Suitable Water Temperature Research Articles

Patterns of growth of juvenile pink abaloneHaliotis corrugatafed re-hydrated natural feeds at a laboratory and a hatchery

The feasibility of obtaining a similar growth response from juvenile pink abalone Haliotis corrugata at a research laboratory and a hatchery, when using natural feeds was evaluated. Four macroalgae, Egregia menziesii, Eisenia arborea, Macrocystis pyrifera, Gracilaria sp., and the surfgrass Phyllospadix torreyi were used as feeds. Response patterns of abalone were very similar at both facilities in terms of final length, weight, and survival, varying from 13.0 to 15.50 mm, 0.31 to 0.52 g, and 60.0% to 78.6%, respectively. Better growth was obtained when E. menziesii, M. pyrifera, and Gracilaria sp. were offered. Poor results were obtained with surfgrass. The feed conversion ratio was determined at the laboratory and did not vary significantly, ranging from 42.3 to 199.0; although a significant inverse correlation was observed with growth rate. Growth in length and weight and survival rates varied within 1.6–20.2 μm day−1, 0.123–1.664 mgday−1, 0.4–0.64%day−1, respectively. Mean growth rate in length (14.7μm day−1) and weight (1.18 mg day−1) at the hatchery were significantly higher than that obtained at the laboratory (9.4 μm day−1 and 0.77 mg day−1), which is most likely a consequence of more suitable water temperature at the hatchery. Mean survival rate was significantly higher at the laboratory (53.1%day−1) than at the hatchery (46.1%day−1).

If You Build It, Will They Come? Fish and Angler Use at a Freshwater Artificial Reef

AbstractIn November 1999, an artificial reef composed of granite rubble was built in southwestern Lake Michigan to attract smallmouth bass Micropterus dolomieu. Adult fish communities were sampled at the artificial reef site and a nearby reference site before (1999) and after reef construction (2000–2003) to determine whether the artificial reef attracted sport fishes. The total number of fish observed along scuba transects was higher at the artificial reef than at the reference site during 2000–2003. Smallmouth bass, rock bass Ambloplites rupestris, round goby Neogobius melanostomus, and yellow perch Perca flavescens were most commonly observed by divers at the artificial reef site, whereas the round goby was the most prevalent species observed at the reference site. Mean annual total gill‐net catch per unit effort (CPUE) did not differ at the two sites after reef construction. Freshwater drum Aplodinotus grunniens, gizzard shad Dorosoma cepedianum, yellow perch, and salmonines were commonly caught at both locations. The presence of several of these taxa was related to water temperature but not location. Smallmouth bass presence was related to location; CPUE was greater at the artificial reef than at the reference site during 2000–2002. Rock bass CPUE also was greater at the artificial reef than at the reference site during 2002. Smallmouth bass association with the reef was seasonal and correlated with temperature. Although anglers were aware of the artificial reef, fishing effort and success were low, in part because few anglers targeted black bass Micropterus spp. Because water temperature strongly influences the use of structure by centrarchids in deep, cold lakes like Lake Michigan, care must be taken to site artificial reefs in zones of the most suitable water temperature for these species.

Timing and Demographic Characteristics of Redhorse Spawning Runs in Three Great Lakes Basin Rivers

ABSTRACT Boat-electrofishing surveys and fishway monitoring were undertaken to describe the characteristics of redhorse (Moxostoma spp.) spawning runs in the Grand River, Muskegon River and Trent River. Spawning began in early May and was complete by mid-June. Timing of spawning varied among species, rivers, and years. Shorthead redhorse and silver redhorse spawned earlier and at lower water temperatures than black redhorse and river redhorse. Differences between rivers and years likely resulted from differences in the timing of suitable water temperatures and suitable flow levels, respectively. Spawning males were generally smaller, more numerous, and present in spawning areas earlier than females. While males reached sexual maturity at a younger age than females, there were no overall differences in the ages of spawning male and female redhorse.

