Catchment to sea connection: Impacts of terrestrial run-off on benthic ecosystems in American Samoa

2021 ◽  
Vol 169 ◽  
pp. 112530
Author(s):  
Mia T. Comeros-Raynal ◽  
Jon Brodie ◽  
Zoe Bainbridge ◽  
John Howard Choat ◽  
Meagan Curtis ◽  
...  
Keyword(s):  
American Samoa ◽  
Run Off ◽  
Benthic Ecosystems

scholarly journals Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ulrike Braeckman ◽  
Francesca Pasotti ◽  
Ralf Hoffmann ◽  
Susana Vázquez ◽  
Angela Wulff ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Benthic Communities ◽  
Benthic Primary Production ◽  
Community Metabolism ◽  
West Antarctic ◽  
Run Off ◽  
Net Heterotrophy ◽  
Benthic Ecosystems ◽  
The Antarctic

AbstractClimate change-induced glacial melt affects benthic ecosystems along the West Antarctic Peninsula, but current understanding of the effects on benthic primary production and respiration is limited. Here we demonstrate with a series of in situ community metabolism measurements that climate-related glacial melt disturbance shifts benthic communities from net autotrophy to heterotrophy. With little glacial melt disturbance (during cold El Niño spring 2015), clear waters enabled high benthic microalgal production, resulting in net autotrophic benthic communities. In contrast, water column turbidity caused by increased glacial melt run-off (summer 2015 and warm La Niña spring 2016) limited benthic microalgal production and turned the benthic communities net heterotrophic. Ongoing accelerations in glacial melt and run-off may steer shallow Antarctic seafloor ecosystems towards net heterotrophy, altering the metabolic balance of benthic communities and potentially impacting the carbon balance and food webs at the Antarctic seafloor.

scholarly journals Rhodoliths in Brazil: Current knowledge and potential impacts of climate change

2016 ◽  
Vol 64 (spe2) ◽  
pp. 117-136 ◽  
Author(s):  
Paulo Antunes Horta ◽  
Pablo Riul ◽  
Gilberto M. Amado Filho ◽  
Carlos Frederico D. Gurgel ◽  
Flávio Berchez ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Ocean Acidification ◽  
Heat Waves ◽  
Current Knowledge ◽  
Coastal Pollution ◽  
Brazil Current ◽  
Run Off ◽  
Benthic Ecosystems ◽  
Impacts Of Climate Change

Abstract Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the eco-physiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives.

scholarly journals First Report of Phytophthora nicotianae Causing Leaf Blight, Fruit Rot, and Root Rot of Papaya in American Samoa

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 712-712 ◽  
Author(s):  
P. D. Roberts ◽  
E. Trujillo
Keyword(s):  
Fungal Growth ◽  
Soil Surface ◽  
Pathogenic Fungi ◽  
American Samoa ◽  
Wide Distribution ◽  
Phytophthora Nicotianae ◽  
Crown Rot ◽  
Fruit Rot ◽  
Sterile Water ◽  
Run Off

