scholarly journals Cambios en la comunidad de peces por efecto del desarrollo costero en el Parque Nacional Huatulco (México)

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
Luis Gibran Juárez Hernández
Keyword(s):  
Coral Reefs ◽  
Land Surface ◽  
Fish Community ◽  
Coastal Development ◽  
Development Projects ◽  
Fish Samples ◽  
Average Abundance ◽  
Before And After ◽  
Coral Communities ◽  
Inverse Pattern

Coastal development and urbanization have increased the sediments that are washed from the land surface, producing adverse effects on the structure and functioning of coral reefs. The objective of this study was to identify the degree to which excessive sediments have disturbed the fish community in the coral reefs in the Maguey and Violin bays, located in the Huatulco National Park (Mexico). Fish samples were collected before and after disturbances produced by sediments associated with coastal development projects. Indicators of changes in the fish communities included the number and diversity of species as well as equity and dominance before and after the disturbances. The analysis was performed through means comparison tests, similarity analysis (ANOSIM) and similarity percentage analysis (SIMPER). In both locations, it was observed that the diversity, evenness, abundance and number of species were higher prior to the disturbance, but not for dominance, which shows an inverse pattern. In Maguey, significant differences in evenness and dominance were observed (U = 28, p = 0.0401; U = 24, p = 0.0472), as well as in species composition and abundance (ANOSIM = 0.35, p = 0.009). The similarity percentage analysis (SIMPER) indicated that after the disturbance, more than 46 % of the species showed decreases in average abundance, highlighting the absence of Prionurus laticlavius, as well as the decrease in abundance of: P. punctatus, Cirrhitichthys oxycephalus, Microspathodon dorsalis, Lutjanus novemfaciatus and Stegates acapulcoensis. Inadequate planning and implementation of coastal development projects that contribute to the discharge of excessive sediments into the sea were determinants of negative changes in the coral communities in Maguey and Violin, whose effects could be seen in the composition of the species and the abundance, equity, and dominance of the fish community in Maguey.

scholarly journals Coseismic displacements of the 14 November 2016 Mw7.8 Kaikoura, New Zealand, earthquake using an optical cubesat constellation

2017 ◽  
Author(s):  
Andreas Kääb ◽  
Bas Altena ◽  
Joseph Mascaro
Keyword(s):  
New Zealand ◽  
Land Surface ◽  
Near Infrared ◽  
Sar Interferometry ◽  
Optical Methods ◽  
Optical Data ◽  
Surface Displacements ◽  
Before And After ◽  
Optical Satellite Images ◽  
Sentinel 2

Abstract. Satellite measurements of coseismic displacements are typically based on Synthetic Aperture Radar (SAR) interferometry or amplitude tracking, or based on optical data such as from Landsat, Sentinel-2, SPOT, ASTER, very-high resolution satellites, or airphotos. Here, we evaluate a new class of optical satellite images for this purpose – data from cubesats. More specific, we investigate the PlanetScope cubesat constellation for horizontal surface displacements by the 14 November 2016 Mw7.8 Kaikoura, New Zealand, earthquake. Single PlanetScope scenes are 2–4 m resolution visible and near-infrared frame images of approximately 20–30 km × 9–15 km in size, acquired in continuous sequence along an orbit of approximately 375–475 km height. From single scenes or mosaics from before and after the earthquake we observe surface displacements of up to almost 10 m and estimate a matching accuracy from PlanetScope data of up to ±0.2 pixels (~ ±0.6 m). This accuracy, the daily revisit anticipated for the PlanetScope constellation for the entire land surface of Earth, and a number of other features, together offer new possibilities for investigating coseismic and other Earth surface displacements and managing related hazards and disasters, and complement existing SAR and optical methods. For comparison and for a better regional overview we also match the coseismic displacements by the 2016 Kaikoura earthquake using Landsat8 and Sentinel-2 data.

scholarly journals Fish Community Assemblages of Mining-Impacted Freshwaters at Prestea, Ghana

