scholarly journals Biodiversity and conservation of freshwater fishes in selected rivers on Choiseul Island, Solomon Islands

2007 ◽  
Vol 25 (1) ◽  
pp. 16 ◽  
Author(s):  
David Boseto ◽  
Clare Morrison ◽  
Patrick Pikacha ◽  
Tikai Pitakia
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Habitat Degradation ◽  
Solomon Islands ◽  
Substrate Type ◽  
Biodiversity Survey ◽  
Negative Impacts ◽  
Terrestrial Biodiversity ◽  
Fish Harvest ◽  
Watershed Health

During a terrestrial biodiversity survey of Choiseul Island, we conducted freshwater fish surveys in seven sites between July 2005 and August 2006. We found 32 fish species from 15 families (38% of known Solomon Island freshwater fish). Most species were uncommon with the exception of Kuhlia marginata (6/7 sites), K. rupestris (5/7 sites) and Glossogobius sp. 1 (5/7 sites). No introduced species were found in any of the sites. Species richness ranged from 2-14 species per site and was highest in Lumutu River and Kolombangara River. This difference between sites is partially attributed to substrate type (higher richness in sites with gravel substrates than mud) and distance from the coast (higher richness near the coast than inland). The results of this survey in conjunction with a previous survey bring the total number of freshwater fish species on Choiseul Island to 41. This diversity is threatened by habitat degradation through sedimentation and over harvesting of some species. We recommend a number of activities to ameliorate these threats including seasonal banning of fish harvest during breeding periods and mass juvenile migrations, discouraging the practice of streamside agriculture, and education of locals on the negative impacts of logging on watershed health and productivity.

Herpetofauna, community education and logging on Choiseul Island, Solomon Islands: implications for conservation

2007 ◽  
Vol 13 (4) ◽  
pp. 250 ◽  
Author(s):  
Clare Morrison ◽  
Patrick Pikacha ◽  
Tikai Pitakia ◽  
David Boseto
Keyword(s):  
Community Education ◽  
Solomon Island ◽  
Solomon Islands ◽  
Management Plan ◽  
Biodiversity Survey ◽  
The Pacific ◽  
Frog Species ◽  
Education And Awareness ◽  
Species Richness And Abundance ◽  
Terrestrial Biodiversity

Biodiversity in the Solomon Islands Is extremely rich, and in the Pacific is second only to Papua New Guinea. Despite this high diversity there are only rough estimates for the biodiversity of most taxa in the Solomon Islands. As part of a terrestrial biodiversity survey, we conducted nocturnal surveys for frogs in a range of habitats from 10?1 060 m on Choiseul Island. This work was carried out between June 2005 and January 2006. In addition to the nocturnal surveys, we also conducted opportunistic diurnal searches for reptiles as well as community environmental education and awareness workshops. Fifteen frog species (65% of all Solomon Island frogs) including all five endemic species, were found during our surveys of Choiseul Island. Most of the species were fairly widespread and abundant, however, four species (Discodeles bufoniformis, Palmatorrapia solomonis, Brachylodes trossulus and B. wolfi) were fairly restricted in their distribution. In addition, we found 20 reptile species during opportunistic surveys (30% of all Solomon Island reptiles Including four endemics). Important habitats on Choiseul Island based on frog species richness and abundance are mid-altitude rainforest (500?600 m), primary lowland rainforest and lowland coastal forest. Unfortunately, it is these habitats that are most threatened by logging operations on the island. In order to aid biodiversity conservation on Choiseul Island we recommend a number of activities including additional biodiversity surveys, increased community awareness and education about biodiversity and the impacts of logging, and the drawing up of a management plan including all terrestrial taxa for Choiseul Island forests.

scholarly journals Effects of Substrate on Movement Patterns and Behavior of Stream Fish through Culverts: An Experimental Approach

