read for anyone interested in the ecology of fishes on coral reefs. Featuring contributions from leaders in the field, the 36 chapters cover the full spectrum of current research. They are presented in five parts, considering coral reef fishes in the context of ecology; patterns and processes; human intervention and impacts; conservation; and past and current debates. Beautifully illustrated in full-colour, this book is designed to summarise and help build upon current knowledge and to facilitate further research. It is an ideal resource for those new to the field as well as for experienced researchers.
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