Coastal cities in tropical areas are often low-lying and vulnerable to the effects of flooding an... more Coastal cities in tropical areas are often low-lying and vulnerable to the effects of flooding and storms. San Juan, Puerto Rico is a good example of this. It is built around a lagoon-channel complex called the San Juan Bay Estuary (SJBE). A critical channel in the estuary, the Caño Martín Peña, has filled in and now frequently floods the surrounding communities with sewageenriched waters, causing a series of human health and ecological problems. Sediment core analyses indicate that portions of the SJBE now function as settling basins. High urban and sewage runoff to the Caño contributes nitrogen (N), but stable isotope and sediment nutrient analyses indicate that this runoff may also enhance conditions for coupled sulfate reduction-nitrogen fixation. The amount of 'new' bioavailable N created from inert atmospheric N 2 gas may meet or exceed that from the runoff into the Caño Martín Peña. The ecological consequences of this appear to extend beyond the ponded channel, potentially contributing to the poor water quality of the SJBE, greater than contaminated runoff alone.
ABSTRACTA study was conducted to determine the primary sources of fecal pollution in a subtropica... more ABSTRACTA study was conducted to determine the primary sources of fecal pollution in a subtropical watershed using host-specific assays developed in temperate regions. Water samples (n= 534) from 10 different sites along the Rio Grande de Arecibo (RGA) watershed were collected mostly on a weekly basis (54 sampling events) during 13 months. DNA extracts from water samples were used in PCR assays to determine the occurrence of fecal bacteria (Bacteroidales,Clostridium coccoides, and enterococci) and human-, cattle-, swine-, and chicken-specific fecal sources. Feces from 12 different animals (n= 340) and wastewater treatment samples (n= 16) were analyzed to determine the specificity and distribution of host-specific assays. The human-specific assay (HF183) was found to be highly specific, as it did not cross-react with nontarget samples. The cattle marker (CF128) cross-reacted to some extent with swine, chicken, and turkeys and was present in 64% of the cattle samples tested. The swine...
CITATIONS 9 READS 48 6 authors, including: Some of the authors of this publication are also worki... more CITATIONS 9 READS 48 6 authors, including: Some of the authors of this publication are also working on these related projects: Ancient fecal microbiomes and viromes give insight about pre-Columbian Caribbean cultures View project Carlos toledo-hernandez
Coastal cities in tropical areas are often low-lying and vulnerable to the effects of flooding an... more Coastal cities in tropical areas are often low-lying and vulnerable to the effects of flooding and storms. San Juan, Puerto Rico is a good example of this. It is built around a lagoon-channel complex called the San Juan Bay Estuary (SJBE). A critical channel in the estuary, the Caño Martín Peña, has filled in and now frequently floods the surrounding communities with sewageenriched waters, causing a series of human health and ecological problems. Sediment core analyses indicate that portions of the SJBE now function as settling basins. High urban and sewage runoff to the Caño contributes nitrogen (N), but stable isotope and sediment nutrient analyses indicate that this runoff may also enhance conditions for coupled sulfate reduction-nitrogen fixation. The amount of 'new' bioavailable N created from inert atmospheric N 2 gas may meet or exceed that from the runoff into the Caño Martín Peña. The ecological consequences of this appear to extend beyond the ponded channel, potentially contributing to the poor water quality of the SJBE, greater than contaminated runoff alone.
ABSTRACTA study was conducted to determine the primary sources of fecal pollution in a subtropica... more ABSTRACTA study was conducted to determine the primary sources of fecal pollution in a subtropical watershed using host-specific assays developed in temperate regions. Water samples (n= 534) from 10 different sites along the Rio Grande de Arecibo (RGA) watershed were collected mostly on a weekly basis (54 sampling events) during 13 months. DNA extracts from water samples were used in PCR assays to determine the occurrence of fecal bacteria (Bacteroidales,Clostridium coccoides, and enterococci) and human-, cattle-, swine-, and chicken-specific fecal sources. Feces from 12 different animals (n= 340) and wastewater treatment samples (n= 16) were analyzed to determine the specificity and distribution of host-specific assays. The human-specific assay (HF183) was found to be highly specific, as it did not cross-react with nontarget samples. The cattle marker (CF128) cross-reacted to some extent with swine, chicken, and turkeys and was present in 64% of the cattle samples tested. The swine...
CITATIONS 9 READS 48 6 authors, including: Some of the authors of this publication are also worki... more CITATIONS 9 READS 48 6 authors, including: Some of the authors of this publication are also working on these related projects: Ancient fecal microbiomes and viromes give insight about pre-Columbian Caribbean cultures View project Carlos toledo-hernandez
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