摘要:

We used mark–recapture techniques to examine the effects of four types of road crossings on fish movement during spring base flows and summer low flows in small streams of the Ouachita Mountains, west-central Arkansas. We assessed movement for 21 fish species in seven families through culvert, slab, open-box, and ford crossings and through natural reaches. We detected no seasonal or directional bias in fish movement through any crossing type or the natural reaches. Overall fish movement was an order of magnitude lower through culverts than through other crossings or natural reaches, except no movement was detected through the slab crossing. In contrast, open-box and ford crossings showed little difference from natural reaches in overall movement of fishes. Numbers of species that traversed crossings and movement within three of four dominant fish families (Centrarchidae, Cyprinidae, and Fundulidae) also were reduced at culverts relative to ford and open-box crossings and natural reaches. In spring, retention of fishes was consistently highest in stream segments upstream of crossings and lowest in downstream segments for all crossing types, a response attributed to scouring associated with spring spates. Water velocity at crossings was inversely related to fish movement; culvert crossings consistently had the highest velocities and open-box crossings had the lowest. A key requirement for improving road crossing designs for small-stream fish passage will be determination of critical levels of water velocity through crossings.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0637:RCABTS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We investigated how water flow, food availability, and individual fish size or condition affected the downstream movement of juvenile coho salmonOncorhynchus kisutchexposed to winter conditions in artificial channels. The experimental design involved four treatments (two flow treatments crossed with two feeding treatments). Our results indicated that a water flow increase with winter conditions caused coho salmon to emigrate from our experimental channels, and the magnitude of emigration was higher when the flow increase was higher. Fish emigration rate decreased as temperature fell, but it was not affected by the presence of food, even though the fish continued to feed at temperatures below 4°C.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0645:EOFAFO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Coded wire tags (CWTs) are routinely injected into the snouts of Pacific salmonOncorhynchusspp. as fry to estimate contributions of tagged populations to spawning escapements and near-shore fisheries and to assess straying. Because not all fish are tagged, tag recoveries are extrapolated to include contributions of nontagged fish released at the same time and location. A key assumption in the extrapolations is that CWTs do not affect homing ability and therefore migratory pathways. We studied tag position within the heads of homing and straying adult pink salmonO. gorbuschareturning to Prince William Sound, Alaska, to test the hypothesis that poor tag position induces straying. Heads from straying and homing tagged adults were recovered in 1992 and 1994 and X-rayed. Tag locations were categorized into critical and noncritical areas, based on tag position relative to olfactory organs and nerves. In 1992, the 37 analyzed pink salmon that strayed were more likely to have tags in critical positions than the 154 analyzed fish that homed. In 1994, no such correlation was detected among the 66 fish tested, and we hypothesize that other factors influencing straying might have obscured a relationship. We interpret these results to indicate that tag position can affect adult homing ability in pink salmon tagged as fry.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0652:CWTPAH>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Juvenile red swamp crayfish (or crawfish),Procambarus clarkii(20–41 mm in total length) were collected from a crayfish culture pond by dipnetting and tagged with sequentially numbered, standard length, binary-coded wire tags. Four replicates of 50 crayfish were impaled perpendicular to the long axis of the abdomen with a fixed needle. Tags were injected transversely into the ventral surface of the first or second abdominal segment and were imbedded in the musculature just beneath the abdominal sternum. Tags were visible upon inspection. Additionally, two replicates of 50 crayfish were not tagged and were used as controls. Growth, survival, and tag retention were evaluated after 7 d in individual containers, after 100 d in aquaria, and after 200 d in field cages. Tag retention during each sample period was 100%, and average mortality of tagged crayfish within 7 d of tagging was 1%. Mortality during the remainder of the study was high (75–91%) but was similar between treatment and control samples. Most of the deaths were probably due to cannibalism. Average total length increased threefold during the course of the study, and crayfish reached maturity. Because crayfish were mature by the end of the study, we concluded that the coded wire tag was retained through the life history of the crayfish.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0658:TRGASO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Ecological studies of the early life history stages of many fishes are challenging in part because of the difficulty of identifying larval fish to the species level. I present an identification technique using cellulose acetate protein electrophoresis that is useful for distinguishing species of larval sunfish (LepomisCentrarchidae). Using this technique in a survey of four Michigan lakes, I found that the species composition of larvalLepomisin the limnetic zone differed among lakes and through time. Larvae of bluegillsL. macrochirus, pumpkinseedsL. gibbosus, and green sunfishL. cyanelluswere all present in the limnetic zone of some lakes. Prior to this survey, the only larvalLepomisspecies identified as migrating to the limnetic zone was the bluegill.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0661:VISCOT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The Fox River, Oshkosh, Wisconsin, has a history of fish kills, dating back to the late 1950s, with at least 58 fish kills occurring during April–October 1988. Twenty fish species, including lake sturgeonAcipenser fulvescens, were affected. In situ bioassay tests of fathead minnowPimephales promelasidentified the origin of toxicity to be a motor endurance testing facility. Additional testing showed carbon monoxide (CO) to be the cause of toxicity. Blood samples taken both during in situ bioassays and from captured fish during fish kill episodes showed blood carboxyhemoglobin (COHb) levels of 32–97%. Fish kill episodes were enhanced by flow reversals in the Fox River caused by seiches from 55,730-ha Lake Winnebago. The motor endurance testing facility remains in operation; however, testing has been reduced and is monitored for compliance.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1998)127<0669:FKITFR>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor