The Scotia Sea is one of the most biologically rich regions of Antarctica, and it hosts a large community of upper trophic-level predators. Long-term at-sea monitoring provides valuable information on the Antarctic ma...The Scotia Sea is one of the most biologically rich regions of Antarctica, and it hosts a large community of upper trophic-level predators. Long-term at-sea monitoring provides valuable information on the Antarctic marine ecosystem and relationships among top predators. This paper presents the results of at-sea monitoring of seabirds and cetaceans over five consecutive summer seasons （2010--2014） in the Scotia Sea, Antarctica. A total of 11 656 flying birds belonging to 24 species were recorded in 884 ten-minute counts. Six Procellariiformes species were abundant： Black-browed Albatross, Cape Petrel, Southern Fulmar, Antarctic Prion, Wilson＇s Storm-petrel, and Black-bellied Storm-petrel. Only three of these species accounted for 82% of the total abundance： Antarctic Prion （40%）, Southern Fulmar （22%）, and Cape Petrel （20%）. A total of 678 baleen whales belonging to five species were recorded along a sampling effort of 2 351 nautical miles： Humpback, Sei, Southern Right, Fin, and Minke whales, which had different abundances during the study. The Fin Whale had the highest mean encounter rate for the 5 years （0.29 whales per nautical mile）, followed by the Humpback Whale （0.09 whales per nautical mile）. Annual dissimilarity in abundance of both seabirds and cetaceans occurred in conjunction with changes in the sea surface temperature and ice cover, showing the dependence of top predators on environmental changes. The largest aggregations of all top predators （seabirds and cetaceans） were recorded in two regions, west and south of the South Orkney Islands, suggesting important prey availability （especially krill） in those areas.展开更多
During the ARK-XXIII/3 expedition of icebreaking RV Polarstern in the high Arctic Ocean(partim north of 73°N)from 25 August to 10 October 2008,550 transect counts lasting 30 min were devoted to seabird and marine...During the ARK-XXIII/3 expedition of icebreaking RV Polarstern in the high Arctic Ocean(partim north of 73°N)from 25 August to 10 October 2008,550 transect counts lasting 30 min were devoted to seabird and marine mammal counts from the bridge.In the whole area,the three most numerous species,kittiwake Rissa tridactyla,fulmar Fulmarus glacialis and Brünnich’s guillemot Uria lomvia represented 90%of the total of 12000 individuals registered,followed by ivory gull Pagophila eburnea,black guillemot Cepphus grylle and Ross’s gull Rodostethia rosea.Four geographical zones were recognized on the basis of number of species and density.Both were especially low in the deeper areas(mean depth of 3000 m),both ice-free and heavily ice-covered:0.3 birds per 30 min count belonging to three and four species respectively.The most numerous species was kittiwake with 0.25 per count(50 individuals)in the ice-covered area.Pinniped numbers were very low as well,the most numerous of the four species tallied being 20 harp seals Phoca groenlandica and 10 ringed seal Pusa hispida.Seven polar bears Ursus maritimus were encountered.These observations were basically confirmed during 12 helicopter flights lasting one hour each with very low numbers:50 kittiwakes and 13 harp seals,almost none in the ice-covered deep zone.A comparison between data obtained from ship and from helicopter seems however to reflect the importance of seabird followers including for long distances.The only cetaceans were two adult belugas Delphinapterus leucas tallied from helicopter.展开更多
The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to...The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to January 2020,a survey of seabirds was carried out on the board icebreaker R/V Xuelong 2 in the Cosmonaut Sea and the Cooperation Sea.Twenty-three bird species were recorded.Antarctic petrel(Thalassoica antarctica),Antarctic prion(Pachyptila desolata),and Arctic tern(Sterna paradisaea)were the most abundant species.A total of about 37500 birds belonging to 23 species were recorded.Around 23%of the region had no record of birds.A large number of birds was recorded in 39°E-40°E,44°E-46°E and 59°E-60°E.Many areas,such as 33°E-35°E,39°E-41°E,44°E-46°E and 59°E-60°E show a great richness.More than two-thirds of seabirds(71%)were observed in the zone near the ocean front.The prediction of the distributions of the most dominant species Antarctic petrel also showed that the area near the ocean front region had an important ecological significance for seabirds.The results suggest that the distribution of seabirds in the Cosmonaut Sea is highly heterogenous.展开更多
