scholarly journals Assessing the Drivers behind the Structure and Diversity of Fish Assemblages Associated with Rocky Shores in the Galapagos Archipelago

2021 ◽  
Vol 9 (4) ◽  
pp. 375
Author(s):  
Stijn Bruneel ◽  
Wout Van Echelpoel ◽  
Long Ho ◽  
Heleen Raat ◽  
Amber Schoeters ◽  
...  
Keyword(s):  
Environmental Management ◽  
Fish Assemblages ◽  
Oceanic Islands ◽  
Nutrient Concentrations ◽  
Fish Diversity ◽  
Rocky Shores ◽  
Santa Cruz ◽  
Galapagos Archipelago ◽  
Pristine Area ◽  
Α Diversity

Oceanic islands harbor unique yet fragile marine ecosystems that require evidence-based environmental management. Among these islands, the Galapagos archipelago is well known for its fish diversity, but the factors that structure communities within and between its islands remain poorly understood. In this study, water quality, physical habitats and geographical distance were assessed as potential predictors for the diversity and structure of fish assemblages. Differences in the structure of fish assemblages of the two studied islands (Santa Cruz and Floreana) were most likely driven by temperature and nutrient concentrations. In the relatively highly populated island Santa Cruz, the structure of fish assemblages was more affected by water conditions than physical habitats while the contrary was true for the more pristine area of Floreana. A wide variety of species with different geographical origins were distributed over the different islands, which indicates that most fish species are able to reach the islands of the archipelago. However, temperature gradients and elevated nutrient levels cause large differences in the structure of local fish assemblages. In addition, in Santa Cruz nutrient concentrations were negatively correlated with α diversity. Since pollution is a clear pressure on the fish assemblages of oceanic islands, environmental management of the coastal areas is of paramount importance.

scholarly journals Space-time dynamics in monitoring neotropical fish communities using eDNA metabarcoding

2020 ◽  
Author(s):  
Naiara Guimarães Sales ◽  
Owen Simon Wangensteen ◽  
Daniel Cardoso Carvalho ◽  
Kristy Deiner ◽  
Kim Præbel ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Anthropogenic Impacts ◽  
Fish Communities ◽  
River Mouth ◽  
Fish Diversity ◽  
12S Rrna ◽  
Rain Event ◽  
Time Dynamics ◽  
Α Diversity ◽  
Spatio Temporal

ABSTRACTThe biodiverse Neotropical ecoregion remains insufficiently assessed, poorly managed, and threatened by unregulated human activities. Novel, rapid and cost-effective DNA-based approaches are valuable to improve understanding of the biological communities and for biomonitoring in remote areas. Here, we evaluate the potential of environmental DNA (eDNA) metabarcoding for assessing the structure and distribution of fish communities by analysing sediments and water from 11 locations along the Jequitinhonha River catchment (Brazil). Each site was sampled twice, before and after a major rain event in a five-week period and fish diversity was estimated using high-through-put sequencing of 12S rRNA amplicons. In total, 252 Molecular Operational Taxonomic Units (MOTUs) and 34 fish species were recovered, including endemic, introduced, and previously unrecorded species for this basin. Spatio-temporal variation of fish assemblages was detected, richness during the first campaign was nearly twice as high as in the second sampling round; though peaks of diversity were primarily associated with only four locations. No correlation between β-diversity and longitudinal distance or presence of dams was detected, but low species richness observed at sites located near dams indicates that these anthropogenic barriers might have an impact on local fish diversity. Unexpectedly high α-diversity levels recorded at the river mouth suggest that these sections should be further evaluated as putative “eDNA reservoirs” for rapid monitoring. By uncovering spatio-temporal changes, unrecorded biodiversity components, and putative anthropogenic impacts on fish assemblages, we further strengthen the potential of eDNA metabarcoding as a biomonitoring tool, especially in regions often neglected or difficult to access.

scholarly journals Galápagos Rail Laterallus spilonotus population change associated with habitat invasion by the Red-barked Quinine Tree Cinchona pubescens

