t s2 a1 hourston bird - international riversymposium title: microsoft powerpoint -...
TRANSCRIPT
Native and feral fish distribution i l d l k d tl d f thin enclosed lakes and wetlands of the
southern Swan Coastal Plain
Mathew Hourston & Chris BirdDepartment of Fisheries W.A.,
Australia
YanchepStudy area
Perth
Enclosed water bodies
“N ti fi h”“Native fish”Finfish that naturally occur in theoccur in the water bodies of the catchments of the study area.
Busselton
Mapped perennial tl d
Perennial wetlands 2008
wetlands
Perennial wetlands 2008Look as though th t i t May have water 1019 (50%)they contain water
Look as though th t i t
Perennial wetlands 2008
they contain water May have water 1019
Likely to have water 806
(50%)
(40%)
Look as though th t i t
Perennial wetlands 2008
they contain water May have water 1019
Likely to have water 806
(50%)
(40%)
Wetlands that werei it d i th fi ld
Perennial wetlands 2008
visited in the field May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Perennial wetlands 2008Lakes visited that
t i d t May have water 1019
Likely to have water 806
(50%)
(40%)
contained water
Visited in the field 366
Accessible lakes th t t i d t
Perennial wetlands 2008
that contained water May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
Perennial wetlands 2008Accessible lakes th t t i d t May have water 1019
Likely to have water 806
(50%)
(40%)
that contained water
Visited in the field 366
Sampled wetlands 114
Fish were caughtPerennial wetlands 2008
May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
Fish present 88 (77%)
Native freshwater fishPerennial wetlands 2008
May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114Western minnow
Swan River gobyPseudogobius olorum
23
= 32
Fish present
Native fish presentWestern pygmy perchEdelia vittata
Western minnowGalaxias occidentalis
= 23
= 10
88
50
(77%)
(44%)Edelia vittata
NightfishBostokia porosa = 8
Western hardyheadLeptatherina wallacei = 4
Black-stripe minnow 1Black stripe minnowGalaxiella nigrostriata = 1
Western pygmy perch
Western minnow
NightfishNightfish
Swan River goby
David Morgan
Western hardyhead
David M
Black-stripeminnow
Morgan
minnow
Mark Allen
Feral freshwater fishPerennial wetlands 2008
May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
MosquitofishGambusia holbrooki = 72
G ldfi h Fish present
Native fish present
Feral fish present
GoldfishCarassius auratus = 10 88
50
76
(77%)
(44%)
(66%)
ONLY feral f h t fi h
Perennial wetlands 2008
freshwater fish May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
Fish present
Native fish present
Feral fish present
88
50
76
(77%)
(44%)
(66%)
Only feral fish present 37 (32%)
Mosquitofish
DavidDavidMorgan
ONLY native f h t fi h
Perennial wetlands 2008
freshwater fish May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
Fish present
Native fish present
Feral fish present
88
50
76
(77%)
(44%)
(66%)
Only native fish present 11 (9%)
Only feral fish present 37 (32%)
ONLY native f h t fi h
Perennial wetlands 2008
freshwater fish May have water 1019
Likely to have water 806
(50%)
(40%)
Visited in the field 366
Sampled wetlands 114
Fish present
Native fish present
Feral fish present
88
50
76
(77%)
(44%)
(66%)
Only native fish present 11 (9%)
Only feral fish present 37 (32%)
(0.5%)Native fish in mapped perennial wetlands
Take home message
Our native freshwater fish species are under threatOur native freshwater fish species are under threat from multiple aspects
Drying lakesDrying lakesFeral introductions
What is needed?
A comprehensive survey of permanent water bodiesA t f th i t ti b t f l d ti iAssessment of the interactions between feral and native speciesAssessment of the remnant native fish populations