Factors Affecting the Occurrence of Saugers in Small, High‐Elevation Rivers near the Western Edge of the Species' Natural Distribution

AbstractFactors affecting the occurrence of saugers Sander canadensis were studied throughout the Wind River basin, a high‐elevation watershed (>1,440 m above mean sea level) on the western periphery of the species' natural distribution in central Wyoming. Adult saugers appeared to have a contiguous distribution over 170 km of streams among four rivers in the watershed. The upstream boundaries of sauger distribution were influenced by summer water temperatures and channel slopes in two rivers and by water diversion dams that created barriers to upstream movement in the other two rivers. Models that included summer water temperature, maximum water depth, habitat type (pool or run), dominant substrate, and alkalinity accounted for the variation in sauger occurrence across the watershed within the areas of sauger distribution. Water temperature was the most important basin‐scale habitat feature associated with sauger occurrence, and maximum depth was the most important site‐specific habitat feature. Saugers were found in a larger proportion of pools than runs in all segments of the watershed and occurred almost exclusively in pools in upstream segments of the watershed. Suitable summer water temperatures and deep, low‐velocity habitat were available to support saugers over a large portion of the Wind River watershed. Future management of saugers in the Wind River watershed, as well as in other small river systems within the species' native range, should involve (1) preserving natural fluvial processes to maintain the summer water temperatures and physical habitat features needed by saugers and (2) assuring that barriers to movement do not reduce upstream boundaries of populations.

Conservation of the horseshoe crab at Kinmen, Taiwan: strategies and practices

In order to conserve the horseshoe crab, Tachypleus tridentatus, a famous ‘living fossil’ in Kinmen and Taiwan, several investigations related to its basic biology were conducted, and public education/participation programs were implemented. Biological investigations included artificially inducing spawning in the laboratory and field, rearing of juveniles, monitoring of habitat characteristics, and establishing a protected area. The grain size of the sediment of the spawning ground was 0.4–1.8 mm in diameter and that of the juvenile nursing ground was 0.11–0.19 mm. The most suitable water temperature for incubating eggs and rearing juveniles ranged from 28 to 31 °C. A total of 800 ha of the coastal zone on Kinmen was designated a protected area for the horseshoe crab, based on the Fishery Law, in December 1999. Fishing is prohibited for the 5-year period from 2000 to 2004. Public education programs were conducted to help local people learn about the basic biology of the horseshoe crab, to become aware of its importance and the necessity for conservation, and to empower them to actively participate in the conservation of this species. In addition, a horseshoe crab conservation program has also been incorporated as an element of the local ecotourism industry. Biotechnology business opportunities that may be created as a result of viable horseshoe crab populations will also be promoted.

PENGARUH SUHU AIR TERHADAP DAYA TETAS TELUR DAN PERKEMBANGAN LARVA NILA MERAH (Oreochromis sp.)

Artificial incubations of red tilapia eggs and fry were conducted in the effort to increase fish seed production and its quality. These experiments were done to determine suitable water temperature for egg incubation and larvae rearing. Four different water temperature­s, 24, 27, 30, and 33oC with variance 1oC and ambient temperature were tested in triplicates. One liter of plastic incubators made from soft drink bottles were set to water re-circulation system and provided with filter means.The fertilized eggs were stocked at 150 eggs. The hatching rate of egg increased as the increase of water temperature. The increase of water temperature decreased the incubation time of eggs, but increased hatching rate and the growth of larvae. The optimum water temperature was 29,87oC.

FLOOD DISTURBANCE REGIMES INFLUENCE RAINBOW TROUT INVASION SUCCESS AMONG FIVE HOLARCTIC REGIONS

There is growing awareness that predicting biological invasions will require the development of conceptual models for specific taxa at appropriate scales. Salmonids are ideal taxa for testing factors that influence invasions, because large numbers have been introduced worldwide for long periods and their ecology is well known. We evaluated the hypothesis that, among regions with suitable water temperatures, environmental resistance from flood disturbances that wash away trout fry strongly influence invasion success of rainbow trout (Oncorhynchus mykiss), the most widely introduced fish species. We predicted that flow regimes in regions where rainbow trout invasions are successful would match those in their native range and would differ from those in regions where invasions are moderately successful or failed. We tested six specific predictions about how timing, predictability, frequency, duration, and annual variability of floods, as well as timing of low flows, will differ relative to timing of rainbow trout fry emergence among five Holarctic regions. Analysis of hydrologic regimes for eight rivers each in the native range (Pacific Coast) and four regions where rainbow trout invasions varied from highly successful (Southern Appalachians) to moderate (Colorado, USA, and Hokkaido Island, Japan) or failed (Honshu Island) showed that winter flooding and summer low flows in Pacific Coast rivers that favor spring emergence of rainbow trout were closely matched by Southern Appalachian flow regimes. In contrast, the other three regions had spring or summer flooding that hampered rainbow trout recruitment to different degrees, and winter low flows. Rainbow trout invasion success was best explained by a match between timing of fry emergence and months of low flood probability. Alternatively, cold water temperatures, which hamper reproduction, and biotic interactions with brown trout (Salmo trutta) and whirling disease parasites may account for low invasion success in European regions. However, differences in genetic makeup of donor stocks and propagule pressure are unlikely mechanisms to explain invasions. Understanding how abiotic disturbances interact with timing of critical life history events to limit nonnative species will help ecologists develop more robust theories to predict invasion success.

