The utility of simple fish community metrics for evaluating the relative influence of fishing vs. other environmental drivers on Caribbean reef fish communities

2014 ◽  
Vol 16 (4) ◽  
pp. 649-667 ◽  
Author(s):  
Henri Vallès ◽  
Hazel A Oxenford
Food Webs ◽  
2020 ◽  
Vol 24 ◽  
pp. e00147
Author(s):  
Chelsea M. Brown ◽  
Avery B. Paxton ◽  
J. Christopher Taylor ◽  
Rebecca V. Van Hoeck ◽  
Michael H. Fatzinger ◽  
...  

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.


2021 ◽  
Vol 12 (2) ◽  
pp. 383-394
Author(s):  
W. Aaron Wilson ◽  
Maria Wipfler ◽  
Josh Stevens

Abstract We analyzed 33 y of fish community data collected from a low-order, urban stream in central Illinois, USA, to determine the effects of municipal wastewater management projects and urbanization on fish communities. From 1985 to 2017, species richness, number of pollution-intolerant species, and alternative index of biotic integrity significantly increased at sites across this system. Species diversity likewise increased, but was mostly significant only at sites downstream of the effluent outflow. Ceasing the chlorination of wastewater in 1990 resulted in significant increases in fish community metrics both upstream and downstream of effluent outflow, although effects varied from site to site. Completing a combined sewer overflow abatement project in 2008 resulted in some significant increases in species richness, diversity, and number of pollution-intolerant species at sites downstream of effluent outflow. From 2001 to 2016, the change in the number of pollution-intolerant species correlated inversely with the increased percentage of impervious cover in the study system. There was no significant correlation of other metrics with the change in percent impervious surfaces. These results suggest that urbanization at upstream sites limited to some extent the benefits of water management interventions that improved fish community metrics at downstream sites.


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>


2004 ◽  
Vol 61 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Mike D Nicholson ◽  
Simon Jennings

Abstract Community metrics describe aspects of community structure and are often calculated from species-size-abundance data collected during fish stock monitoring surveys. Several community metrics have been proposed as indicators to support ecosystem-based fishery management. These metrics should be sensitive to fishing impacts and respond rapidly to management action, so that managers can assess whether changes in the fish community are a desirable or undesirable response to management. It should also be possible to estimate metrics with sufficient precision so that changes in the community can be detected on management time scales of a year to a few years. Here, we test the power of a large-scale annual trawl survey (North Sea International Bottom Trawl Survey, IBTS) to detect trends in six community metrics: mean length, mean weight, mean maximum length, mean maximum weight, slope of the biomass size spectrum, and mean trophic level. Our analyses show that the power of the trawl survey to detect trends is generally poor. While community metrics do provide good long-term indicators of changes in fish community structure, they are unlikely to provide an appropriate tool to support short-term management decisions. If fish community metrics are to provide effective support for ecosystem-based management, and management time scales cannot be extended, then the power of many surveys to detect trends in fish community structure will need to be improved by increased replication and standardization.


2016 ◽  
Author(s):  
James PW Robinson ◽  
Ivor D Williams ◽  
Andrew M Edwards ◽  
Jana McPherson ◽  
Lauren Yeager ◽  
...  

Fishing pressure on coral reef ecosystems has been frequently linked to reductions of large fishes and reef fish biomass. Associated impacts on overall community structure are, however, less clear. In size-structured aquatic ecosystems, fishing impacts are commonly quantified using size spectra, which describe the distribution of individual body sizes within a community. We examined the size spectra of coral reef fish communities at 38 US-affiliated Pacific islands, spanning from near pristine to highly human populated. Reef fish community size spectra slopes ‘steepened’ steadily with increasing human population and proximity to market due to a reduction in the relative biomass of large fishes and an increase in the dominance of small fishes. In contrast, total fish community biomass was substantially lower on inhabited islands than uninhabited ones, regardless of human population density. Comparing the relationship between size spectra and reef fish biomass, we found that on populated islands size spectra steepened linearly with declining biomass, whereas on uninhabited islands size spectra and biomass were unrelated. Size spectra slopes also were steeper in regions of low sea surface temperature but were insensitive to variation in other environmental and geomorphic covariates. In contrast, reef fish biomass was highly sensitive to biophysical conditions, being influenced by oceanic productivity, sea surface temperature, island type, and habitat complexity. Our results suggest that community size structure is more robust than total fish biomass to increasing human presence and that size spectra are reliable indicators of exploitation impacts across regions of different fish community compositions, environmental drivers, and fisheries types. Size-based approaches that link directly to functional properties of fish communities, and are relatively insensitive to abiotic variation across biogeographic regions, offer great potential for developing our understanding of fishing impacts in coral reef ecosystems.


2017 ◽  
Vol 164 (12) ◽  
Author(s):  
Ann H Opel ◽  
Colleen M Cavanaugh ◽  
Randi D Rotjan ◽  
Joey Pakes Nelson

Wetlands ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 1107-1116
Author(s):  
Katya E. Kovalenko ◽  
Valerie J. Brady ◽  
Jan J.H. Ciborowski ◽  
George E. Host ◽  
Lucinda B. Johnson

2016 ◽  
Author(s):  
James PW Robinson ◽  
Ivor D Williams ◽  
Andrew M Edwards ◽  
Jana McPherson ◽  
Lauren Yeager ◽  
...  

Fishing pressure on coral reef ecosystems has been frequently linked to reductions of large fishes and reef fish biomass. Associated impacts on overall community structure are, however, less clear. In size-structured aquatic ecosystems, fishing impacts are commonly quantified using size spectra, which describe the distribution of individual body sizes within a community. We examined the size spectra of coral reef fish communities at 38 US-affiliated Pacific islands, spanning from near pristine to highly human populated. Reef fish community size spectra slopes ‘steepened’ steadily with increasing human population and proximity to market due to a reduction in the relative biomass of large fishes and an increase in the dominance of small fishes. In contrast, total fish community biomass was substantially lower on inhabited islands than uninhabited ones, regardless of human population density. Comparing the relationship between size spectra and reef fish biomass, we found that on populated islands size spectra steepened linearly with declining biomass, whereas on uninhabited islands size spectra and biomass were unrelated. Size spectra slopes also were steeper in regions of low sea surface temperature but were insensitive to variation in other environmental and geomorphic covariates. In contrast, reef fish biomass was highly sensitive to biophysical conditions, being influenced by oceanic productivity, sea surface temperature, island type, and habitat complexity. Our results suggest that community size structure is more robust than total fish biomass to increasing human presence and that size spectra are reliable indicators of exploitation impacts across regions of different fish community compositions, environmental drivers, and fisheries types. Size-based approaches that link directly to functional properties of fish communities, and are relatively insensitive to abiotic variation across biogeographic regions, offer great potential for developing our understanding of fishing impacts in coral reef ecosystems.


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