2010 ◽  
Vol 21 (2) ◽  
pp. 221-227 ◽  
Author(s):  
W. GREGORY SHRIVER ◽  
JAMES P. GIBBS ◽  
HARA W. WOLTZ ◽  
NICOLE P. SCHWARZ ◽  
MARGARET A. PEPPER
Keyword(s):  
Population Change ◽  
Oceanic Islands ◽  
Native Vegetation ◽  
Santa Cruz Island ◽  
Santa Cruz ◽  
Vegetation Communities ◽  
Galapagos Archipelago ◽  
Management Actions ◽  
Cinchona Pubescens ◽  
Habitat Invasion

SummarySpecies on oceanic islands are more likely to be endemic as well as more extinction-prone than those on continents. The Galápagos Rail Laterallus spilonotus, endemic to the Galápagos Archipelago, is presently known to occur on just four of its seven previously occupied islands and is facing multiple threats to its persistence. In this study, we compared the rail’s occurrence and abundance at 193 survey points between 2000 and 2007 on Santa Cruz Island and examined the influence of an invasion of the habitat of the species by the exotic Red-barked Quinine Tree Cinchona pubescens. We detected a 13% reduction in rail occurrence and a 31% reduction in abundance between 2000 and 2007. Rail abundance declined more in low elevation areas (< 719 m) and outside of Cinchona pubescens removal areas but not in areas where Cinchona pubescens was removed. Insofar as Galápagos Rails responded positively to management actions that promote and maintain native vegetation, we conclude that restoration projects that restore native vegetation communities benefit this apparently declining endemic bird for which more focused conservation attention is warranted.

scholarly journals Linking Habitat and Associated Abiotic Conditions to Predict Fish Hotspots Distribution Areas within La Paz Bay: Evaluating Marine Conservation Areas

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 212
Author(s):  
Francisco Javier Urcádiz-Cázares ◽  
Víctor Hugo Cruz-Escalona ◽  
Mark S. Peterson ◽  
Rosalía Aguilar-Medrano ◽  
Emigdio Marín-Enríquez ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Management Plan ◽  
Marine Conservation ◽  
Fish Diversity ◽  
Rocky Shores ◽  
Conservation Areas ◽  
Niche Modelling ◽  
La Paz ◽  
Abiotic Conditions ◽  
Presence Data

Hotspots are priority marine or terrestrial areas with high biodiversity where delineation is essential for conservation, but equally important is their linkage to the environmental policies of the overall region. In this study, fish diversity presences were linked to abiotic conditions and different habitat types to reveal multi-species and hotspots models predicted by ecological niche modelling methods within the Bay of La Paz, Mexico (south of Gulf of California). The abiotically suitable areas for 217 fish species were identified based on historical (1975–2020) presence data sets and a set of environmental layers related to distances from mangroves and rocky shores habitats, marine substrate, and bottom geomorphology conditions. Hotspot model distribution was delineated from a multi-species model identifying areas with ≥60 species per hectare and was compared to the marine conservation areas such Balandra Protected Natural Area (BPNA), illustrating how these models can be applied to improve the local regulatory framework. The results indicate that (1) there is a need for the BPNA to be enlarged to capture more of the delineated hotspot areas, and thus an update to the management plan will be required, (2) new conservation areas either adjacent or outside of the established BPNA should be established, or (3) Ramsar sites or other priority areas should be subject to legal recognition and a management plan decreed so that these vital habitats and fish diversity can be better protected.

FISH DIVERSITY IN THE DOWNSTREAM REGION OF CIPANAS RIVER INDRAMAYU, WEST JAVA INDONESIA

Zoo Indonesia ◽  
2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Titin Herawati ◽  
Gema Wahyudewantoro ◽  
Yuli Andriani ◽  
Heti Herawati ◽  
Naomi Masnida Yunisia Siregar
Keyword(s):  
Water Quality ◽  
Census Data ◽  
Fish Assemblages ◽  
Survey Methods ◽  
Upstream Region ◽  
Fish Diversity ◽  
West Java ◽  
Fish Collection ◽  
Java Sea ◽  
Downstream Area

