The catch performance of a traditional Ligurian boat seine, which is not in line with the European Union regulation, was compared with an experimental surrounding net without the purse line as a potential legal alternative. The relative catch performance between the two gear types was assessed using a new catch comparison method requiring neither paired data collection nor equal number of hauls with ...

The assumption of a proportional relationship between catch-per-unit-effort (CPUE) and the abundance of sharks caught by pelagic longliners is tenuous when based on fisher logbooks that report only retained specimens. Nevertheless, commercial logbooks and landings statistics are often the only data available for stock status assessments. Logbook data collected from local and foreign pelagic longline ...

A stage structured fishery model with three stages; recruits, immature fish and mature fish is formulated and utilized to analyse maximum sustainable yield (MSY) and optimal harvesting composition in a fishery with two heterogeneous fleets. The stage structured model developed bundles the age classes found in age structured models into stage classes based on their level of maturity, but also the ...

Gear selectivity and discards are important issues related to fisheries management but separately modelled. This work examines for the first time the overall size-selection pattern on the total amount of individuals of a species entering the trawl codend. An innovative approach was used based on modelling the escapement through the codend in the sea and the subsequently selection process by the ...

The dense aggregations of Northeast Atlantic cod (Gadus morhua) in the Barents Sea have led to a new fishing practice termed “buffer towing.” In this fishery, many trawlers redeploy the trawl directly after taking the catch onboard in an attempt to secure a continuous supply of fish and avoid any unnecessary stops during processing. If the approximate desired amount of fish is caught or exceeded ...

Gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate (PBSAT) were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon (PA) nets. The relative catch efficiency between the two gillnet 15 types was evaluated over the entire winter fishing season for cod (<i>Gadus morhua</i>) in northern Norway. The ...

Vertebral coalescence and malformation in the lateral line are reported in a specimen of cultured cyprinid fish <i>Hypophthalamichthys nobilis </i>. Severe vertebral fusion was observed and described. Lateral line showed unusual undulation in the trunk region. Genetic and epigenetic causes may be implicated in these anomalies.

Fishing trials were carried out to compare the relative fishing efficiency of gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate, PBSAT) with conventional (nylon) nets. The fishing trials covered two consecutive fishing seasons (2016 and 2017) for cod (<i>Gadus morhua</i>) and saithe (<i>Pollachius virens</i>) in northern Norway. Results generally showed ...

Estimation of the opportunity cost is necessary for the economic assessment of environmental conservation policies. This paper considers the case where an environmental good is negatively affected in the process of the production of marketable goods. In the presence of externalities, conservation implies the undertaking of abatement measures by polluters. A relevant measure of opportunity cost in ...