scholarly journals Patterns of fish utilisation in a tropical Indo-Pacific mangrove-coral seascape, New Caledonia

2018 ◽  
Author(s):  
A Dubuc ◽  
N. Waltham ◽  
R. Baker ◽  
C. Marchand ◽  
M. Sheaves
Keyword(s):  
Fish Assemblages ◽  
New Caledonia ◽  
Lunar Cycle ◽  
Forest Edge ◽  
Temporal Variations ◽  
Conservation Strategies ◽  
Small Scale ◽  
Mangrove Forests ◽  
Species Specific ◽  
Main Component

AbstractMangrove forests are important habitats for fish. However, their utilisation by fish, and the specific values they confer, are still not fully understood. This study describes how fish use mangrove forests in an Indo-Pacific mangrove-coral reef seascape. Sampling was conducted using underwater video cameras (UVCs) to describe spatial and temporal variations in fish assemblages across a small-scale (~ 2.5 km2) system, and over the tidal and lunar cycle. UVCs were deployed in the two main component habitats of mangrove forests: at the mangrove forest edge, and inside the forest (5 m from the forest edge), to establish patterns of utilisation of fish across the tidal and lunar cycle. Proximity to coral reefs had a strong influence on the mangrove fish community, as most fish recorded were reef-associated. Juveniles of 12 reef species were observed, including two species classified as vulnerable on the IUCN list, and one endemic species. Fish assemblages on the mangrove edge differed significantly from those inside the forest. Most fish utilised the forest edge, with few species making regular use of in-forest habitats, supporting the contention that most fish species remain on the edge and potentially retreat into the forest for opportunistic feeding, or when threatened by larger predators. Species-specific patterns of utilisation varied across the tidal and lunar cycle. Small differences in depth profiles and substrate across the small-scale system had a significant effect on fish assemblages, highlighting the importance of accounting for spatial heterogeneity in these factors. These data provide important information for managers to implement adequate conservation strategies that include broader interconnected habitat mosaics.

scholarly journals The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 432
Author(s):  
Robin Gutting ◽  
Ralf-Uwe Syrbe ◽  
Karsten Grunewald ◽  
Ulf Mehlig ◽  
Véronique Helfer ◽  
...  
Keyword(s):  
Global Climate ◽  
Structural Parameters ◽  
Management Strategies ◽  
Small Scale ◽  
Mangrove Forests ◽  
Food Provisioning ◽  
Local Data ◽  
Climate Regulation ◽  
North Brazil ◽  
Species Specific

Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mapping. We modelled and spatialised the two ES from different perspectives, the demand (ES1) and the supply (ES2) side respectively. This was performed by combining worldwide databases related to the global human population (ES1) or mangrove distribution and canopy height (ES2) with locally derived parameters, such as crab catches (ES1) or species-specific allometric equations based on local estimates of tree structural parameters (ES2). Based on this approach, we could estimate that the area delivers the basic nutrition of about 1400 households, which equals 2.7 million USD, and that the mangrove biomass in the area contains 2.1 million Mg C, amounting to 50.9 million USD, if it were paid as certificates. In addition to those figures, we provide high-resolution maps showing which areas are more valuable for the two respective ES, information that could help inform management strategies in the future.

Mangrove community response to subsidence inflicted sea level change in Car Nicobar Island, India

2020 ◽  
Vol 63 (5) ◽  
pp. 419-427
Author(s):  
Nehru Prabakaran
Keyword(s):  
Sea Level ◽  
Land Surface ◽  
Sea Level Change ◽  
Community Response ◽  
Conservation Strategies ◽  
Nicobar Island ◽  
Ecological Processes ◽  
Mangrove Species ◽  
Level Change ◽  
Species Specific

AbstractThe inter-specific resilience among mangrove species to sea level rise (SLR) is a key to design conservation strategies for this economically important ecosystem that is among the most vulnerable to SLR. Tectonic processes can cause sudden increases or drops in sea level due to subsidence or uplift of the land surface, which can also provide insights for the mangrove community responses to rapid sea level change. This study aimed to investigate the responses of mangrove species to rapid SLR caused by land subsidence of 1.1 m during the 2004 Sumatra-Andaman earthquake at Car Nicobar Island. The Rhizophora spp. showed remarkable resilience to this rapid SLR, while the landward mangrove vegetation comprising Bruguiera spp., Lumnitzera spp., Sonneratia spp. etc., were unable to survive. Also, Rhizophora spp. establishment in the previous landward mangrove zones was more rapid than the landward mangrove species establishment in the previous terrestrial zones. The observed resilience of Rhizophora spp. may be due to the local specific geological legacy and species-specific ecological processes. However, further studies focusing on microcosm experiments to understand the Rhizophora spp. resilience to rapid SLR at the study site is required to strengthen these observations.

