Japan chub
Description on Japanese chub mackerel fisheries with emphasis on those seasonality and fishing grounds
This document provided the decadal monthly catch from Japanese chub mackerel fisheries and the pictures of fishing grounds. The monthly catch showed a periodic change annually over recent decade, which started to increase after July to October, when it touched bottom annually, reached summit in the 3rd quarter to the 4th quarter of the following year and finally dropped to the bottom. The fishing year reflecting this seasonal change of catch has been applied in the Japanese domestic stock judgment. It was recommended that the introduction of fishing year should be considered in development of the NPFC stock assessment of chub mackerel according to seasonal variation of collect and biological background of target species.
JAPAN
by T. Nakayama
Introduction
Do you realize kawamutsu? It is seen in narrow waterways , a lot of rivers. In early summer, we watch the fish modify color.
Taxonomy
Its scientific name is Nipponcypris temminckil. It is a member ofCypriniformes（called “koi” in japan). It is called Dark chub in English.
Range & Ecology
Kawamutsu is major river fish in Japan. Its size is cm and is found in many rivers. It lives in West Japan and East Japan. During breeding season, Kawamutsu’s body alter breeding color. Male kawamutsu change into red tint, in body, shallow moisture eat aquatic insects, crustacean, small fish, and algea. Kawamutsu is omnivorous.
Use & Conservation
Kawamutsu called one of species “Haya” staple Ugui, and Oikawa . “Haya” origin Japanese word “Hayai” In Japan, people ingest “Kanroni”,”Karaage” and so on.
Where to see in Kochi
Kawamutsu is seen a lot of river and constricted waterways. So we can watch near Kochi the recent Golden Week holiday, I went to Yusuhara town. Yusuhara town acquire river source of Shimanto river. It very stunning. It is important to
Scientific name
Scomber japonicus
Production method
Wild-caught Purse seinesIUCN status
Least affectStock status
Japan’s chub mackerel is managed as two separate stocks: the Pacific group and Tsushima Current. The status of the Tsushima Current stock is considered uncertain.
Ecological effects
Purse seines acquire minor impact on endangered, threatened, protected (ETP) bycatch. Bycatch is assumed to be minor when targeting schools of small pelagic. Chub mackerel is an important food root for hammerhead sharks and as such plays an vital role in the food chain. However, fishery pressures carry out not negatively impact the ecosystem. Purse seine is not causing destructive impacts to seabeds, reefs and benthic communities.
Management
Japanese fisheries are managed under the Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF) and the Fisheries Agency. The overall management is partly effective. Vessels are required to use the Vessel Monitoring System to combat illegal, unreported and unregulated (IUU) fishery.
Image ©NRF-SAIAB. For
Catch, weight, and maturity at age of the chub mackerel of Japan
Stock assessment of chub mackerel in the Northwest Pacific has long been conducted by tuned virtual population analysis (VPA) in Japan. For nearly half a century, the length and age data of chub mackerel are collected based on the hold from the Pacific coast of Japan. Catch data are unhurried by month, prefecture, and gear type. Measurement of length information is obtained from the major landing port and roughly individual length data are obtained annually. Length data are sorted and reported by month, prefecture, location, and gear type. Length frequency of the catch data is expanded from the length measurement data and developed by month, prefecture, and gear type basis. Age data are obtained from the subsample of mackerels which fork length are measured and annulus of scale or annual increments of otolith are counted. The age data are subdivided into the northeastern and southwestern part of Pacific coastal prefectures of Japan to construct age-length key using “forward age-length key” method. Age-length key is app
Catch, weight, and maturity at age of the chub mackerel of Japan
Stock assessment of chub mackerel in the Northwest Pacific has long been conducted by tuned virtual population analysis (VPA) in Japan. For nearly half a century, the length and age data of chub mackerel are collected based on the hold from the Pacific coast of Japan. Catch data are unhurried by month, prefecture, and gear type. Measurement of length information is obtained from the major landing port and roughly individual length data are obtained annually. Length data are sorted and reported by month, prefecture, location, and gear type. Length frequency of the catch data is expanded from the length measurement data and developed by month, prefecture, and gear type basis. Age data are obtained from the subsample of mackerels which fork length are measured and annulus of scale or annual increments of otolith are counted. The age data are subdivided into the northeastern and southwestern part of Pacific coastal prefectures of Japan to construct age-length key using “forward age-length key” method. Age-length key is app