Community Structure of Pleistocene Coral Reefs of Curacao, Netherlands Antilles

AbstractCoral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003-2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing these two life history strategies may be better suited to cope with warmer oceans and thus may warrant protective status under climate change.

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Struktur Komunitas Ikan Karang dan Tutupan Karang pada Terumbu Buatan Artificial Patch Reef (APR)

Jurnal Kelautan Tropis ◽

10.14710/jkt.v23i3.9171 ◽

2020 ◽

Vol 23 (3) ◽

pp. 333-340

Author(s):

Munasik Munasik ◽

Aldion Adin Nugroho ◽

Retno Hartati ◽

Agus Sabdono ◽

Sugiyanto Sugiyanto ◽

...

Keyword(s):

Community Structure ◽

Coral Reefs ◽

Reef Fish ◽

Coral Cover ◽

Patch Reef ◽

Habitat Type ◽

Artificial Reef ◽

Reef Fishes ◽

Live Coral ◽

Natural Coral

Artificial Patch Reef (APR) have been applied as a new method for Biodiversity Conservation Program at Panjang Island, Jepara since 2015. Previous study suggested that design and location of artificial reefs installation affected to abundance of reef fishes, associated with the artificial reef. This study aims to investigated community structure of reef fishes associated to artificial patch reef comparing to reef fishes in nearby natural reefs. Assessment of coral reef condition on two habitats were conducted on July 2019, after 4 years deployment. The results show that artificial patch reefs with a percentage of live coral cover are less than half of natural coral reefs, and have succeeded in increasing the abundance of reef fish with nearly the same density and community structure resembling reef fish in natural coral reefs. The similarity in community structure of the two habitats is probably due to the similarity in habitat type and morphology of the hard corals. The results indicate that Artificial Patch Reef (APR) reefs have increased the coral cover of Acropora branching and resulted in increased reef fish abundance which is compatible with reef fish communities associated with natural coral reefs around it. Aplikasi metode baru terumbu buatan Artificial patch Reef (APR) pada Program Konservasi Bioiversitas Pulau Panjang, Jepara telah dilakukan sejak 2015. Hasil studi menunjukkan bahwa pemilihan desain dan lokasi pemasangan terumbu buatan yang tepat akan meningkatkan kelimpahan ikan karang. Tujuan penelitian ini adalah untuk mengetahui keberhasilan penerapan terumbu buatan APR melalui kelimpahan ikan karang yang berasosiasi pada terumbu buatan dan terumbu karang alami di sekitarnya. Penilaian kondisi terumbu karang tersebut telah dilakukan pada Juli 2019 setelah 4 (empat) tahun pemasangan terumbu buatan. Hasil studi menunjukkan bahwa terumbu buatan dengan persentase tutupan karang hidup lebih kecil, separuhnya dari tutupan pada terumbu karang alami telah berhasil meningkatkan kelimpahan ikan karang dengan densitas hampir sama dan struktur komunitasnya menyerupai ikan karang yang berasosiasi dengan terumbu karang alami. Kesamaan struktur komunitas kedua habitat kemungkinan akibat kesamaan tipe habitat dan morfologi karang keras penyusunya. Hasil ini mengindikasikan bahwa terumbu buatan Artificial patch Reef (APR) telah meningkatkan tutupan karang bercabang Acropora dan berakibat terhadap meningkatnya kelimpahan ikan karang yang sesuai dengan komunitas ikan karang yang berasosiasi dengan terumbu karang alami di sekitarnya.

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Integrating Oceanographic Data and Benthic Community Structure Temporal Series to Assess the Dynamics of a Marginal Reef

Frontiers in Marine Science ◽

10.3389/fmars.2021.762453 ◽

2021 ◽

Vol 8 ◽

Author(s):

Julia Biscaia Zamoner ◽

Anaide Wrublevski Aued ◽

Luis Carlos Pinto Macedo-Soares ◽

Vitor André Passos Picolotto ◽

Carlos Alberto Eiras Garcia ◽

...

Keyword(s):

Community Structure ◽

Coral Reefs ◽

Wave Energy ◽

Structural Changes ◽

Anthropogenic Impacts ◽

Benthic Communities ◽

Structural Complexity ◽

Marine Species ◽

Oceanic Islands ◽

Brazilian Province

Reefs are the richest marine ecosystems. Their benthic communities generate structural complexity and participate in nutrient cycles, providing habitat and food for many marine species. These ecosystems have been threatened by local and global anthropogenic impacts and changes in community structure have led to loss of biodiversity, ecosystem function and services worldwide. Most studies about these structural changes have been conducted in Caribbean and Indo-Pacific coral reefs. In the Southwestern Atlantic, where reefs are naturally algae-dominated, these efforts are incipient, especially at oceanic islands where local anthropic impacts tend to be lower, and natural and climate-induced fluctuations might be easily detected. We conducted the first temporal assessment of benthic communities and the influence of oceanographic parameters between 2013 and 2019 in Fernando de Noronha (FNA), the largest Brazilian oceanic archipelago. We annually sampled benthic communities in FNA’s shallow reefs (2–21 m) using photoquadrats, quantified and gathered organisms in major groups according to their functional roles. We also characterized and tested “sea surface temperature,” “marine heatwaves,” “diffuse attenuation coefficient,” and “wave energy” influence for the same period. The most abundant groups were epilithic algal matrix (EAM; mean annual coverage: 23–60%), macroalgae (15–35%) and calcifiers (15–29%), followed by cyanobacteria (1–37%), suspension/filter-feeders (<2%), zoanthids (<1%) and other invertebrates (<0.1%). EAM was negatively correlated with “marine heatwaves” and positively correlated with “wave energy,” while macroalgae and calcifiers showed opposite responses to “marine heatwaves” and “wave energy,” respectively. Cyanobacteria was positively correlated with “marine heatwaves.” The dominance of EAM and macroalgae was already described for reefs along the Brazilian Province and we demonstrated the persistence of this structure over the years in FNA, with the exception of 2019 when there was a substantial increase of cyanobacteria after a strong marine heatwave. Our results suggest a flickering dynamic between EAM and macroalgae, which vary according to the oceanographic conditions, reinforcing its distinct dynamics from most tropical coral reefs. However, the increase of cyanobacteria added to projections of more frequent and stronger marine heatwaves worldwide indicate possible structural changes in this community. Continued monitoring of community and oceanographic drivers is key for better understanding and predicting changes in important marginal reefs.

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