scholarly journals Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba

2008 ◽  
Vol 122 (2) ◽  
pp. 129 ◽  
Author(s):  
Matthew E. Reiter ◽  
Clint W. Boal ◽  
David E. Andersen
Keyword(s):  
Boreal Forest ◽  
Forest Edge ◽  
Habitat Associations ◽  
Probability Of Detection ◽  
Spatial And Temporal Variation ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Landscape Types ◽  
Species Specific ◽  
Monitoring Protocols

Distribution, abundance, and habitat relationships of anurans inhabiting subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to experience changes in climate and, in some areas, are experiencing habitat alteration due to high rates of herbivory by breeding and migrating waterfowl. To better understand subarctic anuran abundance, distribution, and habitat associations, we conducted anuran calling surveys in the Cape Churchill region of Wapusk National Park, Manitoba, Canada, in 2004 and 2005. We conducted surveys along ~1-km transects distributed across three landscape types (coastal tundra, interior sedge meadow–tundra, and boreal forest–tundra interface) to estimate densities and probabilities of detection of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Lithobates sylvaticus). We detected a Wood Frog or Boreal Chorus Frog on 22 (87%) of 26 transects surveyed, but probability of detection varied between years and species and among landscape types. Estimated densities of both species increased from the coastal zone inland toward the boreal forest edge. Our results suggest anurans occur across all three landscape types in our study area, but that species-specific spatial patterns exist in their abundances. Considerations for both spatial and temporal variation in abundance and detection probability need to be incorporated into surveys and monitoring programs for subarctic anurans.

scholarly journals Small-scale spatio-temporal characteristics of accumulation rates in western Dronning Maud Land, Antarctica

2008 ◽  
Vol 54 (185) ◽  
pp. 315-323 ◽  
Author(s):  
Helgard Anschütz ◽  
Daniel Steinhage ◽  
Olaf Eisen ◽  
Hans Oerter ◽  
Martin Horwath ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Temporal Variations ◽  
Spatial Variations ◽  
Small Scale ◽  
Accumulation Rates ◽  
Order Of Magnitude ◽  
Dronning Maud Land ◽  
Spatio Temporal ◽  
Ground Penetrating ◽  
Firn Core

AbstractSpatio-temporal variations of the recently determined accumulation rate are investigated using ground-penetrating radar (GPR) measurements and firn-core studies. The study area is located on Ritscherflya in western Dronning Maud Land, Antarctica, at an elevation range 1400–1560 m. Accumulation rates are derived from internal reflection horizons (IRHs), tracked with GPR, which are connected to a dated firn core. GPR-derived internal layer depths show small relief along a 22 km profile on an ice flowline. Average accumulation rates are about 190 kg m−2 a−1 (1980–2005) with spatial variability (1σ) of 5% along the GPR profile. The interannual variability obtained from four dated firn cores is one order of magnitude higher, showing 1σ standard deviations around 30%. Mean temporal variations of GPRderived accumulation rates are of the same magnitude or even higher than spatial variations. Temporal differences between 1980–90 and 1990–2005, obtained from two dated IRHs along the GPR profile, indicate temporally non-stationary processes, linked to spatial variations. Comparison with similarly obtained accumulation data from another coastal area in central Dronning Maud Land confirms this observation. Our results contribute to understanding spatio-temporal variations of the accumulation processes, necessary for the validation of satellite data (e.g. altimetry studies and gravity missions such as Gravity Recovery and Climate Experiment (GRACE)).