Cipanas River is one river in West Java where its upstream region in Tampomas Mountain, Sumedang and it is emptied into the Java Sea, Indramayu. The study was aimed to investigate fish diversity in the downstream area of Cipanas River. The study was conducted by survey methods with census data collection techniques, taken place at 3 stations of Santing, Tempalong, and Cemara of Indramayu Regency. The parameters measured consisted water quality and fish assemblages. Water quality was measured referring to standard laboratory protocol, and fish collection was made by case net with different mesh sizes. The results showed that water quality conditions of the Cipanas River downstream was suitable for inhabiting fishes. There were as many as 548 individual fishes caught belonging to 21 species, 16 genera, and 14 families. Fish diversity was categorized as medium with 1.6 ≤ H ’≤ 2.2 indicating fairly good community structure, and the Evenness index was 0.81 ≤ E ≤ 0.86 to show highly evenly distributed.

scholarly journals Dredging fundamentally reshapes the ecological significance of 3D terrain features for fish in estuarine seascapes

2022 ◽  
Author(s):  
Hayden P. Borland ◽  
Ben L. Gilby ◽  
Christopher J. Henderson ◽  
Rod M. Connolly ◽  
Bob Gorissen ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Three Dimensional ◽  
Ecological Impacts ◽  
Fish Diversity ◽  
Urban Landscapes ◽  
Ecological Significance ◽  
Landscape Modification ◽  
Eastern Australia ◽  
Coastal Landscapes ◽  
Terrain Features

Abstract Context Landscape modification alters the condition of ecosystems and the structure of terrain, with widespread impacts on biodiversity and ecosystem functioning. Seafloor dredging impacts a diversity of flora and fauna in many coastal landscapes, and these processes also transform three-dimensional terrain features. The potential ecological significance of these terrain changes in urban seascapes has, however, not been investigated. Objectives We examined the effects of terrain variation on fish assemblages in 29 estuaries in eastern Australia, and tested whether dredging changes how fish associate with terrain features. Methods We surveyed fish assemblages with baited remote underwater video stations and quantified terrain variation with nine complementary metrics (e.g. depth, aspect, curvature, slope, roughness), extracted from bathymetry maps created with multi-beam sonar. Results Fish diversity and abundance were strongly linked to seafloor terrain in both natural and dredged estuaries, and were highest in shallow waters and near features with high curvature. Dredging, however, significantly altered the terrain of dredged estuaries and transformed the significance of terrain features for fish assemblages. Abundance and diversity switched from being correlated with lower roughness and steeper slopes in natural estuaries to being linked to features with higher roughness and gentler slopes in dredged estuaries. Conclusions Contrasting fish-terrain relationships highlight previously unrecognised ecological impacts of dredging, but indicate that plasticity in terrain use might be characteristic of assemblages in urban landscapes. Incorporating terrain features into spatial conservation planning might help to improve management outcomes, but we suggest that different approaches would be needed in natural and modified landscapes.

Biodiversity of free-living marine nematodes on the coast of Brazil: a review

Zootaxa ◽  
2010 ◽  
Vol 2568 (1) ◽  
pp. 39 ◽  
Author(s):  
VIRÁG VENEKEY ◽  
VERÔNICA G. FONSECA-GENEVOIS ◽  
PAULO J. P. SANTOS
Keyword(s):  
Sandy Beaches ◽  
Oceanic Islands ◽  
Taxonomic Composition ◽  
Artificial Substrates ◽  
Rocky Shores ◽  
Coastal Habitats ◽  
Free Living ◽  
Generic Composition ◽  
Faunal List ◽  
First Time

The taxonomic richness of the marine Nematoda in coastal habitats of Brazil and similarities in generic composition among them are analysed. A complete faunal list is presented, containing 11 orders, 59 families, 294 genera and 231 species, among which 1 family, 10 genera and 87 species were discovered for the first time in Brazil. Seven habitats were considered (sandy beaches, estuaries, phytal, oceanic islands, beach rocks, salt works and artificial substrates): sandy beaches had the greatest generic richness (241), followed by estuaries (142) and the phytal environment (126). Taxonomic composition was similar to that of other coastal habitats sampled worldwide, with Chromadoridae and Xyalidae the most representative families. The three major habitats (beaches, rocky shores and estuaries), showed statistically significant differences in faunas. Estuaries were the most uniform in composition.

