Fish of channelized and unchannelized sections of the Bunyip River, Victoria

1983 ◽  
Vol 34 (3) ◽  
pp. 441 ◽  
Author(s):  
KG Hortle ◽  
PS Lake

The distribution and abundance of fish at three channelized and three unchannelized sites on the Bunyip River in southern Victoria were investigated. Ten species of native fish, including the Australian grayling (Prototroctes maraena), and two species of introduced fish were collected in three sets of seasonal samples by electrofishing. The unchannelized sites and a channelized site directly above a small weir had significantly higher species richness, total fish biomass, numerical density and standing crop (P<0.05) than the other two channelized sites. Ammocoete lamprey larvae, short-finned eels, southern pigmy perch and brown trout were most abundant at the unchannelized sites, whereas the common jollytail was most abundant at the channelized sites. Total numbers and biomass of fish and species richness were all positively correlated (P<0.01) with the area of snags present, and species richness and fish biomass correlated positively (P<0.01) with the area of slack water. It appears that the absence of suitable habitat (viz, area of snags, area of slack water, length of bank fringed with vegetation) accounts for the lower abundance and lower species richness of fish after channelization. A small weir at one of the channelized sites ameliorated partly the effects of channelization.

1994 ◽  
Vol 51 (5) ◽  
pp. 1128-1138 ◽  
Author(s):  
Clay L. Pierce ◽  
Joseph B. Rasmussen ◽  
William C. Leggett

We assessed species richness, biomass, and community type of littoral fish in 10 southern Quebec lakes in relation to several limnological and prey resource variables. Lake, yearly, and seasonal variation in biomass was evaluated by quantitative, replicated seining. Species richness averaged 12.8 in our lakes, and 24 species were collected overall. Total littoral fish biomass averaged 13.5 g∙m−2 overall and varied significantly among lakes (range 6.1–26.9 g∙m−2) and between early and late summer. Yellow perch (Perca flavescens), golden shiner (Notemigonus crysoleucas), and pumpkinseed (Lepomis gibbosus) occurred in all lakes and were the most abundant species overall, averaging 57% of the total fish biomass. Principal component ordination of littoral fish communities showed little evidence for aggregation of community types. Species richness was positively correlated with lake surface area (r2 = 0.62), as has been shown in other studies. Total fish biomass was positively correlated with biomass of chironomids (r2 = 0.57), which constituted 24% of the littoral invertebrate biomass in our lakes and are important prey of many fish species. We found no significant correlation between total fish biomass and total invertebrate biomass or between biomass of any of the dominant fish species and limnological or prey variables.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4455 ◽  
Author(s):  
Janina Seemann ◽  
Alexandra Yingst ◽  
Rick D. Stuart-Smith ◽  
Graham J. Edgar ◽  
Andrew H. Altieri

Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfishScarus isericomprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.


2021 ◽  
pp. 167-173
Author(s):  
Norce Mote ◽  
Rosa Delima Pengaribuan

Wetland or stagnant swamp refers to an ecosystem of inland water that is vulnerable to population decline. Kampung Nasem in Merauke has quite promising fish resources. This research aimed to determine the diversity of fish species found in Kampung Nasem of Merauke. The fish sampling was performed for three months, from September to November 2017 at three research stations by functioning digital camera, ruler and manual as tools for documentation, while tool for fishing used gill net in the size of 1, 1.5, 2, 2.5, 3 and 4 inches; casting nets and scoop net. Fish found in the field were preserved with 10% formalin for identification purpose in the laboratory. The observed biological parameters were species richness, diversity index (H’), evenness index (E) and dominance index (C). The research finding obtained 15 fish species richness coprising 11 native fish species and 5 introduced fish species. The value of H’ was classified into moderate while the uniformity value was high, hence the fish were spread evenly in each research site and no species was found with domination. In addition, the Tilapia (Oreochromis niloticus) and Glass (Agrammus ambassadors) were species to have sufficient widespread distribution and numerous presence of presentation within the three research stations.


2021 ◽  
Author(s):  
Rick Stafford ◽  
Zach Boakes ◽  
Alice Hall ◽  
Georgia Jones

Abstract The ocean is a net sequester of carbon dioxide, predominantly through low biomass, high productivity phytoplankton photosynthesis. Selective removal of predatory fish through extractive fishing alters the community structure of the ocean, with an increased biomass of more productive, low trophic level fish and higher overall respiration rates, despite possible decreases in total fish biomass. High pressure fishing on predators may result in as much as a 19% increase in respiration from fish communities and could prove highly significant in global carbon budgets.


