| 中文摘要 |
我國之遠洋魷釣船隊約由100艘漁船組成。 船隊之目前(2013)之作業水域有三，規模依序為－－西南大西洋、西北太平洋(主要是秋刀魚) 及東南太平洋。 魷釣船隊(squid jigging fleet)利用之對象主要資源有四，分別為阿根廷魷(Illex argentinus)、赤魷(Ommastrephes batramii)或秋刀魚(Cololabis saira)，及美洲大赤魷(Dosidicus gigas)。 目前我國遠洋魷魚漁業之作業漁場，以西南大西洋(Southwest Atlantic, SWA) 及東南太平洋(Southeast Pacific, SEP) 漁場為主。 以近十年(2004~2013)的漁產量分析，遠洋魷魚之平均年產量為12.6萬公噸(最高為2007之29.9萬噸，最低2004之5.8萬噸)；其中西南大西洋漁場佔80.8 %，東南太平洋漁場產量約佔17.2 %。 本計畫總目標為對我國遠洋魷魚及秋刀魚漁業所使用的資源進行資源量動態分析，評估資源之現況，建議漁業管理之方針。 本研究所用之資料組為西南大西洋之漁獲記錄，由1994-2013，共二十年之資料。 此資料組有217,638筆作業記錄(8,702 records added)，資料之主要內容為作業時間(年、月及日)，作業地點(經度及緯度)，水溫，深度及分級漁獲箱數及重量等資料錄。 本報告對西南大西洋之阿根廷魷進行下列11項分析： 1. 魷漁業之目前狀況，2. 西南大西洋的魷漁業及阿根廷魷之年漁獲量變動趨勢，3. 本年漁獲量、努力量及漁獲率之空間分布，4. 年內漁獲量及漁獲率之時間分布，5. 年內月別漁獲量、努力量和漁獲率之空間分布，6. 漁獲努力量之標準化 (船間漁獲率差異)，7. 雙週別之CPUE空間分布，8. 雙週別之水溫空間分布，9. 評估各年之資源量，10. 體長頻度分布，及11. 政治水域劃分。 目前進度顯示，本(2013)年之總產量為123,403 t y-1，為去年98,126 t y-1 的126 %，漁獲情形較去年為佳。 此產量是1994年以來排序第十一的產量，恰位於中位數的位置。 本年之漁獲努力投入9,597 v-d y-1，十分接近去年的9,549 v-d y-1，距2007年峰值產量時的11,433 v-d y-1仍有一段距離(只有83.9 %)。 每船之到岸量(landing quantity)為1,209 t v-1 y-1，多於去年的 991 t v-1 y-1，約為去年的122 %，大部分的作業船成績可以平盤滿載。 西南大西洋之作業，其總產量之變化約有3-8年之上下波動(fluctuation)週期，2010年漁況位於波谷， 2011年反彈上來，今年更加強一些，達到115,644 t，產量為均衡值之75 %。 漁場利用情形有集中之傾向；大部分漁船作業均集中在200 m等深線之向陸一側，而很少走向中陸棚區。 在緯度方面也先集中在45 ~ 47 oS的中間漁場，漁期之中期才向福克蘭的經濟水域挺進。 潛在漁場約含蓋459個半度方格，本年漁場範圍較去年稍寬，增加11個方格(74)，行漁業活動僅及全漁場的16 %。 本年之漁獲量最高的方格發生區域在46.5 ~ 47.5oS之間及49 ~ 51oS ＆ 60.5 ~ 63oW間，由東北向西南角延伸，200m等深綫內側處。 大約是Falkland之北及西北之FICZ，這些位置的年漁獲量都有5,000 t以上。 月別漁獲量集中在三 ~ 五月，且此三個盛漁期之月別總產量相當一致，每月都有三萬噸的產出量。 此三個月的累計已達一萬噸。 月別之漁獲率則由二月逐漸向五月攀升，然後倏爾間於六月結束出漁之情況。 年內月別之空間分布顯示：一及二月之漁獲量僅出現在45 - 47oS之陸棚外棚坡處，惟以46oS左右之斜坡較多。 三月除留在46oS稍南附近漁況不錯而外，向正南延伸至FICZ的海域也有不錯的成績。 四月時，西南方之作業成績反超過FICZ之正北區域。 五月FICZ之西北方是漁獲量大量之重心。 六月Falkland附近已無出產，徒留44oS以北之零星漁獲。 本年共回收88艘船之漁獲資料。 本航次平均每船捕獲˙1,184 t v-1，各船間之差異為654 t之標準差，最小的漁獲量為166 t v-1，最高之漁獲量為3,119 t v-1，而船間有55.3 %之變異係數，顯示船間之差異頗大。 努力量標準化係數之差異大於去年。 漁獲努力量經標準化後，單船之產量(Y)大體上與標準漁獲努力量(X)成正相關之關係(Y = 9,588 X + 279,319)，同時，也顯示每日之估計漁獲率(C/X)與標準化後之努力量成不顯著之相關關係，亦即本年之努力量標準化之成效已達預定目標。 雙週別之CPUE空間分布圖顯示：本(2013)年之第一及第二個雙週，由漁船作業位置所反應的魚群出現位置與去年(2012)幾乎相同，但本年之CPUE相對較低，至少差了兩個豐度級數。 第三個雙週(F3)，魚群向正南延伸，但豐度沒有提高，不像去(2012)年時，魚群稍微向東南移動，而且維持高於均值級數的豐度。 第四個雙週(F4)更向南分布，但少有移向東南方的跡象，也沒有向陸棚洄游的傾向；CPUE值約同於去年，甚至較差。 第五~六個雙週時，與第四雙週差不多，第七個雙週(F7)時，CPUE均值向上提升，魚群之質量豐度上升，第八個雙週，CPUE值再提升，且分布之經度範圍擴大，而緯度範圍縮小；此高CPUE之情況維持至第九及十雙週，但範圍逐漸縮小，相較於去(2012)年，本年之情況相當不錯。 資源量之多寡受單位密度及漁場面積大小之影響。本(2013)年的漁獲量，在最近的十年內，與2011 ＆ 2012最接近，漁場範圍也一樣大。 以目前之漁場規模而言，2013年處於平均水準稍稍高的部位。 本年之CPUE不算太低，但MORAN’s I則與去(2012)年成雙，位於是最低，表示空間相關性不高，這表示本年之魚群成補丁狀(patch)，而不是堆狀或塊狀。 在第一 ~ 三雙週，所捕獲的魷魚體型偏小，第四個雙週起，出現體型在30 cm以上之魷魚，以同一個雙週來比較，則發現本年之體型較去年為小。 將西南大西洋的漁場，依政治管轄劃分發現：最主要的魷魚生產區為福克蘭過渡保育區，共生產阿84,390 t (73.0 %)，次為公海的17,190 t (14.9 %)。 |
| 英文摘要 |
