Bottlenose dolphin abundance in coastal Moreton Bay 2000
University of California, Irvine
Dataset credit
Vimoksalehi Lukoschek, University of California, Irvine
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Contacts
Role | Name | Organization | |
Primary contact |
Vimoksalehi Lukoschek |
University of California, Irvine |
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Data entry |
Ei Fujioka |
Duke University |
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Citation
Lukoschek, V. 2010. Bottlenose dolphin abundance in coastal Moreton Bay 2000. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/494) on yyyy-mm-dd. Halpin, P.N., A.J. Read, E. Fujioka, B.D. Best, B. Donnelly, L.J. Hazen, C. Kot, K. Urian, E. LaBrecque, A. Dimatteo, J. Cleary, C. Good, L.B. Crowder, and K.D. Hyrenbach. 2009. OBIS-SEAMAP: The world data center for marine mammal, sea bird, and sea turtle distributions. Oceanography. 22(2):104-115.
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Abstract
Marine megafauna populations in coastal waters are increasingly threatened by anthropogenic impacts. Moreton Bay, a large embayment in south-east Queensland, lies adjacent to one of the fastest growing regions in Australia and has a resident population of bottlenose dolphins, Tursiops aduncus. Evaluation of the effectiveness of any proposed management strategy requires robust population abundance estimates.
We estimated abundances of bottlenose dolphins in central eastern Moreton Bay (350 km2) using two commonly used abundance estimation methods for cetaceans: photo-identification mark-recapture and line-transect surveys. Mark-recapture data were analyzed in CAPTURE using a model that allowed capture probabilities to vary between sampling events and between individuals. Based on an estimated 76% of the population identifiable photographically, total abundance estimates were 673 ± 130 s.e. (1997) and 818 ± 152 s.e. (1998). Line-transect data, analyzed using DISTANCE, gave an abundance estimate of 407 ± 113.5 s.e. (2000). These abundance estimates are large compared with many other coastal bottlenose dolphin populations. The line-transect surveys comprised a pilot study, and the lower line-transect abundance estimate is probably best attributable to methodological issues. In particular, smaller mean group size was estimated for the line-transects surveys (2.85 ± 0.29 s.e.) than the mark-recapture surveys (4.87 ± 0.39 s.e., 1997; 5.78 ± 0.73 s.e., 1998), and line-transect group sizes were probably underestimated. In addition, the line-transect detection probability (g(o)) was assumed to be one but was almost certainly less than one. However, the possibility of an actual decline in population size cannot be ruled out. Coefficients of variation (CV) were lower for mark-recapture than for line-transect surveys, however, CVs of line-transect estimates could be lowered through improved survey design. We evaluated the power of these surveys to detect trends in potential population declines for bottlenose dolphins in Moreton Bay and make recommendations for ongoing monitoring strategies.
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Purpose
N/A
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Supplemental information
Effort data do not include date/time.
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References
Lukoschek, V. and B.L. Chilvers. 2008. A robust baseline for bottlenose dolphin abundance in coastal Moreton Bay: A large carnivore living in a region of escalating anthropogenic impacts. Wildlife Research. 35(7):593-605.
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Attributes
Overview
This section explains attributes included in the original dataset.
OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only.
Should you need other attributes described here, you are encouraged to contact the data provider.
Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downloadable online. Other attributes may be obtained upon provider's permission.
Attributes in dataset
Attribute (table column) | Description |
obs_date | Date |
obs_time | Time. Seconds are not proviced. |
sight_id | Total sights |
obs_count | Group size, combining adult, juvenile and calf. |
adult | Number of adult |
juv | Number of juveline |
calf | Number of calf |
longitude | longitude |
latitude | latitude |
sp_obs | Species observed |
sp_tsn | ITIS taxonomic serial number. This field added by OBIS-SEAMAP |
behaviour | Behavior of the animals |
oid | Unique ID number (generated by SEAMAP) |
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OBIS-SEAMAP ID | 494 |
Seabirds | 0 |
Marine mammals | 48 |
Sea turtles | 0 |
Rays and sharks | 0 |
Other species | 0 |
Non spatial | 0 |
Non species | 0 |
Total | 48 |
Date, Begin | 2000-01-08 |
Date, End | 2000-11-08 |
Temporal prec. | 111110 |
Latitude | -27.58 - -27.16 |
Longitude | 153.26 - 153.55 |
Coord. prec. | 6 decimal digits |
Platform | Boat |
Data type | Animal sighting |
Effort | YES (ID: 495) |
if ($show_effort_stat) {
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Traveled (km) | 179 |
Effort hours | 0 |
}
if ($sources != null and $sources != "" and $dataset_id != 427) { // Do not show ESAS
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Contr. through | |
}
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Registered | 2009-03-04 |
Updated | 2010-07-29 |
Status | Published |
Sharing policy |
CC-BY-NC (Minimum) |
Shared with |
OBIS
GBIF (via DOI) |
See metadata in static HTML |
See metadata in FGDC XML |
See download history / statistics |
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