摘要:計畫目標:
本計畫之目標是探討魩鱙漁業之資源量、漁獲努力量及漁獲量之時間(年及季)及空
間(漁場)之變化;另外亦鑑定漁獲物之物種組成,探討目標魚種和混獲物種之利用
狀態。 魩及鱙魚為臺灣經濟海域之鯷及鯡科小體型魚類之集合名詞,魩為仔魚,鱙
為稚魚,均為重要的經濟魚類資源。魩鱙漁業是臺灣和日本沿岸漁業的特色之一。
魩及鱙魚也是沿岸海洋生態系中之構成及功能性要員,其族群量之大小悠關生態系
之棲位多寡,進而影響生態系之產能及穩定,也悠關上層漁業,如鯖、鯵漁業之資
源波動。魩仔漁業所捕獲之魚種約等於傳統底拖網漁業之數目,但其生質量及數量
組成則不同。魩仔漁業之主要漁獲組成為鯷及鯡科之表層洄游魚,而非鯷及非鯡科
之仔魚則通稱為混獲魚種。除非在鯷科魚種孵化之頂峰時期(不超過兩週),均有數
十至百餘種具經濟價值之魚種混同罹網,成為混獲魚種。魩仔魚共有八個主要魚種
(以日漁獲量計,一度超過5%),其前三位為異葉公鯷、刺公鯷及日本鯷。
架構:
為有效管理該漁業,中央政府於1999年盼地方政府依會議結論,辦理開放漁業之公
告,並加強管理;嗣後並決定2001年5月底為縣政府公告開放之截止日。縣政府在規
範中明訂所轄漁區之漁船數、容許總漁獲量及禁漁期(06/01~08/31 - 花蓮、宜蘭、
臺北及基隆,06/16~09/15 - 桃園、新竹、臺中、高雄及屏東)等限制條件。同時訂
定本項漁業之開放為期五年,此期間迭有全面禁止之呼籲。2002年時,中央政府擬
於2005年底各縣政府核准之執照屆滿時,即於稍後之2006年1月1日全面禁止魩鱙漁
業。嗣後,慮及漁民生計,延緩全面禁漁之議,加註之作業許可遂延長至2008年
12月31日。為減輕漁民生計上之衝擊,2009年之政策轉為有效管理之輔導性措施。
因此,本計畫之重要工作為調查、掌握在各漁場活動之相關縣市之努力量容量及實
際漁業規模大小(漁獲量及漁獲努力量)。
預期效益:
為方便有效管理之施行,產銷班之建立及總許可漁獲量(TAC)之制定為重要關鍵,本
計畫擬對東北及西南漁場進行TAC之估算,做為產銷班作業自律之機制。本年計畫擬
基於過去對東北及西南漁場所做出結果加以檢討,並促資源管理臻合理及有效。計
畫執行後之效益為:估得管理所需之參數,分別為漁獲努力容量(capacity)、漁獲
努力量、漁獲量、魚種組成及體長頻度分布等,其成果則以混獲率、總容許漁獲量
及最適漁業規模呈現。
Abstract: Objectives:
The objectives of this project are to get the latest information to
assist fisheries management, including (1) to estimate the stock size of
major species, (2) to explore the fishing effort and catches, and (3) to
quantify their temporal and spatial variations.
Larval anchovy is an important resource for coastal artisan fishery in
Taiwan, although harvesting fish at early stages may impose crucial
impact on fragile resource, and cause conservation concerns.The fisheries
that catch larval anchovy are called "Bua fishery" in Taiwan, and they
utilize specialized fishing types fit to various coastal geo-morph. The
Bua catches are appreciated with high prices, resulted in very
complicated cases governmental regulations. From different perspectives,
both larval and adult anchovies are important mid-way component in
coastal marine ecosystem, where they function as bio-energy converter
between plankton and higher trophic levels. The fluctuation of anchovy
population influences not only the amount of fisheries catches, but also
the stability of coastal ecosystem. Previous studies have shown that the
mechanism for the formation of apt fishing sites may relate to global
meteorological events, such as ENSO and typhoon. The species richness of
Bua catches resembles that of traditional bottom trawls, but with
different percentage of species composition in biomass. The Bua catch is
primarily composed of engraulia and clupeid fishes, however tens to
hundred “non-Bua” species are also caught, among which some are of
economic importance. Major Bua fishes, accounted by more than 5% in any
single day, are identified to 8 species. The top 3 species, i.e.,
Encrasicholina heteroloba ,Encr. punctifer, and Engraulis japonicus, are
composed about 90% of total catches.
Frameworks:
Fish compositions in two major fishing seasons of spring and autumn are
comprehensively documented, however, population size of major species is
dynamic. For effectively regulating the fishing activity at a suitable
level, county governments set the limits of vessel number, total
allowable catches and no-catch period for their fishermen. In the
meanwhile, the licensing time was set to a period of 5 years. Phasing-out
of the Bua fishery was also announced that was effective on January 1,
2006 at first. However, for the sake of mitigating difficult position in
local economy, deferring was put forward to extend the licensing period
until December 31, 2008. In 2009, effective regulation of the fisheries
was established to replace the then phasing-out hoping to reduce socioeconomic
impact. To facilitate effective regulation, the major tasks of
this project are set to assess potential fishing capacity, and realized
fishing effort and catches.
Expected benefits:
This project will work on three major fishing grounds: the northeast,
northwest and southwest in sequences. In the end, this project will get
following parameters: fishing capacity, fishing effort, catches, catch
compositions, and length frequencies. These parameters will be analyzed
to conclude the by-catch rate, total allowable catch, and optimal size of
the fisheries.