Effects of an anti-salt intrusion dam on tropical fish assemblages

2010 ◽  
Vol 61 (3) ◽  
pp. 288 ◽  
Author(s):  
Tuantong Jutagate ◽  
Amonsak Sawusdee ◽  
Thanitha Thapanand-Chaidee ◽  
Sovan Lek ◽  
Gaël Grenouillet ◽  
...  
Keyword(s):  
Species Richness ◽  
Chlorophyll A ◽  
Environmental Conditions ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Tropical Fish ◽  
Food Sources ◽  
Salt Intrusion ◽  
Open Phase ◽  
Salinity Gradients

Following the construction of an anti-salt intrusion dam in Pak Panang River, Thailand, changes in the environmental conditions and fish assemblages were monitored both in the estuary and in the river. The present study was conducted during two different phases: when the sluices were open; and when they were closed. Salinity in the estuary declined (P < 0.001), but increased in the river during the open phase (P = 0.002). In the river, the pH increased (P < 0.001) during the closed phase, but was relatively constant in the estuary. No differences were found for water temperatures, chlorophyll a and abundance of phytoplankton. During the closed phase, the abundance of zooplankton was higher in the estuary, but the abundance of benthos in the river declined. Ninety-four fish species were collected. Species richness and the diversity index did not differ in the estuary, but were significantly different in the river; abundance was higher during the open phase. Fish moved between the two systems during the open phase and changes in fish assemblages correlated with salinity gradients and food sources. Sluice regulation to allow fish to move between the river and the estuary is recommended.

Distribution, abundance, and diversity of stream fishes under variable environmental conditions

2006 ◽  
Vol 63 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Christopher M Taylor ◽  
Thomas L Holder ◽  
Riccardo A Fiorillo ◽  
Lance R Williams ◽  
R Brent Thomas ◽  
...  
Keyword(s):  
Species Richness ◽  
Environmental Conditions ◽  
Community Dynamics ◽  
Local Community ◽  
Fish Assemblages ◽  
Fish Distribution ◽  
Stream Fish ◽  
Spatial And Temporal Variability ◽  
Regional Patterns ◽  
Abundance And Diversity

The effects of stream size and flow regime on spatial and temporal variability of stream fish distribution, abundance, and diversity patterns were investigated. Assemblage variability and species richness were each significantly associated with a complex environmental gradient contrasting smaller, hydrologically variable stream localities with larger localities characterized by more stable flow regimes. Assemblages showing the least variability were the most species-rich and occurred in relatively large, stable environments. Theory suggests that species richness can be an important determinant of assemblage variability. Although this appears to be true in our system, we suggest that spatial and temporal heterogeneity in the environment largely determines both assemblage richness and variability, providing a more parsimonious explanation for the diversity–variability correlation. Changes in species richness of local assemblages across time were coordinated across the landscape, and assemblages formed spatially and temporally nested subset patterns. These results suggest an important link between local community dynamics and community-wide occurrence. At the species level, mean local persistence was significantly associated with regional occurrence. Thus, the more widespread a species was, the greater its local persistence. Our results illustrate how the integrity of local stream fish assemblages is dependent on local environmental conditions, regional patterns of species distribution, and landscape continuity.

scholarly journals Benthic structure drives butterflyfish species composition and trophic group abundance

2019 ◽  
Author(s):  
Miguel Barbosa ◽  
Neil Coupland ◽  
Clara Douglas ◽  
Ellen Harrison ◽  
Kelly M James ◽  
...  
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblages ◽  
Coral Cover ◽  
Food Sources ◽  
Fish Diversity ◽  
Live Coral ◽  
Benthic Composition

Corals provide structure and food sources vital for the maintenance of coral reef fish diversity. However, coral reefs are currently under threat from climate change, which has led to the largest recorded loss of live coral. The loss of live coral, and corresponding shift in reef benthic composition, are predicted to impact the abundance and composition of coral reef fish species and communities. In this study, we investigate the effect of changes in reef benthic composition (eg. live coral, dead coral, algae), on the diversity and composition in an assemblage of butterflyfish species, in Faafu Atoll in the Maldives after the 2016 bleaching event. We show that differences in community composition of butterflyfish are associated to benthic structure, reflecting species feeding preferences. Interestingly, however, we also show that lower coral cover is not associated to lower abundance and species richness of butterflyfish. Our results suggest that maintenance of coral reef structure after a disturbance provides key microhabitats to accommodate non-corallivorous butterflyfish, thus maintaining abundance and species richness. Overall our study provides support for regulation of richness and abundance of coral reef fish assemblages to short term changes in coral reef benthic composition after disturbance via turnover in composition.