Application of otolith analyses to investigate broad size distributions of young yellow perch in temperate lakes

Otolith analyses were used to back‐calculate young‐of‐the‐year (YOY) yellow perch Perca flavescens hatch‐date estimates to interpret broad length distributions observed within a small Great Lake, Lake St. Clair, and a small inland lake, Lake Opinicon, during 1998. For the Great Lake, the earliest observed hatch date occurred 2 weeks after suitable water temperatures and latest hatch dates occurred the same week temperatures were considered too warm for spawning. For the inland lake, the earliest hatch date occurred 4 weeks after suitable water temperatures and the latest hatch dates occurred 2 weeks after the water temperatures were considered too warm for spawning. It is inferred that spawning in each lake had a duration of >9 weeks. This suggests that natural perch populations can protract their spawning season opportunistically under the appropriate environmental cues. During 1998, these cues involved a shortened winter, earlier spring, and slow warming to typical summer temperatures, caused by the El Niño‐Southern Oscillation. Time of YOY hatch determined the absolute opportunity for growth and resulted in a match or mismatch with optimal foraging conditions and contributed to the development of the observed YOY length distributions.

An experimental study on a modified design compact shallow solar pond

In this study a design of compact shallow solar pond modified from that of Kudish (Kudish and Wof, 1978) is studied experimentally. The difference between this design and that of Kudish is that the water depth is allowed to be changed from 2–15 cm and is not fixed as in the mentioned reference design. The thermal insulation of the cover is installed between the reflector and the inner surface of the wooden cover. In the design of the reference (Kudish and Wof, 1978), the insulation is fixed on the outer surface of the cover, where it will probably be damaged by water, wind, dust etc. Also in our design, the level of water in the bag is measured using a static pressure manometer. The tests were carried out both in winter and in summer whereas they have been done only in summer in the mentioned reference. The results show that the compact shallow solar pond can provide a suitable water temperature to be used for low and moderate temperature applications even in a cold winter and with 10 cm water depth.

Manatee metabolism and its influence on distribution in Florida

The metabolic rate of three captive manatees was measured at different water and air temperatures. The animals responded metabolically to cold water (15–20°C), but not to cold air (10–20°C). Average metabolic rates in the thermal neutral zone ( T 1 ≊ 24° ) were 15–22% of predicted weight-specific values, and thermal conductances were 117–229% of predicted levels. Body temperatures averaged 36·4°C. The low heat production and high thermal conductance suggest that manatees are poorly adapted energetically to winter water temperatures in much of Florida. These results support behavioural observations of captive and free-living manatees which suggest that 20°C is the minimum suitable water temperature for manatees. Manatees wintering in colder waters are probably in marginal habitat and are most susceptible to cold-related mortality. Warm water refuges reduce energetic maintenance costs and probably temper the effects of occasional periods of severely cold weather, particularly in northern Florida.

Some Problems of Private Trout Hatchery Operators

Abstract Disease, nutritional, and environmental problems in commercial production of trout are discussed, including mortality and age of spawners, copepod and gyrodactylid infections, suitable water temperatures, diseases (especially red mouth and back peel) and inspection of fish. It is concluded that experiences with hatchery procedures have varied greatly and often the commercial trout producer must adjust methods to fit his particular needs and conditions.

The Trout Fishery of the Tailwater below Dale Hollow Reservoir

The 7.3 miles of tailwater below Dale Hollow Dam were initially stocked with rainbow trout (Salmo gairdneri) in 1950. In 1953, creel records indicated that a minimum of 16 percent of the 16,500 fingerling-stocked fish were captured by anglers within 12 months after stocking. The rainbow trout creeled averaged 9.4 inches long, and had grown at a monthly rate of 15 millimeters in length and 26 grams in weight. On the basis of growth rates it was decided that an annual stocking of approximately 25,000 fingerling rainbow trout would most benefit the fishery. To maintain suitable water temperatures throughout the tailwater in the summer, a minimum cold-water discharge below the dam was established. Threadfin shad (Signalosa petenensis) were stocked in the reservoir in an attempt to establish a supplemental food supply for trout in the tailwater. The stocking of brown trout (Salmo trutta), brook trout (Salvelinus fontinalis), and cutthroat trout (Salmo clarki) in the tailwater has been only slightly successful. The Dale Hollow tailwater presently supports 7,000 put-and-take trout-fishing trips per year at a cost to the Tennessee Game and Fish Commission of less than 20 cents per trip.