scholarly journals The Trophic Basis of Fish Assemblages in Temperate Estuarine and Coastal Ecosystems

2021 ◽  
Author(s):  
Belinda K. Goddard ◽  
Alistair Becker ◽  
David Harasti ◽  
James A. Smith ◽  
Iain M. Suthers
Keyword(s):  
Fish Assemblages ◽  
The Other ◽  
Estuarine Fish ◽  
Energy Sources ◽  
Seagrass Habitat ◽  
Fish Biomass ◽  
Underwater Video ◽  
Coastal Fish ◽  
Functional Feeding Group ◽  
Feeding Group

Abstract More than half of the fish biomass of coastal rocky reefs depends on zooplankton; however, the trophic basis of estuarine fish assemblages remains unknown. We quantified the trophic basis (i.e. basal energy sources) of fish community biomass inhabiting three habitat types (seagrass, natural reef and artificial reef) in two estuaries, and at two coastal rocky reef sites. Estuarine fish assemblages were surveyed with Baited Remote Underwater Video (BRUVs). Species abundance, richness and biomass of fish were classified into 9 functional feeding groups (3 elasmobranch and 6 teleost). Comparable metrics for coastal fish assemblages were obtained from published surveys using BRUV, remote underwater video and visual census survey methods. Using the functional feeding group biomass and the group-specific diet composition, the breakdown of energy sources was calculated using a food web analysis. Estuarine reef habitats had different species and different functional feeding group composition than seagrass habitat. The majority of fish biomass in the seagrass habitat was supported by detritus (51% at one estuary) or macrophytes (58% at the other estuary). In contrast, zooplankton supported most fish biomass (45-59%) at the coastal reef locations, and in reef habitat in one estuary (35-43%), but not the other estuary (33-34%). The trophic basis of estuarine and coastal fish assemblages reveals their potential response to urbanisation including changes to habitat, nutrient supply and current flow.

Optimisation of baited remote underwater video sampling designs for estuarine fish assemblages

2012 ◽  
Vol 429 ◽  
pp. 28-35 ◽  
Author(s):  
William Gladstone ◽  
Steven Lindfield ◽  
Melinda Coleman ◽  
Brendan Kelaher
Keyword(s):  
Fish Assemblages ◽  
Estuarine Fish ◽  
Underwater Video

Polityka klimatyczno-energetyczna Unii Europejskiej

2014 ◽  
pp. 104-121
Author(s):  
Aleksandra Kułaga
Keyword(s):  
Negative Impact ◽  
Renewable Energy Sources ◽  
Energy System ◽  
The Other ◽  
Energy Sources ◽  
Climate Protection ◽  
The European Union ◽  
Eu Member States ◽  
The Subject ◽  
Climate And Energy Policy

The article is devoted to the subject of the goals of the climate and energy policy of the European Union, which can have both a positive, and a negative impact on the environmental and energy policies. Positive aspects are the reduction of greenhouse gas emissions, diversification of energy supplies, which should improve Europe independence from energy imports, and increasing the share of renewable energy sources (RES) in the national energy system structures. On the other hand, overly ambitious targets and actions can lead to large losses for the economies of EU Member States. The article also highlights the realities prevailing in the international arena and noncompliance of international actors with global agreements on climate protection.

Decreasing Richness And Biomass During A Flood Pulse Observed In A Southeastern US Coastal Floodplain Following A Multi-Year, Supra-Seasonal Drought

2021 ◽  
Author(s):  
Erica L. Johnson ◽  
Erin F. Abernethy ◽  
J. Checo Colón-Gaud
Keyword(s):  
Community Composition ◽  
Climate Change Impacts ◽  
Flood Pulse ◽  
Macroinvertebrate Communities ◽  
Biological Productivity ◽  
Aquatic Communities ◽  
Functional Feeding Group ◽  
Seasonal Flooding ◽  
Southeastern Us ◽  
Feeding Group

Abstract Floodplains of the southeastern United States exhibit high biological productivity, maintained by periodic floodplain inundation as a result of seasonal flooding. To examine the relationship between biological productivity and seasonal flooding following periods of drought, we quantified aquatic macroinvertebrate communities monthly in an inundated floodplain during the annual flood pulse (December-April) in two years, one following a multi-year drought and one following a larger than average flooding event. We predicted that floodplain communities would differ in richness, biomass, and community composition between years and that differences would be driven by discharge at the main stem and organic matter availability. We collected macroinvertebrates from the floodplain of the Altamaha River, an unimpounded 6th order river in the Coastal Plain region of the southeastern US that experiences floodplain connectivity. With invertebrates identified to genus, we elucidated richness, abundance, biomass, community composition, and functional feeding group. Richness was generally higher in the drought year but decreased throughout the flood pulse, while during the flood year richness was lower and increased. Biomass decreased throughout the flood pulse following the drought year and increased during the flood year. There was a high degree of overlap in invertebrate community composition based on abundance data during both years of the study with collector gatherers being the most highly abundant functional feeding group. As climate change impacts (i.e., severe droughts) become more common, it is critical to investigate how aquatic communities are responding to increasingly unpredictable flow conditions in unimpounded and seemingly unaltered rivers.

