Population dynamics, distribution and secondary production of the brown shrimp Crangon crangon (L.) in a southern European estuary. Latitudinal variations

摘要: The population structure, growth, distribution and secondary production of the brown shrimp Crangon crangon (L. 1758) were examined between June 2003 August 2005 at five stations in Mondego Estuary, Portugal, using a 2-m beam trawl. Occurrence immature shrimps suggested almost continuous reproduction with two main recruitment periods November March/April; this pattern is unique represents latitudinal transition species’ life cycle. Severe drought winter 2004 caused spatial shifts along north arm estuary regarding post-larval settlement spring 2005. Mean growth all cohorts was 0.06 mm TL day -1 , much lower than rates calculated elsewhere. Secondary (P) C. estimated 4.6 mg AFDW m -2 y (P/B– ratio 8.7) 2003/2004 2.4 10.9) 2004/2005. High abundances individuals, predominantly juveniles, observed spring/summer peaks 2003, April July This study shows that species dynamics must be analysed context, meaning contribution each component systems can vary according to environmental climate variables.