scholarly journals Marine habitat use of Peruvian boobies: a geographic and oceanographic comparison between inshore and offshore islands

2010 ◽  
Vol 67 (5) ◽  
pp. 940-951 ◽  
Author(s):  
Carlos B. Zavalaga ◽  
Joanne Halls ◽  
Giacomo Dell'Omo
Keyword(s):  
Habitat Use ◽  
Abiotic Factors ◽  
Austral Summer ◽  
Marine Habitat ◽  
Chl A ◽  
Engraulis Ringens ◽  
Competition For Food ◽  
Sula Variegata ◽  
Hydrographic Features ◽  
Heavy Loads

AbstractZavalaga, C. B., Halls, J., and Dell'Omo, G. 2010. Marine habitat use of Peruvian boobies: a geographic and oceanographic comparison between inshore and offshore islands. – ICES Journal of Marine Science, 67: 940–951. Foraging areas of Peruvian boobies (Sula variegata) from Isla Lobos de Tierra (LT, inshore) and Isla Lobos de Afuera (LA, offshore) were overlaid with concurrent data on wind patterns and remotely sensed hydrographic features to identify the main abiotic factors that affect booby distribution and to compare habitat use between birds from inshore and offshore islands. Birds used across winds and across headwinds when commuting to their feeding grounds and across tailwinds when returning to their colonies. This strategy increased flight speeds by 38–53% in relation to headwinds, probably resulting in a reduction in energy costs when birds returned to their nests with heavy loads of food. Sea surface temperature of the foraged and the available areas were similar around LT and LA. Boobies from LT fed over the continental shelf and alongshore in areas with chlorophyll a (Chl a) concentration higher than expected from a random distribution. Conversely, birds from LA never came inshore, feeding over the shelf break and in waters with concentrations of Chl a similar to those in the available area. Remote-sensing measurements of primary productivity predicted the distribution of Peruvian boobies only for LT. Plumes of enriched water alongshore are formed during the austral summer, favouring the aggregation of anchoveta (Engraulis ringens), the main prey of Peruvian boobies. Boobies from LA may have potentially foraged inshore in an area also used by birds from LT, but it is likely that competition for food and energy constraints to raise three-chick broods restricted foraging range to waters far from the mainland.

scholarly journals Stingray Habitat Use Is Dynamically Influenced by Temperature and Tides

2022 ◽  
Vol 8 ◽  
Author(s):  
Chantel Elston ◽  
Paul D. Cowley ◽  
Rainer G. von Brandis ◽  
James Lea
Keyword(s):  
Habitat Use ◽  
Acoustic Telemetry ◽  
Monsoon Season ◽  
Abiotic Factors ◽  
Environmental Drivers ◽  
Shallow Waters ◽  
Shallow Marine ◽  
Tidal Cycles ◽  
Management Plans ◽  
Passive Acoustic

Abiotic factors often have a large influence on the habitat use of animals in shallow marine environments. Specifically, tides may alter the physical and biological characteristics of an ecosystem while changes in temperature can cause ectothermic species to behaviorally thermoregulate. Understanding the contextual and relative influences of these abiotic factors is important in prioritizing management plans, particularly for vulnerable faunal groups like stingrays. Passive acoustic telemetry was used to track the movements of 60 stingrays at a remote and environmentally heterogeneous atoll in Seychelles. This was to determine if habitat use varied over daily, diel and tidal cycles and to investigate the environmental drivers behind these potential temporal patterns. Individuals were detected in the atoll year-round, but the extent of their movement and use of multiple habitats increased in the warmer NW-monsoon season. Habitat use varied over the diel cycle, but was inconsistent between individuals. Temperature was also found to influence stingray movements, with individuals preferring the deeper and more thermally stable lagoon habitat when extreme (hot or cold) temperature events were observed on the flats. Habitat use also varied over the tidal cycle with stingrays spending a higher proportion of time in the lagoon during the lowest tides, when movement on the flats were constrained due to shallow waters. The interplay of tides and temperature, and how these varied across diel and daily scales, dynamically influenced stingray habitat use consistently between three species in an offshore atoll.