scholarly journals Spatial and temporal variation in fish assemblages in three small unpolluted estuarine rivers and associated lagoons in Kouchibouguac National Park, southern Gulf of St. Lawrence, Canada

2015 ◽  
Vol 129 (2) ◽  
pp. 121 ◽  
Author(s):  
Amanda M. Bremner ◽  
D. A. Methven ◽  
Kelly R. Munkittrick ◽  
Katherine A. Frego
Keyword(s):  
Water Temperature ◽  
Dominant Species ◽  
Gasterosteus Aculeatus ◽  
Fish Assemblages ◽  
Vegetation Coverage ◽  
Spatial And Temporal Variation ◽  
Fish Diversity ◽  
Spatial Gradient ◽  
Scaling Analysis ◽  
Pungitius Pungitius

Estuaries have among the highest primary production rates of ocean waters and provide essential habitat for many organisms. Recognition of the need to conserve these critical habitats is coupled with the need for baseline data to allow assessment of ecosystem changes. This study compares natural variations in, and correlations between, the composition of fish assemblages and environmental factors at several sites over two years in three rivers emptying into estuaries in the southern Gulf of St. Lawrence, Canada. Fish diversity and abundance were determined by beach seining and related to water temperature, salinity, substrate, and vegetation. From May to September 2000 (14 sites) and May to August 2001 (15 sites), 20 fish species were collected, seven of which accounted for 98% of the total catch. The dominant species, Mummichog (Fundulus heteroclitus), represented 44% of the catch. Its abundance and that of the other dominant species — Threespine Stickleback (Gasterosteus aculeatus) 16%, Blackspotted Stickleback (G. wheatlandi) 13%, Banded Killifish (F. diaphanus) 12%, Fourspine Stickleback (Apeltes quadracus) 7%, Atlantic Silverside (Menidia menidia) 4%, and Ninespine Stickleback (Pungitius pungitius) 2% — differed significantly both spatially and temporally. Multidimensional scaling analysis showed a spatial gradient in abundance from upstream to lagoon sites and a temporal gradient from spring to fall. Upstream sites were low in salinity and had a higher organic content and a higher proportion of silt–clay in the sediment. Variation within fish populations was related to site and seasonal changes in environmental conditions and species’ tolerance of water temperature, salinity, vegetation coverage, and fine sediments.

scholarly journals Contrasting effects of mangroves and armoured shorelines on fish assemblages in tropical estuarine seascapes

2019 ◽  
Vol 76 (4) ◽  
pp. 1052-1061 ◽  
Author(s):  
Christopher J Henderson ◽  
Ben L Gilby ◽  
Thomas A Schlacher ◽  
Rod M Connolly ◽  
Marcus Sheaves ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Urban Expansion ◽  
Ecological Impacts ◽  
Spatial Context ◽  
Fish Diversity ◽  
Mangrove Forests ◽  
Habitat Types ◽  
Tropical Estuarine ◽  
Eastern Australia ◽  
Close Proximity

Abstract Coastal seascapes are composed of a diversity of habitats that are linked in space and time by the movement of organisms. The context and configuration of coastal ecosystems shapes many important properties of animal assemblages, but potential seascape effects of natural and artificial habitats on nearby habitats are typically considered in isolation. We test whether, and how, the seascape context of natural and urban habitats modified fish assemblages across estuaries. Fish were sampled with underwater videos in five habitat types (mangroves, rock bars, log snags, unvegetated sediments, armoured shorelines) in 17 estuaries in eastern Australia. Different habitats supported distinct fish assemblages, but the spatial context of mangroves and armoured shorelines had pervasive ecological effects that extended across entire estuaries. In most estuarine habitats, fish diversity and abundance was greatest when they were in close proximity of mangroves, and decreased due to the proximity of armoured shorelines. Many cities are centred on estuaries, and urban expansion is often associated with the fragmentation of mangrove forests. Our findings emphasize that these transformations of urban estuarine landscapes are likely to propagate to broader ecological impacts detectable in multiple habitats beyond mangrove forests.

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