MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS
The Common tern (Sterna hirundo) is considered a sentinel wildlife species for monitoring mercury (Hg) and other contaminants within the St. Lawrence River Cornwall/Massena Areas of Concern (AOC). Here, I investigate the relationship between Hg bioaccumulation and diet using stable isotopes of carbo...
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ftcanadathes:oai:collectionscanada.gc.ca:OKQ.1974/8063 2023-05-15T15:56:22+02:00 MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS Baird, CHRISTOPHER Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) 2013-06-01 19:35:59.665 http://hdl.handle.net/1974/8063 en eng Canadian theses http://hdl.handle.net/1974/8063 This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. mercury common terns ecotoxicology isotopes Thesis 2013 ftcanadathes 2013-12-22T00:49:10Z The Common tern (Sterna hirundo) is considered a sentinel wildlife species for monitoring mercury (Hg) and other contaminants within the St. Lawrence River Cornwall/Massena Areas of Concern (AOC). Here, I investigate the relationship between Hg bioaccumulation and diet using stable isotopes of carbon (δ13C) and nitrogen (δ15N) in adult and chick Common terns from three colonies along a 160 km transect of the upper St. Lawrence River. The foraging range of the colony furthest downstream (EMC) includes both the Massena and Cornwall AOC’s while the two upstream colonies (213 and Ice) are more removed from known point sources of Hg. I also sampled winter- and summer-grown breast feathers to compare diet and Hg exposure on the terns’ breeding ground vs. the terns’ wintering grounds. Hg exposure in summer-grown feathers was significantly higher than Hg exposure in winter grown feathers. Stable carbon (δ13C) and nitrogen (δ15N) isotopes revealed a switch from a marine-based diet during the winter months to a freshwater-based diet on the breeding grounds. Among colonies in summer-grown and chick feathers, the only significant difference in total mercury (THg) exposure was found in chick feathers where Hg was significantly lower at 213 than Ice – both of which are upstream from the AOC’s. However, THg was negatively correlated with δ13C in both winter and summer feathers, and the most parsimonious multi-regression model for winter and summer feathers indicated that δ13C explains 24 and 25% of the variation in Hg exposure, respectively. This suggests terns foraging offshore bioaccumulate more Hg than individuals foraging inshore or in freshwater (winter feathers), and that during the breeding period, terns foraging in pelagic habitats bioaccumulate more Hg than terns foraging in littoral habitats (summer feathers). For the upper St. Lawrence River, these results provide strong evidence that foraging habitat is more important than colony location in determining Hg exposure in a top trophic consumer. Thesis (Master, Biology) -- Queen's University, 2013-06-01 19:35:59.665 Thesis Common tern Sterna hirundo Theses Canada/Thèses Canada (Library and Archives Canada) Cornwall ENVELOPE(-59.688,-59.688,-62.366,-62.366) Lawrence River ENVELOPE(-115.002,-115.002,58.384,58.384) |
institution |
Open Polar |
collection |
Theses Canada/Thèses Canada (Library and Archives Canada) |
op_collection_id |
ftcanadathes |
language |
English |
topic |
mercury common terns ecotoxicology isotopes |
spellingShingle |
mercury common terns ecotoxicology isotopes Baird, CHRISTOPHER MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
topic_facet |
mercury common terns ecotoxicology isotopes |
description |
The Common tern (Sterna hirundo) is considered a sentinel wildlife species for monitoring mercury (Hg) and other contaminants within the St. Lawrence River Cornwall/Massena Areas of Concern (AOC). Here, I investigate the relationship between Hg bioaccumulation and diet using stable isotopes of carbon (δ13C) and nitrogen (δ15N) in adult and chick Common terns from three colonies along a 160 km transect of the upper St. Lawrence River. The foraging range of the colony furthest downstream (EMC) includes both the Massena and Cornwall AOC’s while the two upstream colonies (213 and Ice) are more removed from known point sources of Hg. I also sampled winter- and summer-grown breast feathers to compare diet and Hg exposure on the terns’ breeding ground vs. the terns’ wintering grounds. Hg exposure in summer-grown feathers was significantly higher than Hg exposure in winter grown feathers. Stable carbon (δ13C) and nitrogen (δ15N) isotopes revealed a switch from a marine-based diet during the winter months to a freshwater-based diet on the breeding grounds. Among colonies in summer-grown and chick feathers, the only significant difference in total mercury (THg) exposure was found in chick feathers where Hg was significantly lower at 213 than Ice – both of which are upstream from the AOC’s. However, THg was negatively correlated with δ13C in both winter and summer feathers, and the most parsimonious multi-regression model for winter and summer feathers indicated that δ13C explains 24 and 25% of the variation in Hg exposure, respectively. This suggests terns foraging offshore bioaccumulate more Hg than individuals foraging inshore or in freshwater (winter feathers), and that during the breeding period, terns foraging in pelagic habitats bioaccumulate more Hg than terns foraging in littoral habitats (summer feathers). For the upper St. Lawrence River, these results provide strong evidence that foraging habitat is more important than colony location in determining Hg exposure in a top trophic consumer. Thesis (Master, Biology) -- Queen's University, 2013-06-01 19:35:59.665 |
author2 |
Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
format |
Thesis |
author |
Baird, CHRISTOPHER |
author_facet |
Baird, CHRISTOPHER |
author_sort |
Baird, CHRISTOPHER |
title |
MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
title_short |
MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
title_full |
MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
title_fullStr |
MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
title_full_unstemmed |
MERCURY AND STABLE ISOTOPES IN COMMON TERNS (STERNA HIRUNDO) FROM THE ST. LAWRENCE RIVER: A COMPARISON BETWEEN BREEDING AND WINTER HABITATS |
title_sort |
mercury and stable isotopes in common terns (sterna hirundo) from the st. lawrence river: a comparison between breeding and winter habitats |
publishDate |
2013 |
url |
http://hdl.handle.net/1974/8063 |
long_lat |
ENVELOPE(-59.688,-59.688,-62.366,-62.366) ENVELOPE(-115.002,-115.002,58.384,58.384) |
geographic |
Cornwall Lawrence River |
geographic_facet |
Cornwall Lawrence River |
genre |
Common tern Sterna hirundo |
genre_facet |
Common tern Sterna hirundo |
op_relation |
Canadian theses http://hdl.handle.net/1974/8063 |
op_rights |
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
_version_ |
1766391806018191360 |