Session: Biologic Response to Water Temperature
Wednesday, February 7, 2007 - 2:20 to 4:15 PM
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| In this session: | |
| Condition Factor Indices of Outmigrating Juvenile Trinity River Anadromous Fish at Willow Creek, CA | Tim Hayden & Bill Pinnix |
| Breeding phenology of the Foothill Yellow-legged Frogs 2004-2006 | James Bettaso, Don Ashton & Hartwell Welsh |
| Comparative Life History Characteristics of Western Pond Turtle Populations on the Trinity River Mainstem and the South Fork Trinity | Don Ashton, James Bettaso & Hartwell Welsh |
| Basking Patterns and Thermal Regulatory Behaviors of Western Pond Turtles: Comparing responses to thermal regimes in dammed and undammed tributaries of the Trinity River | James Bettaso, Don Ashton, Hartwell Welsh & Robert M. Sullivan |
| Temperature Effects on Reproductive Performance of Trinity River Spring-Run Chinook Salmon | Keith Marine, Kendall Ross & Chris Myrick |
| Discussion Session: Biologic Response to Water Temperature | |
Condition Factor Indices of Outmigrating Juvenile Trinity River Anadromous Fish at Willow Creek, CA
Tim Hayden, Yurok Tribal Fisheries Program, hayden@snowcrest.net, (530) 625-4130
Bill Pinnix, U.S. Fish and Wildlife Office, AFWO, bill_pinnix@fws.gov, (707) 822-7201
The primary goal of the Trinity River Restoration Program (TRRP) is to restore alluvial river features, resulting in increased fry rearing habitat and subsequent increased production of outmigrating anadromous fish populations. Water temperature modulation through in-stream flow releases are also expected to improve fish growth rates and increase survival of Trinity River outmigrants. Although outmigrant populations are expected to increase as result of cumulative management actions, documenting long-term trends in the health/condition of Trinity River outmigrants will also provide a metric to assess the effectiveness of TRRP restoration actions. As partners of the TRRP, the Yurok Tribal Fisheries Program and the U.S. Fish and Wildlife Service, Arcata Fish and Wildlife Office have cooperatively conducted juvenile outmigrant monitoring operations on the lower Trinity River at Willow Creek since 2002. Multiple rotary screw-traps are operated annually at Willow Creek to collect empirical data to develop efficiency-based population estimates, discharge based abundance indices and biological data such as length and weight of Chinook salmon, coho salmon and steelhead outmigrants. Fulton 's Condition Factor (CF) indices have been developed for Chinook salmon outmigrants from 1998-2006 based on the relationship between fish length and weight throughout the annual monitoring period, typically from March through September. Although annual variation has been observed, in general; preliminary CF indices indicate relatively low CF indices for natural Chinook salmon outmigrants during their early outmigration period, with gradual increases through the spring rearing period. Condition Factors also increased substantially following releases of Trinity River Hatchery Chinook smolts in May. Preliminary CF indices have not detected a substantial trend increase in the condition of outmigrating Chinook salmon smolts since recent implementation of full ROD flow releases. We expect to observe a detectable increase in fish health/condition once upstream rearing habitats are rehabilitated and combined with annual temperature regulating flow releases.
Presentation notes:
Condition factors in 2005 for 0+ Chinook were 1.1 (fair to good); in 2006 condition factors were 0.9, but increased to 1.1 later in the season. Condition factor in 2006 for 1+ coho were 1.1 for natural and 1.0 for hatchery fish. Hayden recommended outmigrant surveys be coordinated between the lower and upper river.
Questions: The sample size of fish was 1000. Poor condition factors were associated with high turbidity. It was suggested that these researchers coordinate their efforts with those on the Sacramento and Klamath Rivers .
Breeding phenology of the Foothill Yellow-legged Frogs 2004-2006
James B. Bettaso, U.S. Fish and Wildlife Service, Arcata , CA 95521 jamie_bettaso@fws.gov . (707) 825-5193
Don T. Ashton & Hartwell H. Welsh, Redwood Sciences Laboratory, U.S. Forest Service, Arcata , CA 99521 dashton@fs.fed.us, hwelsh@fs.fed.us (707) 825-2984
Flow regimes are measured for magnitude, frequency, duration, timing and rate of change. These parameters can act as proximal cues to influence when native biota reproduce. The foothill yellow-legged frog (Rana boylii) is one such species occurring in the Trinity River Basin that typically breeds in large river systems in the spring. We have conducted breeding surveys on the Mainstem, North Fork and South Fork Trinity Rivers in 2004, 2005 and 2006. In addition to breeding surveys, in 2006 we tracked the breeding phenology, size of larvae, and time and size to metamorphosis of foothill yellow-legged frogs. Surveys conducted from Douglas City to the confluence of the North Fork Trinity River have yielded 26, 12, and 7 egg masses in 2004, 2005 and 2006, respectively. In one mile of reach on the lower North Fork Trinity River, we have detected 69, 72 and 55 egg masses in 2004, 2005 and 2006, respectively. For an approximate 10 mile reach on the South Fork Trinity River, we have detected 62, 852 and 489 egg masses in 2004, 2005 and 2006, respectively. Breeding phenology is discussed in relation to flows and temperatures between these three rivers, as well as their influence on larval growth parameters in 2006.
