Spawning Run Research Articles

Importance of Reservoir Inflow in Determining White Bass Year-Class Strength in Three Virginia Reservoirs

Abstract The relationship between spring inflows and the year-class strength of white bass Morone chrysops was examined in three main-stem Virginia reservoirs. The catch of age-1 white bass in fall gill-net samples from 1980 to 1998 was used as an index for year-class strength in Claytor Lake and Kerr Reservoir. Claytor Lake was sampled by electrofishing during the spring spawning run in 1996, and the residuals associated with catch-curve regressions were computed to estimate year-class strength. In Leesville Reservoir, white bass recruit to gill nets at age-0; therefore, the catch per effort of age-0 white bass was used as an indicator of year-class strength. Strong year-classes (≥0.03 fish/9.29 m2 of gill net) were rare in each reservoir. In Claytor Lake, strong year-classes were produced in 1987 and 1993, both years of high spring inflows. Lake inflows during April were also positively related to the year-class strength of white bass in Kerr and Leesville reservoirs and explained about 90% of the varia...

Population Biology of Steelhead Spawning Runs in Three Pennsylvania Tributaries to Lake Erie

Little is currently known about the population biology of steelhead ( Oncorhynchus mykiss) that spawn in Pennsylvania's Lake Erie tributaries or the role of natural reproduction in supporting this fishery despite its popularity and importance. The goal of this study was to describe the population characteristics of steelhead spawning runs in Crooked Creek, Godfrey Run, and Trout Run, three Pennsylvania Lake Erie tributaries that are annually stocked with 80,000 to 200,000 yearling steelhead. From fall 1997 to spring 1999, returning adult steelhead were sampled during both fall and spring spawning runs using seines and backpack electrofishing gear. Sex was determined using external characteristics, total length was measured, and a scale sample was collected from each fish. Scales were analyzed to determine age, life history patterns, and relative contributions of wild and hatchery-reared fish to seasonal spawning runs. Male steelhead dominated sex ratios in both Godfrey Run and Trout Run during both seasons, while female steelhead were more prevalent in Crooked Creek. Stream-age 1 steelhead were predominant in both fall and spring runs in all three streams. During both seasons in all streams, the majority of males returned after spending only one summer in Lake Erie while most female steelhead returned at lake-age-2. The relative contribution of wild steelhead to Pennsylvania spawning runs was minimal in all three streams for both seasons. As a result, future success of Pennsylvania's steelhead fishery will likely require the continuation of annual tributary stocking of steelhead smolts.

Isotopic turnover in aquatic predators: quantifying the exploitation of migratory prey

In the tidal freshwaters of Virginia, U.S.A., the blue catfish (Ictalurus furcatus), an introduced piscivore, derives a significant proportion of its nutrition from spawning anadromous fish (genus Alosa, including blueback herring (A. aestivalis), American shad (A. sapidissima), and alewife (A. pseudoharengus)). Because the Alosa are not continually available to I. furcatus, there is an isotopic turnover, defined as change in isotope composition due to growth and metabolic tissue replacement, in I. furcatus tissues associated with the diet switch from freshwater to anadromous fishes. However, isotopic turnover rates for ictalurid fish are unknown. This study determined the maximum isotopic turnover rate of channel catfish (Ictalurus punctatus) tissues and compared this maximum rate with that of I. furcatus captured in the field over the 3-month Alosa spawning run. Maximum turnover rates for δ13C were 0.014 and 0.017‰ per day in muscle and blood. For δ34S, rates were 0.017 and 0.020‰ per day in muscle and blood, respectively. Isotopic turnover of muscle carbon reflected growth rate, but sulfur did not match growth as well. Ictalurus furcatus captured in the field showed no enrichment during the Alosa spawning run owing to slow turnover and variable diet. In aquatic ecosystems that have migrating prey, exploitation by predators may be underestimated using isotopes because of slow tissue turnover.