scholarly journals Seagrass Structural Traits Drive Fish Assemblages in Small-Scale Fisheries

2021 ◽  
Vol 8 ◽  
Author(s):  
Benjamin L. Jones ◽  
Lina M. Nordlund ◽  
Richard K. F. Unsworth ◽  
Narriman S. Jiddawi ◽  
Johan S. Eklöf
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Fish Assemblages ◽  
Human Impacts ◽  
Structural Complexity ◽  
Tropical Fish ◽  
Small Scale ◽  
Seagrass Species ◽  
Seagrass Meadows ◽  
Seagrass Cover

Seagrasses – a group of foundation species in coastal ecosystems – provide key habitat for diverse and abundant faunal assemblages and support numerous ecosystem functions and services. However, whether the habitat role of seagrasses is influenced by seagrass diversity, by dominant species or both, remains unclear. To that end, we sought to investigate the specific seagrass characteristics (e.g., species diversity, seagrass traits) that influence tropical fish assemblages, and place this in the context of small-scale fishery use. We surveyed seagrass variables at 55 plots, nested within 12 sites around Zanzibar (Tanzania) in the Western Indian Ocean, and used Baited Remote Underwater Video (BRUV) systems to assess fish assemblages across plots. Using linear mixed models, we reveal that seagrass structural complexity and depth were the best predictors of fish abundance, with higher abundance occurring in deeper meadows or meadows with high canopy, leaf length and number of leaves per shoot. Moreover, an interaction between seagrass cover and land-use was the best predictor of fish species richness, where sites closer to human impacts were less affected by cover than sites with lower human impact. Overall, models with seagrass species richness or functional diversity as predictors poorly explained fish assemblages. Fish taxa that were important for small-scale fishery sectors (e.g., emperors, snappers, rabbitfish, and parrotfish) were primarily driven by seagrass structural complexity. Our results provide a unique analysis of the relationship between seagrass habitat and its associated fish assemblages in that we show that seagrass species diversity had little effect on seagrass fish assemblages, which instead appear driven by specific seagrass traits and seagrass cover. If conserving high value species that support adjacent fisheries is the priority for protecting seagrass meadows, then seagrass areas should be chosen with high cover and structural complexity that are in deeper waters. Any conservation measures also need to balance the needs of fishers that use the resources supported by seagrasses.

scholarly journals Benthic structure drives butterflyfish species composition and trophic group abundance

2019 ◽  
Author(s):  
Miguel Barbosa ◽  
Neil Coupland ◽  
Clara Douglas ◽  
Ellen Harrison ◽  
Kelly M James ◽  
...  
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblages ◽  
Coral Cover ◽  
Food Sources ◽  
Fish Diversity ◽  
Live Coral ◽  
Benthic Composition

Corals provide structure and food sources vital for the maintenance of coral reef fish diversity. However, coral reefs are currently under threat from climate change, which has led to the largest recorded loss of live coral. The loss of live coral, and corresponding shift in reef benthic composition, are predicted to impact the abundance and composition of coral reef fish species and communities. In this study, we investigate the effect of changes in reef benthic composition (eg. live coral, dead coral, algae), on the diversity and composition in an assemblage of butterflyfish species, in Faafu Atoll in the Maldives after the 2016 bleaching event. We show that differences in community composition of butterflyfish are associated to benthic structure, reflecting species feeding preferences. Interestingly, however, we also show that lower coral cover is not associated to lower abundance and species richness of butterflyfish. Our results suggest that maintenance of coral reef structure after a disturbance provides key microhabitats to accommodate non-corallivorous butterflyfish, thus maintaining abundance and species richness. Overall our study provides support for regulation of richness and abundance of coral reef fish assemblages to short term changes in coral reef benthic composition after disturbance via turnover in composition.

