 Subjects -> WATER RESOURCES (Total: 160 journals)
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | | We no longer collect new content from this publisher because the publisher has forbidden systematic access to its RSS feeds. |
|
|
- The Sea Slug Tethys fimbria Linnaeus, 1767 (Nudibranchia: Tethydidae)
Expands its Distribution Northwards to the Sea of Marmara
Authors: Cansu SARAÇOĞLU; Nur Eda TOPÇU
Abstract: This study reports our observation of the large sea slug Tethys fimbria Linnaeus, 1767 in the northern-eastern Sea of Marmara (the Princes’ Islands). We observed T. fimbria on the detrital bottom of the sea at a depth of 35 m in June 2022. This species had previously been reported during spawning in a recent study conducted in the southern part of the Çanakkale Strait (the Dardanelles Strait that connects the Marmara Sea with the Aegean Sea). Prior to 2022 there had been no reports of this conspicuous species from the Marmara Sea in the scientific literature or in photo-records among divers. Following our observation of the species in the sea around the Princes’ Islands, underwater photographers reported pictures of T. fimbria from different locations in the Marmara Sea on social media platforms. The sea slug seems to extend its distribution northwards. The potentially new arrival of the large sea slug in the Sea of Marmara, rather than a distribution shift from deoxygenated deep Marmara basins or a climate-related northwards expansion, is discussed.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
- Sturgeon Aquaculture Potentiality in Egypt in View of the Global
Development of Aquaculture and Fisheries Conservation Techniques: An
Overview and Outlook
Authors: Ashraf I. G. ELHETAWY; Lydia M. VASİLYEVA, Nataliia SUDAKOVA, Mohamed M. ABDEL-RAHİM
Abstract: Sturgeon conservation is a global issue, with wild sturgeon amounts dropping rapidly and continuously. This article explores the essential role that aquaculture plays in the conservation of these critically endangered fish, the replenishing of the natural population, fulfilling the expanding demand and possibilities for caviar markets, and reducing pressure on fisheries’ catch. It also reviews the history of controlled breeding programs designed to supplement wild Caspian Sea populations, the possibilities for sturgeon aquaculture production, and the worldwide caviar trade industry in the coming years. Globally, the successful and profitable expansion of captive sturgeon farming over the last three decades has fulfilled the consumer market's demand for caviar and meat, resulting in a considerable decline in the global caviar price. Given the presence of successful sturgeon farming inthe Arabian Gulf region (Saudi Arabia and the United Arab Emirates), the prospect of introducing the sturgeon farming industry in Egypt is underlined. In comparison to other nations in the region, Egypt has excellent prospects for establishing such an aquaculture business, as Egypt's aquaculture sector is by far the largest in Africa and the sixth largest internationally. Furthermore, the availability of qualified workers, the diversity of water sources, and Egypt's moderate climate and environment increasethe likelihood of successful sturgeon farming.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
- Fish and Shellfish Diversity of Malam Beel, Bangladesh: Status, Trends,
and Management Strategies
Authors: Mst. Jannatul FERDOUS; Mst. Armina SULTANA, Rasel MİA, Debasısh PANDIT, Mohd Golam Quader KHAN, Md. Samsul ALAM
Abstract: Most of the waterbodies in Bangladesh's north-eastern haor basin have seen a gradual decline in their biodiversity, but little study has been done to determine their current condition. To address this issue, this research was conducted in the Malam beel under the Hakaluki haor – one of the largest wetland resources of the country. The study was conducted using a pre-tested questionnaire and a direct catch assessment survey in the beel. From 11 orders and 32 families, a total of 69 fish and shellfish species were identified. Of the species documented, 15.94% were classified as abundant, 39.13% were common, 27.54% were moderately available, and 17.39% were rare. Among the orders, Cypriniformes accounted for 37.68% of the total fish recorded. The most prevalent family was Cyprinidae found in Malam beel. Based on the findings, it can be concluded that Malam beel is a highly valuable inland open water body that has the potential to function as a key source of fishery resources as well as a gene bank for various fish species. However, some manmade and natural threats such as fishing by dewatering, brush pile fishing, illegal/destructive fishing and siltation were identified during the present study. Therefore, to ensure the sustainable maintenance of these water bodies, ecosystem-based fisheries management involving the local community is strongly advised.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
