Effect of Water Level Fluctuations on Fishery and Anglers’ Catch Data of Economically Utilised Fish Species of Lake Balaton Between 1901 - 2011

Abstract

Weiperth et al.: Effect of water level fluctuations on fishery and anglers' catch data of economically utilised fish species of Lake Abstract. Surveys aiming at analysing spatial and temporal changes of the fish stock of Lake Balaton have an almost 100 year history. Drastically low water levels which could be observed in the past years and which were most probably caused by global climate change provide a good reason to study population dynamic changes induced by water level fluctuations. The present study attempts to give a historical description of changes in the catch data of economically utilised fish species in relationship with water level fluctuations, based on catch data of the Balaton Fish Management Non-Profit Ltd.(predecessor: Lake Balaton Fishing Ltd.) and its predecessors, covering a 110-year period.

Management of pikeperch stocking in Lake Balaton: effect of season, area, fish size and method of release on the rate and distribution of recaptures

“…Because of its high rate of harvesting (Weiperth et al, 2014;Specziár and Erős, 2016), an early-life dietary bottleneck (Specziár, 2005(Specziár, , 2011 and high rate of predation and cannibalisms related juvenile mortality (Specziár, 2010), maintaining the pikeperch population requires regular stocking. Although commercial fishery, which harvested 2-237 (mean: 83) tons of pikeperch per year between 1901 and 2011 has been stopped in Lake Balaton since 2014, but anglers still put a heavy pressure on the population.…”

Source of bigheaded carp (Hypophthalmichthysspp.) in Lake Balaton, Hungary: natural recruitment or continuous escapement from aquaculture?

“…During the past decade 9-to14-year-old bigheaded carp dominated the fisheries catches, and it is unlikely that fish older than 32 years could be present in substantial numbers. Moreover, the average age of fish captured by size-selective gillnets have not changed considerably during the past decade, and fishery yields remained relatively high and constant (Weiperth et al 2014), implying a steady source of recruitment independent of the stockings in the 1970s and 1980s.…”

“…Bigheaded carp biomass remained high after 1983, however, and has not declined during the past decades despite the intensive and continuous size-selective fishery that lasted until 2013 (Weiperth et al 2014).…”

Aktivitas Penangkapan Dan Produksi Ikan Di Kabupaten Hulu Sungai Utara Kalimantan Selatan

“…Hal ini dapat diakibatkan beragamnya alat penangkapan ikan yang digunakan nelayan untuk menyesuaikan kondisi perairan. Menurut Weiperth et al (2014), bahwa hasil tangkapan di perairan daratan lebih dipengaruhi oleh adanya variasi alat penangkapan ikan yang ditujukkan agar tangkapan lebih selektif terhadap sepesies target. Hasil tangkapan tangkap tidak terpengaruh secara signifikan terhadap fluktuasi tinggi muka air, dikarenakan beragamnya alat penangkapan ikan yang dimiliki nelayan dan penggunaan secara bergantian sesuai dengan kondisi lingkungan yang diinginkan.…”