scholarly journals Ecological dependencies make remote reef fish communities most vulnerable to coral loss

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Giovanni Strona ◽  
Pieter S. A. Beck ◽  
Mar Cabeza ◽  
Simone Fattorini ◽  
François Guilhaumon ◽  
...  

AbstractEcosystems face both local hazards, such as over-exploitation, and global hazards, such as climate change. Since the impact of local hazards attenuates with distance from humans, local extinction risk should decrease with remoteness, making faraway areas safe havens for biodiversity. However, isolation and reduced anthropogenic disturbance may increase ecological specialization in remote communities, and hence their vulnerability to secondary effects of diversity loss propagating through networks of interacting species. We show this to be true for reef fish communities across the globe. An increase in fish-coral dependency with the distance of coral reefs from human settlements, paired with the far-reaching impacts of global hazards, increases the risk of fish species loss, counteracting the benefits of remoteness. Hotspots of fish risk from fish-coral dependency are distinct from those caused by direct human impacts, increasing the number of risk hotspots by ~30% globally. These findings might apply to other ecosystems on Earth and depict a world where no place, no matter how remote, is safe for biodiversity, calling for a reconsideration of global conservation priorities.

Rekayasa ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Elok Faiqoh ◽  
I Wayan Gede Astawa Karang ◽  
Dwi Budi Wiyanto

<p>ABSTRAK<br />Pemutihan karang merupakan salah satu dampak dari perubahan iklim global, kenaikan suhu tersebut memberikan dampak negatif bagi keseimbangan ekosistem terumbu karang. ­Terumbu karang yang memutih dan kehilangan zooxanthella nya akan rentan terkena infeksi dan penyakit. Populasi komunitas ikan karang pemakan hewan karang dan makrozoobenthos juga akan menurun. Tujuan dari penelitian ini adalah untuk mengetahui besar dampak kerusa­kan terumbu karang dan dampaknya bagi populasi ikan dan makrozoobenthos. Survey dilakukan pada 3 titik di wilayah perairan Tejakula dengan metode reefcheck. Hasil penelitian menunjukkan kematian terumbu karang sebesar 5-7.5%, jumlah alga yang menutupi 3.125%. Kondisi ikan kepe-kepe yang merupakan pemakan hewan karang juga sudah ditemukan dalam jumlah cukup banyak. Keberadaan ikan herbivora dan makrozoobenthos herbivore membantu mengurangi jumlah alga yang menutupi. Sedangkan keberadaan ikan pemakan terumbu karang dan ikan predator memperlihatkan bahwa sistem ekologi yang ada di terumbu karang tersebut hampir kembali normal. <br />Kata Kunci: terumbu karang, komunitas ikan karang, makrozoobenthos.</p><p><strong>The Impact of Hard Coral Bleaching in Coral and Macrozoobenthos Fish Communities in Tejakula, Buleleng, Bali Water Areas</strong></p><p>ABSTRACT<br />Coral bleaching is one of the consequences of global climate change, as the rise of temperature negatively impacts the ecological balance of reef ecosystems. Bleached coral reefs lose their zooxanthellae, increasing vulnerability to infection and disease and consequently, causing population decline of macrozoobenthos and reef fish communities which prey on coral-consuming organisms. This research aims to determine the degree of coral reef damage and its impact on fish and macrozoobenthos population. The survey was conducted on 3 stations in Tejakula waters with the reef check method. Results show that coral reef death reaches 5-7.5%, with algal coverage of 3.125%. Kepe-kepe fish which prey on coral-consuming animals were also found in relatively high abundance. The presence of herbivore fish and macrozoobenthos help reduce algal cover. Meanwhile, the presence of coral-consuming and predator fish indicate that the coral reef ecological system has mostly returned to normal. <br />Keywords: coral reef, reef fish community, macrozoobenthos</p>


2009 ◽  
Vol 52 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Marcelo Carneiro de Freitas ◽  
Regine Helena Silva dos Fernandes Vieira ◽  
Maria Elisabeth de Araújo

This study aimed to assess the impact of harbor construction at Pecém (Brazil) upon the reef fish communities in tide pools. The monitoring was carried out through a visual census and sea water quality was evaluated by microbiological analyses. From March to December 2001, 1,425 individuals of 17 families and 25 species were registered. The most frequent species were Haemulon parra, Acanthurus chirurgus, Abudefduf saxatilis and Sparisoma axillare. The average species diversity for the whole period was 1.77 bits.ind -1. There was evidence that the tide pools gradually silted up, resulting in a reduction in species diversity and richness. The microbiological analyses indicated the presence of faecal coliforms in the water though not at significant levels. The present study could be useful as an early reference for future projects, using the fish communities as indicators for the impact upon the environment of the harbor construction and other human activities.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Mairin A. Balisi ◽  
Blaire Van Valkenburgh

AbstractEcological specialization has costs and benefits at various scales: traits benefitting an individual may disadvantage its population, species or clade. In particular, large body size and hypercarnivory (diet over 70% meat) have evolved repeatedly in mammals; yet large hypercarnivores are thought to be trapped in a macroevolutionary “ratchet”, marching unilaterally toward decline. Here, we weigh the impact of this specialization on extinction risk using the rich fossil record of North American canids (dogs). In two of three canid subfamilies over the past 40 million years, diversification of large-bodied hypercarnivores appears constrained at the clade level, biasing specialized lineages to extinction. However, despite shorter species durations, extinction rates of large hypercarnivores have been mostly similar to those of all other canids. Extinction was size- and carnivory-selective only at the end of the Pleistocene epoch 11,000 years ago, suggesting that large hypercarnivores were not disadvantaged at the species level before anthropogenic influence.


PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0140682 ◽  
Author(s):  
Joshua A. Drew ◽  
Kathryn L. Amatangelo ◽  
Ruth A. Hufbauer

2013 ◽  
Vol 1 (2) ◽  
pp. 117
Author(s):  
Fakhrizal Setiawan ◽  
Janny D Kusen ◽  
Georis JF Kaligis

In order to look at changes in coral and reef fish communities during the period of 2006 to 2013, this research was carried out at Bunaken National Park (BNP) with 26 observation sites. The existing data and information of reef fish communities in the park generally could not be used as representative for describing the whole region. Percentage of coral cover and fish abundance during the study period shows that Bunaken Island is more similar to other locations. Reef fish community structure as seen from ecological index (H' at all sites being categorized, E category labile and low category C) shows the condition of the reef fish community is still good. Changes in the structure of reef fish communities showed declining conditions compared to 2006, and coral cover continued to decrease compared to 1998 and 2007. Good overall reef fish and coral cover have decreased; it is thought to be related to the pressure in BNP. Some of the pressures in the region were (i) increasing numbers of domestic as well as foreign visitors, (ii) increasing number of residents in the region, as well as the burden of waste and trash from the Bay of Manado. Penelitian dilakukan di Taman Nasional Bunaken (Utara dan Selatan)   pada 26 lokasi  pengamatan untuk menganalisis perubahan struktur komunitas ikan karang melalui kajian dari suatu time series data dari beberapa penelitian sebelumnya. Data primer mengenai ikan-ikan karang diperoleh melalui visual sensus bawah air yang bersamaan dengan observasi terumbu karang menggunakan point intercept transect. Nilai persentase tutupan karang dan kelimpahan ikan menunjukkan bahwa pada lokasi pengamatan Pulau Bunaken paling baik dibandingan lokasi lainnya. Struktur komunitas ikan karang yang dianalisis dengan indeks ekologi menunjukkan indeks keanekaragaman (H’) di semua site masuk kategori sedang, indeks kesamaan (E) kategori labil dan indeks Dominansi (C) kategori rendah. Hasil penelitian ini menunjukkan bahwa kondisi komunitas ikan karang masih baik, sekalipun  perubahan struktur komunitas ikan karang menunjukkan kondisi yang menurun dibandingkan tahun 2006, begitu juga tutupan karang yang terus turun dibandingkan tahun 1998 dan 2007. Secara keseluruhan baik ikan karang maupun tutupan karang mengalami penurunan, hal ini diduga terkait dengan tekanan yang dialami kawasan TN. Bunaken. Salah satu tekanan terhadap kawasan adalah jumlah turis dari dalam maupun luar negeri yang semakin meningkat tiap tahunnya, penambahan jumlah penduduk di dalam kawasan, serta beban limbah dan sampah dari Teluk Manado.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Mohammed A. Dakhil ◽  
Marwa Waseem A. Halmy ◽  
Walaa A. Hassan ◽  
Ali El-Keblawy ◽  
Kaiwen Pan ◽  
...  

Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperuspingii var. pingii, J.tibetica, and J.komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1241
Author(s):  
Stanko Vršič ◽  
Marko Breznik ◽  
Borut Pulko ◽  
Jesús Rodrigo-Comino

Earthworms are key indicators of soil quality and health in vineyards, but research that considers different soil management systems, especially in Slovenian viticultural areas is scarce. In this investigation, the impact of different soil management practices such as permanent green cover, the use of herbicides in row and inter-row areas, use of straw mulch, and shallow soil tillage compared to meadow control for earthworm abundance, were assessed. The biomass and abundance of earthworms (m2) and distribution in various soil layers were quantified for three years. Monitoring and a survey covering 22 May 2014 to 5 October 2016 in seven different sampling dates, along with a soil profile at the depth from 0 to 60 cm, were carried out. Our results showed that the lowest mean abundance and biomass of earthworms in all sampling periods were registered along the herbicide strip (within the rows). The highest abundance was found in the straw mulch and permanent green cover treatments (higher than in the control). On the plots where the herbicide was applied to the complete inter-row area, the abundance of the earthworm community decreased from the beginning to the end of the monitoring period. In contrast, shallow tillage showed a similar trend of declining earthworm abundance, which could indicate a deterioration of soil biodiversity conditions. We concluded that different soil management practices greatly affect the soil’s environmental conditions (temperature and humidity), especially in the upper soil layer (up to 15 cm deep), which affects the abundance of the earthworm community. Our results demonstrated that these practices need to be adapted to the climate and weather conditions, and also to human impacts.


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