e-journal

Effect of spatial differences in growth on distribution of seasonally co-occurring herring Clupea harengus stocks

---

The mechanisms most likely to determine the distribution of the two major herring Clupea harengus stocks in their common early summer feeding ground in the eastern North Sea, Skagerrak and Kattegat were investigated through analysis of acoustic survey data from six consecutive years. No change was detected in biomass of North Sea autumn spawning C. harengus (NSAS) over time, whereas the biomass of western Baltic spring spawning C. harengus (WBSS) declined severely. Analyses of centre of abundance by stock showed no change in NSAS distribution, whereas the WBSS changed to a more western distribution over time. Contrary to previous perception of the juvenile migration, NSAS were found to leave the study area at the age between 1 and 2 years and WBSS 1 year olds were encountered in the Skagerrak. The estimated parameters of von Bertalanffy growth equations showed marked differences between areas with fish in the eastern part of the area having the lowest size at age at all ages. Further, their growth conditions appeared to deteriorate progressively over the period studied. Both NSAS and WBSS showed the highest condition in the North Sea and Skagerrak while condition was substantially lower in age Kattegat. The westward movement of spring spawners over time suggests that growth rate and possibly density of conspecifics influence the migration pattern and distribution of C. harengus in the area. In contrast, there was no evidence to suggest that distribution was constant over time within stocks or that distribution reflected size-dependent limitations on migration distance.

Key words: acoustic surveys; condition; migration; Skagerrak; stock identity.

---

Ketersediaan

Tidak ada salinan data

Informasi Detail

Judul Seri

Journal of Fish Biology

No. Panggil

-

Penerbit

Denmark : The Fisheries Society of the British Isles., 2014

Deskripsi Fisik

Journal of Fish Biology 2015

Bahasa

English

ISBN/ISSN

doi:10.1111/jfb.1257

Klasifikasi

-

Tipe Isi

-

Tipe Media

-

Tipe Pembawa

-

Edisi

(2015) 86, 228–247

Subjek

PERIKANAN

Info Detail Spesifik

-

Pernyataan Tanggungjawab

Mutia/Agus

Versi lain/terkait

Lampiran Berkas

Komentar

---

Anda harus masuk sebelum memberikan komentar