Fish Farms at Sea: The Ground Truth from Google Earth

In the face of global overfishing of wild-caught seafood, ocean fish farming has augmented the supply of fresh fish to western markets and become one of the fastest growing global industries. Accurate reporting of quantities of wild-caught fish has been problematic and we questioned whether similar discrepancies in data exist in statistics for farmed fish production. In the Mediterranean Sea, ocean fish farming is prevalent and stationary cages can be seen off the coasts of 16 countries using satellite imagery available through Google Earth. Using this tool, we demonstrate here that a few trained scientists now have the capacity to ground truth farmed fish production data reported by the Mediterranean countries. With Google Earth, we could examine 91% of the Mediterranean coast and count 248 tuna cages (circular cages >40 m diameter) and 20,976 other fish cages within 10 km offshore, the majority of which were off Greece (49%) and Turkey (31%). Combining satellite imagery with assumptions about cage volume, fish density, harvest rates, and seasonal capacity, we make a conservative approximation of ocean-farmed finfish production for 16 Mediterranean countries. Our overall estimate of 225,736 t of farmed finfish (not including tuna) in the Mediterranean Sea in 2006 is only slightly more than the United Nations Food and Agriculture Organization reports. The results demonstrate the reliability of recent FAO farmed fish production statistics for the Mediterranean as well as the promise of Google Earth to collect and ground truth data

Lymphocystis disease virus (LCDV) in aquatic environment

Lymphocystis disease virus is an iridovirus which has a global distribution. It is the etiological agent of Lymphocystis disease, which is a common viral disease affecting marine, brackish and freshwater fish species. It is a self-limiting disease which retards the expected breeding time, causing significant economic losses. The mortality rate is usually low but it increases in aquaculture species as it is related to both environmental and management stress factors. Nodular lesions consisting of lymphocysts are the main pathognomonic characteristic of LCD. It is a dermatropic disease with the skin and fins being the primary target organs. However, in heavily affected fish they may cover the entire body establishing a systemic infection. Real-time PCR has been proposed as the best validated technique to detect LCDV in symptomatic, asymptomatic infected or fish that have recovered and other potential reservoirs. Disease control is based on preventive husbandry practices, as no effective treatments or commercially available vaccines currently exist. As the virus is horizontally and vertically transmitted, selection of LCDV-free fish, fish screening, removal of affected animals and other potential reservoirs, quarantine and disinfection rely on the basic principles of biosecurity. Cooperation between related scientists will develop general strategies, in order to come through viral disease prevention and control while vaccination as a specific prophylactic measure would be the key to LCD elimination. © 2019 Elsevier B.V. All rights reserved

Efficacy and toxicity of orally administrated anti-coccidial drug treatment on Enteromyxum leei infections in sharpsnout seabream (Diplodus puntazzo C.)

Three drugs effective against myxosporeans and commonly used to treat spore-forming para- sites were tested in sharpsnout sea bream (Diplodus puntazzo) infected by Enteromyxum leei. Two medicated diets were applied, one containing salinomycin and amprolium and the second containing fumagillin. Compared to untreated fish, both treatments resulted in significant reduc- tions in prevalence, intensity of all developmental myxosporean stages, and mortality. The effect was more prominent with the salinomycin and amprolium combination, where the significant reductions in intensity, prevalence, and mortality were unaccompanied by any histopathological evidence of toxic side effects or growth reduction. Sporoblasts and mature spores with distorted structures were observed in both drug treatments, but were more prevalent in the salinomycin and amprolium treatment than in the fumagillin treatment, indicating direct effectiveness on the parasite. Salinomycin with amprolium is a promising treatment for myxosporean infections in intensively cultured warmwater fish, leading to parasite elimination

The Effect of Seasonality on the Health and Growth of a Newly Recorded Myxobolus Species Infecting Cultured Sharp Snout Seabream (Diplodus puntazzo C.)

The prevalence, intensity, and pathology of a Myxobolus sp. affecting the kidneys of cultured Diplodus puntazzo C. during the period 2003-2005 are described. The study included data collected from the largest farm in southern Greece where a high rate of mortality due to myxosporean infection occurred. Sharp snout seabream reared in sea cages in southern Greece underwent microbiological, parasitological, and histological examinations, while measurement and identification of parasites was performed immediately after sampling. Samplings were made daily from winter 2003 to autumn 2005. Prevalence was estimated for each season (autumn, winter, spring, and summer) each year (2003, 2004, and 2005). The Myxobolus sp. was detected in high numbers and with a high prevalence of infection in the renal interstitial tissue, especially during the summer months. The growth rate of infected D. puntazzo was very slow during the study period in comparison to cultured Sparus aurata L. and uninfected D. puntazzo

Cryptosporidium in fish: Implications for aquaculture and beyond

Aquaculture industries are expanding worldwide and control of Cryptosporidium is of great importance. Cryptosporidiosis is a serious waterborne/foodborne disease, responsible for infectious outbreaks globally. Current knowledge on the Cryptosporidium species in the aquatic environment and their occurrence in piscine hosts is steadily increasing since the Cryptosporidium species have been detected in marine, freshwater, cultured, captive and ornamental fish in a wide range of geographical regions. The zoonotic potential of these parasites and their pathological impact on piscine hosts have been increasingly reported and the fishborne zoonotic risk from Cryptosporidium spp. is of major importance from a public health point of view. Zoonotic subtypes in fish have been described in various studies and are probably related to water contamination from animal and human wastes. This review critically evaluated existing scientific data, related to Cryptosporidium species in piscine hosts, emphasizing transmission routes and the potential impact of piscine cryptosporidiosis in aquaculture. This knowledge will facilitate consumers, authorities and water industries such as fisheries and aquaculture, the prevention and control of waterborne and fishborne cryptosporidiosis in fish products