Design features of constructed floodplain ponds influence waterbird and fish communities in northern New Zealand

1. Ponds can provide important refuges for aquatic biota on developed floodplains and are increasingly being constructed in an effort to enhance native biodiversity and ecosystem services in degraded landscapes. This study examined 34 constructed ponds to investigate the influence of design features on community composition, native biodiversity, and the biomass or abundance of common fish and waterbirds on the lower Waikato River floodplain, northern New Zealand.
2. Inundation frequency appeared to be a key factor affecting biomass of the native shortfin eel Anguilla australis and three invasive fish species (common carp [Cyprinus carpio], brown bullhead [Ameiurus nebulosus], and goldfish [Carassius auratus]), suggesting that colonisation occurred during flooding by adjacent waterbodies. Linear models indicated that shortfin eel abundance and total eel biomass were positively associated with the biomass of potential fish prey, the area occupied by islands and cover by trees in the riparian zone.
3. Native waterbird species richness was strongly related to water area, edge length (including islands) and area:perimeter ratio, with little increase in richness for ponds >1 ha in area, perimeters longer than 800 m, and ratios over 20. The protected grey teal (Anas gracilis), and the recreationally hunted species phenotypically assigned as mallard (Anas platyrhynchos + hybrids) and grey duck (Anas superciliosa + hybrids) appeared most strongly influenced, respectively, by perimeter length, water depth, and biomass of potential macroinvertebrate food supplies, suggesting variable effects of pond design attributes among waterfowl species.
4. Overall, these results indicate that constructed ponds can be designed to promote native waterbird diversity, enhance eel fishery and waterfowl gamebird services, and also limit the proliferation of some non-native invasive fish species in degraded floodplain landscapes. A hierarchy of constructed pond design attributes was identified, involving landscape position and connectivity, pond morphology and complexity, and riparian maturity and buffering, which were associated with direct (habitat) and indirect (food supply, physicochemistry) effects on biodiversity and provisioning services.

     

Summer algal communities and primary productivity in fish ponds

The paper presents data on primary productivity and phytoplankton communities in new experimental ponds which received the following treatments; ammonium nitrate and triplesuperphosphate, triplesuperphosphate, cracked corn (10% crude protein) and Auburn No. 3 fish feed (36% crude protein). Comparative data on algal communities were also obtained from production ponds which received feeds or fertilizers. Basic ecological data on macro-algae are also presented.

1. All nutrient additions to experimental ponds resulted in higher levels of gross photosynthesis and greater concentrations of chlorophyll a than were found in the control treatments. Fertilization with both nitrogen and phosphorus gave the highest values. Chlorophyll a and gross photosynthesis were higher in ponds receiving high protein content feed (Auburn No. 3) than in ponds to which low protein content feed (corn) was applied.
2. Persistent blooms of blue-green algae occurred in ponds receiving nitrogen and phosphorus fertilization. Phosphorus only fertilization produced blooms of blue-greens, but these blooms did not persist as in the ponds to which nitrogen was also added. Control ponds were dominated by green algae. Blue-green algae were seldom abundant in feed treatments.
3. Production ponds had high level of gross photosynthesis and large concentrations of chlorophyll a.
4. Many of the production ponds which received feed applications developed heavy blooms of blue-green algae.
5. The major species of blue-green algae observed in the present study were Oscillatoria sp., Raphidiopsis curvata, Anacystis nidulans, A. aeruginosa, Spirulina sp., and Anabaena circinalis. Heterocyst bearing forms, which can presumably fix nitrogen, were seldom noted in ponds that received continuous additions of nitrogen from fish feeds.
6. Macro-algae are abundant in many fish ponds. Data illustrating the competition of macro-algae with phytoplankton are presented.

