Monitoring seabirds population in marine ecosystem: The use of strip-transect aerial surveys

2008 ◽  
Vol 112 (8) ◽  
pp. 3314-3322 ◽  
Author(s):  
Grégoire Certain ◽  
Vincent Bretagnolle
Keyword(s):  
Marine Ecosystem ◽  
Aerial Surveys ◽  
Strip Transect

scholarly journals Estimated pup production of harp seals Pagophilus groenlandicus in the White Sea, Russia, in 2000

2003 ◽  
Vol 60 (5) ◽  
pp. 1012-1017 ◽  
Author(s):  
V.A Potelov ◽  
A.P Golikov ◽  
V.A Bondarev
Keyword(s):  
Standard Error ◽  
White Sea ◽  
Survey Design ◽  
The White Sea ◽  
Adult Females ◽  
Aerial Surveys ◽  
Pagophilus Groenlandicus ◽  
The 1960S ◽  
Adult Abundance ◽  
Strip Transect

Abstract Since the 1960s pup production of harp seals Pagophilus groenlandicus in the White Sea was estimated from aerial photographic surveys of visible adult females on the ice. Adult abundance estimations were underestimated because an unknown number of females were in the water during the survey. The absence of a reliable estimation of pup production constrained management initiatives. Aerial photographic surveys of whelping harp seals were conducted in the White Sea 10–12 March 2000. Using a systematic strip transect survey design approach, the number of pups present was estimated as 294 914 with a standard error (s.e.) of 36 168. When pups caught by Russian sealers in the White Sea before the aerial surveys (30 729 pups) were included the total estimated number of pups was 325 643 (s.e. 36 168), whereas the number of adult harp seals was 215 943 (s.e. 22 630). The pup estimate was not corrected for pups born after the survey, but this was not considered to be significant. The new estimation of pup production is higher than thought earlier.

scholarly journals Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

2013 ◽  
Vol 41 (1-2) ◽  
Author(s):  
Maria Danise de Oliveira ALVES ◽  
João Carlos Gomes BORGES ◽  
Maria Elisabeth De ARAÚJO
Keyword(s):  
Sea Turtles ◽  
Water Clarity ◽  
Aerial Survey ◽  
Northern Coast ◽  
Sampling Area ◽  
Turbid Waters ◽  
Aerial Surveys ◽  
Low Visibility ◽  
Marine Megafauna ◽  
Strip Transect

This study aimed to investigate the feasibility of strip-transect aerial survey for the study of the marine megafauna in northern coast of Alagoas, chosen as the pilot area due to the better water clarity and the occurrence of the Antillean manatee. It was sighted 15 dolphins, 13 sea turtles and 10 manatees. From five aspects tested on the experimental flight, three adjustments were necessary on the methodology as following: 1) reduction of the transect angle to 40º to increase the sampling area; 2) constant transects of 1.5 nautical miles from shore to standardize the area of coverage; and 3) transects restricted to the mouths of estuaries due to low visibility in turbid waters. This study demonstrated the effectiveness of aerial surveys for the detection of marine megafauna. However, the adjustments proposed are necessary to minimize the characteristic limitations of each species and/or habitat. Keywords: aerial method, manatees, dolphins, sea turtles, limitations

Aerial survey of the dugong (Dugong dugon Muller 1776) in coastal waters of the Lease Islands, East Inodonesia

1995 ◽  
Vol 46 (4) ◽  
pp. 759 ◽  
Author(s):  
HH de Iongh ◽  
R Wenno ◽  
B Bierhuizen ◽  
B van Orden
Keyword(s):  
Coastal Waters ◽  
Aerial Survey ◽  
Neonatal Calf ◽  
Aerial Surveys ◽  
Coastal Shelf ◽  
Strip Transect

During December 1990 and August 1992, aerial surveys of dugongs were made along the coastlines of the Lease Islands in East Indonesia. The aerial surveys followed a strip transect covering the coastal shelf and totalled 3.5 h of observation. During the first survey, 17 dugongs were observed, one of which was a neonatal calf; during the second survey, 10 dugongs were seen but no neonates. The minimum population of dugongs was estimated to be between 22 and 37 animals. The population probably interacts with a larger unidentified reservoir of dugongs in the coastal waters of nearby Seram and Buru Islands.

Distribution and Abundance of Belugas, Delphinapterus leucas, and Narwhals, Monodon monoceros, in the Canadian High Arctic

1985 ◽  
Vol 42 (4) ◽  
pp. 676-684 ◽  
Author(s):  
T. G. Smith ◽  
M. O. Hammsll ◽  
D. J. Burrage ◽  
G. A. Sleno
Keyword(s):  
Scientific Literature ◽  
High Arctic ◽  
Delphinapterus Leucas ◽  
Confidence Limits ◽  
Canadian High Arctic ◽  
Monodon Monoceros ◽  
Aerial Surveys ◽  
Strip Transect

Opportunistic reconnaissance aerial surveys of Lancaster Sound, Barrow Strait, Peel Sound, and Prince Regent Inlet were conducted between 1974 and 1982 to determine the distribution and abundance of belugas, Delphinapterus leucas, and narwhals, Monodon monoceros. In 1981, two stratified strip-transect surveys were flown. From these we estimate that a total of 6300 – 18 600 belugas and approximately 13 200 –18 000 narwhals summer in Lancaster Sound and adjoining waterways. Improvement in the precision of these estimates would require a substantial increase in survey coverage and may not be justified considering the significant increase in costs. Our review of the results of surveys conducted since 1975 in the same study area, of which most of the information is not yet available in the scientific literature, shows much duplication of effort, little increase in information, and a lack of confidence limits for the estimated numbers.

Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

2020 ◽  
Vol 637 ◽  
pp. 117-140 ◽  
Author(s):  
DW McGowan ◽  
ED Goldstein ◽  
ML Arimitsu ◽  
AL Deary ◽  
O Ormseth ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Gulf Of Alaska ◽  
Data Series ◽  
Limited Information ◽  
Important Species ◽  
Multiple Data ◽  
Spatial And Temporal Dynamics ◽  
Spawning Areas ◽  
Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

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