A comparison of the fish assemblages on natural and artificial reefs off Sal Island (Cape Verde)

2012 ◽  
Vol 93 (2) ◽  
pp. 437-452 ◽  
Author(s):  
Miguel N. Santos ◽  
Miguel T. Oliveira ◽  
João Cúrdia
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Cape Verde ◽  
Artificial Reefs ◽  
Visual Census ◽  
Mean Values ◽  
Marine Habitats ◽  
Fish Biodiversity ◽  
Santa Maria

Tourism is a growing activity in Cape Verde, which can lead to more intensive and uncontrolled fishing and diving activities, affecting the quality of marine habitats. To mitigate this biodiversity problem, a private diving operator, supported by the local authorities, decided to deploy the first artificial reefs (ARs) in the Archipelago just off Santa Maria Bay (Sal Island). To evaluate the ARs capacity to promote marine fish biodiversity in Santa Maria Bay, the fish assemblages were compared to those from nearby natural reefs (NRs), located at the same depth (10 and 28 m depth), by means of visual census. All study sites were surveyed by visual census in August 2009. A total of 64 species were recorded, mostly consisting of sedentary and/or benthophagous demersal species, followed by highly-sedentary benthic cryptic species. ‘Tchuklassa’ NR showed the highest species richness (58 species), while the lowest was recorded at ‘Santo Antão’ AR (48 species). An overall positive relationship was observed between habitat rugosity and mean species richness. The results showed a high percentage of common species on both reef types. Higher mean values of community descriptors (number of species, Shannon–Weaver diversity index, Simpson dominance index and equitability) and fish density were found on the ARs, with slightly higher densities recorded on the deeper reefs. These results suggest that ARs can have an important role promoting the local fish biodiversity and supporting local sustainable development of diving tourism.

scholarly journals Benthic structure drives butterflyfish species composition and trophic group abundance

2019 ◽  
Author(s):  
Miguel Barbosa ◽  
Neil Coupland ◽  
Clara Douglas ◽  
Ellen Harrison ◽  
Kelly M James ◽  
...  
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblages ◽  
Coral Cover ◽  
Food Sources ◽  
Fish Diversity ◽  
Live Coral ◽  
Benthic Composition

Corals provide structure and food sources vital for the maintenance of coral reef fish diversity. However, coral reefs are currently under threat from climate change, which has led to the largest recorded loss of live coral. The loss of live coral, and corresponding shift in reef benthic composition, are predicted to impact the abundance and composition of coral reef fish species and communities. In this study, we investigate the effect of changes in reef benthic composition (eg. live coral, dead coral, algae), on the diversity and composition in an assemblage of butterflyfish species, in Faafu Atoll in the Maldives after the 2016 bleaching event. We show that differences in community composition of butterflyfish are associated to benthic structure, reflecting species feeding preferences. Interestingly, however, we also show that lower coral cover is not associated to lower abundance and species richness of butterflyfish. Our results suggest that maintenance of coral reef structure after a disturbance provides key microhabitats to accommodate non-corallivorous butterflyfish, thus maintaining abundance and species richness. Overall our study provides support for regulation of richness and abundance of coral reef fish assemblages to short term changes in coral reef benthic composition after disturbance via turnover in composition.

scholarly journals The system of faunacomponents conception and its application to qualify the degree of naturalness of fish assemblages

2007 ◽  
pp. 93-101
Author(s):  
Péter Sály
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Native Species ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Shannon Diversity Index ◽  
Human Influence ◽  
Shannon Diversity ◽  
Biogeographic Regions ◽  
Special Case

The increase of species richness in communities of natural biogeographic regions in an anthropogenic way can be expressed as biogeographic pollution. Where there is contaminated fauna, one must investigate how this occured. I studied how the members of Hungarian fishfauna could be present resident and have managed to workout a so-called system of fauna component conception which is suitable for this requirement.The expression of ’faunacomponent’ includes other expressions. That kind of species belong to a certain faunacomponent that reached the studied area in the same way. Species reached the studied area without an anthropogenious contribution are qualified as native fauna components. These kind of species are endemic species, occasional species and settlers. In contrast to native faunacomponents, some kind of human influence is always detectable in connection with the way reached the studied area by non-native species. Accordingly, group of non-native species includes directly or indirectly facilitated settlers, species that are introduced accidentally and those introduced intentionally. It is obvious that classifying a given species could be construed solely in connection with a certain area.Applying Shannon diversity index I have initiated the assemblage natural index (ANI) in order to show a way how to use the system of faunacomponent conception in practice. ANI refers to the degree of naturalness of faunistical samples. If ANI > 1 it means there are not any non-native species and ANI < 1 it means there are some non-native species in the sample respectively. In the latter case ANI decreases proportionally with the number of non-native species and specimens. In that special case when only one specimen of only one non-native species can be found in the faunistical sample ANI = 1.

