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PERANAN PEMASARAN DALAMAN DALAM MENINGKATKAN TINGKAH LAKU INOVATIF PEKERJA: KES PEKERJA SEKTOR PENDIDIKAN DI JORDAN
No full textNile tilapia (Oreochromis niloticus) invasion impacts trophic position and resource use of commercially harvested piscivorous fishes in a large subtropical river
No full textBackground Although freshwater ecosystems cover less than 1% of the earth?s surface, they support extremely high
levels of biodiversity and provide vital ecosystem services. However, due to the introduction of non-native fishes,
aquatic ecosystem functioning has been altered, and in some cases, declined sharply. Quantifying the impacts of
invasive species has proven problematic. In this study, we examined the relative trophic position of native piscivorous
fishes to estimate the effects of invasive Nile tilapia on food webs in the downstream sections of an invaded large
subtropical river, the Pearl River, China. Furthermore, we quantified how native piscivorous fish diets changed as the
Nile tilapia invasion progressed.
Results The trophic position of the widely distributed and locally important economically harvested piscivorous culter
fish (Culter recurviceps), mandarinfish (Siniperca kneri), and catfish (Pelteobagrus fulvidraco) lowered significantly in
the invaded Dongjiang River compared to an uninvaded reference Beijiang River. The lower trophic position of these
piscivorous fishes was reflected by a major reduction in the proportion of prey fish biomass in their diets following the
Nile tilapia invasion. Small fishes in the diet of culter fish from the reference river (33% small fishes, 17% zooplankton)
shifted to lower trophic level zooplankton prey in the invaded river (36% zooplankton, 25% small fish), possibly due
to the presence of Nile tilapia. Additionally, small fishes in the diet of mandarinfish in the reference river (46% small
fishes, 11% aquatic insects) declined in the invaded river (20% aquatic insects, 30% small fishes). Similarly, the diet of
catfish from the reference river shifted from fish eggs (25% fish eggs, 25% aquatic insects) to aquatic insects in the
invaded river (44% aquatic insects, 5% fish eggs).
Conclusions The results of this study contributed to a growing body of evidence, suggesting that Nile tilapia can
modify trophic interactions in invaded ecosystems. It is crucial to understand the processes outlined in this study in
order to better assess non-native aquatic species, conserve the stability of freshwater ecosystems, and improve current
conservation strategies in reaches of the Pearl River and other similar rivers that have experienced invasions of
non-native species
Assessment of water quality and its effect on prawn abundance in three tributaries of Shiwalik rivers: Chenab and Ravi of Jammu, India?a case study
No full textThe freshwater rivers from Shiwalik Himalayas have abundant prawn resources of high economic value and play a major
role in the livelihood of local fishermen. The present study aimed to determine the variation in prawn abundance explained
by changes in water quality among three different streams (Gho Manhasa stream, Chadwal stream and Nagri stream). The
highest abundance of prawns was found in the Gho Manhasa during the premonsoon season and lowest in the Chadwal stream
during the monsoon season. Chadwal stream witnessed maximum anthropogenic activities resulting in the decline of the water
quality affecting prawn fauna. Cluster analysis based on similarity in terms of prawn abundance revealed that the Chadwal
stream is different from the other two streams whereas non-metric multidimensional scaling plot based on species abundance
corresponding to different seasons and physiochemical parameters showed the water quality of the monsoon season of the
Chadwal stream to be extremely different. Principal component analysis showed clear separation across various sites and
seasons based on physicochemical parameters. Karl Pearson correlation coefficient and canonical correspondence analysis
indicated that the turbidity, total dissolved solids, nitrate, chloride, calcium, magnesium and dissolved oxygen are significant
parameters influencing the abundance of prawns. The population of Macrobrachium dayanum and Macrobrachium kistnense
was very less in the Chadwal stream owing to unfavorable physicochemical parameters. Therefore, conservation measures
are suggested which should be immediately implemented before the streams witness a further decline in their populations
Effects of Formulated Diet and Frozen Fresh Fish on Growth, Serum Biochemical Indexes, Liver Antioxidant, and Lipid Metabolism of Juvenile Cobia (Rachycentron canadum)
No full textFeed is the main source of material and energy for farmed fish, and its nutritional value and balance are important factors affecting
fish?s growth rate and physical health. In order to explore the effects of two different feed sources on the growth, serum biochemical
indexes, liver antioxidant capacity, and lipid metabolism of young cobia fish, 300 young cobia fish with an initial body weight of
43.14 1.25 g were selected for the experiment and randomly divided into two treatments. Each treatment had five replicates, and
each replicate had 30 fish. They were fed with formulated feed and frozen fresh fish, respectively, for 12 weeks. The results showed
that the weight gain rate, specific growth rate, and feed conversion rate of juvenile cobia fish fed with formulated diet were
extremely significantly lower than those of the frozen fresh fish group (P<0:01), and condition factor was significantly lower than
that of the frozen fresh fish group (P<0:05). However, protein efficiency rate, hepatosomatic index, and viscerosomatic index were
significantly higher than those of frozen fresh fish group (P<0:05). The content of water, crude protein, and crude ash in the whole
fish had no significant difference (P>0:05), while the content of crude lipid decreased significantly (P<0:05). The serum aspartate
aminotransferase activity and sugar content of cobia in the formulated diet group were significantly higher than those in the frozen
fresh fish group (P<0:05). In contrast, the total cholesterol, triglyceride content, alkaline phosphatase activity, and phosphorus
content were significantly lower than those in the frozen fresh fish group (P<0:05). Compared with the frozen fresh fish group, the
antioxidant enzyme activities in the liver of the formulated diet group were significantly decreased (P<0:05) except malondialdehyde
(MDA) and the activity of fatty acid synthase, while there was no significant difference in the malate dehydrogenase. The
study showed that under the experimental conditions, frozen fresh fish was more suitable for feeding juvenile cobia, and the
formulated diet had adverse effects on the liver of juvenile cobia. Therefore, the nutritional composition of frozen fresh fish and
the metabolic characteristics of cobia were used for reference to optimize and adjust the nutritional formula of juvenile cobia
Interspecies and spatial differences in the shell microbiome of Atlantic rock crab Cancer irrotatus and European green crab Carcinus maenas from Atlantic Canada
No full textThe native Atlantic rock crab (Cancer irrotatus) and the invasive
European green crab (Carcinus maenas) are commercially and ecologically
important crustacean species in Atlantic Canada. The importance of
microbiomes for host health and ecology has been recognized in many
species, although very few studies have focused on crustaceans or their
external shell microbiome. This is the first-ever study to characterize and
analyze the microbial communities associated with the external carapace of C.
