Reconstructing Sakhalin Taimen ( Hucho perryi Hucho perryi ) ) Reconstructing Sakhalin Taimen ( Historical Distribution and Identifying Causes Historical Distribution and Identifying Causes for Their Local Extinction for Their Local Extinction Michio FUKUSHIMA , National Inst. Environ. Studies (NIES), Tsukuba, Japan Hiroto SHIMAZAKI , NIES Pete S. RAND , Wild Salmon Center, Portland, Oregon, USA Masahide KAERIYAMA , Hokkaido University IUCN World Conservation Congress, Barcelona 2008
INTRODUCTION Sakhalin taimen ( Hucho perryi ) Regionally anadromous Iteroparous Russian Far East and Japan Maximum record >130 cm, >21 kg Least studied salmonid Critically Endangered, IUCN SSG (2006)
Local Extinction of Sakhalin Taimen Subpopulations 1 Subpopulation = 1 River
Collaborative Research by US, Russian and Japanese Scientists in Hokkaido, Japan
Also in Far Eastern Russia …
OBJECTIVES 1. To model and reconstruct historical distribution of Sakhalin taimen based on observed presence and absence data by river basin 2. To model causes for local extinction of Sakhalin taimen subpopulations in Japan
Modelling Historical Distribution of Sakhalin taimen
Historical Records of Sakhalin Taimen Occurrence CONTINELTAL RUSSIAN Amur River SAKHALIN Tatar Strait FAR EAST Sea of Okhotsk k s v o r a b a h K L S I D R N U A K L Sapporo S I Vladivostok HOKKAIDO n a p a J f o a e HONSHU S N A P A J Taimen absent or unknown Taimen present 0 125 250 500 KM
Taimen Records by Region and River Basin Occurrence Sakhalin CRFE Japan Kurils Total Present 110 20 46 6 182 Absent 93 640 794 0 1527 Unknown 177 218 303 86 784 Total 380 878 1143 92 2493
1) Drainage Area 2) Mean Elevation 3) Area < 20 m a.s.l. Basin_area Mean_Elevation E20 AREA_ SQKM E_ mean E20 12 - 384 -1 - 83 0 - 10 385 - 1340 84 - 164 11 - 32 1341 - 2896 165 - 246 33 - 65 2897 - 5718 247 - 337 66 - 116 5719 - 10579 338 - 441 117 - 200 10580 - 19404 442 - 579 201 - 368 19405 - 33171 580 - 831 369 - 652 33172 - 60971 832 - 1528 653 - 2339 4) Lagoon Area 5) Air Temperature 6) Precipitation Lagoon_ Area Air_ temp Precipitation LGN_ A Tmp Pre 0 - 2 -7.3 - -1.7 46.05 - 57.35 3 - 8 -1.6 - 1.9 57.36 - 68.63 9 - 20 68.64 - 82.74 2.0 - 5.1 21 - 45 5.2 - 7.8 82.75 - 99.90 46 - 72 7.9 - 10.5 99.91 - 122.50 73 - 151 10.6 - 13.0 122.51 - 151.79 152 - 211 13.1 - 15.0 151.80 - 183.89 212 - 451 15.1 - 19.1 183.90 - 237.70
7) Spatial Autocorrelation − n 1 ∑ = autocor w y i ij j = j 1 1 = w ij l ij ⎧ ⎫ 0 = 1 ⎨ ⎬ y j ⎩ ⎭
NO 316 (178) Spatial Autocorrelation < 0.010 Historical Taimen Distribution Model 1709 (182) 1393 (4) YES
Historical Taimen Distribution Model Spatial Autocorrelation < 0.010 1709 (182) Drainage Area < 949 km 2 Drainage Area < 87 km 2 1298 (0) 95 (4) 117 (34) 199 (144)
Historical Taimen Distribution Model Spatial Autocorrelation < 0.010 1709 (182) Drainage Area < 949 km 2 Drainage Area < 87 km 2 Elevation < 131 m Precipitation < 96 mm 1298 (0) 95 (4) Air Temperature < 0.7 C Precipitation < 54 mm 71 (11) 28 (9) 9 (0) 37 (23) 9 (2) 162 (133) P=0.622 P=0.821
Prediction 0.00 - 0.05 0.06 - 0.16 0.17 - 0.23 0.24 - 0.33 0.34 - 0.63 0.64 - 0.83 Observation
Modelling Local Extinction of Sakhalin taimen Subpopulations in Japan
Status of Sakhalin Taimen Subpopulations in Japan Extant subpopulations (12) vs. Extinct subpopulations (36)
Possible Factors Explaining Extinctions Number of dams Human population Number of alien species Presence of rainbow trout Deforestation Agricultural development Drainage area Air temperature Precipitation Elevation Percent lowland Presence of lagoons etc.
NO 17 (0) Air Temperature < 5.2 C 48 (12) 31 (12) Classification Tree YES
Classification Tree Air Temperature < 5.2 C YES NO 48 (12) Elevation < 82 m 17 (0) 8 (7) 23 (5)
Classification Tree Air Temperature < 5.2 C YES NO 48 (12) Elevation < 82 m 17 (0) Farmland < 21 % 8 (7) Percent Area Below 20 m < 13 % 5 (3) 13 (0) 5 (2)
Farmland Distribution and 5 º C Air Temperature Contour Farmland 5 º C Contour
Classification Tree Regional-scale agricultural development is minimal Air Temperature < 5.2 C YES NO 48 (12) Elevation < 82 m 17 (0) Watershed-scale agricultural development Farmland < 21 % 8 (7) Percent Area Below 20 m < 13 % 5 (3) 13 (0) 5 (2)
Agricultural development Channelization, bank revetment, and construction of dams and weirs Destruction of taimen habitats
CONCLUSIONS Historical Distribution 1) Sakhalin taimen tend to occur contagiously and are more likely to occur in larger drainages. 2) The species might have had wider distribution in the past, especially in the northern part of Japan. Local Extinction 1) Agricultural development was an important cause for the Sakhalin taimen local extinction, 2) Extant subpopulations tended to survive in drainages with lower elevations (perhaps due to more wetland habitats). This technique – Spatially Explicit Modeling - may be applied to red list assessments for other species (e.g. Hucho taimen ).
Thank you!
Recommend
More recommend
