Environmental influence on the inter-annual demographic variation of the narrownose smooth-hound shark (Mustelus schmitti, Springer 1939) in the Northern Argentine Coastal System (El Rincón, 38–42°S)

CAMIOLO, MARTINA DANIELA; JAUREGUIZAR, ANDRÉS JAVIER; DE WYSIECKI, AGUSTÍN MARÍA

MARINE BIOLOGY RESEARCH

TAYLOR & FRANCIS AS

Año: 2020 vol. 16 p. 600 - 615

1745-1000

Understanding the environmental influence on the demographic structure of a shark population within a specific ecosystem has direct implications for developing effective management and conservation measures. We studied the physical environment influence on the inter-annual demographic variation of the narrownose smooth-hound shark (Mustelus schmitti) in a key coastal ecosystem. The analyses were based on the size assemblage concept of co-occurring length classes that share common traits. We used bottom-trawl datasets (n = 334) collected over 8 spring periods (1994-2012). The analyses indicated that the population was structured in eight size assemblages that represented its main ontogenetic levels. Those corresponding to sub-adult females, young adult males, and juveniles contributed to most of the population similarity. The population structure presented high (>57.7%) inter-annual dissimilarities and showed three main similarity levels with significant differences associated with a higher abundance and similarity contribution of the main assemblages. All size assemblages were more abundant in shallow (14.9 °C), and fresher (