Taiwanese distant-sea squid fleet is composed of ~100 vessels, which geared with jigging machine for squid and/or stick-held dip net for saury. Typically, the fishing sites are located in Southwest Atlantic (SWA), Northwest Pacific (NWP) and Southeast Pacific (SEP), catching Argentine flying squid (Illex argentinus), Neon flying squid (Ommastrephes batramii) or saury fish (Cololabis saira), and Jambo squid (Dosidicus gigas), respectively. For squid catching, SWA produced the highest amount in 2013, and followed by SEP. In the last decade (2004~2013), annual squid production is averaged 126 k t, with highest of 299 k t (2007), and lowest of 58 k t (2004); in which SWA counted to 80.8 % and SEP 17.2 %. This project includes three sub-items, working on fisheries targeted species to realize their population dynamics, to evaluate current stock size and to formulize feasible management plans. The sub-item working for the SWA squid is based on a dataset, composed of catch statistics of 1994-2013. The dataset includes up-to-date fishing logs of 217,638 records (8,702 of 2013 amended), and each record contains numerical figures of fishing time, location, in situ water temperature, depth, and mantle-size graded amounts of harvests. Eleven points are addressed in the studies of the Argentine squid －－ 1. Current squid fishing status in general, 2. Production trends of Argentine squid fisheries, 3. Spatial distribution of annual catch, effort and catch rate in SWA (2013), 4. Temporal (monthly and daily) variation of catch and catch rate in 2013, 5. Spatial distribution of catch, effort and catch rate by month, 6. Standardization of fishing efforts among vessels, 7. Spatial distribution of CPUE fortnightly, 8. Spatial distribution of water temperature fortnightly, 9. Estimates of annual stock size, 10. Mantle length frequency, and finally breakdown of production by political areas. In 2013, the SWA production is counted to 123,403 t y-1, that is 126 % to the last year. The amount is ranked 11 from 1994, that right positioned median in the past two decades. A total of 9,597 v-d y-1 was deployed annually; almost the same to the past year's 9,549 v-d y-1, but far from 200's 11,433 v-d y-1. Vessel landings are averaged to 1,209 t v-1 y-1, higher than 2012's 991 t v-1 y-1 (122 %). The catches of SWA fluctuated annually, with an irregular cycle of 3-8 years, that shows 2010 sat in a valley, 2011 rebound and the current shot to 115,644 t. The potential fishing ground of SWA is estimated occupying 459 cells of half-degree square. However, the available fishing sites for 2013's season are totaled to 74, which shared 16 % of the potential fishing ground. The zone of 46.5 ~ 47.5oS and 49 ~ 51oS between 60.5 ~ 63oW highlighted higher