Seasonal variation in coastal marine habitat use by the European shag: Insights from fine scale habitat selection modeling and diet

2017 ◽  
Vol 141 ◽  
pp. 224-236 ◽  
Author(s):  
Candice Michelot ◽  
David Pinaud ◽  
Matthieu Fortin ◽  
Philippe Maes ◽  
Benjamin Callard ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Habitat Selection ◽  
Habitat Use ◽  
Fine Scale ◽  
Marine Habitat ◽  
Coastal Marine

Camera-trapping successfully and non-invasively reveals the presence, activity and habitat choice of the Critically Endangered White-winged Flufftail Sarothrura ayresi in a South African high-altitude wetland

2019 ◽  
Vol 29 (03) ◽  
pp. 463-478 ◽  
Author(s):  
ROBIN B. COLYN ◽  
ALASTAIR CAMPBELL ◽  
HANNELINE A. SMIT-ROBINSON
Keyword(s):  
Habitat Use ◽  
High Altitude ◽  
Activity Patterns ◽  
Site Occupancy ◽  
Austral Summer ◽  
Camera Trapping ◽  
Critically Endangered ◽  
Invasive Technique ◽  
Low Density ◽  
Wetland Habitat

SummaryThe ‘Critically Endangered’ White-winged Flufftail Sarothrura ayresi is regarded as one of the rarest and most threatened rallids in Africa. Due to the species’ low density, habitat preference, cryptic colouration, elusive behaviour and lack of auditory cues has resulted in it being one of the most challenging species to survey using traditional methods such as auditory surveys and rope dragging. Numerous data deficiencies exist regarding facets of the species’ ecology, distribution, habitat-use and population status. A stratified array of nine camera localities was used within high-altitude palustrine wetland habitat to ascertain if this non-invasive technique could successfully document the first estimate of site occupancy, fine scale habitat use and activity patterns of this very rare species. Our study accumulated a total of 626 camera days and eight independent sightings of White-winged Flufftail across the respective austral summer season. Furthermore, our study confirms the applicability of camera trapping to other rare and elusive rallid species. Our results confirm that White-winged Flufftail is a low-density habitat specialist species, with site occupancy influenced positively by basal and canopy vegetation cover and detection probability influenced negatively by water depth within associated wetland habitats. Activity pattern analyses displayed that peak activity occurred at dawn and dusk, which yielded the highest degree of activity overlap with the only other migratory rallid recorded, Spotted Crake Porzana prozana. Our study also recorded the first apparent territorial display behaviour noted for the species. Our study supports the need for conservation initiatives focused on securing contiguous sections of suitable wetland habitat in order to accommodate the persistence of this globally threatened species.

scholarly journals Distribution and recurrence of phytoplankton blooms around South Georgia, Southern Ocean

2013 ◽  
Vol 10 (1) ◽  
pp. 217-231 ◽  
Author(s):  
I. Borrione ◽  
R. Schlitzer
Keyword(s):  
Southern Ocean ◽  
Austral Summer ◽  
Wide Field ◽  
Phytoplankton Blooms ◽  
Chl A ◽  
South Georgia ◽  
The North ◽  
Wide Field Of View ◽  
Georgia Basin ◽  
Second Peak

Abstract. South Georgia phytoplankton blooms are amongst the largest of the Southern Ocean and are associated with a rich ecosystem and strong atmospheric carbon drawdown. Both aspects depend on the intensity of blooms, but also on their regularity. Here we use data from 12 yr of SeaWiFS (Sea-viewing Wide Field-of-view Sensor) ocean colour imagery and calculate the frequency of bloom occurrence (FBO) to re-examine spatial and temporal bloom distributions. We find that upstream of the island and outside the borders of the Georgia Basin, blooms occurred in less than 4 out of the 12 yr (FBO < 4). In contrast, FBO was mostly greater than 8 downstream of the island, i.e., to the north and northwest, and in places equal to 12, indicating that blooms occurred every year. The typical bloom area, defined as the region where blooms occurred in at least 8 out of the 12 yr, covers the entire Georgia Basin and the northern shelf of the island. The time series of surface chlorophyll a (Chl a) concentrations averaged over the typical bloom area shows that phytoplankton blooms occurred in every year between September 1997 and September 2010, and that Chl a values followed a clear seasonal cycle, with concentration peaks around December followed in many years by a second peak during late austral summer or early autumn, suggesting a bi-modal bloom pattern. The bloom regularity we describe here is in contrast with results of Park et al. (2010) who used a significantly different study area including regions that almost never exhibit bloom conditions.

scholarly journals Using Predicted Patterns of 3D Prey Distribution to Map King Penguin Foraging Habitat

2021 ◽  
Vol 8 ◽  
Author(s):  
Roland Proud ◽  
Camille Le Guen ◽  
Richard B. Sherley ◽  
Akiko Kato ◽  
Yan Ropert-Coudert ◽  
...  
Keyword(s):  
Habitat Use ◽  
Marine Protected Area ◽  
Austral Summer ◽  
Acoustic Energy ◽  
King Penguin ◽  
The South ◽  
Fish Schools ◽  
South Georgia ◽  
Mesopelagic Zone ◽  
Acoustic Surveys