2018 ◽  
pp. 1-9
Author(s):  
Osei O. Antobre ◽  
Nat Owusu-Prempeh ◽  
Michael J. Twumasi-Ankrah
Keyword(s):  
Fish Community ◽  
Average Length ◽  
Mesh Size ◽  
Fish Diversity ◽  
Freshwater Ecosystem ◽  
Fish Community Structure ◽  
Average Width ◽  
H Index ◽  
Community Assemblage ◽  
Fish Samples

The study evaluated the fish community assemblage in the sections of the Subri river, the Ankobra river, and the “galamsey” pond within the Prestea community as impacted by alluvial mining activities. Gill nets of length 10 m and mesh size 1.27 cm were used to trap fish of average length 25.25 cm whilst cane baskets were used to trap fish of average width 10.40 cm using the catch and recapture method. All the 46 fish samples identified belong to 10 genera and 5 families. The Chichlidae was the dominant family, accounting for 60% of the total families observed. With an H’ index of 1.57 the Subri river had the most fish diversity in comparison with the Ankobra river and the “galamsey” pond, which had 1.21 and 0.71, respectively. Similarly, the Subri river had a more complex fish community structure than the Ankobra and “galamsey” pond. The dominant species, Oreochromis niloticus, has not yet been evaluated by the IUCN, but the least dominated Brienomyrus brachyistus could be regarded as “least concern”. Notwithstanding, these fish are essential for food by the local communities. There is a possibility that the alluvial mining might have influenced the complexities of fish species communities. Thus conservation efforts must be promoted to sustain fish communities and overall freshwater ecosystem health.

scholarly journals Short-term change in fish assemblages after the passage of a typhoon in a temperate, coastal bay

2021 ◽  
Vol 51 (2) ◽  
pp. 175-183
Author(s):  
Mitsuharu Yagi
Keyword(s):  
Fish Assemblages ◽  
Japanese Anchovy ◽  
Short Term ◽  
Faunal Change ◽  
Short Term Change ◽  
Term Change ◽  
Fish Samples ◽  
Before And After ◽  
Coastal Bay ◽  
Tachibana Bay

To study the effects of a typhoon on a temperate, coastal bay community, the species composition, catch amount, and diversity of epipelagic fish assemblages were investigated. Fish samples were taken from catches of a purse seine fishery in Tachibana Bay, Japan between May and July 2011, covering before and after the passage of a typhoon in the area. Although major changes in total catch amount were not observed before and after the passage of the typhoon, the abundance of the Japanese anchovy, Engraulis japonicus Temminck et Schlegel, 1846, markedly decreased and bycatch of species increased, accompanied by increasing levels of diversity of the fish assemblage. Multivariate analysis showed that community differences before and after the passage were quantitative rather than qualitative. Comparisons in total length frequencies between the two periods indicated that specimens of the species compared were bigger in size for Trachurus japonicus (Temminck et Schlegel, 1844) and smaller for E. japonicus in the “after” period. These results suggest that the passage of the typhoon triggered not only interspecific faunal change but also intraspecific recruitment shifts in and around the bay.

scholarly journals STATUS TERUMBU KARANG DI PERAIRAN PESISIR NEGERI HUKURILA

2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
Dicky Sahetapy ◽  
Laura Siahainenia ◽  
Debby A J Selanno ◽  
Johannes M S Tetelepta ◽  
Novianty C Tuhumury
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Species ◽  
Similarity Index ◽  
Ecological Index ◽  
Stony Coral ◽  
The Status ◽  
Coral Communities ◽  
Line Intercept