Papaya trees (Carica papaya) were observed in 1997 with symptoms of acute chlorosis and wilting of foliage, circular whitish lesions with necrotic centers on fruits, and root and trunk rots that killed the diseased trees. Identical symptoms were observed on many trees in fields interplanted with other crops and in home gardens on two of the five islands of American Samoa. A Phytophthora sp. was consistently isolated on water agar from symptomatic stems, fruits, and roots. The fungus was grown in pure culture on V8 juice medium at 25°C under continuous fluorescent illumination, and was identified, on the basis of spherical to broadly ovoid (34 to 67 × 40 to 50 µm), intercalary to terminal sporangia, chlamydospores (20 × 40 µm), and uniform to uneven hyphae (5 to 7 µm wide), as Phytophthora nicotianae Breda de Haan (= P. parasitica Dastur) (1,2). Ten 4-week old papaya seedlings grown on pasteurized soil in 15-cm pots were inoculated with a 2-ml suspension of 100 sporangia per ml in sterile water applied to the soil surface. Six uninoculated plants were used as controls. Two mature fruit that had reached the climacteric point were inoculated with 200 µl of sterile water containing approximately 20 sporangia. Inoculum was placed inside a 1-cm-diameter rubber circle that had been attached to the surface of the fruit to prevent run-off. Two uninoculated fruits served as controls. Inoculations of seedlings and fruit were conducted three times. Wilting symptoms developed on inoculated plants in less than 5 days and plant death accompanied by crown rot occurred in 14 days. Inoculated fruit developed lesions covered with a whitish fungal growth within 10 days after inoculation. Plants and fruits exposed to sterile water were healthy. The pathogen was reisolated from the diseased plants and fruits and it was morphologically identical to the original isolate, confirming its role as the causative agent of the disease. The wide distribution of diseased plants over an estimated one-quarter of the area of the island of Tutuila (approximately 24 sq. km) and on the adjacent island of Ofu indicates that the disease was not of recent introduction. References: (1) H. H. Hob et al. The genus Phytophthora in Taiwan. Inst. Bot., Ac. Sinica, Monogr. Ser. 15., 1995. (2) G. M. Waterhouse and J. M. Waterhouse. C.M.I. Descriptions of Pathogenic Fungi and Bacteria No. 34, 1964.

Quality Improvement Project in American Samoa to Increase Adherence to Secondary RHD Prophylaxis

PEDIATRICS ◽  
2016 ◽  
Vol 137 (Supplement 3) ◽  
pp. 379A-379A
Author(s):  
Elizabeth A. Parker ◽  
Amber Michelle Rogers Bock ◽  
Tangra L. Broge
Keyword(s):  
Quality Improvement ◽  
American Samoa ◽  
Quality Improvement Project ◽  
Improvement Project

STRUKTUR BASIS DATA SISTEM INFORMASI MANAJEMEN ALOKASI LAHAN DALAM PENATAAN RUANG

2019 ◽  
Vol 3 ◽  
pp. 385
Author(s):  
Dinar Dwi Anugerah Putranto ◽  
Agus Lestari Yuono ◽  
Sarino Sarino ◽  
IC Juliana
Keyword(s):  
Run Off

Perubahan Pemanfaatan lahan yang begitu cepat, telah merubah pola-pola pengaliran permukaan (run-off) pada wilayah sub sistem sungai yang ada di daerah perkotaan. Permasalahan limpasan air permukaan dan genangan (storm watter), dipengaruhi oleh beberapa faktor, seperti masalah okupasi bantaran sungai, penimbunan rawa yang tidak sesuai, pengaruh pasang-surut sungai, yang mempengaruhi kapasitas sub sistem sungai pada wilayah bersangkutan (Putranto, 2016). Penelitian ini akan membahas isu spasial pada sistem aliran air permukaan dalam perencanaan tata ruang wilayah kota dengan menekankan integrasi aliran air permukaan (run-off) dan manajemen alokasi lahan. Metode yang digunakan dalam penelitian ini adalah melakukan analisis secara spasial menggunakan semua parameter Run-off dalam struktur database dengan memanfaatkan interface Sistem Informasi Manajemen Alokasi Lahan (SIMAL) yang dibangun untuk menguji besarnya puncak banjir menggunakan metode HSS Nakayatsu, dengan studi kasus sub sistem sungai Jakabaring, di Kota Palembang. Hasil yang diperoleh mampu melihat alih fungsi lahan rawa, yang dimanfaatkan untuk Kawasan Palembang Sport City dalam menghadapi Asian Games 2018 di Kota Palembang, telah menyebabkan genangan banjir pada wilayah sungai Kedukan, bagian dari Sub DAS Jakabaring, Kawasan Seberang Ulu, Kota Palembang, Indonesia. Berdasarkan Analisis menggunakan model hydrograft satuan Nakayatsu, terjadinya puncak banjir akan terjadi saat curah hujan mencapai lebih dari 120 mm/jam yang menyebabkan debit sungai kedukan mencapai hingga 400m3/det. Pembuatan danau buatan sebagai kolam retensi dan sekaligus sebagai venue olah raga, belum mampu mengurangi tinggi genangan yang terjadi sekitar 0,6 – 1,2 m dpl.

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