Presentation notes:
Egg laying occurs in mid-May, metamorphosis in late July. It takes 2 to 3 years to reach reproductive status. Searches were conducted for egg masses since these are easy to find. Cobble bars along the river were the areas searched. Start of breeding has been observed to start at 12 C in the Eel River .
Questions: Might high flows inhibit breeding? What happens to juveniles on the mainstem? Not certain, but these are thought to be important.
Comparative Life History Characteristics of Western Pond Turtle Populations on the Trinity River Mainstem and the South Fork Trinity
Don T. Ashton, USFS Redwood Sciences Laboratory, dashton@fs.fed.us,(707) 825.2984
James B. Bettaso, USFWS, Arcata Office, Jamie_bettaso@fws.gov , (707) 825.5193
Hartwell H. Welsh, USFS RSL, hwelsh@fs.fed.us, (707) 825.2956
Body size is an important life history characteristic of vertebrates. In poikilothermic species, such as turtles, body size is often related to reproductive output by influencing the size and number of ova per clutch, frequency of clutches, and life-time reproductive output. Previous studies show that smaller turtles are more vulnerable to predation and produce smaller clutches so a decrease in body size has potential to reduce survivorship, reproductive output, and viability of offspring. We examined the influence of water temperature on body size and age to maturity of western pond turtles (Clemmys marmorata) by analyzing data collected from two separate populations, over two different periods, from 1991-1996 and 2004-2006. We compared populations from the dammed and non-dammed forks of the Trinity River, Trinity County , California . The dammed Mainstem Trinity River (MSTR) has a water temperature that averages about 10ºC colder than the non-dammed South Fork Trinity River (SFTR). Body sizes (carapace length and weight) per given age were significantly greater on the non-dammed SFTR compared to MSTR for both sexes. Gravid females were also significantly larger on the non-dammed SFTR compared to the dammed MSTR. The lower temperatures and reduction in thermal diversity following damming of the MSTR may influence the expression of phenotypic traits regulating body size and consequently lower both reproductive output and survivorship of MSTR turtle populations.
Presentation notes:
The western pond turtles can be very old aged-over 50 years old. The Trinity Dam was completed in 1963 and therefore trapped the 1964 floods on the mainstem. Both the South Fork and the mainstem have low population densities of turtles, but the mainstem has fewer juveniles.
Questions: why are mainstem turtles smaller? Not sure, but cold water on the mainstem is suspected.
Basking Patterns and Thermal Regulatory Behaviors of Western Pond Turtles: Comparing responses to thermal regimes in dammed and undammed tributaries of the Trinity River
James B. Bettaso, U.S. Fish and Wildlife Service, Arcata , CA 95521, hwelsh@fs.fed.us, (707) 825-5193
Don T. Ashton & Hartwell H. Welsh, Redwood Sciences Laboratory, U.S. Forest Service, Arcata, CA 99521, dashton@fs.fed.us, (707) 825-2984
Robert M. Sullivan, U.S. Forest Service, Hat Creek Ranger District, Lassen National Forest, Fall River Mills, CA 96028, rsullivan@fs.fed.us, (530) 336-5758
Basking activities of western pond turtles (Clemmys marmorata) were studied on two forks of the Trinity River in northern California, the dammed Mainstem Trinity River (MSTR) and the undammed South Fork Trinity River (SFTR). The thermal regimes of these two forks are extremely different due to the hypolimnetic release from the Lewiston Dam on the Mainstem Trinity River. Turtles on the MSTR were exposed to summer water temperatures that are 10°C lower than the control population on the SFTR. Since 2004, we have monitored turtle basking behaviors on both rivers and in some ponds. In 2005 we placed radio-transmitters (Holohil PD-2) and micro-temperature loggers on 10 turtles on the MSTR and 15 turtles on the SFTR. We tested the null hypothesis of no difference in time devoted to thermal regulatory behavior between the two populations . Our results indicated that there were significant differences in thermal regulatory behavior, with the MSTR population spending more time in aquatic thermal refugia and emergent basking than the SFTR population (T-value =3.2493, P = 0.002). Individual turtles from the undammed SFTR tended to emergent bask for shorter periods of time per day and utilized main channel aquatic basking behaviors more compared to turtles from the MSTR. The artificially colder thermal regime created by the hypolimnetic releases from the Lewiston Dam appears to be influencing the turtles' thermoregulatory behavior on the MSTR and forcing these animals to compensate by seeking alternative aquatic thermal refugia.
Presentation notes:
They could tell when the turtles were basking by the increased temperature data of the loggers. The data indicate more basking occurs in the mainstem due to the colder water there. Temperature profiles can give estimates of nesting. Cold stress may be reason for smaller turtles and more basking. Cortisone levels, or indicators of stress, are higher in turtles from the mainstem.