     

Impact of exotic fish removal on native communities in farm ponds

Introduced largemouth bass (Micropterus salmoides spp.) and bluegill (Lepomis macrochirus spp.) are thought to threaten native aquatic organisms worldwide and hence their eradication has recently begun in Japan. Our previous studies suggested that the removal of largemouth bass increases native fish, shrimp, dragonflies, and exotic crayfish, but decreases macrophytes. To test this prediction, we removed the exotic fishes by draining farm ponds and compared the numbers of these organisms before and after the drain, as well as between drained and undrained ponds. The number of dragonfly Pseudothemis zonata, crayfish, shrimp, and goby increased rapidly after the drain, but the coverage of macrophyte declined. The reduction in macrophyte is assumed to be caused by increased herbivory by crayfish. The number of exuviae of damselfly Cercion calamorum and the total number of species of odonate also decreased after the drain. These decreases can be due to the reduction of macrophyte because reduced odonate species are known to use macrophytes as oviposition sites. Therefore, the removal of largemouth bass has a potential to cause negative effects on some native organisms. We propose that reduction of exotic crayfish should be considered when eradicating the exotic fishes.     

Relationships between habitat structure and fish communities on coral

The influence of habitat structure on reef-fish communities at Bar Reef Marine Sanctuary, Sri Lanka, was investigated. The relationship between habitat characteristics and the distribution and abundance of 135 species of fishes was examined on two reef types: coral and sandstone reefs. Results suggested that the reef-fish communities were strongly influenced by various aspects of reef structure. However, relationships between habitat variables and fish communities structure, varied between the two reef types. Fish species diversity was correlated with a number of habitat variables on the sandstone reefs, although structural complexity seemed to play the dominant role. There were no correlations between habitat structure and fish diversity on the coral reefs. Total abundance was not related to any one habitat parameter on either reef type. However, abundances of some species, families and trophic groups were correlated with habitat features. These specific correlations were commonly related to food or shelter availability. For example, coral feeders were correlated with live coral cover, and pomacentrid species, which used branching corals for protection, showed a significant relationship with the density of Acropora colonies. This shows that a summary statistic such as total abundance may hide important information. Effects of habitat structure on the distribution patterns of the fish communities was further investigated using multi-dimensional scaling ordination (MDS) and the RELATE-procedure. With the MDS ordinations for both habitat and fish-community composition it was possible to show that the multivariate pattern between the two ecological components was clearly correlated.     

The role of historic and climatic factors in the distribution of crustacean communities in Iberian Mediterranean ponds

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Direct and indirect impacts of wildfire on faunal communities of Mediterranean temporary ponds

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Effects of fish predation and habitat type on stream benthic communities

The influence of habitat on interactions between a fish predator (brown trout Salmo trutta) and a benthic invertebrate community was studied in nine field enclosures (8 ×3 m) in a creek in southern Sweden. Three habitat treatments were tested, a shallow sandy habitat, a deep habitat containing a mixture of large and small cobbles and a moderately deep habitat with large cobbles. The one month-long experiment showed that there were no major differences in the abundance and biomass of the benthic macroinvertebrate fauna among these habitats as no functional groups of invertebrates and only a few taxa differed between treatments. Invertebrate drift rates decreased over time, which was probably related to seasonal changes in invertebrate life cycles or to effects of predation independent of habitat type, as there was no difference between treatments.     

Personality‐related differences in response to habitat in Mediterranean blue tits

Habitat‐specific selection pressures have been widely recognized, but whether selection favours different personality types in different habitats has rarely been evaluated. This study aimed to test whether personality‐related differences in annual reproductive success differed between two populations of blue tits (Cyanistes caeruleus) occupying different Mediterranean habitats (oakwood and pinewood). We measured exploration and parental provisioning behaviours and used a path analysis to ask how the interplay between these two behavioural traits affected reproductive success in each of these two habitats. We found that blue tits breeding in the pinewood were slow‐exploring compared to blue tits breeding in the oakwood, suggesting the occurrence of personality‐related differences in settlement, or behavioural plasticity in response to habitat. Exploration behaviour and feeding rates were positively associated, suggesting that they affect each other or that there is an environmental factor affecting both traits simultaneously. Finally, fast explorers were favoured in the pinewood, while there was no selection acting on exploration behaviour in the oak habitat. These findings emphasize the importance of integrating habitat selection, plasticity and personality in the study of behavioural evolution.     

