Search results for "Fishing"

Sztuczna mucha i czysta gra. Wędkarstwo jako dystynktywna praktyka kulturowa

2019

Artykuł jest próbą przedstawienia wędkarstwa jako praktyki kulturowej o społecznie – w zasadzie głównie klasowo – różnicującym potencjale. Szczególnie pod tym względem interesujący i znaczący jest przypadek tak zwanej sztucznej muchy – metody, która stanowi wysoce skodyfikowany kulturowo obszar społecznie dystynktywnych znaczeń i działań. Artykuł w głównej mierze odnosi się do faktów poświadczonych dla XIX wieku, kiedy to tworzyły się podstawowe reguły muszkarstwa, które bądź to w postaci zinstytucjonalizowanej, bądź poprzez nieformalne ramy kształtowały prawomocne praktyki sportowego łowienia ryb szlachetnych.

Marine food web perspective to fisheries-induced evolution

2021

Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life-histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the populational dynamics of a single species are well emphasised, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fishing-induced evolution, driven by size-selective fishing, might resonate throu…

Artificial Reefs in Sicily: An Overview

2000

Sicilian cave drawings from the Grotta del Genovese, Isle of Levanzo (west Sicily) ca. 12 000 B.C. show silhouettes of dolphins, tuna, groupers and bass which, together with remains offish (tuna, groupers, bass and others), limpets and oysters from Grotta dell Uzzo, north-western Sicily, indicate the importance of fish and shellfish in the diet of coastal populations of that time (Villari, 1992a, 1992b). Remains of turtles (Caretta caretta), tuna and sharks are evidence of fishing activity during this period (Villari, 1995).

Distribution and spatial structure of pelagic fish schools in relation to the nature of the seabed in the Sicily Channel (Central Mediterranean).

2009

Hydroacoustic data collected during two echosurveys carried out in the Sicily Channel in 1998 and 2002 were analysed to investigate the distribution and spatial structure of small pelagic fish species in relation to the sedimentological nature of the sea bottom. The study was carried out on two contiguous areas (labelled ZONE 1 and ZONE 2) of the continental shelf off the southern coast of Sicily, characterised by different dominant texture, ‘sand’ for ZONE 1 and ‘clayey-silt’ for ZONE 2. Simultaneous information on small pelagic fish schools and the seabed was obtained using a quantitative echo-sounder (SIMRAD EK500) that measures echoes due to the scattering from both fish schools and the…

Density Decline in a Mediterranean Seahorse Population: Natural Fluctuations or New Emerging Threats?

2021

Illegal wildlife trade is considered one of the most serious threats to biodiversity worldwide, along with habitat loss/degradation and overfishing of wild stocks. Seahorses are considered at high risk as these fish represent an important component of traditional Chinese medicine but are also sold as curios and ornamental fish. On a worldwide level, illegal trade is controlled by numerous laws and regulations, but it seems to continue by assuming more dynamic routes. In the Mediterranean Sea, Hippocampus guttulatus formed one of the largest populations at Mar Piccolo di Taranto in South-Eastern Italy. During the routine monitoring of this population in 2016, a dramatic density decrease was …

The dynamics of Italian competitive positioning in the Mediterranean Bluefin tuna industry

2020

The bluefin tuna or Thunnus thynnus is one of the widely recognised fish species since ancient times. Italy is the most important players in the international arena, however, the introduction of a system of total allowable catches and other measures established by the International Commission for the Conservation of Atlantic Tunas, has deeply changed the competitive positioning of Italy. The aim of this study is to perform an analysis of the comparative advantage of Italy by using the relative trade advantage index. Findings reveal that Italy has gained a competitive advantage in the Maltese market and has suffered a loss of the historical competitive advantage in the Japanese one. Results …

Impacts of anthropogenic factors on fish community structure in Lebialem-Mone Forest Landscape of Cameroon

2010

Two sites of the Cross River within the Lebialem-Mone forest landscape of Cameroon were chosen, one of the sites faced with human activities (test site) and the other with no human pressure (control site). The lengths and weights of fish obtained from both sites were analyzed in SPSS. Fish communities living within these 2 sites were compared after collecting fish from them using gill nets within 2 months of sampling (September-October 2009). Questionnaires were distributed to the fishers to respond to questions related to their fishing practices. Each fish from a sample of 240 fishes obtained from both sites was identified with its length and weight recorded. Fishing pressure constitutes t…

Multiple-batch spawning: a risk-spreading strategy disarmed by highly intensive size-selective fishing rate

2022

Can the advantage of risk-managing life-history strategies become a disadvantage under human-induced evolution? Organisms have adapted to the variability and uncertainty of environmental conditions with a vast diversity of life-history strategies. One such evolved strategy is multiple-batch spawning, a spawning strategy common to long-lived fishes that ‘hedge their bets' by distributing the risk to their offspring on a temporal and spatial scale. The fitness benefits of this spawning strategy increase with female body size, the very trait that size-selective fishing targets. By applying an empirically and theoretically motivated eco-evolutionary mechanistic model that was parameterized for …

Sustainability of interlocked fishing district -management concept for commercial fishing in Finnish lake fishery

2012

Empirical links between natural mortality and recovery in marine fishes

2017

Probability of species recovery is thought to be correlated with specific aspects of organismal life history, such as age at maturity and longevity, and how these affect rates of natural mortality ( M ) and maximum per capita population growth ( r max ). Despite strong theoretical underpinnings, these correlates have been based on predicted rather than realized population trajectories following threat mitigation. Here, we examine the level of empirical support for postulated links between a suite of life-history traits (related to maturity, age, size and growth) and recovery in marine fishes. Following threat mitigation (medium time since cessation of overfishing = 20 years), 71% of 55 tem…