Search results for "aquaculture."

2019

Hosts are typically infected with multiple strains or genotypes of one or several parasite species. These infections can take place simultaneously, but also at different times, i.e. sequentially, when one of the parasites establishes first. Sequential parasite dynamics are common in nature, but also in intensive farming units such as aquaculture. However, knowledge of effects of previous exposures on virulence of current infections in intensive farming is very limited. This is critical as consecutive epidemics and infection history of a host could underlie failures in management practices and medical intervention of diseases. Here, we explored effects of timing of multiple infections on vir…

Infectivity of trematode eye flukes in farmed salmonid fish — Effects of parasite and host origins

2009

Abstract Parasites cause significant economic losses in fish farming, and knowledge of the mechanisms underlying their effects on hosts is an essential prerequisite of preventative procedures for the parasite problem in hatcheries. One such mechanism is local adaptation of parasites, which should lead to higher infectivity of parasites in sympatric host–parasite combinations compared to corresponding allopatric combinations. In this study, we investigated the infectivity of two ubiquitous species of trematode eye flukes, Diplostomum sp. and Tylodelphus clavata, in their farmed salmonid fish hosts with respect to origin of the parasite and the host. First, we exposed two anadromous and one l…

First estimates of metabolic rate in Atlantic bluefin tuna larvae.

2020

Atlantic bluefin tuna is an iconic scombrid species with a high commercial and ecological value. Despite their importance, many physiological aspects, especially during the larval stages, are still unknown. Metabolic rates are one of the understudied aspects in scombrid larvae, likely due to challenges associated to larval handling before and during respirometry trials. Gaining reliable estimates of metabolic rates is essential to understand how larvae balance their high growth needs and activity and other physiological functions, which can be very useful for fisheries ecology and aquaculture. This is the first study to (a) estimate the relationship between routine metabolic rate (RMR) and …

Effect of methylparaben in Artemia franciscana.

2017

In this study, the toxicity of methylparaben (MeP) an emerging contaminant, was analysed in the sexual species Artemia franciscana, due to its presence in coastal areas and marine saltworks in the Mediterranean region. The acute toxicity (24 h-LC50) of MeP in nauplii was tested and its chronic effect (9 days) evaluated by measuring survival and growth under two sublethal concentrations (0.0085 and 0.017 mg/L). Also, the effect on several key enzymes involved in: antioxidant defences (catalase (CAT) and gluthathion-S-transferase (GST)), neural activity (cholinesterase (ChE)) and xenobiotic biotransformation (carboxylesterase (CbE), was assessed after 48 h under sublethal exposure. The result…

Mussel Farming and Its Potential in the Baltic Sea

2017

Abstract The paper covers research findings on mussel farming and the analysis of current situation in mussel farming in the Baltic Sea. The mussel farming has a development potential in the Baltic Sea region. Some developers have chosen progressive activities to achieve the aim. For example, in Sweden the development of mussel farming is suggested as one of the instruments for reducing eutrophication. Several countries in the Baltic Sea region are in the beginning phase of the mariculture development. The following research methods were used in the research: studies of scientific publications, case studies and document studies on some important factors impeding the development of mussel fa…

A financial feasibility study of an aquaponic system in a Mediterranean urban context

2019

Abstract Aquaponics is largely recognized as a solution for sustainable food production as it follows a biomimetic natural system and the circular economy principles, allowing large food productivity on nonagricultural land, and at the same time strongly reducing inputs and waste. In this study, we collected technical, economic and production data from a pilot aquaponic plant producing lettuce (Lactuca sativa) and Nile tilapia (Oreochromis niloticus) realized in an urban context in Sicily (Southern Italy), very suitable area for aquaponic production in relation to the Mediterranean climate. Through the determination of Net return and Break Even Point, analysing on one side the items which c…

Surgical implantation of electronic tags does not induce medium-term effect: insights from growth and stress physiological profile in two marine fish…

2020

Abstract Background Telemetry applied to aquatic organisms has recently developed greatly. Physiological sensors have been increasingly used as tools for fish welfare monitoring. However, for the technology to be used as a reliable welfare indicator, it is important that the tagging procedure does not disrupt fish physiology, behaviour and performance. In this communication, we share our medium-term data on stress physiological profile and growth performance after surgical tag implantation in two important marine fish species for European aquaculture, the sea bream (Sparus aurata) and the European sea bass (Dicentrarchus labrax). Results Blood samples after surgical tag implantation (46 day…

Incidental catch of loggerhead sea turtles (Caretta caretta) along the Sicilian coasts by longline fishery

2018

It has been estimated that 44,000 Caretta caretta turtles die every year due to anthropomorphic activity in the Mediterranean Sea, and that longline fishing is one of the most significant causes of mortality. A total of 482 specimens of C. caretta were rescued from different parts of the Sicilian coast (Mediterranean Sea) from 2014 to 2016. The most numerous stranding was recorded during the spring and summer seasons, mainly along the north and eastern coasts of Sicily. The curved carapace length for all the specimens ranged from between 19 and 95 cm and most of these were young or sub adults. The highest number of strandings was recorded in 2014 and 2015, with 206 and 169 individuals, resp…

Introduced alien signal crayfish (Pacifastacus leniusculus) in Finland : uncontrollable expansion despite numerous crayfisheries strategies

2018

In Finland, massive signal crayfish introductions started towards the end of 1980s, with an estimated total of 2.2 million signal crayfish been stocked before year 2016. During that period, Finnish fisheries authorities have implemented three national management strategies setting guidelines for the crayfish introductions. The main aims of the strategies have been conservation of native noble crayfish stocks and a controlled spreading of the alien signal crayfish within a designated region. In this study, we report the current distribution of signal crayfish in Finland in comparison to the guidelines set in these three national strategies. The present distribution area of the signal crayfis…

Sex- and size-selective harvesting of corkwing wrasse (Symphodus melops)—a cleaner fish used in salmonid aquaculture

2016

Fishery-induced changes in sex ratios can have negative effects on reproductive rates and affect sexual selection and evolutionary trajectories. Here, we investigate sex- and size-selectivity of the fishery for corkwing wrasse (Symphodus melops) in Western Norway. The males that build and guard nests (nesting males) grow faster than females and sneaker males. Corkwing wrasse were tagged (n = 1057) during (May–June) and after (July) the spawning period in 2014 within a no-take site and in a nearby site open for fishing. We monitored the fishery within and nearby the tagging sites from June to October and sampled recaptures on all commercial fishing trips. Fishing mortality was higher for nes…