Depauperate freshwater fish communities in Sabah: the role of barriers to movement and habitat quality

Up to 30 species of fish were generally found in medium-sized rainforest streams in Sabah, Malaysia. However, depauperate fish communities were found in two streams above large (>8 m) waterfalls (five and nine species) and in two very small streams located in deep forest (five and six species). A fifth stream with small cascades and waterfalls had a faunal list of 12 species. Species resident above waterfalls were predominantly herbivores while fishes in the two forest streams were from a variety of trophic groups. Abundance and biomass of fishes above waterfalls were significantly lower than all other sites. A translocation experiment was performed in one stream to distinguish between the hypotheses that fish communities above waterfalls were determined solely by colonization ability and were unsaturated with species or that they were limited by habitat quality or food. Seven species (775 individuals) were trans located into one isolated section and four species (570 individuals) into another. Species that were trans located included trophic groups that were not represented by resident species. Twelve months after translocation, only four and one trans located species were collected in the two sections, all at greatly reduced densities. After 20 months, the number of species were three and two, respectively. One trans located species, Rasbora sumatrana , had increased in abundance from 12 months and juveniles were present in the population. Individuals of other trans located species appeared to be remnants of stocked populations. Abundance and biomass of resident species fluctuated widely between years. Interpretation of results was complicated by a large flood which substantially changed habitat conditions about a month after translocations were performed. It is suggested that two different factors were responsible for depauperate communities: movement barriers for waterfall sites and physicochemical conditions and/or habitat availability at other sites.     

A spatial approach to matching marine fish diversity and abundance with habitat features

Current issues in marine resource management have in common a geospatial component and a need to integrate both biotic and abiotic data from various sources. We propose a practical approach to address these issues looking at the American plaice (Hippoglossoides platessoides) and the demersal fish fauna in the Gulf of St. Lawrence (Canada). Central to our approach was the use of a common spatial grid and three different methods to match biotic and abiotic features at a broad regional scale, (1) matching plaice distribution with habitat categories determined a priori on the basis of abiotic features (cluster analysis), (2) habitat categories determined taking into consideration both plaice density and abiotic features (simple regression tree), and (3) habitat categories determined taking into consideration demersal fish species density (70 fish species) and abiotic features (multivariate regression tree, MRT). Hot spots and cold spots of plaice abundance in summer were described and matched with specific habitats. The spatial distribution of habitats was similar whether biotic variables were used in the classification or not. The MRT, however, identified 56 different fish species in the plaice habitat (median species richness by 100 km² cell = 12), pointing to potential interactions with other fish species.     

The effects of an abandoned roast yard on the fish and macroinvertebrate communities of surrounding beaver ponds

Recently formed beaver-ponds surrounding an abandoned copper-nickel ore roast yard near Sudbury, Ontario, Canada, were influenced by highly acidic and heavy-metal contaminated effluent. Fish, including Culaea inconstans, Phoxinus neogaeus, Phoxinus eos, and Pimephales promelas, were found in the ponds upstream of the roast yard only. Macroinvertebrate taxon richness and diversity were greater in the upstream ponds than in the downstream ponds. Acid intolerant taxa, including Mollusca and Hyalella azteca, were found upstream only; acid tolerant taxa, including Enallagma and Ischnura (Odonata: Coenagrionidae) were found in the downstream ponds. One taxon, a species of Chironomus, was especially tolerant of both acid and metal stresses, and was the only invertebrate taxon found in the pond located directly on the roast yard itself. We conclude that long-abandoned mining and refining sites can continue to have a marked effect on aquatic communities.     