Small-scale spatial and temporal variations in mid-ocean ridge crest magmatic processes

Geology ◽  
1994 ◽  
Vol 22 (4) ◽  
pp. 375-379 ◽  
Author(s):  
M. R. Perfit ◽  
D. J. Fornari ◽  
M. C. Smith ◽  
J. F. Bender ◽  
C. H. Langmuir ◽  
...  
Keyword(s):  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Small Scale ◽  
Ridge Crest ◽  
Mid Ocean Ridge ◽  
Magmatic Processes ◽  
Ocean Ridge

scholarly journals Relationships between water transparency and abundance of Cynodontidae species in the Bananal floodplain, Mato Grosso, Brazil

2009 ◽  
Vol 7 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Cesar Enrique de Melo ◽  
Jane Dilvana Lima ◽  
Eliete Francisca da Silva
Keyword(s):  
Fish Assemblages ◽  
Water Transparency ◽  
Predatory Fish ◽  
Mato Grosso ◽  
Central Brazil ◽  
Fish Group ◽  
Species Specific ◽  
Abundance And Distribution ◽  
Number Of Individuals ◽  
Habitat Affinities

The Cerrado in the Central Brazil is currently one of the most threatened ecosystems in the world. As a result, the aquatic habitats in this biome also undergo great impacts. Alterations related to land-use change increase sediment loadings in rivers, streams and lakes, resulting in sedimentation and decrease in water transparency. Water transparency determines underwater visibility conditions, and as a consequence fish assemblages respond to spatial and temporal changes in this variable. This work aimed to examine the influence of transparency on the abundance and distribution of Cynodontidae species, a visually oriented predatory fish group. Fish sampling was conducted in 15 sites located between Mortes and Araguaia rivers in the Bananal floodplain, Mato Grosso State. Regression analysis between relative abundance of Cynodontidae (in number of individuals and biomass) and water transparency showed a positive and highly significant correlation, indicating that this group shows species-specific habitat affinities for clearer waters. These results suggest that the increase in water turbidity in this region can affect the patterns of abundance and distribution of the Cynodontidae species, as well as other visually oriented fishes.

scholarly journals Experimental evaluation of influence of FADs on community structure and fisheries in coastal Kenya

2018 ◽  
Vol 31 ◽  
pp. 6 ◽  
Author(s):  
Emmanuel K. Mbaru ◽  
Dorcas Sigana ◽  
Renison K. Ruwa ◽  
Elizabeth M. Mueni ◽  
Collins K. Ndoro ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Fish Stocks ◽  
Coastal Fisheries ◽  
Small Scale Fisheries ◽  
Open Sea ◽  
Catch Composition ◽  
Structural Indices ◽  
Fish Aggregating Devices

Fish aggregating devices (FADs) have been widely used by commercial fisheries to increase the catchability of pelagic stocks in the open sea. FADs have the potential to enhance nearshore small-scale fisheries where stocks are often overfished. This study examined changes in catch composition, abundance, catch and effort, and aspects of diversity in Kenya's nearshore coastal fisheries after deployment of anchored fish aggregating devices (AFADs). The study combined both fishery independent and dependent methods in assessing changes in fish assemblages post-deployment. Results showed orders of magnitude increase in length, weight, commercial value, and catch per unit effort (CPUE) of landed catch after deployment of FADs suggesting that FADs had a positive effect on the local fishery. Species richness at FAD sites increased post-deployment (n = 281) compared to pre-deployment values (n = 223). Simultaneous use of several complementary structural indices may be required in order to accurately describe and monitor fish assemblages around the FADs. The findings suggest that AFADs are capable of creating both short and long-term impacts on livelihoods, with the potential to deflect pressure on the overfished nearshore fish stocks. However, more research will be needed on redistribution of fish around FADs, design and placement configuration, and site selection amongst others.

scholarly journals ICHTHYOFAUNA IN THE INNER CONTINENTAL SHELF NEXT TO THE PARANAGUÁ ESTUARINE COMPLEX, SOUTHERN BRAZIL

2021 ◽  
Vol 46 (4) ◽  
pp. 1-13
Author(s):  
Cesar SANTOS ◽  
Roberto SCHWARZ JUNIOR ◽  
Helen Audrey PICHLER ◽  
Olímpio Rafael CARDOSO ◽  
Marcelo Renato LAMOUR ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
Temporal Variations ◽  
Otter Trawl ◽  
Rainfall Regime ◽  
Wet Season ◽  
Environmental Characteristics ◽  
The North ◽  
Inner Continental Shelf