Check List ◽  
2009 ◽  
Vol 5 (2) ◽  
pp. 154 ◽  
Author(s):  
Renildo Ribeiro de Oliveira ◽  
Marcelo Salles Rocha ◽  
Maeda Batista dos Anjos ◽  
Jansen Zuanon ◽  
Lúcia H. Rapp Py-Daniel

This study was conducted in an Amazonas state conservation unit, the Catuá-Ipixuna Extractive Reserve (Catuá-Ipixuna RESEX). The main purpose was to provide an ichthyological survey of its small streams, all them tributaries of the Solimões River. Nine small streams (up to 4 m width and 1 m depth) were sampled in September 2006. A total of 1,525 specimens were captured, belonging to 78 species, 24 families and eight orders. Eight species had higher abundances and represented altogether 61.4 % of all collected specimens (Hemigrammus belotii, Microphilypnus amazonicus, Physopyxis ananas, Apistogramma agassizii, Elachocharax pulcher, Apistogramma cf. cruzi, Gladioglanis conquistador and Copella nigrofasciata). Based on the high number of singletons and doubletons present in our samples, as well as the estimated number of species for those streams (106 spp.), we believe that the total fish species richness present in the Catuá-Ipixuna Extractive Reserve may be considerably higher than indicated by our samples. This seems especially true when considering the dimensions of the Catuá-Ipixuna RESEX and the dense hydrographic network present in the area.


1983 ◽  
Vol 61 (11) ◽  
pp. 2446-2464 ◽  
Author(s):  
Lawrence C. Halyk ◽  
Eugene K. Balon

Fish species richness in floodplain pools results from species addition by spring invasion from the stream and species subtraction by local extinction throughout the summer. Local extinction is the more important of the two components. Nineteen floodplain pools (1 to 597 m2) and an adjacent section of Irvine Creek (43°44′ N, 80°25′ W), Ontario, Canada, were treated with a piscicide to test if the pools contribute significantly to the resource potential of the river basin. Altogether, 41 626 fishes of 20 species were collected. Number of days of stream connection in the spring was not significantly correlated with fish species richness in the pools (P < 0.10). A significant correlation (P < 0.05, r = 0.7413) was found between species richness and the logarithm of pool area. The total fish production for the Irvine Creek section, adjusted to account for dominant and nondominant species, was 298 kg∙ha−∙year−1. Production for this site was underestimated by 49% when weights and densities were backcalculated to time of annulus formation. Total production estimates of the floodplain pools ranged from 135 to 314 kg∙ha−1∙year−1. Stream connection duration affects pool fish production by regulating accessibility to the young of stream spawning species. Floodplain pools are beneficial to the Irvine Creek system. As nursery areas, floodplain pools produce fish biomass which can return to the stream during periods of stream–pool connection. These pools may also act as fish havens if catastrophic stream mortality occurs.


1980 ◽  
Vol 31 (1) ◽  
pp. 61 ◽  
Author(s):  
PD Jackson ◽  
WD Williams

Eight species of native fish and two of introduced fish were found during studies of the distribution of fishes in streams in three areas of southern Victoria; namely in the upper part of the catchment of the Yarra River, in the Otway Ranges, and on Wilsons Promontory. S. trutta does not occur on Wilsons Promontory, but does occur in the other two areas. Results provide circumstantial evidence that S. trutta has deleteriously affected the occurrence of Galaxias olidus and possibly G. brevipinnis. Some native fishes appear able to coexist with S. trutta.


2020 ◽  
Vol 47 (2) ◽  
pp. 186
Author(s):  
Yuqing Chen ◽  
Bruce Doran ◽  
Sharyn Sinclair-Hannocks ◽  
John Mangos ◽  
Philip Gibbons

Abstract ContextThe common brushtail possum (Trichosurus vulpecula) is a protected native species in Australia that can access buildings in urban areas and cause considerable damage or disruption to building occupants. Although several strategies to discourage this species from entering buildings have been recommended, few have been evaluated empirically. AimsOur study aims to analyse how landscaping and building construction influence occupancy of buildings by the common brushtail possum. MethodsWe collated reports of possums occupying 134 buildings over 12 years on the campus of The Australian National University (ANU), in the Australian Capital Territory (ACT). We used generalised linear modelling (GLM) to identify associations between the total number of reported possum-related incidents for buildings and a range of landscape and building characteristics. Key resultsControlling for the effect of building size, we found that the number of reported possum-related incidents in buildings was positively associated with the percentage of tree and shrub canopy cover within the calculated home-range buffer distance of 49m from buildings, length of canopy overhanging roofs and building age, and negatively associated with tree species richness and number of trees with natural hollows and nest boxes within 49m of buildings. There were likely to be more possum-related reports from buildings in areas where the dominant tree genus was native, buildings with parapets (walls extending above the roof), buildings with structures penetrating from the roof, buildings with tile roofs and gable roofs. ConclusionsA combination of suitable habitat surrounding buildings, suitable access to the roofs of buildings and weak points in building roofs (e.g. parapets, roof penetrations), makes them more vulnerable to occupancy by the common brushtail possum. Implications Our results provided clues for managing existing buildings, or designing new buildings, in a way that may reduce the likelihood of occupancy by the common brushtail possum. Our study also demonstrated how building-maintenance records can be used to address human–wildlife conflict over time.