Spatial patterns and GIS habitat modelling of fish in two French Mediterranean coastal areas

The spring and summer distribution of adults and larval fish stages of Sparids and Scorpaenids was studied in two sites in the western Mediterranean. Fish adults and larvae of those two taxa were identified and sorted according to their life stages in order to study their distribution and develop suitable habitat maps. Study areas were located on French coastal waters, the “Côte Bleue” Marine Park (CBMP) has an east-west orientation with substratum dominated by Posidonia beds and the Marine Reserve of Cerbère-Banyuls (MRCB) runs north–south and is dominated by rocky substrates. Generalised Additive Models (GAM) combined with Geographic Information System (GIS), were used to model the suitable habitats for fish larvae and adults. During spring months, waters exhibit low Sea Surface Temperatures (SST), low Photosynthetically Active Radiation (PAR), high values of Sea Surface Chlorophyll-a concentration (Chl-a), and mostly negative values of Sea Level Anomaly (SLA) indicating anticyclonic eddies. During summer months, waters have higher values of SST, lower values of Chl-a and positive values of SLA indicating cyclonic eddies. The results revealed different environmental responses in the distribution of fish adults and larvae in the CBMP and MRCB. Suitable habitats for adult were mainly dependent on the substrate types (Posidonia meadows and sand) and they were found close to the coast, whereas fish larvae were dependent on environmental cues (Chl-a, SLA, SST) with a sparse spatial distribution.     

Stream fish communities and their associations to habitat variables in a rain forest reserve in southeastern Brazil

This paper describes the spatial variability of fish communities and identifies patterns of association between fish communities and habitat variables, including anthropogenic factors. We sampled streams inside and in the surroundings of a rain forest reserve in the southeast of Brazil in the rainy season. We could distinguish three main groups of streams: upland streams (draining the upland, flat portions of the mountain ridge of Serra de Paranapiacaba), adventitious streams of clearwater mountain torrents (small streams draining confined valleys in the slopes of this sierra), and large streams of clearwater mountain torrents (relatively unconstrained large streams close to the foots of the mountains). Despite the high variability of fish communities associated with these streams we identified some patterns using exploratory statistical analyses. These patterns were corroborated by additional field observations and information from the scientific literature. The main differences in fish community composition and diversity among the three groups of streams are probably related to large-scale factors such as elevation and position of the stream in the watershed. However, differences within these three groups seem to be mostly due to site-specific factors. Differences of instream characteristics are likely to be caused by natural variability of the ecosystems but also, in some cases, by human disturbances like pollution from human settlements, agriculture and mining.     

Changes in trophic state and aquatic communities in high Arctic ponds in response to increasing goose populations

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The restoration of fish ponds in agricultural landscapes

Fish ponds in central and eastern Europe are artificial lakes of less than 1 ha to several 100 ha in size. Some of them were created around 900 years ago. These fish ponds form an important part of the hydrological system in the landscape; they also serve as water purification systems and sediment traps, provide habitat for many plant and animal species, as well as being used for recreation purposes—but above all, they are dedicated to fish production. The original oligo- or mesotrophic character of these fish ponds has been altered to one of eutrophic or even hypertrophic conditions due to the nature of the intensive management for high fish production, as well as agriculture practices within the catchment area. It can also be due to other uses of fish ponds, such as wastewater recipients. A thick layer of black anaerobic sediment invariably develops and serves as an uncontrolled internal source of nutrients. In order to stop the development of water blooms and restore the lake to reasonable healthy conditions, both the external and internal loading has to be reduced. An example of such a fish pond restoration within the Czech Republic is described. The phosphorus budget of the Vajgar fish pond (40 ha, S Bohemia) was evaluated and the dry matter, organic matter, nutrients, heavy metals and other metals content were estimated in the vertical profile of the fish pond's sediment. A precision suction dredger was designed, constructed, and used for the selective removal of 330 000 m³ black sediment from the Vajgar fish pond. The sediment was pumped to settling ponds at a distance of 2.5 km. Later, the suction dredger was used for sediment removal from other fish ponds. In one case, 40 000 m³ of eutrophic sediment was directly applied on an agriculture field. In another case, sediment containing oil products was decontaminated by using a biocatalyst and bacterial culture. Sediment removal from Vajgar fish pond resulted in a temporary negative phosphorus budget (lower concentrations in the outflow than the inflow). The temporary absence of cyanobacteria (Microcystis sp.) blooms was the result of the removal of the black sediment layer. The improvement of water quality after sediment removal was, however, temporary. A more holistic approach, aimed at the reduction of matter losses from the fish pond's catchment area, is therefore being adopted. The principles of such an holistic approach are described.     

