scholarly journals Fishing degrades size structure of coral reef fish communities

2016 ◽  
Author(s):  
James PW Robinson ◽  
Ivor D Williams ◽  
Andrew M Edwards ◽  
Jana McPherson ◽  
Lauren Yeager ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Fish Community ◽  
Size Structure ◽  
Fish Communities ◽  
Fish Biomass ◽  
Community Size ◽  
Size Spectra ◽  
Coral Reef Ecosystems ◽  
Total Fish

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.

scholarly journals Fishing degrades size structure of coral reef fish communities

2016 ◽  
Author(s):  
James PW Robinson ◽  
Ivor D Williams ◽  
Andrew M Edwards ◽  
Jana McPherson ◽  
Lauren Yeager ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Fish Community ◽  
Size Structure ◽  
Fish Communities ◽  
Fish Biomass ◽  
Community Size ◽  
Size Spectra ◽  
Coral Reef Ecosystems ◽  
Total Fish

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.

scholarly journals Habitat degradation and fishing effects on the size structure of coral reef fish communities

2010 ◽  
Vol 20 (2) ◽  
pp. 442-451 ◽  
Author(s):  
S. K. Wilson ◽  
R. Fisher ◽  
M. S. Pratchett ◽  
N. A. J. Graham ◽  
N. K. Dulvy ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Size Structure ◽  
Habitat Degradation ◽  
Fish Communities

scholarly journals Dampak Pemutihan Karang Keras pada Komunitas Ikan Karang dan Makrozoobenthos di Wilayah Perairan Tejakula, Buleleng, Bali

Rekayasa ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Elok Faiqoh ◽  
I Wayan Gede Astawa Karang ◽  
Dwi Budi Wiyanto
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Bleaching ◽  
Fish Community ◽  
Global Climate ◽  
Population Decline ◽  
Fish Communities ◽  
Bleached Coral ◽  
Check Method ◽  
The Impact

<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>

scholarly journals The importance of sponges and mangroves in supporting fish communities in degraded coral reefs in Caribbean Panama

2017 ◽  
Author(s):  
Janina Seemann ◽  
Alexandra Yingst ◽  
Rick D Stuart-Smith ◽  
Graham J Edgar ◽  
Andrew H Altieri
Keyword(s):  
Coral Reefs ◽  
Fish Community ◽  
Trophic Structure ◽  
Habitat Degradation ◽  
Human Impacts ◽  
Small Body ◽  
Fish Communities ◽  
Trophic Levels ◽  
Fish Biomass ◽  
Total Fish

Fish communities associated with coral reefs worldwide are threatened by overexploitation and other human impacts such as bleaching events that cause habitat degradation. We assessed the fish community on coral reefs on the Caribbean coast of Panama, as well as those associated with mangrove and seagrass habitats, to explore the influences of habitat cover, connectivity and environmental characteristics in sustaining biomass, richness and trophic structure in a degraded tropical ecosystem. Overall, 94 % of all fishes across all habitat types were of small body size (≤11 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Moreover, total fish biomass was very low, small fishes from low trophic levels were over-represented, and top predators were under-represented relative to other Caribbean reefs. For example, herbivorous/omnivorous/detrivorous fishes (trophic level 2-2.7) comprised 37 % of total fish biomass, with the diminutive parrotfish Scarus iseri comprising 72 % of the parrotfish biomass. However, the abundance of sponges and proximity of mangroves were found to be important positive drivers of reef fish richness, biomass and trophic structure on a given reef, presumably by promoting functional processes of ecosystems. The masked goby (Coryphopterus personata) was a strong indicator of reef degradation, apparently benefiting from the reduced density of large predators on local reefs. The damselfish Abudefduf saxatilis was more common on reefs with high sponge cover, and also to proximity to mangroves. Our study suggests that a diverse fish community can persist on degraded coral reefs, and that the availability of habitat forming organisms other than corals, including sponges and mangroves, and their arrangement on the landscape, is critical to the maintenance of functional processes in these ecosystems.

