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Bio-functions of carvacrol-supplemented feeds on lipopolysaccharide-induced rainbow trout (Oncorhynchus mykiss Walbaum, 1792)
Full text linkTo investigate the effects of carvacrol supplementation in rainbow trout induced by lipopolysaccharide (LPS), relative gene expressions levels of some pro-inflammatory cytokines and apoptosis markers in kidney and liver were measured. Fish with a mean weight of 44.71±1.33 g were studied using four different treatments with three replicates each. Inflammation and apoptosis were performed using LPS of Escherichia coli (25 µg ml ^-1) except in the control group and only carvacrol (100 µg ml ^-1 diet) containing diets were fed to this group (CAR). The last group was the infected fish fed carvacrol supplemented diet (+CAR). Kidney and liver tissues were removed 3 days after to determine the levels of interleukin-1β (IL-1β), interferon gamma (INF-γ), caspase 3 (Cas 3), caspase 8 (Cas 8) using Real-Time PCR analyses. IL-1β expressions of both kidney and liver was significantly decreased (12.9 and 2.14 fold, respectively) in LPS treated cells (p<0.05). While IFN-γ expression was up regulated in kidney, it had down regulation in liver. LPS decreased both Cas 3 and 8 expressions in kidney but increased in liver. +CAR increased expressions of IL-1β and IFN-γ compared with the control (up to 2-3 fold) in all tissues except caspase gene expressions that were similar in the control. In all tissues, IL-1β and IFN-γ expressions increased in +CAR group, expect IFN-γ in the kidney. However, Cas 3 and 8 expressions including apoptosis was induced by up-down regulations in all tissues compared to LPS-injected fish. The results showed that carvacrol had pro-inflammatory and apoptotic effects especially on liver tissue of LPS-induced inflammation model of Oncorhynchus mykiss
Ertrags- und Einnahmeverluste bei Dorsch, Hering und Sprotte durch Unterfischung von Dorsch in der östlichen Ostsee.
Full text linkKurzfassung: Aus dem aktuellen WGBFAS-Bericht des ICES geht hervor, dass Nahrungsmangel in der östlichen Ostsee Kümmerwachstum und damit einen Verlust an Produktivität bei Dorsch verursacht. Dieser Zustand, zunächst unbemerkt, verschlimmert sich seit etwa 30 Jahren. Hungernde Bestände müssen unbedingt vermieden werden, denn, nur der über den Grundbedarf hinausgehende Anteil der assimilierten Nahrung, wird für das Wachstum eingesetzt. Eine Reduktion der Bestandsgröße ist erforderlich! Der Internationale Rat für Meeresforschung (ICES) hat jedoch die Schließung der Fischerei auf Dorsch empfohlen. Betrachten wir die Fischerei durch die Brille der Aquakultur, stellen wir fest, dass diese Empfehlung kritisch hinterfragt werden muss. Nutzt man den „gemästeten“ Dorschbestand nicht ausreichend, werden mögliche Erträge ebenfalls nicht realisiert. Zusätzlich zu diesem Verlust verliert man das zur Mast eingesetzte Futter. Denn, als Alternative zur Dorschmast wären Erträge aus der Fischerei auf Hering und Sprotten möglich. Im Gegensatz dazu verursacht die Überfischung des Dorschbestandes zwar Ertragseinbußen, eröffnet aber gleichzeitig erweiterte Fangmöglichkeiten auf die Futterfischbestände. Die Überarbeitung der verwendeten Bestandsmodelle und die Hinwendung vom Einartenansatz über den Ökosystemansatz, hin zu Ansätzen, die Ökonomie und Ökologie vereinen, sind notwendig. Vergleicht man die Futterkosten mit den späteren Erlösen wird klar, dass bei der Mast von Dorsch über einer Körpermasse von etwa 1 kg mehr Geld in der alternativen Futterfisch-Fischerei verloren wird, als bei der Fischerei auf Dorsch gewonnen wird. Ein reflexartig geforderter Bestandsschutz verursachte in den vergangenen Jahrzehnten geringe Wachstumsraten bei Dorsch durch Unterfischung in der östlichen Ostsee und damit einen Rückgang der Produktivität auch bei anderen Arten. Man kann keine ertragreiche Fischerei auf Dorsch, Hering und Sprotten erwarten, wenn man einen hungernden Dorschbestand duldet. Um nun aber größere Dorsche fangen zu können, muss die Zahl der Rekruten ausreichend gering sein. Wir wissen es aus unserem Kleingarten. Wenn wir die Radieschenreihen nicht ausdünnen, können wir nur kleine Radieschen ernten. Das Gleiche gilt für den Kabeljau in der Ostsee. Wenn wir die Zahl der Rekruten nicht frühzeitig reduzieren, werden wir immer kleinen Kabeljau zu unattraktiven Preisen fangen.
