Transcript Capelin (Mallotus villosus) distribution and climate

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, Capelin
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 1013℃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
Deeper water spawning
Beach 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
feeding and spawning seasons
• The objective of this analysis was to
provide a quantitative framework for
predicting the likely response of
capelin to climate change
Methods
• The literature was searched for
descriptions 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
pelagic trawl.
• between Iceland and East Greenland was
verified 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
range from 3 to 35 psu
The magnitude of capelin distribution
changes was associated with sea
temperature changes
The relationship was non-linear and best
described 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 in
temperature are associated
with changes in
distribution over scales of
hundreds of kilometres
Longer-term changes that result
in new spawning locations
The 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)
THANKS FOR
YOUR
LISTENING