Features of Temporal Differentiation of the Chum Salmon Oncorhynchus ketaof the Anadyr Bay Region at Different Abundance Levels

The temporal heterogeneity of chum salmon stock of the Anadyr Bay region was investigated on the basis of a set of discrete external morphological features and fluctuating asymmetry level of some meristic structures. Differentiation of Anadyr Bay chum salmon during the spawning run was found to be associated with the abundance level of spawning stock in a particular year. Sharply pronounced temporal heterogeneity, based on the investigated characteristics, in the area near the river mouth can be considered as an indicator of the subsequent deficiency of spawners on the spawning grounds of rivers in the Anadyr Bay region.

Isotopic turnover in aquatic predators: quantifying the exploitation of migratory prey

In the tidal freshwaters of Virginia, U.S.A., the blue catfish (Ictalurus furcatus), an introduced piscivore, derives a significant proportion of its nutrition from spawning anadromous fish (genus Alosa, including blueback herring (A. aestivalis), American shad (A. sapidissima), and alewife (A. pseudoharengus)). Because the Alosa are not continually available to I. furcatus, there is an isotopic turnover, defined as change in isotope composition due to growth and metabolic tissue replacement, in I. furcatus tissues associated with the diet switch from freshwater to anadromous fishes. However, isotopic turnover rates for ictalurid fish are unknown. This study determined the maximum isotopic turnover rate of channel catfish (Ictalurus punctatus) tissues and compared this maximum rate with that of I. furcatus captured in the field over the 3-month Alosa spawning run. Maximum turnover rates for δ13C were 0.014 and 0.017‰ per day in muscle and blood. For δ34S, rates were 0.017 and 0.020‰ per day in muscle and ...

Exploitation and Mortality of Paddlefish in the Lower Tennessee and Cumberland Rivers

Abstract We estimated commercial and sport fishing exploitation of the paddlefish Polyodon spathula population in the lower Cumberland and Tennessee rivers from 1991 to 1994 using tag and reward methods. Exploitation for fish tagged over 3 years was 20.0% in Lake Barkley, 25.4% in the Kentucky Dam tailwater, and 14.4% in Kentucky Lake, most of which was commercial in Kentucky Lake (88%) and sport in Lake Barkley (65%). Although commercial harvest is prohibited in the Kentucky Dam tailwaters, some paddlefish moved to areas where commercial fishing is allowed. Most paddlefish were harvested in the lake where they were tagged, but nine individuals moved among the major tributaries of the Mississippi River. We compared the Kentucky Lake commercial paddlefish harvest during the winter spawning run of 1991–1992 with that of 1985–1986. The 1985–1986 harvest followed high roe prices and earlier intense fishing pressure, resulting in high annual mortality (69%) and a relatively lower mean length (691 mm) and weigh...

Disturbance of Small-Stream Habitat by Spawning Sockeye Salmon in Alaska

Abstract We examined how the spatially and temporally predictable disturbance caused by a spawning run of native sockeye salmon Oncorhynchus nerka temporarily affected benthic and invertebrate drift communities of two small streams in southwestern Alaska. Surface gravel size temporarily increased as a consequence of this mechanical disturbance, and periphyton biomass decreased in one stream. The postspawning rise in periphyton biomass in Bear Creek (larger sockeye salmon run) likely reflects nutrient release by decomposing sockeye salmon. Total benthic invertebrate and larval chironomid density decreased during spawning in one stream, but most invertebrate taxa in both streams did not exhibit clear spawning-related impacts. In contrast, invertebrate drift almost always increased during daylight hours when sockeye salmon were present, but it was difficult to separate mechanical effects of sockeye salmon acting via redd construction versus swimming. Total daytime drift density during spawning was four times...