scholarly journals Comparative Analysis of Distribution of Intertidal Fish Assemblages in Different Estuarine Systems on Northern Coast of Brazil

2017 ◽  
Vol 10 (2) ◽  
pp. 26 ◽  
Author(s):  
Milton Goncalves Silva Junior ◽  
Antonio Carlos Leal Castro ◽  
Ulrich Saint-Paul
Keyword(s):  
Comparative Analysis ◽  
Fish Assemblages ◽  
Coastal Region ◽  
Fish Fauna ◽  
Estuarine Fish ◽  
Northern Coast ◽  
Tidal Creeks ◽  
Estuarine Systems ◽  
Using Data ◽  
High Dynamics

The northern coast of Brazil has more than 30 estuaries distributed along 650 km of coastline. These conditions favor the presence of relatively large fish communities in estuarine environments, but published information on the fish fauna in tidal creeks in northern Brazil is only available for some mangrove systems, and comparative studies between fish estuarine communities in different tidal creeks are less common. The choice of the study area was based on the fact that it has been poorly investigated with regard to estuarine fish fauna in comparison in mangrove tidal creeks using the same fishing gear. The objective of the present study was to compare the composition of the relative biomass of taxonomic, functional and ecological guilds of fish assemblages occurring in estuarine systems along the northern coast of Brazil. The study area of the present comparative analysis extended from the southeastern edge of the Marajoara Gulf to the western edge of the Maranhense Gulf. A comparative analysis among different estuarine systems was performed using data from other studies. The abundance of juveniles was greater in the Caeté, Curuçá and Cururuca estuaries than other estuaries. Cluster analysis separated the estuaries into two distinct groups and significant differences between these groups only exist in relation to geographical proximity. The present investigation indicates that the coastal region between the states of Pará and Maranhão is characterized by high dynamics and environmental heterogeneity, particularly with regard to changes in river discharge and tidal fluctuations. The present results underscore the importance of ecological information on ichthyofauna in tropical estuaries in order to include appropriate descriptors in conservation or restoration processes of marine communities and habitats.

Use of stereo baited remote underwater video systems to estimate the presence and size of white sharks (Carcharodon carcharias)

2017 ◽  
Vol 68 (7) ◽  
pp. 1391 ◽  
Author(s):  
D. Harasti ◽  
K. A. Lee ◽  
R. Laird ◽  
R. Bradford ◽  
B. Bruce
Keyword(s):  
Relative Abundance ◽  
Fish Assemblages ◽  
New South ◽  
Underwater Video ◽  
Carcharodon Carcharias ◽  
South Wales ◽  
Video Systems ◽  
Near Shore ◽  
Number Of Individuals ◽  
Non Destructive

Stereo baited remote underwater video systems (stereo-BRUVs) are commonly used to assess fish assemblages and, more recently, to record the localised abundance and size of sharks. The present study investigated the occurrence and size of white sharks (Carcharodon carcharias) in the near-shore environment off Bennett’s Beach, part of a known nursery area for the species in central New South Wales, Australia. Six stereo-BRUV units were deployed approximately fortnightly between August and December 2015 for periods of 5h in depths of 7–14m. Stereo-BRUVs successfully recorded 34 separate sightings of 22 individual white sharks. The highest number of individuals detected during a single day survey was eight. All C. carcharias observed on stereo-BRUVs were juveniles ranging in size from 1.50 to 2.46-m total length (mean±s.e., 1.91±0.05m; n=22). The time to first appearance ranged from 15 to 299min (mean±s.e., 148±15min). This study demonstrates that the use of stereo-BRUVs is a viable, non-destructive method to obtain estimates of the size and presence of white sharks, and may be useful in estimating relative abundance in near-shore environments where white sharks are known to frequent.

scholarly journals The contribution of environmental factors to fish assemblages in the Río Acahuapa, a small drainage in Central America

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Francisco S. Álvarez ◽  
Wilfredo A. Matamoros ◽  
Francisco A. Chicas
Keyword(s):  
Fish Species ◽  
Habitat Structure ◽  
Fish Assemblages ◽  
Species Abundance ◽  
Main Channel ◽  
Estuarine Fish ◽  
Species Origin ◽  
High Temperature Water ◽  
Distribution Of Fish ◽  
Temperature Water

