Recent developments in aquaculture statistics

The FAO Fisheries Information, Data and Statistics Unit has been systematically collecting and disseminating global aquaculture production by weight and value since 1984. The mechanisms for collecting data and the coverage and quality of data on production from aquaculture provided by countries to FAO have been constantly under review, with the aim of improving their quality and relevance to future national and global needs. Such future needs are highlighted and a discussion presented as to how some of these needs are being currently addressed. The following topics are covered: aquaculture as an economic activity; definition of aquaculture; unidentified aquatic organisms; proposed changes for reporting global production from fisheries; quantitative structural information on aquaculture; and, current status and constraints of collecting aquaculture statistics

Sperm activation in Nile tilapia Oreochromis niloticus and the effects of environmentally relevant pollutants on sperm fitness

In externally fertilizing fishes, multiple factors of the spawning environment may affect the sperm viability, and thus the fertilization rate. In this thesis, the sperm activation effect of osmolality of non-electrolytes and electrolytes activation media, pH and ion channel inhibitors on Nile tilapia, Oreochromis niloticus, and the effect of environmentally relevant pollutants (cadmium, malathion and rotenone) on sperm fitness (motility and morphology) were investigated. Seminal fluid samples collected from male fishes (200-250g) were subjected to activation treatments, then analyzed for sperm motility using motility score, and motility variables using Hobson sperm tracker for straight line velocity (VSL), beat cross frequency (BCF) and percentage of motile cells (MOT). For the ion channel inhibitors and pollutants, the effect on sperm motility variables of VSL, VCL (curvilinear velocity) and LIN (linearity) were determined. Multivariate analysis was also carried out to determine the effects of ion channel inhibitors and pollutants on sperm subpopulations. The effects of pollutants on sperm morphology were observed using microscopy techniques, namely, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Sperm motility was initiated when the sperm were exposed to hypoosmotic electrolytes and non-electrolytes solution. We also found that sperm show optimal activity at pH range of 6-8 which depicts that the effect of pH on sperm motility is negligible. Lanthanum (calcium channel blocker) and flunarizine (sodium-calcium exchanger pump blocker) were found to inhibit sperm motility at 25 and 5 µM, respectively, suggesting that both ion channels play a significant role in sperm activation in O. niloticus. In contrast amiloride, ouabain and quinine showed no effects on activation, indicating that epithelial sodium channels, sodium-potassium ATPase and voltage gated potassium channels respectively are unlikely to have major roles in sperm activation or motility. The spermatozoa of Oreochromis niloticus were uniflagellate with clearly differentiated oval-shaped head, midpiece and flagellum. Sperm exposed to hypoosmotic shock showed swelling of the midpiece and sleeve structure. The pollutants showed dose- and time-dependent effect on sperm motility of the fast linear sperm subpopulation. Sperm morphology was not affected. Sperm motility was inhibited at 0.44, 0.03 and 0.063 µM, cadmium, malathion and rotenone respectively. Both cadmium and malathion exerted effects very quickly after exposure. The effect of cadmium, which can exert toxicity by calcium antagonism, is consistent with the effects of calcium channel blockes and further supports an important role for calcium in sperm activation and motility. Malathion had effects at relatively low, environmentally relevant concentrations, suggesting the presence of functionally important acetylcholinesterase activity in sperm, and also the presence of activation cytochrome P450 activity. Rotenone, a well known mitochondrial poison, affected motility only after 15 min of pretreatment. The alteration of sperm trajectories in fast linear spermatozoa subpopulation by pollutants at submicromolar concentrations as demonstrated in our study implies potentially serious consequences for fish populations in polluted environments. Furthermore the results indicate that fish sperm motility as assessed by CASA could be an ecologically relevant, sensitive, and ethically acceptable method for toxicity testing in environmental risk assessment.EThOS - Electronic Theses Online ServiceGovernment of MalaysiaGBUnited Kingdo

Inter-household and intra-household patterns of fish and meat consumption in fishing communities in two states in Nigeria

Fish is generally regarded as a primary source of protein for many poor African fishing communities. The present study compared the relative importance of fish as a high-quality dietary protein source with meat in fishing communities in two states in Nigeria. Fifty fishing households in which active fishing was the primary activity and fifty non-fishing households (agriculture being stated as primary activity) in traditional fishing communities were randomly selected in the coastal state of Lagos and the inland state of Niger. A simple weighing balance was designed and given to each household to measure fish or meat entering the household for consumption. A comparison of consumption using this method against the 24 h recall method revealed that the recall method accounted for only one third of actual fish consumed. Overall, the price of fish was higher and consumption lower in Lagos compared with Niger State. At the household level in both states, the consumption of fish in fishing households was twice that of non-fishing households, whereas meat consumption was similar. A total of thirty-nine different fish species were consumed, with Tilapia contributing 24 % by weight of the fish consumed. In both states, beef was the most frequently consumed meat, followed by goat meat. The study revealed a high preference for fresh fish. The highest fish consumption occurred in March, corresponding to the period of lowest meat consumption. On a unit weight basis, heads of households consumed 59 % more fish than their wives or children