2019 ◽  
Vol 11 (2) ◽  
pp. 470 ◽  
Author(s):  
Kyla Johnson ◽  
Lindsay Wait ◽  
Suzanne Monk ◽  
Russell Rader ◽  
Rollin Hotchkiss ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Functional Groups ◽  
Fish Species ◽  
Swimming Behavior ◽  
Small Fish ◽  
Natural Substrate ◽  
Substrate Type ◽  
Low Velocity ◽  
Large Flow ◽  
Leatherside Chub

Culverts can provide a significant barrier to fish passage by fragmenting fish habitats and impeding the passage success of small-bodied fish. Geographical connectivity is critical to the maintenance of diverse fish assemblages. Culverts with high cross-sectional velocity can cause population fragmentation by impeding passage of small, freshwater fish. Behavioral responses of small fish to high velocities can differ among functional groups, and swimming behavior of many species is not well known. We tested effects of substrate type on swimming behavior in two small, freshwater fish species—southern leatherside chub (Lepidomeda aliciae, a midwater species), and longnose dace (Rhinichthys cataractae, a benthic species)—across three substrate treatments: (1) a bare flume, (2) large flow obstacles, and (3) a natural cobble substrate. Both longnose dace and southern leatherside chub used paths of low velocity and swam in the near-substrate boundary area. Fish in the bare flume and large obstacle treatments swam along the corners of the flume in a straight swim path, whereas fish in the natural substrate treatment used all parts of the flume bed. There was no relationship between passage success of fish and substrate type, fish species, or their interaction. In contrast, substrate type, fish species, and their interaction were significant predictors of passage time. Southern leatherside chub passed through the test section about two to four times faster than longnose dace. Both species took longer to pass through the large flow obstacle treatment compared to the bare flume or natural substrate. The natural substrate created a complex velocity profile with areas of low velocity throughout the entire flume, in contrast to the other two treatments. Our data suggest natural substrates can improve the passage of small fish in high-velocity culverts for both benthic and midwater functional groups.

scholarly journals Forecasting the future establishment of invasive alien freshwater fish species

2021 ◽  
Author(s):  
Sam Wenaas Perrin ◽  
Kim Magnus Bærum ◽  
Ingeborg Palm Helland ◽  
Anders Gravbrøt Finstad
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Freshwater Fish Species ◽  
The Future

Major threats to European freshwater fish species

2021 ◽  
pp. 149105
Author(s):  
Maria João Costa ◽  
Gonçalo Duarte ◽  
Pedro Segurado ◽  
Paulo Branco
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Freshwater Fish Species

Performance of a pool-and-weir fish pass for small bottom-dwelling freshwater fish species in a regulated lowland river

2007 ◽  
Vol 57 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Evelien Maerten ◽  
Marcel Eens ◽  
Guy Knaepkens
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Fish Assemblages ◽  
Regulated River ◽  
Lowland River ◽  
Stone Loach ◽  
Spined Loach ◽  
Freshwater Fish Species ◽  
Cottus Gobio ◽  
Fish Pass

AbstractAlthough small benthic freshwater fish species are an important biological component of fish assemblages and free instream movement is indispensable for their survival, they are often neglected in fish pass performance studies. In this study, a capture-mark-recapture approach was used to assess whether small bottom-dwelling species, including gudgeon (Gobio gobio), stone loach (Barbatula barbatula), spined loach (Cobitis taenia) and bullhead (Cottus gobio), were able to cross a pool-and-weir fish pass in a regulated lowland river. Some tagged individuals of stone loach (18%), gudgeon (7%) and spined loach (2%) managed to successfully ascend the fish pass under study, despite the fact that water velocity levels in the different overflows of the facility (between 0.55-1.22 m/s) exceeded the critical swimming speed of all three species. Although this suggests that a pool-and-weir fish pass is a able to facilitate upstream movement of some small benthic species in a regulated river, more detailed research incorporating advanced tagging and retrieving techniques is necessary.

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