Cessation of the Norwegian drift net fishery: changes observed in Norwegian and Russian populations of Atlantic salmon

Jensen, A. J., Zubchenko, A. V., Heggberget, T. G., Hvidsten, N. A., Johnsen, B. O., Kuzmin, O., Loenko, A. A., Lund, R. A., Martynov, V. G., Naesje, T. F., Sharov, A. F., and Okland, F. 1999. Cessation of the Norwegian drift net fishery: changes observed in Norwegian and Russian populations of Atlantic salmon. ‐ ICES Journal of Marine Science, 56: 84‐95. The aim of this study was to evaluate eVects of the ban on the Norwegian coastal drift net fishery in 1989 on the spawning run of Atlantic salmon (Salmo salar) populations in four Norwegian and four Russian rivers. Catches/escapements, size distribution, sea-age proportions, and mean weights of diVerent sea-age groups were collected from oYcial catch statistics and analyses of scale samples. In three of the Norwegian rivers, catches of grilse (1SW) increased significantly after the ban on the drift net fishery. No changes were recorded for multi-sea-winter (MSW) fish. In addition, the proportion of grilse increased in all the Norwegian rivers, and 2SW salmon increased in three of them. The mean weight of grilse increased in all four Norwegian rivers, whereas the mean weight of 2SW fish decreased in the two rivers in southern Norway. The size of 3SW fish did not change. These changes correspond well to actual net selection curves and reported mean weight of drift net catches in diVerent parts of Norway. Trends in the Russian populations were more varying. In the three rivers draining to the Barents Sea, changes were similar to those in the Norwegian rivers. However, these changes were less obvious than those observed in Norwegian populations. The authors conclude that the ban of the drift net fishery significantly aVected the structure of the spawning run in Norwegian Atlantic salmon populations. Furthermore, the results indicate that the drift net fishery aVected Russian salmon populations in rivers draining to the Barents Sea to a lesser extent than Norwegian salmon, and had no eVect in rivers draining to the White Sea.

Contribution of Marine-Derived Organic Matter to an Atlantic Coast, Freshwater, Tidal Stream by Anadromous Clupeid Fishes

This study used stable isotope analysis to evaluate the hypothesis that upstream migrations by anadromous clupeid (Alosa spp.) fishes represent an ecologically important seasonal subsidy to annual energy and nutrient budgets for coastal waters of the Atlantic slope. Dual stable isotope ratio analyses (δ ¹³C and δ ¹⁵N, ‰) were conducted on >200 samples representing major ecological components of Wards Creek, Virginia, and temporal trends in the stable isotope signatures of these components were related to the timing of Alosa-derived allochthonous inputs. Carbon ratios (δ ¹³C) for migratory (oceanic) Alosa spp. arriving in Wards Creek were enriched by 10.2‰ compared to ratios for resident fishes. The timing and magnitude of shifts in the δ ¹³C values of documented Alosa predators suggest that predators in Wards Creek derive a substantial proportion of their biomass carbon from marine sources during the Alosa spawning run. The unique trophic structure of Wards Creek may be related to ecological linkages between tidal fresh waters and coastal marine systems and the greater taxonomic complexity of tidal freshwater faunal assemblages compared to other aquatic systems.

Kinetic behavior of muscle carnitine palmitoyltransferase I in the lampreyGeotria australis, before and after the marine trophic phase

This study was aimed at determining whether the marked changes that occur in the diet during the life cycle of the lamprey Geotria australis, and thus also in the fatty acid composition of the triacylglycerol stores, are accompanied by alterations in the νmax and apparent K0.5 of skeletal muscle carnitine palmitoyltransferase I (CPT I) towards the CoA derivatives of the fatty acids 16:0, 16:1n-7, 18:1n-9, 18:2n-6, and 22:6n-3. The activity of CPT I towards the last four of these acyl CoAs increased progressively from the microphagous larvae to young adults, prior to the onset of their marine trophic phase, to fully grown adults, which had ceased feeding on fish and embarked on their spawning run. For example, the νmax of CPT I towards 18:1n-9 rose from 4.4, to 7.6 to 11.5 nmol · min–1 · mg mitochondrial protein–1 over the course of the three life-cycle stages. The values for the νmax of lamprey muscle CPT I towards the various CoA esters were not directly correlated with the percentage contributions of the corresponding fatty acids to the triacylglycerol stores. Despite very pronounced differences in the biochemistry, physiology, and physical activity of each life-cycle stage, as well as in the fatty acid composition of the triacylglycerols, before and after the adult trophic phase, the νmax for CPT I was always greatest for 16:1n-7 and 18:1n-9. Because the reactivity of CPT I towards the latter two monoenoic fatty acids is also high in teleost fishes and in rat, such a characteristic may have been conserved throughout vertebrate evolution. J. Exp. Zool. 281:6–11, 1998. © 1998 Wiley-Liss, Inc.