The composition and structure of fish assemblages in the inner continental shelf of the Paraná State are affected by cold fronts and the rainfall regime. Data from fishing activities in this region, as well as the analysis of environmental characteristics, are the main tools available for understanding fish dynamics, under influence of increasing human activities. In order to better understand patterns and temporal variations in fish assemblages in the inner continental shelf of the Paraná State, a total of 24 double trawls were performed with an otter trawl between August 2000 and July 2001, in two sampling areas, the North area in front of the northern mouth of the Paranaguá Estuary Complex, and the South area, in front of the Leste beach. A total of 45,277 fish specimens belonging to 35 families and 97 species were caught. Sciaenidae was the most abundant family, with 37.1% of the total number of individuals caught, and with the highest richness (18 species). Statistical analyses evidenced significant differences in environmental characteristics and in fish fauna, and that both areas disturbances were observed in the fish assemblages during the dry and wet season, being more intense in the Southern area, disturbances that would be related to the shrimp fishing present in the two areas sampled in this study.

scholarly journals Coalescence times, life history traits and conservation concerns: an example from four coastal shark species from the Indo-Pacific

2021 ◽  
Author(s):  
Pierre Lesturgie ◽  
Serge Planes ◽  
Stefano Mona
Keyword(s):  
Population Structure ◽  
Life History ◽  
Life History Traits ◽  
New Caledonia ◽  
Demographic History ◽  
Conservation Strategies ◽  
Shark Species ◽  
Effective Population ◽  
Demographic Models ◽  
Mobile Species

Dispersal abilities play a crucial role in shaping the extent of population genetic structure, with more mobile species being panmictic over large geographic ranges and less mobile ones organized in meta-populations exchanging migrants to different degrees. In turn, population structure directly influences the coalescence pattern of the sampled lineages, but the consequences on the estimated variation of the effective population size (Ne) over time obtained by means of unstructured demographic models remain poorly understood. However, this knowledge is crucial for biologically interpreting the observed Ne trajectory and further devising conservation strategies in endangered species. Here we investigated the demographic history of four shark species (Carharhinus melanopterus, Carharhinus limbatus, Carharhinus amblyrhynchos, Galeocerdo cuvier) with different degrees of endangered status and life history traits related to dispersal distributed in the Indo-Pacific and sampled off New Caledonia. We compared several evolutionary scenarios representing both structured (meta-population) and unstructured models and then inferred the Ne variation through time. By performing extensive coalescent simulations, we provided a general framework relating the underlying population structure and the observed Ne dynamics. On this basis, we concluded that the recent decline observed in three out of the four considered species when assuming unstructured demographic models can be explained by the presence of population structure. Furthermore, we also demonstrated the limits of the inferences based on the sole site frequency spectrum and warn that statistics based on linkage disequilibrium will be needed to exclude recent demographic events affecting meta-populations.

Evidence supporting panmixia in Greenland halibut (Reinhardtius hippoglossoides) in the Northwest Atlantic

2014 ◽  
Vol 71 (5) ◽  
pp. 763-774 ◽  
Author(s):  
Denis Roy ◽  
David C. Hardie ◽  
Margaret A. Treble ◽  
James D. Reist ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Structure ◽  
Population Genetic ◽  
Conservation Strategies ◽  
Greenland Halibut ◽  
Northwest Atlantic ◽  
Population Genetic Differentiation ◽  
Conservation Implications ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
Species Specific

Assessment of population structure is critical to the design and implementation of sound management and conservation strategies. However, population structure must be assessed using markers attuned to population genetic processes such as genetic drift and gene flow, which reflect actual levels of reproductive isolation among putative genetic clusters. This is critical for highly exploited, commercial species that form the backbone of regional and local economies. Here, we show extremely low levels of population genetic differentiation among Greenland halibut (Reinhardtius hippoglossoides) collected from throughout the Northwest Atlantic, which cannot be statistically differentiated from panmixia using 12 species-specific polymorphic microsatellite markers. In contrast, some previous studies have demonstrated significant differences among individuals collected from various parts of the species’ range using a variety of both genetic and nongenetic techniques. In accordance with other reports and consistent with the species’ life history, we demonstrate that the most parsimonious explanation reconciling observed patterns is a repeated high degree of local differentiation of new recruits and colonizers originating from a common gene pool. Such a scenario has important conservation implications in terms of devising more appropriate strategies balancing species persistence and replenishment with sustainable resource use.

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