跳到主要內容區塊

以非漁業依賴方法進行鯖鰺漁業資源生態研究

  • 日期:111-10-24
  • 計畫編號:110農科6.1.2-水-A2(5)
  • 年度:2021
  • 領域:漁業科技研發
  • 主持人:陳瑞谷
  • 研究人員:潘佳怡、黃鼎傑、陳人裕、張海龍

科學魚探部分:
竿釣結果顯示兔頭豚及花腹鯖為主要釣獲對象,兩者釣獲水深以50公尺為界,故單體標物反射強度著重於50公尺以深之資料進行分析。透過釣獲以及魚探資料之配對,建立體長與反射強度之關係式,其解釋度為0.98。將釣獲期間之魚探資料套入關係式,並與實際釣獲之體長進行比較,雖略有低估現象,但整體趨勢相符。由於花腹鯖為較不易圈養之物種,不適合以水槽進行活體反射強度量測實驗。未來將嘗試限制活體花腹鯖游動空間後,置於魚探音鼓下方進行探測,以增加反射強度分析之準確性。在穿越線調查部分,在宜蘭灣北側測得之全水層豐度較低,而較大體型之生物主要分布於龜山島周圍。將花腹鯖回訊及相應水層獨立進行分析後,在龜山島周圍之豐度有較高之現象,且較大體型之生物亦主要分布於龜山島周圍。密度方面整體之NASC達20046 m2/nm2 ,平均為32.59 m2/nm2,整體以龜山島南側較為密集,其密度最高達574.48 m2/nm2。根據本研究建立之關係式回推,評估體長介於31.69至35.85公分,主要分布於33公分,其比例達51 %。將轉換之體長與深度資料進行比對,發現花腹鯖以65至75公尺為主要聚集深度,且體型亦較為集中。

日魚卵生產模式部分:
從717尾成魚樣本推算平均雌魚濕重為562.4 g,性比為0.43,平均批次孕卵數為80,064 eggs,當日產卵比例則為0.3。海上魚卵調查顯示花腹鯖魚卵熱點是在三貂角外海與龜山南側海域,推估產卵場面積為1.4 x 109 m2,從魚卵發育程度反推今年度產卵高峰時間約在18:00,以指數衰減模式推估所得日產卵量為29.4 or 42.8 eggs/m2,將這些參數套入日魚卵生產模式,可得110年三月底宜蘭灣花腹鯖產卵群現存量約在1,317~5,208噸之間。

研究報告摘要(英)


The species sampled by the pole-and-line sampling were blue mackerel and pufferfish. The two species were caught in different depths by which we can grasped blue mackerels’echoes. The TS-TL conversion formula for blue mackerel were then been established (R2 is 0.98). We found that most of the blue mackerel migrated in Yilan Bay reached matured size and the larger blue mackerel mainly gathered around the Guishan Island. The estimated fork length is between 31.69 and 35.85 cm, mainly distributed in 33 cm, and the proportion is 51 %. Comparing estimated fork length and depth, it is found that the echoes of blue mackerel are mainly distributed between 65 to 75 meters.

From 717 adult fishes, the mean weight of mature female was 562.4 g, the sex ratio was 0.43, the mean batch fecundity was 80,064 hydrated oocytes and the spawning fraction was 0.3. The highest density of eggs were recorded in waters off Shandiao and southern area off Guishan Island and the estimated spawning area was 1.4x109 m2 . Based on the embryonic features of eggs, we assumed 18:00 was the spawning peak. The mean daily egg production obtained by the exponential decay model was 29.4 or 42.8 eggs/m2. Preliminary estimates of spawning biomass for Yilan Bay during late March 2021 were within 1,317 and 5,208 tonnes.