Questions: What are the effects of having such a long-lived species? These long-lived individuals are sometimes referred to as "ghost populations" and their numbers may reflect more the conditions under which they were born and reared. As the system has changed, and these older aged turtle die, the population structure will eventually change and may disappear.
Temperature Effects on Reproductive Performance of Trinity River Spring-Run Chinook Salmon
Keith Marine, North State Resources, Inc., marine@nsrnet.com, (530) 222-5347
Kendall Ross, Colorado State Univ., kross@warnercnr.colostate.edu, (970) 491-5830
Chris Myrick, Colorado State Univ., Chris.Myrick@colostate.edu, (970) 491-5657
Key uncertainties regarding the adequacy of temperature management criteria for protecting over-summering and spawning spring-run Chinook salmon were identified by the Trinity River Flow Evaluation. The ongoing investigation summarized here is evaluating the stock-specific physiologic and reproductive performance of Trinity River spring-run Chinook salmon relating to water temperature regimes. Data have been collected and are being analyzed on (1) metabolic response of adult spring salmon to over-summer water temperatures, (2) adult temperature tolerance and temperature-mediated disease, and (3) egg and larval temperature tolerance during incubation. Preliminary findings are presented here. A final report will be submitted in June 2007.
In 2005 and 2006, we used flow-through respirometry to measure the resting oxygen consumption rate (MO 2 ; mg-O 2 /min) of 30 adult spring-run Chinook salmon from the Trinity River d uring the pre-spawning and spawning period from (July-September) held at 10 °C to 19 °C (50-67°F). MO2 was significantly related to temperature and increased by 0.3 mg-O 2 for each 1 °C increase in water temperature. All fish held at temperatures exceeding 10 °C experienced complete mortality prior to spawning. Egg viability of a female held in captivity and spawned at 10-12 °C was comparable to spring run spawned at Trinity River Hatchery at similar temperatures.
Fungal infection was complicit in all pre-spawning mortalities at all temperatures. We developed an index from necropsy observations describing infection by body location and confirmed score designation through digital image analysis. Fungal growth was significantly greater on the head of fish in all treatments compared to other locations. The average fungal score the warm treatment scores' were notably higher than those of ambient fish . We also measured field MO 2 of nine adult spring-run Chinook captured between July 25 and August 2, 2005 in the Trinity River (10.5 °C) . MO 2 was not significantly related to weight and varied widely among individuals. We are examining the potential application of these results for refining assumptions used in salmon population and life history models concerning the effects of pre-spawning thermal experience on subsequent gamete viability.
Temperature-specific mortality rates of incubating eggs and pre-emergent larvae between 10 °C and 16.6°C (50-62°F) was evaluated during the fall of 2004 and 2006. The experiment was performed as an incomplete block design on eggs of 10 separate matings across the two study years. A critical water temperature threshold was identified at 14.5°C (58°F) above which the mortality of incubating eggs and pre-emergent fry rapidly increases. Latent mortality of post-emergent fry generally increased for eggs incubated at and above 13.3°C (56°F) compared with eggs incubated at lower temperatures. This latter result suggests that the temperature conditions during egg incubation and its effects on embryonic development persist after fish begin to exogenously feed.
Presentation notes:
Maintaining adult fish at high temperatures was difficult. All fish in treatments over 15 C eventually died. Eggs raised at lower temperatures had slower rates of development.
Questions: Why were late August fish chosen for the study? This was a default of the study and obtaining the fish. How did they know these fish were spring run? They used the California Fish and Game's cutoff date and chose fish caught before mid-August. The 60 F and increased mortality of eggs is not surprising-it was suggested that Marine compare his results to those of a Sacramento River study. What was the goal of the phylogenetic modeling? It was to examine correspondence of laboratory and field results and to see what energy is required for egg development. How easy was it to measure oxygen use? They used a clinical grade oxygen meter and had to reduce flow to a level where there was a measurable oxygen difference between incoming water and outgoing water. The dissolved oxygen and ammonia were monitored in the holding tanks for the adult fish. The water in these tanks turned over five times per day.
Discussion Session: Biologic Response to Water Temperature
Panelists: Tim Hayden, James Bettaso, Don Ashton, and Keith Marine
Any information or ideas about mainstem turtles before dam? Not too much is known but pre-dam individuals are out there. We do get "outliers" in the data sets (large individuals), and these seem to be older turtles. Comment: This is one of the best studies in that is utilizes decade scale, spatial controls and explanatory mechanism.
Why start frog studies at Douglas City? Habitat not as developed upstream. Early studies did look at upstream but did not find very much breeding. There is limited breeding in Rush Creek .
What about turtles upstream? As stream channel gets narrower there is less basking opportunities.
Regarding changes since dam, can one back calculate growth rates on older animals to look for differences? Older animals can't be aged as rings are worn off. There may be other ways to get at age.
What does the age density look like on the river? There is an age group that could be 20-70 yrs old. If so old, why don't we have a zillion turtles? Turtles grow slowly, 10 years to reach sexual maturity, small clutch sizes, reproduce every other year, and baby turtle are eaten easily.