Anomalous migrations of anadromous herrings revealed with natural chemical tracers

Anadromous herrings of the genus Alosa are generally thought to leave their natal river or estuary at the end of the first growing season and return as mature adults to spawn. Nevertheless, immature yearling alosines have been observed in large numbers in the Hudson River estuary during and after the spring spawning run. I analyzed the stable isotopic ( delta 13C, delta 15N) compositions of 26 blueback herring (Alosa aestivalis), eight American shad (Alosa sapidissima), and 10 alewife (Alosa pseudoharengus) collected from 55-225 km above the estuary mouth during April-July and compared them with isotopic compositions of young-of-year (resident) alosines, as well as adults (marine phase). delta 13C of the May-caught American shad and alewife indicated a marine origin (greater than -22.5omicron); blueback herring split into both marine and freshwater ( delta 13C less than -25.5omicron) groups. June-caught fish had intermediate values. Microprobe traces of Sr in these fishes' otoliths helped further to discriminate between resident fishes and those that had migrated to sea (or brackish water) and then moved back upriver for a period of several weeks. The combination of biogeochemical tracer methods holds promise for elucidating complex life histories of fishes and helps to pose questions about plasticity of migration.

Oxygen consumption by adults of the Southern hemisphere lampreyGeotria australis in air

Adults of the lamprey Geotria australis are capable of surviving and taking up considerable volumes of oxygen when in humidified air. This accounts for their ability to leave water, move through moist vegetation and up and over dam walls, and thereby overcome barriers to their upstream migration. Immature adults of G. australis, which had been on their spawning run for 3–4 months, survived for at least 30 hr and without apparent discomfort in humidified air at 15°C during a light/dark/light regime paralleling field conditions. The mean hourly rate of oxygen consumption of these lampreys stabilised at c. 48 μl.gm−1.hr−1 during the light phase, but then rose during the dark phase and remained at c. 66 μl.gm−1.hr−1, before declining during the second light phase to a level similar to that in the initial light phase. The mean standard rate of oxygen consumption in air and in light, based on the minimal values recorded for individual animals during the period when their oxygen consumption was low and stable, was 33.6 μl.gm−1.h−1, which is virtually identical to the standard rate of oxygen consumption of immature adult G. australis, measured previously in water and light at the same temperature. However, the above mean rate for standard oxygen consumption in air is significantly less (P < 0.001) than the mean rate of 50.4 μl.gm−1.hr−1, determined in the same manner in air during those periods at night when oxygen consumption was high and stable. At the end of the spawning run, when maturity is attained, the mean standard rates of oxygen consumption of male and female G. australis in air and light at 15°C were 32.8 μl.gm−1.hr−1 and 22.6 μl.gm−1.hr−1, respectively. © 1996 Wiley-Liss, Inc.

Epidermal Tumors on Rainbow Smelt and Atlantic Salmon from Nova Scotia

Epidermal tumors on rainbow smelt Osmerus mordax are described in detail for the first time. These tumors apparently progress from small preneoplastic lesions to papillomas, and to carcinomas on some males. These tumors and similar tumors on Atlantic salmon Salmo salar have not been previously reported from Canada. Tumors were found on rainbow smelt mainly in freshwater during the spring spawning run and on Atlantic salmon grilse in freshwater in October, These tumors varied in size and number on each fish. The smaller growths were usually translucent and whitish, with a smooth surface. Some larger tumors were papillomatous and appeared reddened because of increased vascularization. Preneoplastic lesions and papillomas had a thickened epidermis with an intact basement membrane, and most of the cells were enlarged. fn papillomas of rainbow smelt, tumor cells that were not close to papillae were vacuolated, and necrotic regions were present. Carcinomas on the heads of male rainbow smelt had regions of pleomorphic cells which invaded the subepithelial tissues and penetrated the cartilage of the mandible of two specimens found in brackish and seawater. Intranuclear basophilic inclusions suggestive of a viral agent were present in the tumors of both rainbow smelt and Atlantic salmon.