You can find the English version of the manuscript here: https://ssrn.com/abstract=3419758
Abstract: The latest ICES WGBFAS report shows that food shortages in the eastern Baltic Sea are causing poor growth and thus a loss of cod productivity. This situation, initially unnoticed, has been worsening for about 30 years. It is essential to avoid starving stocks, because only the part of assimilated food that exceeds basic needs is used for growth. A reduction of the stock size is necessary! However, the International Council for the Exploration of the Sea (ICES) has recommended the closure of the cod fishery. If we look at fishing through the eyes of aquaculture, we see that this recommendation must be questioned critically. If the "fattened" cod stock is not used sufficiently, potential yields will not be realised either. In addition to this loss, the feed used for fattening is also lost. Because, as an alternative to cod fattening, yields from fishing for herring and sprat would be possible. In contrast, overfishing of the cod stock may result in a loss of yield, but at the same time it opens up greater fishing opportunities for forage fish stocks. A revision of the stock models used and a shift from the one-species approach via the ecosystem approach to approaches that combine economy and ecology are necessary. If one compares the feed costs with the later revenues, it becomes clear that when fattening cod beyond a body mass of about 1 kg more money is lost in the alternative forage-fish fishery than is gained when fishing for cod. A reflex-like demand for stock protection has caused low growth rates for cod in recent decades due to underfishing in the eastern Baltic Sea and thus a decline in productivity for other species as well. You cannot expect high-yield fishing for cod, herring and sprat if you tolerate a starving cod population. In order to catch larger cod, however, the number of recruits must be sufficiently low. We know this from our allotment garden. If we don't thin out the rows of radishes, we can only harvest small radishes. The same applies to cod in the Baltic Sea. If we do not reduce the number of recruits beforehand, we will always catch small cod at unattractive prices
Identification of Fish Prey of an Irrawaddy Dolphin (Orcaella brevirostris) using Mitochondrial Cytochrome c Oxidase 1 Sequence Analysis
Full text linkThis study used mitochondrial cytochrome c oxidase 1 in the identification of the fish prey from the gut samples collected from a stranding of a dead Irrawaddy dolphin in Pulupandan, Negros Occidental. Obtained consensus sequences were searched against the nucleotide database of NCBI and reference sequences, and sample sequences were used for generating the dendrogram and the pairwise genetic distances between species. Results showed that most of the sample sequences were 99% identical to the reference sequences.Eubleekeria splendens and Conger japonicus were the identified species in the stomach contents. E. splendens is a demersal and coastal species while C. japonicus is a demersal species and has not been previously recorded in the Philippines. Conflict in the taxonomy of the Conger genus may suggest that this may be identified as C. jordani. This study reports the first record of fish prey identification of the Irrawaddy dolphin in the country. Continuous monitoring of the Irrawaddy dolphin in the Guimaras Strait, including their feeding ecology, is needed to understand the population further and to improve their conservation
Growth, Development and Survival of Holothuria scabra Larvae in Different Microalgal Regimens and Water Rearing Media
Full text linkDifferent aspects of Holothuria scabra larval production, including feeding regimen and water treatment, were investigated under experimental conditions. This study highlights the optimization of techniques and simplification of the requirements of sea cucumber larval rearing. The growth performance, development, and survivorship of H. scabra larvae were measured to assess which treatment provides optimum results. Chaetoceros gracilis (Cgr) and Chaetoceros calcitrans (Cc) were administered singly and in combination (Cgr-Cc) to sea cucumber larvae. Growth was highest in combined Cgr-Cc feed with mean final length of 2088µm, followed by Cc with 1855 µm and Cgr with 1800 µm, but with no significant difference (p > 0.05). Similarly, survival rates among treatments were not statistically different (Cgr-Cc = 2.23%; Cgr = 1.6%; Cc = 1.3%) (p > 0.05). However, larval development was better in combined Cgr-Cc and Cc single diet, with 90% and 100% composition of early juveniles on Day 30. Slower development was observed in Cgr single feed, with only 90% early juveniles observed later on Day 35. Different microalgal concentration of Cgr-Cc (10,000, 30,000 and 50,000 cells.mL-1) were also tested. Juveniles (~3 mm) yielded from 50,000 cells.mL-1 microalgal concentrations were five times larger than when fed at 10,000 cells.mL-1 microalgae. Development of larvae was also faster in 50,000 cells.mL-1, yielding harvestable juveniles in 25 days. However, water replenishment in tanks with high microalgal density should also be regularly done at 50-70% rate in two days interval to mitigate fouling. In addition, sand-filtered, chlorinated, and UV-treated seawater were also tested for their efficiency as culture media. Growth rates were significantly highest in sand-filtered seawater (68.3 µm.d-1), followed by UV-treated seawater (52.4 µm.d-1), and by chlorinated seawater (34.8 µm.d-1) (p < 0.05). Larval development did not differ in sand-filtered and UV-treated seawater, yielding ~1 mm juveniles as early as Day 25. Likewise, sand-filtered seawater rendered highest survival of larvae (10.24%) followed by UV-treated seawater (6.24%); chlorinated seawater yielded lowest (2.60%) (p < 0.05). Although a sterilization process is advised, findings on sand-filtered seawater as a rearing medium were notable
