Tracking the southern Brazilian schools of Mugil liza during reproductive migration using VMS of purse seiners
Autor: | Valéria M. Lemos, Débora Fernanda Avila Troca, Jorge Pablo Castello, João Paes Vieira |
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Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
geography geography.geographical_feature_category biology Mugil 010604 marine biology & hydrobiology PREPS Fishing Estuary Shoaling and schooling southern Brazil Aquatic Science spawning temperature Oceanography biology.organism_classification 010603 evolutionary biology 01 natural sciences Spawn (biology) Mullet Fishery mullets Vessel tracking Vessel Monitoring System (VMS) |
Zdroj: | Latin american journal of aquatic research v.44 n.2 2016 SciELO Chile CONICYT Chile instacron:CONICYT |
ISSN: | 0718-560X |
Popis: | Brazilian mullet Mugil liza is a schooling fish that migrates in fall and winter, leaving estuaries and coastal lagoons to spawn in ocean waters. In order to understand the reproductive migration pattern of southern stock along Brazil's coast, we analyzed data collected through the Brazilian Satellite Vessel Tracking Program (Programa Nacional de Rastreamento das Embarcações Pesqueiras por Satélite-PREPS) from 2008 to 2012. The migration period overlaps with the fishing season (May-July) when the licensed purse seine fleet fishes along the southern and southeastern coast of Brazil, motivated to capture mullet by the high value of the roe. During the five fishing seasons the average effort was of 51 active vessels. The average time per season that each vessel navigated in the Speed Compatible with Fishing Operation (SCFO) was 349.3 h, which represented an average of 17% of the total time at sea. From May to July the highest frequency (54%) of SCFO transmissions occurred in June (P < 0.05), and in 95% of the SCFO transmissions the vessels were at depths less than 50 m. The temporal and spatial displacement of the fleet in a south-north direction follows the progression of sea surface temperature SST of 19-21°C (P < 0.05). Most (60%) SCFO signals occurred in areas with this range of temperature, independent of the month and latitude. The south-north displacement of the fleets through the season was similar among the different years (P > 0.05). |
Databáze: | OpenAIRE |
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