catches in the starting of 2013 season, and spread to the north and northwest of the Falkland Island in FICZ. It found with 5,000 t per cell annually. Monthly catch tally indicated the season heated on March, April and May. About 30 k t were harvested catch month, and that sum to 90 % of annual catches. The season closed d by the end of May. Patterns of spatio-temporal distribution of catch and catch rate indicated that small catches in January and February were obtained from narrow zone of shelf-edge at 45 - 47o. The catches escalated in March, when the fishing sites shift southward to the northern FICZ. By April, the catches from the northwestern FICZ outnumbered the due-north of FICZ, and the former area became major catching area. A total of 88-vessels' logs were collected from 2013's operation fleet. The catch is averaged to 1,184 t v-1 for each vessel in the season, with a standard variation of 654 t, ranged 166 - 3,119 t v-1. The coefficient of variation is 55.3 %, indicating substantial differences among vessels. Estimated standardizing coefficient for each vessel varied more than that of the last year. Based on standardized fishing effort (X), production (Y) is linearly related to the fishing effort (Y = 9,588 X + 279,319). The catch per unit standardized effort (C/X, cpue) is independent to the fishing effort, which suggested an effective standardization treatment. Fortnightly CPUE displayed in the fishing ground indicated that in the starting season of the first two spells are largely the same with the past year but the abundance a bit lower in 2013. In the third and fourth spells, the squid moved south and southwest with fair abundance. The following two spells found the squid moved further south while sustained the previous abundance status. Until the seventh spell, the CPUE increased substantially, and the higher abundance run into the end of tenth spell. Compare to the last year, the higher CPUE value sees a higher catch in 2013. The strength of annual recruitment relies on the density of squid and the area covered. Compared to the last two year, 2013's catch amount is a little better but the fishing sites explored is almost the same. Therefore, the stock size of 2013 was positioned moderately to the two-decades' average. The CPUE estimated is considered fair to good, however the spatial pattern of cpue deems a patchy seascape supported by low MORAN’s I obtained. The mantle size is quite small during 1 ~ 3 fortnight spells, and the mantle size did not increase to 30 cm until the forth spell. In general, smaller sized squid are caught in 2013 than 2012. Most of squid catches (84,390 t, 73.0 %) came from FICZ, and followed by high sea (17,190 t, 14.9 %). |