Artificial intelligence (AI): multidisciplinary perspectives on emerging challenges, opportunities, and agenda for research and practice

As far back as the industrial revolution, great leaps in technical innovation succeeded in transforming numerous manual tasks and processes that had been in existence for decades where humans had reached the limits of physical capacity. Artificial Intelligence (AI) offers this same transformative potential for the augmentation and potential replacement of human tasks and activities within a wide range of industrial, intellectual and social applications. The pace of change for this new AI technological age is staggering, with new breakthroughs in algorithmic machine learning and autonomous decision making engendering new opportunities for continued innovation. The impact of AI is significant, with industries ranging from: finance, retail, healthcare, manufacturing, supply chain and logistics all set to be disrupted by the onset of AI technologies. The study brings together the collective insight from a number of leading expert contributors to highlight the significant opportunities, challenges and potential research agenda posed by the rapid emergence of AI within a number of domains: technological, business and management, science and technology, government and public sector. The research offers significant and timely insight to AI technology and its impact on the future of industry and society in general

Husbandry and larval rearing of common snook (Centropomus undecimalis)

Common snook (Centropomus undecimalis) is a relatively new species for aquaculture; considered as a recreational species and not commercial. The aim of this study was to develop common snook larval rearing techniques for stock enhancement. Common snook culture has two main bottlenecks, broodstock management and larval culture. High mortality during the first 6 days is the main limitation for successful larval survival. Broodstock management of common snook is still developing and the only source of common snook eggs is from wild broodstock. Securing a regular supply during the natural spawning was essential to reach the main objective. Finding the optimal spawning sites, as well as optimal spawning time was achieved. Results showed Terra Ceia, Longboat and Cayo Costa to be the best sites for wild broodstock collection. The onset of spawning was triggered by a rise in water temperature. During the 4 years of this study spawning started at the end of May and finished in September. Total capture results and egg quality results, such as fertilization, hatching rate and lipid analysis, indicated June and July as the peak months during the spawning season. Common snook follow a lunar spawning cycle. Results showed that one to three days after the new and full moon were the peak spawning periods and therefore the best days to capture wild stock. Common snook egg lipid composition fits the general marine fish fatty acid composition with saturated fatty acids predominating. On the other hand, the omega 3, omega 6 (n-3/n-6) ratio was lower than the typical marine fish and arachidonic acid values were significantly higher than other marine species. This egg fatty acid profile will be helpful in the future to compare it with captive spawned eggs for egg quality purposes. Description of the common snook embryonic and larval development for the first 14 days was carried out. This has strengthened knowledge for this species’ development, and should provide a helpful tool to identify common snook embryos and larvae in the wild. Novel improvements to existing common snook larval culture protocols were implemented. Larval lipid analysis throughout development, and high mortality around day 6 post hatching, suggested that common snook larvae were dying of starvation. Gross morphological development and ultra-structure findings in the digestive and eye system development during the first three days indicated that day 2 post hatching larvae were capable of capturing and digesting food. Additionally, larval nutritional improvements were made, increasing the larval survival. The most significant ones were: finding a smaller and more nutritional prey (SS type rotifers and copepods), finding an optimal stocking and feeding density and the importance that green water technique has on larval survival. Overall, larval success was improved from a zero percent survival during the first 14 days to a 2% survival rate.EThOS - Electronic Theses Online ServiceMote Marine Laboratory, Sarasota, FloridaGBUnited Kingdo

Oogenesis, hepatosomatic and gonadosomatic indexes, and sex ratio in rosy barb (Puntius conchonius)

Seven stages of oogenesis were identified in the rosy barb (Puntius conchonius). Oogonia were present throughout the reproductive cycle. A group-synchronous ovary with a possible asynchronous ovarian development was observed. The most important event observed during the developmental stages of oogenesis was the observation of the crystalline yolk (at the maturation stage). Maturation of females was observed at 112 days post hatch. Mean hepatosomatic index (HSI) and gonadosomatic index (GSI) increased with increasing mean body weights and lengths during gametogenesis in females. The relationship was statistically significant (<0.05). The sex ratio observed in 300 fish was 210:80 (female:male) and the difference was statististically significant (<0.05).Seven stages of oogenesis were identified in the rosy barb (Puntius conchonius). Oogonia were present throughout the reproductive cycle. A group-synchronous ovary with a possible asynchronous ovarian development was observed. The most important event observed during the developmental stages of oogenesis was the observation of the crystalline yolk (at the maturation stage). Maturation of females was observed at 112 days post hatch. Mean hepatosomatic index (HSI) and gonadosomatic index (GSI) increased with increasing mean body weights and lengths during gametogenesis in females. The relationship was statistically significant (<0.05). The sex ratio observed in 300 fish was 210:80 (female:male) and the difference was statististically significant (<0.05)