Effect of Salmon Carcass Decomposition on Lake Superior Tributary Streams

We investigated the fate of organic matter and inorganic nutrients derived from spawning runs of chinook salmon in tributary streams to Lake Superior during fall and winter 1990. Upstream-downstream comparisons and experimental introduction of carcasses were used to determine how salmon carcass decomposition influenced several stream ecosystem components, including total phosphorus, total nitrogen, soluble reactive phosphorus (SRP), NO₃^-, NH₄⁺, periphyton biomass, and fine particulate organic matter (FPOM) in transport. Total phosphorus, SRP, and periphyton biomass were higher in a river reach that received a spawning run of an estimated 1200 fish than in an upstream reach that lacked spawning salmon. No upstream-downstream gradient in these components occurred in a river that did not receive a spawning run. Total phosphorus, SRP, and periphyton also were elevated where we experimentally introduced salmon carcasses, in the absence of a natural salmon run. Stable isotope analyses revealed that salmon-derived nitrogen was incorporated into grazing mayflies, and to a lesser extent into filter-feeding caddisflies. Salmon-derived carbon was not incorporated into these macroinvertebrates. These results show that salmon carcasses can be an important source of nutrients in streams even when runs are relatively small.

The liver and muscle of early upstream migrant lampreys ( Geotria australis) contain high levels of acetyl-CoA carboxylase and a carnitine palmitoyl transferase I that is sensitive to malonyl-CoA

The exceptionally high lipid levels in the muscle and liver of Geotria australis, at the completion of the marine trophic phase, are both accompanied by a very high activity of acetyl-CoA carboxylase (ACC). ACC activity declines markedly during the subsequent protracted, nontrophic spawning run. The above and other data suggest that, in lampreys, the muscle tissue, as well as the liver, is lipogenic. Carnitine palmitoyl transferase I of lamprey muscle is extremely sensitive to malonyl-CoA, a feature which would enable fatty acid oxidation to be inhibited during any period of lipogenesis in this tissue.

The First Record of the Spawning Run of Masu Salmon Oncorhynchus masou Introduced into the Patagonian Lake General Carrera, Southern Chile.

Masu salmon fry Oncorhynchus mason of two different origins, Chilean stock (MC) of 7.0g size parr and Japanese stock (MJ) of 4.9g size parr, were released in February 1987 and in October 1987, respectively, into a tributary of Lake General Carrera in Chilean Patagonia. The spawning run of the salmon (299 females and 276 males) was observed in the river from March to April 1989. The sex ratio (males per female) was regarded as nearly 1.0, and this suggested that river-resident precocious males were very scarce in the river. Mean fork lengths and weights of spawners were 56.3cm and 1, 715g, respectively. The rate of return was estimated as 1.07% for MC and 0.95 for MJ. No difference between either rate was observed though they were released at different sizes and times. Eyed-stage eggs and alevins were found in the river after the spawning season. These indicated that there is a high possibility of population establishment in the lake by the small parr release of masu salmon.

Basal oxygen consumption, ventilatory frequency, and heart rate during the protracted spawning run of the Southern Hemisphere lamprey Geotria australis

