Chinook Salmon
Source: www.jeffrichphoto.com/ salmon.htm
Chinook Salmon
Source: www.jeffrichphoto.com/ salmon.htm
Fish Trap
Source: Rhonda Zimlich
Salmonid Life Cycle
Source: Haley Harguth
Fish
The restoration project at the Delta Ponds is largely focused on renovation of habitat for key fish species indigenous to the Northwest. One of the main objectives of the restoration project is to improve access and habitat for indigenous fish populations, while at the same time eliminating non-native fish species.
Salmonids
Chinook Salmon (Oncorhynchus tshawytscha) , Cutthroat Trout (Oncorhynchus clarki) , Rainbow Trout/Steelhead (Oncorhynchus mykiss)
Why are the salmonids key species?
Native salmon populations have significantly declined along the Willamette River over the last several decades. By creating improved habitat for salmon spawning and juvenile migration, the restoration project will help to ensure that the salmon will once again flourish along this part of the Willamette River.
What does a salmonid look like?
Chinook Salmon- Chinook can reach 147 cm in length and they can weigh up to 61 kg. They display a greenish-blue to bronze color on their back, often so dark it appears black along their dorsal and adipose fins. Once in the ocean chinook develop a very bright, silvery color. They have large, irregular spots on their sides, back, and tail.
Rainbow Trout/Steelhead-The rainbow trout display spots with irregular shapes both above and below the lateral line of their sides. A rose-red band extends the length of the lateral line at mature ages. Dorsal and ventral rows are reduced or absent.
What are the threats to salmonids at Delta ponds?
Threats to salmonids include invasive fish and amphibian species, such as bullfrogs and bass, which predate juvenile fish. Native and invasive waterfowl also seek out fry hiding in gravel beds and consume them in large quantities. Invasive fish encroach on spawning habitat for the salmon. And, because temperature can alter the incubation period of salmon embryos, the warm temperatures of the Delta Ponds during the summer months could also reduce the survival rate of embryonic salmon.
What are the monitoring methods used to find salmonids at Delta ponds?
Several methods are to be employed in this undertaking: seining, fish trap monitoring, and angler surveys. Seining uses large nets to drag regions of the pond collecting everything within its mesh. The fish trap provides extensive information gathered over a longer period of time from one point in Dedrick slough. The angler survey enables a much broader sample of the ponds.
What are the results of the monitoring for salmonids?
Data is being collected currently and has not been compiled and analyzed. Stay tuned for our final report.
Oregon Chub (Oregonichthys crameri)
Why is the Oregon chub a key species?
Oregon chub are listed as endangered under the federal Endangered Species Act (ESA). In addition the Oregon Department of Fish and Wildlife lists the Oregon chub as sensitive. It is the hope of this project that the Delta Ponds habitat would provide the proper grounds upon which the Oregon chub may once again thrive.
What does an Oregon chub look like?
The chub is a small minnow, reaching only about 8cm in length, and is found only in the middle and coastal forks of the Willamette River.
What are the threats to the Oregon chub at Delta ponds?
Threats are similar to those listed above for the salmonids.
What are the monitoring methods for Oregon chub at Delta ponds?
Several methods are to be employed in this undertaking: seining, fish trap monitoring, and angler surveys. Seining uses large nets to drag regions of the pond collecting everything within its mesh. The fish trap provides extensive information gathered over a longer period of time from one point in Dedrick slough. The angler survey enables a much broader sample of the ponds.
What are the results of the monitoring for Oregon chub?
Data is being collected currently and has not been compiled and analyzed. Stay tuned for our final report.
Bass
Smallmouth Bass (Micropterus dolomieui), Largemouth Bass ( Micropterus salmoides )
Why are smallmouth bass a species of interest?
Smallmouth bass are native to the eastern and central states of North America and have been introduced to the west and to the Willamette River. They are prolific predators and tend to6i&,MvRs3 lfhl˘VY0Ho|s]s]k{g)fg骺Ёu b(ccC*ꍧ,f ҲQNM3-wG#Ұ'oZKidV?6ハ]եaf $k[9 +;Vm4(dX7~ kpr4SY7 ti5+ݖQ0ܟk[Ȅ# γ%ӋHθK3]źpi0ܱ<߃ПZk}: *y`Y4YQ5)dZ7pO A+V^1ġ2puK rE>h>M\*D6E7 T)iԘ95K%1ȍBn n*-^Z3CW'' 5oXClA=yOjڸ#8ʌ ьWNK!WOsњOӯT({('hak ?8qWt{gVp `֣Nk`(\+UKt{N= ˽ٜvoIkiVw(qZ+{_j;I' k*;(3& ZmY8 <3k3I$`3URiVZf~5Y,y2TU/"A L8nDs'WV8+gao+gnH@vU?tOy"o}YxwD%|@K-{~5|I@Ѥ՚dKY~pV
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