- Cyanocidal Effect of H2O2 on the Bloom-Forming Microcystis aeruginosa and
Sphaerospermopsis aphanizomenoides
Authors: Latife KÖKER; Emine Gözde ÖZBAYRAM, Ayça OĞUZ ÇAM, Reyhan AKÇAALAN, Meriç ALBAY
Abstract: Cyanobacterial blooms are a global concern causing water quality problems that have serious effects on recreational activities, irrigation, and drinking water usage. Various approaches are available to control cyanobacterial blooms in which Hydrogen Peroxide (H2 O2 ) emerges as a noteworthy environmentally safe oxidizing agent selectively inhibiting the growth of cyanobacteria and leaving no residue. The objective of this study was to assess how different concentrations of H2 O2 (1, 2, and 4 mg L-1) affect the growth of unicellular Microcystis aeruginosa and filamentous Sphaerospermopsis aphanizomenoides cultures obtained from inland waters in Türkiye and to compare the effectiveness of H2 O2 application in monocultures and mixed cultures. For this purpose, the experimental setups were conducted in 96-well microtiter plates with eight replicates, and the growth of cultures during the experiment was monitored by measuring cell optical density at 665 nm (OD665). The results showed that 1 mg L-1 H2 O2 had a significant effect on the growth of monocultures of Microcystis with cell densities of 100x103 cell mL-1 (p<0.05) and Sphaerospermopsis with 50x103 cell mL-1. The cell growth of Microcystis cultures with higher densities declined at 4 mg L-1 H2 O2 addition, significantly. However, 4 mg L-1 H2 O2 dosage was effective up to 200x103 cell mL-1 Sphaerospermopsis. In the mixtures of these species, 2 mg L-1 H2 O2 application was effective to suppress the tested cell densities in the case of Microcystis dominance.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
- Urban Lakes, South Tangerang City Based on Water Quality Index and
Phytoplankton Composition as Bioindicator
Authors: Yayan Mardiansyah ASSUYUTİ; Ahmad ZULFİKAR WİCAKSONO, Dasumiati DASUMİATİ, Khohirul HİDAYAH, Firdaus RAMADHAN, Alfan Farhan RİJALUDDİN, Dinda Rama HARİBOWO
Abstract: An assessment of water quality in 8 urban lakes in South Tangerang City was conducted, as their condition was a concern. This research aims to assess water quality based on the condition of chemical-physical variables and phytoplankton composition. This research was conducted from late May to early October 2021 (the dry season until the inter-seasonal period). The Water Quality Index (WQI) ranged from 61.18-79.53 (medium-good). Phytoplankton composition consisted of 65 genera from 11 classes and 6 divisions. Oscillatoria, Euglena and Pediastrum were the dominant genera, meanwhile, Cyanophyceae and Chlorophyceae were the dominant class. Phytoplankton communities in all lakes were stable except RL and based on Jaccard index the value of inter-lakes show no identical similarities (≠ 1). In (Nygaard) values ranged from 2.50-undefined (slight-high eutrophication), and X (Saprobic indices) values ranged from 0.33-1.80 (very slight pollution-moderate pollution). The best correlations (both values were r = 0.53) in water quality between the variables were DO (ppm) and BOD (ppm) Urban lakes require further improvement in their lake management to be used as sources of drinking water.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
- Assessment of Lotic Macroinvertebrate Assemblage in the Oconaluftee River
Basin in Cherokee, North Carolina
Authors: Sierra B. BENFİELD; Shem UNGER
Abstract: Macroinvertebrate assemblage assessments act as useful analysis tools for assessing aquatic ecosystems health. These animals also serve as a base trophic level, acting as a source of food for many other aquatic organisms including fish and salamanders. Obtaining baseline data for monitoring aquatic insects and subsequent river health is vital to understand food chains and river ecological interactions. We sampled macroinvertebrate communities in two streams in the Oconaluftee River basin, in the Cherokee Qualla, North Carolina. Over 600 macroinvertebrates were collected and identified to the lowest taxonomic level possible, providing a macroinvertebrate profile of both riffle and run habitats. We identified over 35 genera and report on functional feeding groups, with biotic indices of water quality. Ephemeroptera, Plecoptera, and Trichoptera values varied, 21% and 65.43% for Raven’s Fork and 22% and 79.06% for the Oconaluftee rivers. This macroinvertebrate community suggests healthy stream aquatic insects and above average water quality, in spite of the urban land use found in the riparian zones of the sample sites. This research can be used as a baseline for future monitoring of aquatic streams in the area of the Cherokee Qualla.
PubDate: Mon, 09 Oct 2023 00:00:00 +030
|
Open Access journal
