No abstract

A shift from target species to ecosystem restoration has generated interest in developing fishways that are capable of passing entire fish communities. Although a number of multispecies fishways now exist in North America, evaluations of these fishways are lacking. We used a passive integrated transponder antenna array to quantify passage success and passage duration of fish using a vertical slot fishway (85 m in length, 2.65 m elevation rise, 12 regular pools and 2 turning basins) at a low head dam on the Richelieu River in Quebec, Canada. Fourteen of the 18 tagged species re-ascended the fishway, and passage efficiency was highly variable among species (range 25%-100%); however, it was >50% for five of the species well represented in this study (n > 10) (Atlantic salmon, channel catfish, smallmouth bass, walleye and white sucker). Passage duration was likewise highly variable both among and within species (e.g. 1.0-452.9 h for smallmouth bass, 2.4-237.5 h for shorthead redhorse). Although this fishway design was not uniformly successful in passing fish of all species, this study does reveal the species that have problems with ascent and provides an estimate on the time spent in the fishway that is an important component of passage delay. Such information could be used to inform future design refinements to facilitate passage of the entire assemblage with minimal delay.

Few studies have been conducted to evaluate the effectiveness of nature‐like fishways, particularly in low gradient warmwater streams with diverse fish communities. We evaluated a nature‐like fishway that was installed to facilitate upstream passage at a low head dam on Indian Creek near Spencerville, Ontario, Canada. A passive integrated transponder (PIT) array was used to quantify attraction and passage efficiency for 391 PIT tagged warmwater fish, represented by seven species. Attraction efficiency for the three most common species, common shiner (Luxilus cornutus), creek chub (Semotilus atromaculatus) and white sucker (Catostomus commersonii), was 63.3%, 83.7% and 65.6%, respectively, and passage efficiencies were 5.1%, 38.4% and 25%, respectively. Creek chub were able to locate the fishway in less time than white sucker and common shiner; however, took longer to successfully pass. Manipulation of creek chub release locations was used to separate issues of attraction and passage and revealed that passage efficiency was highest (76.2%) for those released within the fishway and intermediate for those released at the entrance (42.1%). This multispecies fishway improved stream connectivity, but additional work is needed to fine tune its configuration. Similar projects that engage stakeholders in nature‐like fishway construction are a promising approach for the thousands of small dams that occur on low gradient streams around the globe, but those studies should incorporate a biological evaluation to ensure that attraction and passage efficiency are optimised.

No abstract

No abstract