ABSTRACT The ichthyofauna of the Río Acahuapa was analyzed sampling 17 sites that included the basin main channel and its tributaries. Fish were collected using dip-nets, seine-nets and electrofishing. Fish standard length and species abundance were recorded. Species origin and salinity tolerance criteria were used to classify fish species. Water physicochemical variables, habitat structure and sampling sites elevation were recorded. A total of 33 fish species were registered, 12.1% are primary, 45.5% are secondary and 42.4% are of marine derivation. Fish species richness declined with increase of elevation (R2=0.55, p=0.0006). Two assemblages of fishes were identified: the first one associated to sites of low elevations (19-184 masl), composed mainly of secondary and marine-estuarine fish species related with high temperature, water velocity, river width, dissolved oxygen and low sand and silt substrate cover; the second one associated to sites of middle and higher elevations (185-519 masl), composed by primary and secondary freshwater fishes related with high pH, logs and rocks substrate cover. In summary, elevation and environmental variables contributed to the composition and distribution of fish in the Río Acahuapa.

scholarly journals What are the main local drivers determining richness and fishery yields in tropical coastal fish assemblages?

2018 ◽  
Vol 35 ◽  
pp. 1-12
Author(s):  
Cynthia Diniz Souza ◽  
Vandick S. Batista ◽  
Nidia Noemi Fabré
Keyword(s):  
Wind Speed ◽  
Rainy Season ◽  
Fish Assemblages ◽  
Principal Component ◽  
Dry Season ◽  
Community Diversity ◽  
Tropical Species ◽  
Coastal Fish ◽  
Wide Range ◽  
Diversity Profiles

Seasonal ecological effects caused by temperature and photoperiod are typically considered minimal in the tropics. Nevertheless, annual climate cycles may still influence the distribution and abundance of tropical species. Here, we investigate whether seasonal patterns of precipitation and wind speed influence the structure of coastal fish assemblages and fishing yields in northeast Brazil. Research trips were conducted during the rainy and dry seasons using commercial boats and gear to sample the fish community. Diversity was analyzed using abundance Whittaker curves, diversity profiles and the Shannon index. Principal Component Analysis (PCA) was used to analyze associations between the abundance of species and various environmental variables related to seasonality. A total of 2,373 fish were collected, representing 73 species from 34 families – 20 of which were classified as both frequent and abundant. Species richness was greater and more equitable during the rainy season than the dry season – driven by changes in the precipitation rather than to wind speed. Species diversity profiles were slightly greater during the rainy season than the dry season, but this difference was not statistically significant. Using PCA was identified three groups of species: the first associated with wind speed, the second with precipitation, and the third with a wide range of sampling environments. This latter group was the largest and most ecologically heterogeneous. We conclude that tropical coastal fish assemblages are largely influenced by local variables, and seasonally mediated by annual changes related to precipitation intensity and wind speed, which in turn influences fishery yields.

Overlap in fish assemblages observed using pelagic and benthic baited remote underwater video stations

2019 ◽  
Vol 70 (6) ◽  
pp. 870 ◽  
Author(s):  
Thomas M. Clarke ◽  
Sasha K. Whitmarsh ◽  
Peter G. Fairweather ◽  
Charlie Huveneers
Keyword(s):  
Water Column ◽  
Fish Assemblages ◽  
South Australia ◽  
Single Units ◽  
Benthic Fish ◽  
Underwater Video ◽  
Pelagic Species ◽  
Non Invasive ◽  
Pelagic Fishes ◽  
Pelagic Communities

Baited remote underwater video stations (BRUVS) are increasing in popularity as non-invasive and fishery-independent tools for assessing fish assemblages. Although most BRUVS studies have focused on benthic fish communities, recent studies also use BRUVS to examine the comparatively undersampled pelagic communities. However, the propensities of benthic BRUVS to detect pelagic fishes and, likewise, pelagic BRUVS to detect demersal fishes are unknown. This study simultaneously used benthic and pelagic BRUVS deployed either separately (single) or in combination to determine assemblages of demersal and pelagic species at three contrasting sites within temperate South Australia. Assemblages observed by benthic v. pelagic BRUVS differed significantly at all sites, including one as shallow as 7m deep, but there were no significant differences in assemblages observed between BRUVS of the same position (i.e. pelagic or benthic) when BRUVS were deployed as single units or in combination. This study reveals the limitations of using only benthic or pelagic BRUVS, and highlights the necessity for both BRUVS positions to be used together to ensure that a comprehensive representation of entire fish assemblages throughout the water column can be obtained.

Sign in / Sign up

Export Citation Format

Share Document