Capelin (Mallotus villosus) distribution and climate:

a sea“canary”for marine ecosystem change

柳葉魚的分佈與氣候 : 海洋生態系統的金絲雀 (危害檢驗生物 )

Capelin (Mallotus villosus) distribution and climate:

a sea“canary”for marine ecosystem change

柳葉魚的分佈與氣候 : 海洋生態系統的金絲雀 (危害檢驗生物 )

Rose, G. A. 2005. ICES Journal of Marine Science, 62: 1524e1530.

Keywords: capelin, climate change, northern boreal ecosystems, temperature.

Reported : Chi Ting Tseng

Capelin distribution area

Capelin (Mallotus villosus)

• 柳葉魚• 學名 Mallotus villosus (Mler 1776)• 俗名 ( 中 ) 喜相逢； ( 英 )Karafuto-shishamo, Cap

elin• 形態特徵 下頜明顯突出於上頜。鰓蓋上常散佈一些

黑色小斑點。

• 分布 北極洋、北大西洋及北太平洋之溫寒帶海域。 而以沿岸水域較多。深度由 0 ～ 300 公尺。

• 棲所生態 屬於溫寒帶海域沿岸表層洄游性魚類，春至秋季，成魚即游至沿岸沙質或圓石海灘，水溫 10-13℃ 時，進行產卵。常群體游動。

• 以浮游動物、小魚及其他小型無脊椎動物為食。是其他大型魚類 ( 如鱈魚 ) 的餌料生物。

• 體長 最大可達 25 公分，通常為 15 公分。漁業及其利用 主要以圍網捕獲，為大西洋海岸如加拿大、挪威之重要經濟魚種，每年超過 50 萬噸。以春秋季較多。通常製成乾製品，再行燒烤食之。以食用抱卵之母魚為主。國內多生鮮進口食用，價廉，在海鮮及魚市場中常見。

•

Introduction• Capelin (Mallotus villosus) is a classic ‘‘r

’’ adapted pelagic species

• “R” selection 就是採生殖取向• 一般而言所處環境常是變動劇烈，所以多子代

造成之多變異有利於族群延續

R selection

.Its importance to the North Atlantic foodweb

capelin

North Pacific Northwest Atlantic the Northeast Atlantic

• A very recent re-incursion of beach-spawning capelin to the Northwest Atlantic from the North Pacific occurred during the melting of late Wisconsin ice between 6000 and 12 000 years ago.

• During the last glacial maximum (LGM) about 12 000 years ago, the North Atlantic was much colder than it is today

(Vilhja ´lmsson, 1994).

Pacific

Atlantic

補充推斷

Capelin have two modes

• Beach spawning dominates in much of the Pacific and Newfoundland regions• Deeper water spawning dominates in

Icelandic and Norwegian waters• During the LGM, capelin distribution in

the Northwest Atlantic likely shifted to a southern Grand Bank beach-spawning area

Beach spawning

Deeper water spawning

shifts in capelin distribution

• temperature change • distance displaced for capelin during

the feeding and spawning seasons• climate change• related to reproduction

Objective

• temperature change and distance• displaced for capelin during the feedi

ng and spawning seasons• The objective of this analysis was to p

rovide a quantitative framework for predicting the likely response of capelin to climate change

Methods• The literature was searched for descri

ptions and data on reported capelin locations, environmental data, shifts in distribution, and ancillary information such as temperature changes during the period of the shift and distance moved.

feeding and spawning溫度及鹽度的範圍

(Elisabeth Friis-Rødel and Per Kanneworff)2002• From Paamiut (62°N) to Aasiaat (69°N). • Echoes were identified by trawling with a p

elagic trawl. • between Iceland and East Greenland was v

erified and supplemented by 27 trawls and samples.

D is distance moved for feeding P is persistence (note that the recent shifts in the Northwest

Atlantic have not yet reverted)T is temperature change.

Results

• ABOUT temperatures• Capelin are found in

temperatures that range from -1.5 to 14℃

• They are most often found in waters ranging from -1 to 6℃

• Beach spawning occurs at 2 to 10℃• Deepwater spawning is restricted to

about 2 to 7 ℃ (2-5 ℃)

• ABOUT salinities• adults relatively narrow range of salinities, from 33 to 35 psu• Spawning reported over a wide salinity ran

ge from 3 to 35 psu

The magnitude of capelin distribution changes was associated with sea

temperature changes

The relationship was non-linear and bestdescribed by a logarithmic function

log10(distancekm) =0.28 x temperature change C+ 2.16 (p < 0.05, R2=0.91, n = 12)

This relationship indicates that small changes intemperature are associated with changes indistribution over scales of hundreds of kilometres

Longer-term changes that result in new spawning

locationsThe best fit model was log10(persistencey) = 2.62 Xlog10(distancekm)-6.56 (p < 0.05, R2=0.83, n = 13)

Discussion• 1. Distribution change very fast. a sea ‘‘canary’’ for marine ecosystem

change

• 2.food (zooplankton) distribution has as much impact as temperature

• 3.feasibile maximal shift(400-1800KM)

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