This article is part of our long-term study on the quantitative at-sea distribution of the marine "upper trophic levels"—seabirds and marine mammals—in polar ecosystems, aiming at quantifying the factors i...This article is part of our long-term study on the quantitative at-sea distribution of the marine "upper trophic levels"—seabirds and marine mammals—in polar ecosystems, aiming at quantifying the factors influencing their distribution as well as detecting possible spatial and temporal changes, with special attention to hydrography and to global climate changes. During an expedition of icebreaking RV Polarstern in February 2010, along the North–South transect between New Zealand and the Ross Gyre, off the Ross Sea, 3200 seabirds belonging to 22 identified pelagic species were recorded during 338 half-hour transect counts. Four major hotspots were identified. These were in Sub-tropical Water off New Zealand(up to 300 birds per count), and at the main Southern Ocean fronts: the Sub-Antarctic Front(up to 240 per count), the Antarctic Front(up to 150 per count) and the Polar Front(up to 200 per count), representing the vast majority of recorded seabirds. The most numerous species in the three frontal zones were: prions—mainly slender-billed Pachyptila belcheri—and Salvin’s albatross Thalassarche [cauta]salvini. The eight more abundant species represented 2650 birds, i.e. more than 80% of the total. A random forest clustering method identified four groups of seabird species occupying similar oceanographic niches.展开更多
There is now abundant evidence that contemporary climatic change has indirectly affected a wide-range of species by changing trophic interactions,competition,epidemiology and habitat.However,direct physiological...There is now abundant evidence that contemporary climatic change has indirectly affected a wide-range of species by changing trophic interactions,competition,epidemiology and habitat.However,direct physiological impacts of changing climates are rarely reported for endothermic species,despite being commonly reported for ectotherms.We review the evidence for changing physiological constraints on endothermic vertebrates at high temperatures,integrating theoretical and empirical perspectives on the morphology,physiology and behavior of marine birds.Potential for increasing heat stress exposure depends on changes in multiple environmental variables,not just air temperature,as well as organism-specific morphology,physiology and behavior.Endotherms breeding at high latitudes are vulnerable to the forecast,extensive temperature changes because of the adaptations they possess to minimize heat loss.Low-latitude species will also be challenged as they currently live close to their thermal limits and will likely suffer future water shortages.Small,highly-active species,particularly aerial foragers,are acutely vulnerable as they are least able to dissipate heat at high temperatures.Overall,direct physiological impacts of climatic change appear underrepresented in the published literature,but available data suggest they have much potential to shape behavior,morphology and distribution of endothermic species.Coincidence between future heat stress events and other energetic constraints on endotherms remains largely unexplored but will be key in determining the physiological impacts of climatic change.Multi-scale,biophysical modeling,informed by experiments that quantify thermoregulatory responses of endotherms to heat stress,is an essential precursor to urgently-needed analyses at the population or species level.展开更多
Along China’s 18,000-kilometer mainland coastline and across its 4.73 million square kilometers of territorial waters,scenes of crystal-clear waves lapping against pristine shores with flocks of seabirds soaring over...Along China’s 18,000-kilometer mainland coastline and across its 4.73 million square kilometers of territorial waters,scenes of crystal-clear waves lapping against pristine shores with flocks of seabirds soaring overhead are becoming increasingly common.The concept of“harmony between humanity and the sea”has been widely embraced by Chinese people,and numerous bays have become showcases for ecological beauty.展开更多
Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecolog...Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecology of this species and interactions with human stressors to establish management measures.We collected regurgitates(n=182)and blood samples(n=48)to study Little Terns’diet,health condition and isotopic niche,and individually tracked breeding adults(n=9,during 2021 and 2022)at 2 sandy beaches 21 km apart and located within Ria Formosa Natural Park,Algarve,Portugal.Although both areas are adjacent to foraging coastal marine areas and an estuarine lagoon system with saltpans,they differ in human disturbance.We also compared breeding success and adult health measures between these 2 colonies.The main prey for both populations were Sand Smelts Atherina spp.and Gobies Pomatoschistus spp.,and no differences in δ^(13)C and δ^(15)N stable isotopic values between colonies were found.Tracking data revealed that individuals foraged in the surroundings of their breeding colonies.Entrance Channels and Ocean were the most frequently used habitats for foraging by individuals from the less disturbed colony.Adults from the more disturbed colony foraged mostly in Entrance Channels.Overall,all individuals tended to forage during daytime.There were no differences in health measures of individuals between colonies,though breeding success at the most disturbed colony was comparably lower.It is important to protect both breeding areas and adjacent foraging habitats for Little Terns,particularly given the expected increasing pressure from human activities on coastal areas worldwide.展开更多
