A5102787148- Marine and fisheries research
- Fish Ecology and Management Studies
- Marine Bivalve and Aquaculture Studies
- Genetic and phenotypic traits in livestock
- Aquaculture Nutrition and Growth
- Coral and Marine Ecosystems Studies
- Food Industry and Aquatic Biology
Johann Heinrich von Thünen-Institut
2020-2023
There is a need to improve fishing methods select for certain sizes and species while excluding others. Experiments are conducted quantify selectivity of gears how variables such as gear design (e.g., mesh size, shape), environmental parameters light, turbidity, substrate) or biological fish condition) alter selectivity; the resulting data be analyzed using specialized statistical in many cases. Here, we present new tool analyzing this type data: an R package named “selfisher”. It allows...
Diamond-mesh codends are the most commonly used in demersal trawls. However, mesh geometry tends to vary these during fishing, which leads a less well-defined size selection process. This leaves one questioning rationality of regulating exploitation patterns based on when and (or) variation between hauls is highly variable. While it has been speculated theoretically investigated how much variability may contribute selection, remained be quantified experimentally. Therefore, we conducted...
Abstract This article describes a method for the quantitative analysis of fish behaviour relative to selection devices in trawl gears. Based on video observations, estimates probabilities given event happen and establishes behavioural tree diagrams representing quantifying patterns relation device under assessment. Double bootstrapping is used account uncertainty originating from limited number observations natural variation behaviour. The here supplement standard catch data performance...
The brown shrimp (Crangon crangon) fishery is of great socio-economic importance to coastal communities on the North Sea. exploited by beam trawlers often using codends with very small mesh sizes, leading concerns about catch rates undersized shrimp. However, little information available codend size selection, making it difficult provide scientifically based advice alternative designs. Therefore, this study establishes a predictive framework for selection shrimp, large selectivity dataset...
Trawl codends are commonly made of diamond-mesh netting. However, vary in mesh geometry along its length and during fishing due to catch build up. This introduces variability the size selection process. phenomenon compromises rationality regulating exploitation patterns trawl fisheries through adjustments codend size. One technical solution often applied achieve more well-defined is turning netting 45 degrees (square-mesh). there a lack evidence that square-mesh result constant selectivity....
Abstract Fishing gear is constantly being improved to select certain sizes and species while excluding others. Experiments are conducted quantify the selectivity resulting data needs be analyzed using specialized statistical methods in many cases. Here, we present a new estimation tool for analyzing this type of data: an R package named selfisher . It can used both active passive gears, handle different trial designs. allows fitting models containing multiple fixed effects (e.g. length,...
Abstract Fish pots have lower catch efficiency than gillnets and trawls and, therefore, are rarely used for catching Atlantic cod (Gadus morhua) similar species. Fish-retention devices (FRDs), non-return that permit fish to enter the pot while impeding exit, reduce exit rate therefore can increase catches. Conventional FRDs, however, also entry may not improve To pot-catch efficiency, we developed tested a new trigger-type FRD, made of transparent acrylic glass, which named fingers (AFs)....