Mexico. Condition of coral reef ecosystems in central-couthern Quintana Roo, Mexico (part 2: reef fish communities)

2003 ◽  
Vol 496 ◽  
pp. 338-359 ◽  
Author(s):  
Enrique Nunez-Lara ◽  
Carlos González-Salas ◽  
Miguel A. Ruiz-Zarate ◽  
Roberto C. Hernandez-Landa ◽  
J. Ernesto Arias-Gonzales
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Fish Communities ◽  
Quintana Roo ◽  
Coral Reef Ecosystems

scholarly journals The importance of sponges and mangroves in supporting fish communities in degraded coral reefs in Caribbean Panama

2017 ◽  
Author(s):  
Janina Seemann ◽  
Alexandra Yingst ◽  
Rick D Stuart-Smith ◽  
Graham J Edgar ◽  
Andrew H Altieri
Keyword(s):  
Coral Reefs ◽  
Fish Community ◽  
Trophic Structure ◽  
Habitat Degradation ◽  
Human Impacts ◽  
Small Body ◽  
Fish Communities ◽  
Trophic Levels ◽  
Fish Biomass ◽  
Total Fish

Fish communities associated with coral reefs worldwide are threatened by overexploitation and other human impacts such as bleaching events that cause habitat degradation. We assessed the fish community on coral reefs on the Caribbean coast of Panama, as well as those associated with mangrove and seagrass habitats, to explore the influences of habitat cover, connectivity and environmental characteristics in sustaining biomass, richness and trophic structure in a degraded tropical ecosystem. Overall, 94 % of all fishes across all habitat types were of small body size (≤11 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Moreover, total fish biomass was very low, small fishes from low trophic levels were over-represented, and top predators were under-represented relative to other Caribbean reefs. For example, herbivorous/omnivorous/detrivorous fishes (trophic level 2-2.7) comprised 37 % of total fish biomass, with the diminutive parrotfish Scarus iseri comprising 72 % of the parrotfish biomass. However, the abundance of sponges and proximity of mangroves were found to be important positive drivers of reef fish richness, biomass and trophic structure on a given reef, presumably by promoting functional processes of ecosystems. The masked goby (Coryphopterus personata) was a strong indicator of reef degradation, apparently benefiting from the reduced density of large predators on local reefs. The damselfish Abudefduf saxatilis was more common on reefs with high sponge cover, and also to proximity to mangroves. Our study suggests that a diverse fish community can persist on degraded coral reefs, and that the availability of habitat forming organisms other than corals, including sponges and mangroves, and their arrangement on the landscape, is critical to the maintenance of functional processes in these ecosystems.

scholarly journals Fishing degrades size structure of coral reef fish communities

2016 ◽  
Vol 23 (3) ◽  
pp. 1009-1022 ◽  
Author(s):  
James P. W. Robinson ◽  
Ivor D. Williams ◽  
Andrew M. Edwards ◽  
Jana McPherson ◽  
Lauren Yeager ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Size Structure ◽  
Fish Communities

scholarly journals Size structural change in lightly exploited coral reef fish communities: evidence for weak indirect effects

2004 ◽  
Vol 61 (3) ◽  
pp. 466-475 ◽  
Author(s):  
N K Dulvy ◽  
N VC Polunin ◽  
A C Mill ◽  
N AJ Graham
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Indirect Effects ◽  
Size Structure ◽  
Fish Communities ◽  
Weighted Average ◽  
Spatial Gradient ◽  
Size Classes ◽  
Average Maximum

Exploitation influences community structure directly through preferential removal of larger-bodied fishes and indirectly because larger-bodied fishes may exert top-down control upon other community members. We consider the direct and indirect effects of subsistence exploitation upon the size structure of coral reef fish communities along an island-scale spatial gradient of fishing intensity. We explored the effect of fishing intensity and sample date (three dates over a year) at six islands and the overall effect of fishing intensity averaged over sample dates at 13 islands. Fishing intensity consistently explained more of the variation in the size metrics than sample date. In response to exploitation, the mean weight of individuals declined by 52%, the weighted average maximum size (Lmax) declined by 25%, and slopes of community size spectra steepened. The larger size classes (>26 cm) declined in relative numbers by 63% and relative biomass by 61% in response to exploitation. However, the numbers and biomass of the three smallest size classes (<25 cm) increased by 31% and 9%, respectively, in response to exploitation. This increased abundance is consistent with a weak compensatory response presumably from a reduction in predation upon smaller size classes as an indirect effect of exploiting larger size classes.

Community changes of coral reef fishes in Bunaken National Park, North Sulawesi, Indonesia

2013 ◽  
Vol 1 (2) ◽  
pp. 117
Author(s):  
Fakhrizal Setiawan ◽  
Janny D Kusen ◽  
Georis JF Kaligis
Keyword(s):  
Reef Fish ◽  
National Park ◽  
Fish Community ◽  
Time Series Data ◽  
Coral Cover ◽  
Fish Communities ◽  
Reef Fishes ◽  
Series Data ◽  
Fish Community Structure ◽  
Reef Fish Community

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.

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