Linking fish and crustacean taxonomic composition with seasonal contrasts in the soft-bottom intertidal zone

2020 ◽  
Author(s):  
M. A. Gondal ◽  
S. Iqbal ◽  
U. Atique ◽  
N. U. Saher ◽  
N. A. Qureshi ◽  
...  
Keyword(s):  
Species Richness ◽  
Water Temperature ◽  
Fish Species ◽  
Diversity Index ◽  
Taxonomic Composition ◽  
Primary Objective ◽  
Negative Effect ◽  
Fish Species Composition ◽  
One Year ◽  
Sw Monsoon

Abstract The primary objective of this study was to investigate the seasonal fish and crustacean variations concerning taxonomic composition, species richness, and diversity in sandy beach habitat. For this purpose, we investigated the Sonmiani Hor lagoon area during four distinct seasons, i.e., northeast (NE) monsoon, pre-monsoon, south-west (SW) monsoon, and post-monsoon for one year. During each haul, the net was pulled about 100m along the beach in 0.5m depth. The results showed a strong linear correlation between the diversity index and equitability in fishes (r = 0.978). The diversity index was strong negatively correlated with the abundance and biomass (r = -0.978, -0.972, respectively). The physical attributes like sea surface water temperature and salinity showed a strong negative effect on species assemblages (r = -0.981 and -0.943, respectively). The mean air and water temperature illustrated approximately 3°C difference during NE and pre-monsoon seasons. However, salinity, pH, and electrical conductivity did not show any significant seasonal variabilities. Under the ecological indices, the fish species displayed higher diversity (H’ = 3.19) during SW monsoon, whereas the lowest diversity was observed during pre-monsoon (H’ = 1.58). The equitability and species richness, however, remained more noticeable during SW monsoon (J’ = 0.81). The total number of individuals of fish and crustaceans reached 4799 with 3813 fish individuals and 986 individuals of crustaceans. A total of 27 families of fish while five crustacean families comprising of 30 genera and 38 fish species while ten genera and 17 species of crustaceans were recorded. Liza subviridis displayed the highest abundance among the sampled fish species. In conclusion, fish species constituted a significant part of the coastal fauna in the study area. The seasonal variations displayed distinct variations in fish species composition and diversity.

Assemblage Patterns of Hymenoptera at Different Elevations of Gunung Datuk, Rembau

2017 ◽  
Vol 14 (2) ◽  
pp. 1 ◽  
Author(s):  
Noor Nasuha Abd Aziz ◽  
Siti Khairiyah Mohd Hatta ◽  
Idris Abd Ghani ◽  
Saiyid Jalaluddin Saiyid Shaifuddin
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
High Elevation ◽  
Significant Difference ◽  
Index Site ◽  
Evenness Index ◽  
Abundance And Diversity ◽  
Richness Index ◽  
Paired T Test ◽  
Malaise Traps

A study on abundance and diversity of Hymenoptera was conducted in Gunung Datuk, Rembau. Samplings were conducted from November 2014 to February 2015 using six Malaise traps. Three traps were placed at Site 1 at 700m height for high elevation and the remaining traps were placed at Site 2 at 200m height for low elevation. A total number of 221 Hymenopteran were collected which consist of nine families namely Ichneumonidae, Formicidae, Braconidae, Bethylidae, Evaniidae, Tiphiidae, Vespidae, Pompilidae and Apidae. In this study, 93 individuals were obtained from Site 1, comprising nine families and 43 morphospecies while 127 individuals were obtained from Site 2 with nine families and 45 morphospecies. Formicidae was the most dominant family collected from both sites with a total of 104 individuals while the least family recorded was Apidae with only one individual. Shannon’s Weiner Diversity Index (H’) showed Site 1 had the higher diversity value with H’ = 3.17 compared to Site 2 with value H’ = 3.12. For Evenness Index, Site 1 had higher value compared to Site 2 with E’ = 0.84 and E’ = 0.82 respectively. Moreover, for Margalef Richness Index, Site 1 recorded R’ = 9.24 while site two recorded R’ = 9.08 which concluded that Site 1 had higher species richness compared to Site 2. Paired t-test showed that both sites had no significant difference with p>0.05. Overall study showed that the diversity and abundance of Hymenoptera in Gunung Datuk were low since the value of H’ is less than 3.50.

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