Review: A brave start
No full textPacific Handbook for Gender Equity and Social Inclusion in Coastal Fisheries and Aquaculture Barclay K., Leduc B., Mangubhai S. and Donato-Hunt C. (eds.). 2019. First edition Noumea, New Caledonia: Pacific Community. 80 pages. Published by the Secretariat for the Pacific Community (SPC), this handbook was jointly produced under the direction of the SPC Fisheries, Aquaculture and Marine Ecosystems Division and the Social Development Programme. The target readership is the staff of fisheries agencies in Pacific Island countries. The leaders of these agencies discussed the handbook on the occasion of its release in March at the biennial regional Heads of Fisheries meeting in Noumea, New Caledonia
Artificial neural networks model biometric features of marine fish sand smelt
Full text linkIn this study was investigated some biometric properties of the sand smelt with ANN’s, Atherina boyeri Risso, 1810, population in Yamula Dam Lake. Twenty-three morphometric characters of samples were measured. The total length of individuals which were caught between 6.40 and 10.20 cm, and their weight (W) were ranged between 1.50 and 7.31 g. The effect of Artificial Neural Networks was investigated in predicting the statistical of fishery industry. The present study provides the first information on the biometric properties of Atherina boyeri in Yamula Dam Lake by Artificial Neural Networks
Empirical use of growth, mortality and temperature data for anchovy
Full text linkTo estimate the empirical relationships in anchovy, the instantaneous natural mortality rate (M) calculated from von Bertalanffy Growth Function (VBGF) parameters, maximum total length (Lmax) and sea surface temperature (T,°C) were reviewed in the Black Sea. Empirical equations were presented for evaluation of M data in their relationships to VBGF parameters, T and Lmax. Based on biological consideration and regressional definition, it was recommended to use following formulas for estimating of natural mortality rate of small pelagic fish such as anchovy. M = 0.3237 + 1.3174*(K) - 0.0036*(L∞) - 0.0117*(T); M = 0.2639 + 1.3676*(K) - 0.0003*(Lmax) - 0.0124*(T)
Levels of Heavy Metals in Six Aquaculture Commodities Collected from Various Landing Sites of Manila Bay: Relationships with Size and Seasonal Variation
Full text linkFish normally accumulates heavy metals from food, water and sediments which can be harmful to human health. In the present study, levels of Pb, Hg and Cd; relationships with size; and seasonal variation in six aquaculture commodities mud crab, Scylla serrata; milkfish, Chanos chanos; green mussel, Perna viridis; oyster, Crassostrea iridalei; shrimp, Penaeus spp.; and tilapia, Oreochromis niloticus from Manila Bay fish landing sites were determined. Homogenized flesh samples were subjected to microwave-assisted digestion in a mixed solution of nitric acid and hydrogen peroxide before analysis by Atomic Absorption Spectrophotometer. All commodities passed the regulatory limit set by Bureau of Fisheries and Aquatic Resources Fisheries Administrative Order 210s 2001 and European Commission 1881/2006 for Pb and Cd. In contrary, 2.04% O. niloticus from Hagonoy, Bulacan and Navotas City and 5.00% Penaeus spp. from Guagua, Pampanga and Obando, Bulacan exceeded the limit for Hg. Significant negative relationships were found between Cd concentration and fish size in C. chanos and P. viridis, while significant positive correlations were observed between Pb and fish length in O. niloticus and S. serrata; Hg and fish length in P. viridis; and Cd and fish weight in Penaeus spp. Aquaculture commodities were observed to have significantly higher level of accumulation during wet season. Results indicate that metal concentration varies among aquaculture commodities, landing sites and season of catch. Thus, there is a need for risk assessment and regular monitoring for the said commodities
Natural disasters: a heavy price
No full textThe cyclonic wind that swept through the shores of the Indian state of Odisha in the wake of Cyclone Fani have razed the livelihoods of many fisherfolk. On 3 May 2019, as Cyclone Fani swept through the coast of Odisha on the eastern seaboard of India, many homes were either badly damaged or completely shattered. Thousands of trees were uprooted. Most businesses and infrastructure were also destroyed, including the fishing industry, which is the economic backbone of the state’s fisherfolk community of around 600,000-strong
India: organising women
Full text linkFive groups engaged in organizing women in fishing from different parts of India recently got together to share their experiences. Recently, five groups working with women in marine and inland fisheries across a number of states in India came together for a round table discussion to share experiences of organising women in the fishing sector. The five were: SNEHA from Tamil Nadu; Dakshinbanga Matsyajibi Forum (DMF) from West Bengal; Maharashtra Machimar Kruti Samiti (MMKS-Palghar) and Maharashtra Machimar Kruti Samiti (MMKS-Mumbai) from Maharashtra; and Self Employed Women’s Association (SEWA) from Kerala. The discussion was moderated by Nikita Gopal, Principal Scientist, Central Institute of Fisheries Technology, India. The round table highlighted the common issues of women in fisheries and also showed how effective the organised strength of women can be in terms of gaining rights and benefits. This article summarises the experiences shared during the discussion