irrotatus and C. maenas
Editorial: Maritime broadband communications and networking
No full textAs development, production, and services become increasingly digital, the maritime economy is undergoing a process of transformation. Digitalization in the ocean industry is therefore regarded as one of the most signi?cant global trends. The digitalization of numerous maritime activities, such as oil extraction, autonomous shipping, maritime transportation, and ?sh farming, which continue to be rapidly developed, will become a decisive competitive factor for the entire maritime sector and generate a vast quantity of ocean data. The implementation of these processes relies on nationwide broadband and mobile radio networks with high data transfer capabilities, broad coverage, and high stability, which necessitates the development of new broadband maritime communication technology.
The objective of this Research Topic is to accelerate the new research on maritime broadband communications and networking including underwater acoustic, maritime radio channel measurement and modeling, maritime satellite systems, and related applications like collision avoidance
Perceptions and attitudes of residents toward small- scale longline tuna ?shing in the Galapagos Marine Reserve: conservation and management implications
No full textLonglining represents a cost-effective ?shing modality for catching tuna, but its use is contentious due to the unintended catch of endangered, threatened, and protected (ETP) species. In 2000, longlining was banned in the Galapagos Marine Reserve, Ecuador. Since then, local small-scale ?shers have contested this decision. In contrast, longlining ban supporters argue that this regulation is fundamental for conserving ETP species, despite scienti?candanecdotal evidence indicating that its effective implementation is unfeasible. We conducted an online survey to investigate Galapagos residents? perceptions concerning longlining, its ecological impact, and diverse potential management strategies. Our ?ndings revealed misconceptions about longline ?shing, which highlight the need for improved public awareness and education regarding longline ?shing practices, their impact on ETP species, and possible solutions to this complex social-ecological problem. Our study also highlights Galapagos residents? openness to ?nd a solution that addresses both ?shers? livelihoods and the conservation of ETP species. Galapagos residents are receptive to implementing evidence-based solutions, including testing new bycatch mitigation methods and more selective ?shing gears, enhancing monitoring and enforcement, and creating market-based incentives that encourage progressive and adaptive improvements in ?shing practices. To solve the Galapagos longline controversy, we recommend a holistic, adaptive, and evidence-based approach that encourages stakeholders to engage in open dialogue, fosters cross-sector collaboration, and promotes research, communication, and educational initiatives. By raising awareness through comprehensive, rigorous, and unbiased scienti?c information, this ecosystem- based management approach aims to ensure the sustainable development of the small-scale tuna ?shery, while conserving the Galapagos? invaluable and unique marine biodiversity
Measuring the blue economy in the EU: The Polish experience
No full textIt is generally agreed that the blue economy and blue growth play important roles
in the global economy; over the last few years, they have been widely discussed
at both national and international levels. Nevertheless, there is a lack of
consensus on how to measure them, as the accounting methodologies differ
between studies, implying divergent results. This article summarizes previous
studies by comparing blue economy accounting methodologies and highlighting
their strengths and weaknesses. Based on the comparison, a new methodology is
proposed, based primarily on micro- and country-specific local data; this new
methodology has been applied to measure the size of the blue economy in
Poland. The results show that previous analyses have slightly underestimated the
size of the blue economy in Poland, despite similarities concerning general
dynamics and sectoral structure over time. The study concludes that a trade-off
exists between using existing one-size-fits-all methods and country-specific
methods, with a more precise, tailored approach being achieved at the expense
of the accuracy of cross-country comparisons. Finally, the study highlights that,
as there is no unambiguous solution to the problem of the above trade-off,
different methods should be used with regard to the choice of method depends
on the specific research task to be carried out or policy question to be addressed