King penguins (Aptenodytes patagonicus) are an iconic Southern Ocean species, but the prey distributions that underpin their at-sea foraging tracks and diving behaviour remain unclear. We conducted simultaneous acoustic surveys off South Georgia and tracking of king penguins breeding ashore there in Austral summer 2017 to gain insight into habitat use and foraging behaviour. Acoustic surveys revealed ubiquitous deep scattering layers (DSLs; acoustically detected layers of fish and other micronekton that inhabit the mesopelagic zone) at c. 500 m and shallower ephemeral fish schools. Based on DNA extracted from penguin faecal samples, these schools were likely comprised of lanternfish (an important component of king penguin diets), icefish (Channichthyidae spp.) and painted noties (Lepidonotothen larseni). Penguins did not dive as deep as DSLs, but their prey-encounter depth-distributions, as revealed by biologging, overlapped at fine scale (10s of m) with depths of acoustically detected fish schools. We used neural networks to predict local scale (10 km) fish echo intensity and depth distribution at penguin dive locations based on environmental correlates, and developed models of habitat use. Habitat modelling revealed that king penguins preferentially foraged at locations predicted to have shallow and dense (high acoustic energy) fish schools associated with shallow and dense DSLs. These associations could be used to predict the distribution of king penguins from other colonies at South Georgia for which no tracking data are available, and to identify areas of potential ecological significance within the South Georgia and the South Sandwich Islands marine protected area.

scholarly journals Vulnerability of a Top Marine Predator in One of the World’s Most Impacted Marine Environments (Arabian Gulf)

2021 ◽  
Author(s):  
Bruno Diaz Lopez ◽  
Séverine Methion ◽  
Himansu Das ◽  
Ibrahim Bugla ◽  
Maitha Al Hameli ◽  
...  
Keyword(s):  
Habitat Use ◽  
Bottlenose Dolphin ◽  
Prey Availability ◽  
Arabian Gulf ◽  
Marine Environments ◽  
Marine Habitat ◽  
Predator Species ◽  
Marine Predator ◽  
Conservation Measures ◽  
Abundance Estimates

Abstract Knowledge of the habitat use of wildlife in highly impacted areas is essential to identify areas of biological importance and to implement appropriate conservation measures. The Arabian Gulf represents one of the most extreme marine environments and is considered one of the regions in the world with the greatest anthropogenic impact. Information on the habitat use and abundance of marine top predator species is however lacking, despite being a prerequisite for effective planning of conservation measures. Here, we provide novel information for the Indo-Pacific bottlenose dolphin (Tursiops aduncus) in the Arabian Gulf (Abu Dhabi, United Arab Emirates). Data from 80 daily surveys conducted between June 2014 and November 2019 were used both to assess correlates of bottlenose dolphin habitat use and relative density and to calculate mark-recapture abundance estimates. This study confirms the strong adaptability and tolerance of this top marine predator to extreme environmental conditions within a highly heterogeneous and impacted marine habitat. The observed preferences for areas with less human pressure were likely a result of the interactions of environmental factors with prey availability and human disturbance. This study also provides the first abundance estimates for a bottlenose dolphin population in the Arabian Gulf. Our findings support the call for increased marine protected areas and the creation of transboundary conservation areas in the region. Regional connectivity should be of value to marine predators whose wide distribution and vulnerability to human activities means that alteration of their habitats can result in population declines and eventual local or regional extinctions.

scholarly journals INVESTIGATION OF CHLOROPHYLL PIGMENT CONCENTRATION AND SEA SURFACE TEMPERATURE OF THE LAKE VAN

2020 ◽  
Vol 4 (2) ◽  
pp. 69-84
Author(s):  
Mehmet Tahir Kavak
Keyword(s):  
High Resolution ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Pigment Concentration ◽  
Lake Van ◽  
Marine Habitat ◽  
Aquatic Life ◽  
Chl A ◽  
Marine Life

Current study is investigated chlorophyll-a (Chl-a) pigment concentration and its relationship with Sea Surface Temperature (SST) using cloud-free high resolution 59 Landsat-The Operational Land Imager (OLI) images from May 2013 to September 2018 covering Lake Van of Turkey. In addition, the concentrations of coccolithophore which is a kind of phytoplankton was also studied using the same method. The fact that Van Lake is extremely rich in terms of aquatic life has led to the investigation of the factors affecting the marine habitat. Therefore, SST, Chl-a concentrations, as well as the relationship between them and coccolithophore concentrations were investigated to evaluate marine life and ecosystem in the Lake. Satellite-generated data can provide information about the marine life in a particular area worldwide. Coccolithophore, SST and Chl-a were obtained from high resolution 59 Landsat OLI using SeaDAS software. Aforementioned parameters were extracted from images using SeaDAS's OCSSW L2GEN module and then output processed by QGIS (Open Source Geographic Information System) to conduct statistical calculation. Negative correlation coefficients of 74% and 73.7% were found for 2014 and 2017, respectively, and these were not statistically significant. Although the information does not give meaningful results, it may be useful in future studies about the effects of global temperature changes and the marine life for particular region.

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