Basal oxygen consumption, ventilatory frequency, and heart rate were recorded at four different times during the unusually protracted 15–16-month spawning run of the Southern Hemisphere lamprey Geotria australis. At 15°C, the mean basal oxygen consumption of G. australis caught immediately after they had left the sea and embarked on the spawning run (45 μl · g-1 · h-1) was less than in young adults about to commence their marine feeding phase (64 μl · g-1 · h-1), but greater than in large ammocoetes (26.5 μl · g-1 · h-1). Basal oxygen consumption fell progressively during the spawning-run of to 33 μl · g-1 · h-1 after 5 months and 25 μl · g-1 · h-1 after 10 months, before rising to 35 μl · g-1 · h-1 after 15 months when the animals were approaching sexual maturity. The downwards trend in basal oxygen consumption contrasts with that recorded during the spawning run of Lampetra fluviatilis. Furthermore, these values for spawning-run of G. australis are far lower than those measured at any time during the upstream migration of L. fluviatilis or during the parasitic phase of landlocked Petromyzon marinus. A low and declining metabolic rate during much of the spawning run of G. australis would facilitate the conservation of energy reserves during this very long non-feeding period. Trends shown by ventilatory frequency and heart rate essentially parallel those of basal oxygen consumption. The Q10s for basal oxygen consumption, ventilatory frequency and heart rate over the temperature range 5–25°C were 1.6, 1.6, and 1.7, respectively. The trends shown by basal oxygen consumption during metamorphosis and the upstream migration did not parallel those exhibited by circulating thyroid hormones.

筑後川におけるニゴイの回遊について

Distribution and migration of the cyprinid fish Hemibarbus barbus in the Chikugo River were studied during 1986 and 1989. Many mature males and females were caught at the middle reaches in April, whereas most of the subadult fish were caught in the tidal reaches all the year round. According to monthly changes of gonadosomatic index of adult fish, it is clear that this fish spawns mainly in April. In order to elucidate the spawning run, 195 mature fish were marked at the tidal reaches during February and March, 1988, and 4 specimens were recaptured at the middle reaches in early April, 1988. In the tidal reaches, most of the fish were caught in waters less than 0.2 percent in salinity. Yearling fish were recognized in the lower reaches in May and began to be collected in the tidal reaches in July. These observations indicate that the yearling migrates from the lower reaches to the fresh water area of the tidal reaches. After staying there for 3-4 years, mature males and females run up for 20-40km for spawning in spring. Migration occurring wholly within fresh waters is called potamodromous migration. It seems that the migration of H. barbus in the Chikugo River is potamodromous migration and classified as an anadromous migration type.

Biological Characteristics of Commercially Caught Hudson River Striped Bass, 1973–1975

Abstract The purpose of this study was to characterize the spawning run of striped bass Morone saxatilis sampled from the commercial gill-net fishery in the Tappan Zee region of the Hudson River, New York, during the springs of 1973, 1974, and 1975. The sex ratio changed from late March to late May because males passed through the fishery in the Tappan Zee region before females. Females predominated in the commercial catches during 1973–1975. Males were not sexually mature until age IV, but 28% of the males in age-groups IV–VI were immature. Females were not consistently mature until age VII and older. The data suggest that Hudson River male and female striped bass attain sexual maturity at a later age and larger size than striped bass in estuaries elsewhere; however, the fish were collected 32–121 km downstream from major spawning regions. Most of the commercial catch was composed of age-groups IV, V, and VI; frequency modes were at ages IV and V for males and at age V for females. Age-groups older than ...

The induction of spawning behaviour in Puntius gonionotus (Bleeker) by treatment with prostaglandin PGF2α

Groups of Puntius gonionotus were brought into breeding condition by treatment with extracts of homoplastic pituitary material. Spawning in P. gonionotus includes a number of distinctive features which appear to be adaptations to reproduction in a riverine habitat. These features include the absence of a specific substrate requirement, the production of non‐adhesive, buoyant eggs, an elaborate circling display by the male, and a long spawning run during which gametes are dispersed across the current.Spawning activity began 3–4 h after treatment with pituitary material. The relatively sudden increase in female responsiveness and attractiveness to males appears to coincide with the occurrence of ovulation. It is hypothesized that at this time the female releases a chemical signal which attracts and excites the male. Females participate in a number of spawning runs over a period of 30 min, thereafter female activity decreases rapidly.Injections of a prostaglandin (PGF2a) were effective in inducing spawning activity in non‐gravid females. This finding provides support for the hypothesis, based on work with goldfish, Carassius auratus, that prostaglandin provides a link between periovulatory events in the ovary and the brain mechanism governing spawning activity.