Coral reef is one of the important coastal ecosystems that have high biodiversity. This study aims to analyze the composition of the taxa and the distribution of coral species, the ecological index of coral communities and the status of coral reefs. The research was conducted from April-May 2019 in the coastal waters of Hukurila Village, South Leitimur District, Ambon City. Collecting coral data by using the Line Intercept Transect (LIT) method. Determination of coral reef condition based on percent data (value) of coral reef cover. During the study, 116 species of stony coral from 49 genera and 16 families were found, which 50 species of them are protected and 23 species of ornamental coral. The similarity index of stony coral species between coral reef locations ranges from 0.52-0.76 or there is the similarity of stony coral species between locations coral reef in the amount of 52-76%. The coral reefs of Hukurila Village have high diversity of coral species, with a low dominance of coral species in the community, and the compatibility of coral species in the community is classified as stable. Acropora corals contributed a low covering percent value (9.98%), while Non-Acropora corals contributed a relatively high percent of covering value (43.56%). The status of coral reefs between locations in the coastal waters of Hukurila Village is in the criteria of good (healthy).   ABSTRAK Terumbu karang merupakan salah satu ekosistem pesisir penting yang emiliki kenanekaragaman hayati tinggi. Penelitian ini bertujuan untuk menganalisis komposisi taksa dan sebaran spesies karang, indeks ekologi kominitas karang dan status terumbu karang. Penelitian dilakukan dari April-Mei 2019 di perairan pesisir Negeri Hukurila Kecamatan Leitimur Selatan Kota Ambon. Pengumpulan data karang menggunakan metode Line Intercept Transect (LIT). Penentuan kondisi terumbu karang berdasarkan data (nilai) persen penutupan karang batu. Selama penelitian ditemukan 116 spesies karang batu dari 49 genera dan 16 famili, dimana 50 spesies diantaranya dilindungi dan 23 spesies karang hias. Indeks similaritas spesies karang batu antar stasiun terumbu karang berkisar antara 0,52-0,76 atau terdapat kesamaan spesies karang batu antar lokasi terumbu karang sebesar 52-76%. Terumbu karang Negeri Hukurila memiliki diversitas spesies karang tinggi, dengan dominansi spesies karang rendah dalam komunitas, dan keserasian spesies karang dalam komunitas tergolong stabil. Karang Acropora memberi kontribusi nilai persen penutupan rendah (9,98%), sementara karang Non-Acropora memberi kontribusi nilai persen penutupan karang batu relatif tinggi (43,56%). Status terumbu karang antar stasiun terumbu perairan pesisir Negeri Hukurila berada dalam kriteria baik (sehat).   Kata kunci: terumbu, karang batu, keragaman spesies, kesamaan, persen penutupan

scholarly journals Benthic foraminifera as ecological indicators in the Tunda Island Waters, Serang District, Banten Province, Indonesia

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
ISNI NURRUHWATI ◽  
FACHRI ARDIANSYAH ◽  
YUNIARTI ◽  
LINTANG PERMATA SARI YULIADI ◽  
Ruhyat Partasasmita
Keyword(s):  
Water Quality ◽  
Coral Reefs ◽  
Benthic Foraminifera ◽  
Human Activities ◽  
Ecological Factors ◽  
Ecological Indicators ◽  
Coastal Development ◽  
Mangrove Forests ◽  
Benthic Foraminifers ◽  
A Site

Abstract. Nurruhwati I, Ardiansyah F, Yuniarti, Yuliadi LPS, Partasasmita R. 2020. Benthic foraminifera as ecological indicators in the Tunda Island Waters Serang District, Banten Province, Indonesia. Biodiversitas 21: 3142-3148. Coral reef communities all across Southeast Asia are experiencing intense pressures from extensive tourism and massive coastal development. A prediction regarding coral reefs’ capacity to recover is a necessity since it is constantly exposed to damaging events such as mass bleaching and increased erosion. Tunda Island (which is highly rich in biodiversity and include coral reefs, mangrove forests, seagrass, and algae meadows) was sampled at 10 different sites in August 2019. Coral reefs are highly influenced by ecological factors such as temperature variability, salinity, DO, and pH. The assessments were conducted using the FORAM Index (FI) to accurately predict the capacity of coral reefs to recover based on relative abundances of symbiont-bearing larger benthic foraminifera in reef sediments. The FI values ranged from 3.7 to 7.9 with a median of 4.7 and the average of 5 indicates that the water quality should support the recovery of reefs by reef-building corals and symbiont-bearing larger benthic foraminifers. The lowest FI value sampled was recorded from a site with extensive human activities (FI=3.4), while the highest one was recorded from a site with minimal to none human activities (FI=7.9), which indicates that the deterioration of water quality is caused by wastes from tourism activities near the coastal area.

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