Life‐history traits and population decline of the Atlantic mackerel Scomber scombrusin the Adriatic Sea

Abstract

This study investigated demographic structure and reproductive characteristics of the Atlantic mackerel Scomber scombrus, in relation to landing trends in the northern-central Adriatic Sea. Results highlighted the occurrence of only small-sized and young-age individuals, and a marked decline from the 1990s to the present in maximum age (from 8 to 3 years) and total length (L(T); from 420 to 360 mm). Fecundity ranged between 40,000 and 190,000 eggs, and was related to female L(T). High levels of atresia implied lower values of actual fecundity. Sexual maturity was attained by 72·8% of individuals in their first year of life at 200 mm. The reduction in maximum L(T) resulted in a marked decline in the population egg production, while the reduction in maximum age implied that females participated in fewer spawning events.

Reproductive biology of the Atlantic mackerel Scomber scombrus Linnaeus, 1758 in Mediterranean coast of Sinai, Egypt.

“…In the present study, the fecundity of Atlantic mackerel S. scombrus ranged from 54600 to 229500 eggs in fishes sized between 22.0 -30.2 cm. These results nearly agree with the results obtained by Meneghesso et al, (2013), since fecundity ranged between 40 000 and 190 000 eggs. The fecundity (F) of S. scombrus in the North sea range from 130,000 to 1,100,000 eggs in fishes between 28.5-46.0 cm Total length (TL) (Macer,1976) , in northwest Atlantic from 285,000 to 1,980,000 eggs for fish between 307 and 438 mm FL ( Morse,1980 ).…”

“…In the present study, Gonado-Somatic Index (GSI) of Atlantic mackerel S. scombrus in the Mediterranean coast of Sinai ranged from 0.05 to 7.2 in females and from 0.06 to 5.2 in males of. These results lower than that obtained by Meneghesso et al, (2013) in northern-central Adriatic Sea, since GSI ranged from 0.01 to 9.20 in females and from < 0.01 to 8.58 in males.…”

Analysis of Long-Term Changes in a Mediterranean Marine Ecosystem Based on Fishery Landings

“…In the mid-1950s medium pelagic species reached a maximum in landings (1449 kg in 1956), and dramatically declined afterwards. Medium pelagics (mainly the Atlantic mackerel Scomber scombrus) represent an important group of species for the local fish market, whose decline is hardly a consequence of changes in market demand (Meneghesso et al, 2013). Thus, it can be assumed quite conservatively that the decline in catches for medium pelagics reflects a dramatic decline of populations at sea.…”

Habitat Suitability Modeling to Identify the Potential Nursery Grounds of the Atlantic Mackerel and Its Relation to Oceanographic Conditions in the Mediterranean Sea

“…Genetic analysis has revealed a single panmictic population in the northerncentral Adriatic Sea, distinct from the population of the southern Adriatic Sea (Papetti et al, 2013). Moreover, midwater trawl landings decreased and the age structure appears shrinked in the north central Adriatic Sea, which might translate a population decline (Meneghesso et al, 2013). However, our knowledge on the status of Atlantic mackerel Mediterranean stocks is totally absent (no stock assessment of mackerel available in GFCM Stock Assessment Working Groups) and info on the species biology in the Mediterranean is very limited.…”

“…In the Mediterranean, our knowledge on Atlantic mackerel spawning mainly comes from the Adriatic Sea. Atlantic mackerel is reported to spawn from October to April in the eastern part of the Adriatic Sea (Sinovčić, 2001) and from December to April in the western part of the Adriatic Sea (Bottari et al, 2004;Tsikliras et al, 2010;Meneghesso et al, 2013) with a probable peak in January (Gamulin and Hure, 1983;Sinovčić, 2001;Bottari et al, 2004;Meneghesso et al, 2013). As there are no dedicated surveys for this species in the Mediterranean, our knowledge on the distribution grounds, the spawning and nursery habitat of the species mainly relies on past studies of certain areas in the western and central part of the basin.…”