The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca).
Whale watching has become increasingly popular as an ecotourism activity around the globe and is beneficial for environmental education and local economies. Southern Resident killer whales (Orcinus orca) comprise an endangered population that is frequently observed by a large whale watching fleet in...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2015-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4667929?pdf=render |
| _version_ | 1819034796857229312 |
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| author | Juliana Houghton Marla M Holt Deborah A Giles M Bradley Hanson Candice K Emmons Jeffrey T Hogan Trevor A Branch Glenn R VanBlaricom |
| author_facet | Juliana Houghton Marla M Holt Deborah A Giles M Bradley Hanson Candice K Emmons Jeffrey T Hogan Trevor A Branch Glenn R VanBlaricom |
| author_sort | Juliana Houghton |
| collection | DOAJ |
| description | Whale watching has become increasingly popular as an ecotourism activity around the globe and is beneficial for environmental education and local economies. Southern Resident killer whales (Orcinus orca) comprise an endangered population that is frequently observed by a large whale watching fleet in the inland waters of Washington state and British Columbia. One of the factors identified as a risk to recovery for the population is the effect of vessels and associated noise. An examination of the effects of vessels and associated noise on whale behavior utilized novel equipment to address limitations of previous studies. Digital acoustic recording tags (DTAGs) measured the noise levels the tagged whales received while laser positioning systems allowed collection of geo-referenced data for tagged whales and all vessels within 1000 m of the tagged whale. The objective of the current study was to compare vessel data and DTAG recordings to relate vessel traffic to the ambient noise received by tagged whales. Two analyses were conducted, one including all recording intervals, and one that excluded intervals when only the research vessel was present. For all data, significant predictors of noise levels were length (inverse relationship), number of propellers, and vessel speed, but only 15% of the variation in noise was explained by this model. When research-vessel-only intervals were excluded, vessel speed was the only significant predictor of noise levels, and explained 42% of the variation. Simple linear regressions (ignoring covariates) found that average vessel speed and number of propellers were the only significant correlates with noise levels. We conclude that vessel speed is the most important predictor of noise levels received by whales in this study. Thus, measures that reduce vessel speed in the vicinity of killer whales would reduce noise exposure in this population. |
| first_indexed | 2024-12-21T07:39:26Z |
| format | Article |
| id | doaj.art-59b7269da1da4f0db18bdd27f1dc3894 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T07:39:26Z |
| publishDate | 2015-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-59b7269da1da4f0db18bdd27f1dc38942022-12-21T19:11:21ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-011012e014011910.1371/journal.pone.0140119The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca).Juliana HoughtonMarla M HoltDeborah A GilesM Bradley HansonCandice K EmmonsJeffrey T HoganTrevor A BranchGlenn R VanBlaricomWhale watching has become increasingly popular as an ecotourism activity around the globe and is beneficial for environmental education and local economies. Southern Resident killer whales (Orcinus orca) comprise an endangered population that is frequently observed by a large whale watching fleet in the inland waters of Washington state and British Columbia. One of the factors identified as a risk to recovery for the population is the effect of vessels and associated noise. An examination of the effects of vessels and associated noise on whale behavior utilized novel equipment to address limitations of previous studies. Digital acoustic recording tags (DTAGs) measured the noise levels the tagged whales received while laser positioning systems allowed collection of geo-referenced data for tagged whales and all vessels within 1000 m of the tagged whale. The objective of the current study was to compare vessel data and DTAG recordings to relate vessel traffic to the ambient noise received by tagged whales. Two analyses were conducted, one including all recording intervals, and one that excluded intervals when only the research vessel was present. For all data, significant predictors of noise levels were length (inverse relationship), number of propellers, and vessel speed, but only 15% of the variation in noise was explained by this model. When research-vessel-only intervals were excluded, vessel speed was the only significant predictor of noise levels, and explained 42% of the variation. Simple linear regressions (ignoring covariates) found that average vessel speed and number of propellers were the only significant correlates with noise levels. We conclude that vessel speed is the most important predictor of noise levels received by whales in this study. Thus, measures that reduce vessel speed in the vicinity of killer whales would reduce noise exposure in this population.http://europepmc.org/articles/PMC4667929?pdf=render |
| spellingShingle | Juliana Houghton Marla M Holt Deborah A Giles M Bradley Hanson Candice K Emmons Jeffrey T Hogan Trevor A Branch Glenn R VanBlaricom The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). PLoS ONE |
| title | The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). |
| title_full | The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). |
| title_fullStr | The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). |
| title_full_unstemmed | The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). |
| title_short | The Relationship between Vessel Traffic and Noise Levels Received by Killer Whales (Orcinus orca). |
| title_sort | relationship between vessel traffic and noise levels received by killer whales orcinus orca |
| url | http://europepmc.org/articles/PMC4667929?pdf=render |
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