The diversity of macro invertebrate and macrophyte communities in ponds

SUMMARY 1. The range of factors which may influence the wide variation in the structure of pond communities is reviewed.
2. Factors explaining the variation in numbers of macro invertebrate and macrophyte taxa are investigated, using multiple regression analysis, for a group of ponds in which biogeographical effects are likely to be minimal.
3. Numbers of macro invertebrate taxa in these ponds are highly correlated with pH and probably, therefore, with other associated aspects of water chemistry,
4. Many invertebrate taxa, from species to entire phyla, were not found below pH 5.5, but few characteristically'acidophilic'taxa were apparent.
5. Details of species composition of the macro invertebrate fauna differ widely even between ponds of similar pH.
6. The diversity and composition of macrophyte communities are not adequately predicted by any of the factors investigated.     

Comparing fish assemblages and trophic ecology of permanent and intermittent reaches in a Mediterranean stream

Mediterranean streams are characterised by seasonal droughts, the frequency and intensity of which vary spatially and are expected to increase with global change. We studied the potential effects of drought and climate change on the fish assemblage and its trophic ecology in a Mediterranean stream by comparing an intermittent tributary with two more permanent neighbouring reaches. Although the three sites were dominated by the same two fish species, Mediterranean barbel (Barbus meridionalis) and chub (Squalius laietanus), the intermittent tributary had a lower overall fish density and fewer eel (Anguilla anguilla). The intermittent tributary had macroinvertebrates with lower density, smaller taxa and higher diversity. Fish in the intermittent tributary had significantly lower biomasses in their gut contents (adjusted for fish length) and more negative electivities than those in the permanent reaches, as well as significantly lower taxonomic diversity. These results indicate that there was reduced resource availability in the intermittent tributary, which resulted in significantly lower condition and gonadal weight (adjusted for length) of barbel and chub. The data obtained in this Mediterranean stream support the observation that reduced water flow may affect fish at both individual and assemblage levels.     

Exploitation and habitat degradation as agents of change within coral reef fish communities

Over‐exploitation and habitat degradation are the two major drivers of global environmental change and are responsible for local extinctions and declining ecosystem services. Here we compare the top‐down effect of exploitation by fishing with the bottom‐up influence of habitat loss on fish communities in the most diverse of ecological systems, coral reefs. Using a combination of multivariate techniques and path analyses, we illustrate that the relative importance of coral cover and fishing in controlling fish abundance on remote Fijian reefs varies between species and functional groups. A decline in branching Acropora coral is strongly associated with a decline in abundance of coral‐feeding species, and a decrease in coral‐associated habitat complexity, which has indirectly contributed to reduced abundance of small‐bodied damselfish. In contrast, reduced fishing pressure, brought about by declining human populations and a shift to alternate livelihoods, is associated with increased abundance of some piscivores and fisheries target species. However, availability of prey is controlled by coral‐associated habitat complexity and appears to be a more important driver of total piscivore abundance compared with fishing pressure. Effects of both fishing and coral loss are stronger on individual species than functional groups, as variation in the relative importance of fishing or coral loss among species within the same functional group attenuated the impact of either of these potential drivers at the functional level. Overall, fishing continues to have an influence on Fijian fish communities; however, habitat loss is currently the overriding agent of change. The importance of coral loss mediated by climate change is expected to have an increasing contribution to fish community dynamics, particularly in remote locations or where the influence of fishing is waning.