Community structure and coral status across reef fishing intensity gradients in Palk Bay reef, southeast coast of India

Abstract

Coral reef fishes are exploited without the knowledge of their sustainability and their possible effect in altering the community structure of a coral reef ecosystem. Alteration of the community structure could cause a decline in the health of coral reefs and its services. We documented the coral community structure, status of live corals and reef fish assemblages in Palk Bay at the reef fishing hotspots and its nearby reef area with minimum fishing pressure and compared it with a control reef area where reef fishing was banned for more than two decades. The comparison was based on the percent cover of different forms of live corals, their diversity and the density and diversity of reef fishes. The reef fish stock in the reef fishing hotspots and its neighbouring reef was lower by 61 and 38%, respectively compared to the control reef. The herbivore fish Scarus ghobban and Siganus javus were exploited at a rate of 250 and 105 kg month(-1) fishermen(-1), respectively, relatively high comparing the small reef area. Live and dead corals colonized by turf algae were predominant in both the reef fishing hotspots and its nearby coral ecosystems. The percent cover of healthy live corals and live corals colonized by turf algae was <10 and >80%, respectively, in the intensively fished coral ecosystems. The corals were less diverse and the massive Porites and Favia colonies were abundant in the intensive reef fishing sites. Results of this study suggest that the impact of reef fish exploitation was not solely restricted to the intensively fished reefs, but also to the nearby reefs which play a critical role in the resilience of degraded reef ecosystems.

Seagrass metabolism and carbon dynamics in a tropical coastal embayment

“…Highest seagrass biodiversity and density were reported near-shore compared to offshore waters. Healthy live coral patches (66 species of corals belonging to 23 genera) have been reported adjacent to this seagrass meadow (Kumaraguru et al 2003;Manikandan et al 2014). Despite the fact that the region harbors healthy seagrass ecosystems, (Manikandan et al 2011) it is among the least studied ecosystems in India.…”

“…Station 1 is dominated by a high abundance of Cymodocea serrulata, whereas dense cover of two mixed seagrass species [Cymodocea serrulata (70%) and Syringodium isoetifolium (30%)] is present at Station 2. Healthy coral patches, which account for only 26.7% of the corals present in the region with the balance as dead corals colonized by macro/turf algae, have been observed adjacent to seagrass meadows at Station 1 (Manikandan et al 2014).…”

Prayang Innovation Technology on Capture Results

“…Faktor waktu lamanya perendaman atau lama pemasangan prayang pada perairan ternyata hasilnya signifikan dan meningkatkan nilai CPUE bila dibandingkan dengan alat tangkap tanpa menggunakan cahaya (Nguyen, 2019), ekploitasi penangkapan yang berlebihan tidak hanya berdampak terhadap keberlanjutan sumberdaya yang ada saja, namun terjadinya degradasi terhadap ekosistem terumbu yang ada (Manikandan, 2014). Berdasarkan efisiensi penggunaan bahan bakar, ternyata penggunaan jenis lampu LED dan MH dapat menghemat konsumsi bahan bakar hingga 25% bila dibandingkan dengan penggunaan cahaya konvensional (Matsushita, 2012).…”

Bacterial Communities Associated With Healthy and Diseased (Skeletal Growth Anomaly) Reef Coral Acropora cytherea From Palk Bay, India

“…The fringing reef runs parallel to land in east to west direction with an average water depth of 9 meters (Ravindran et al, 2012). In Palk Bay region, scleractinian diversity studies showed a reduction in species richness from >60 species (Pillai, 1971) to 34 species in 40 years of time (Venkataraman and Rajan, 2013). The dominant genera recorded along the Palk Bay regions were Porites sp., Favia sp., Acropora sp., Platygyra sp., Goniastrea sp., Favites sp.…”