Parasitology ◽  
2004 ◽  
Vol 128 (3) ◽  
pp. 305-313 ◽  
Author(s):  
A. M. BAGGE ◽  
R. POULIN ◽  
E. T. VALTONEN

The diversity and abundance of parasites vary widely among populations of the same host species. These infection parameters are, to some extent, determined by characteristics of the host population or of its habitat. Recent studies have supported predictions derived from epidemiological models regarding the influence of host population density: parasite abundance and parasite species richness are expected to increase with increasing host population density, at least for directly transmitted parasites. Here, we test this prediction using a natural system in which populations of the crucian carp, Carassius carassius (L.), occur alone, with no other fish species, in a series of 9 isolated ponds in Finland. The ectoparasite communities in these fish populations consist of only 4 species of monogeneans (Dactylogyrus formosus, D. wegeneri, D. intermedius and Gyrodactylus carassii); the total and relative abundance of these 4 species varies among ponds, with one or two of the species missing from certain ponds. Across ponds, only one factor, total fish population size, explained a significant portion of the variance in both the mean number of monogenean species per fish and the mean total abundance of monogenean individual per fish. In contrast, fish population density did not influence either monogenean abundance or species richness, and neither did any of the other variables investigated (mean fish length per pond, number of fish examined per pond, distance to the nearest lake, and several water quality measures). In our system, proximity among fish individuals (i.e. host population density) may not be relevant to the proliferation of monogeneans; instead, the overall availability of host individuals in the host population appeared to be the main constraint limiting parasite population growth.


1999 ◽  
Vol 47 (1) ◽  
pp. 87 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
C. Palmer ◽  
A. Fisher ◽  
K. Brennan ◽  
R. Southgate ◽  
...  

Eighteen non-marine mammal species (including seven species of bats) were recorded from a total of 49 islands in the Wessel and English Company island chains off north-eastern Arnhem Land, Northern Territory. Most individual species were restricted to, or had higher incidence on, larger islands, and species richness as a whole increased as island size increased. The most notable exception was the semi-aquatic Hydromys chrysogaster, which occurred relatively equitably across island sizes; this species, two bat species and the macropod Petrogale brachyotis were recorded from islands smaller than 10 ha. However, the variation between islands in the number of native terrestrial mammal species was not best predicted by island size, but rather by a combination of sampling effort and altitude (which explained 64% of the deviance in species richness), or altitude and distance to larger land mass (explaining 63% of deviance). Richness–area patterns for individual islands in these chains were reasonably consistent with those of other islands sampled in northern Australia. However, the fauna of the Wessel and English Company groups as a whole was less rich than that of the Pellew and Kimberley islands, and individual islands appeared to have lower species richness than comparable mainland areas. Species that were notably absent or that were recorded from relatively few islands include large macropods, Tachyglossus aculeatus, Antechinus bellus, Phascogale tapoatafa, Sminthopsis spp., Mesembriomys gouldii, Rattus colletti, Leggadina lakedownensis and Pseudomys calabyi. Some of these species may be absent through lack of suitable habitat; others have presumably disappeared since isolation, possibly due to Aboriginal hunting. Richness at the quadrat (50 × 50 m) scale was generally very low. Habitat relationships are described for the 7 species recorded from more than 5 quadrats. At a quadrat-scale, the richness of native mammals was greater on islands larger than 1000 ha than on islands smaller than 1000 ha. Quadrat-scale species richness varied significantly among the islands sampled by the most quadrats (even when the comparison was restricted to either of the two most extensive vegetation types), but this variation was not closely related to either area or altitude. The two most frequently recorded species, the rodents Melomys burtoni and Zyzomys argurus, showed distinct habitat segregation on islands where both were present, but tended to expand their habitat range on islands where only one of the species occurred. The most notable conservation feature of the mammal fauna of the Wessel and English Company Islands is the occurrence of the golden bandicoot, Isoodon auratus, a vulnerable species apparently now extinct on the Northern Territory mainland. Four feral animal species (Rattus rattus, Canis familiaris, Bubalus bubalis and Capra hircus) were recorded from a total of 6 islands.


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