We investigated the role of hydrological features, such as water masses, fronts, eddies, and sea ice, in affecting the distribution of upper trophic level species in the Scotia Sea region during autumn. On board RV Po...We investigated the role of hydrological features, such as water masses, fronts, eddies, and sea ice, in affecting the distribution of upper trophic level species in the Scotia Sea region during autumn. On board RV Polarstern, we performed 365 30-min strip transects recording seabirds and marine mammals along the North Scotia Ridge and the South Sandwich Trench in March--April 2013. Among the 7 identified cetacean species recorded, the humpback whale Megaptera novaeangliae was the most abundant baleen whale （40 individuals）, and noteworthy were sightings of six southern right whales Eubalaena australis. Pinnipeds （3 species, 1650 individuals） were dominated by Antarctic fur seal Arctocephalus gazella （99%）, and seabirds （36 species, 18900 individuals） by Antarctic prion Pachyptila desolata （-50%）. The distribution of these top predators was highly patchy with the majority of observations concentrated in a few counts. This heterogeneity is likely a result of prey availability, and we discuss how hydrological features may have caused the patchiness.展开更多
In recent decades, polar regions of the planet have witnessed an increase in human presence. Antarctica is considered one of the most pristine regions of the world, but it could be affected by pollution owing to anthr...In recent decades, polar regions of the planet have witnessed an increase in human presence. Antarctica is considered one of the most pristine regions of the world, but it could be affected by pollution owing to anthropogenic activities, particularly in the Antarctic Peninsula. Human presence can increase the levels of some trace metals in Antarctic environments, an issue that needs to be evaluated. To acquire data of trace metal contamination in the Antarctic Peninsula region, concentrations （dry weight） of Cd, Pb, As, Cu, Hg and Zn in fresh excrement of Ad61ie penguins were determined by atomic absorption spectrophotometry. During the 2012/2013 austral summer, samples were collected from four important nesting sites on the Antarctic Peninsula： Arctowski Base, Kopaitic Island （both sites in the northern Antarctic Peninsula）, Yalour Island and Avian Island （both sites in the southern Antarctic Peninsula）. Data showed that Ad61ie penguin excreta had significantly higher levels （mg.kg~） of As, Cd, Hg, Pb and Cu at Arctowski Base and Kopaitic Island, both sites that have major anthropogenic activities that probably contributed to increased metal levels. The levels of trace metals in Ad61ie penguins were similar to those reported in excreta of Antarctic species in previous studies, and lower than those in excreta of other Antarctic animals. Data suggest that metals ingested by these penguin species that feed in the sea, end up in terrestrial ecosystems.展开更多
Background: Concerns for bird collisions with wind turbines affect the deployment of onshore and offshore windpower plants.To avoid delays in consenting processes and to streamline the construction and operation phase...Background: Concerns for bird collisions with wind turbines affect the deployment of onshore and offshore windpower plants.To avoid delays in consenting processes and to streamline the construction and operation phase,functional mitigation measures are required which efficiently reduces bird mortality.Vision is the primary sensory system in birds,which for a number of species also includes the ultraviolet spectrum.Many bird species that are known to collide with offshore wind turbines are sensitive in the violet or ultraviolet spectrum.For species that are mainly active at lower ambient light levels,lighting may deter birds from the lit area.Utilizing(ultra)violet lights may in addition not disturb humans.However,we do not know whether UV-sensitive birds in flight actually respond behaviourally to UV lights.Methods: We therefore tested the efficacy of two types of lights within the violet(400 nm) and ultraviolet(365 nm) spectrum to deter birds from the lit area.These lights were placed vertically and monitored continuously between dusk and dawn using an avian radar system.Results: Relative to control nights,bird flight activity(abundance) was 27% lower when the ultraviolet light was on.Violet light resulted in a 12% decrease in overall abundance,and in addition,a vertical displacement was seen,increasing the average flight altitude by 7 m.Although temporal changes occurred,this effect persisted over the season below 40 m above sea level.Conclusions: Although the results from this pilot study are promising,we argue there still is a long way to go before a potentially functional design to mitigate collisions that has proven to be effective in situ may be in place.展开更多
Seabird and marine mammal at-sea distribution in the western Bering Sea and along the eastern Kamtchatka(Kamtsjatka)Peninsula was determined during 114 transect counts,lasting 30 min each,in September 2018.A total of ...Seabird and marine mammal at-sea distribution in the western Bering Sea and along the eastern Kamtchatka(Kamtsjatka)Peninsula was determined during 114 transect counts,lasting 30 min each,in September 2018.A total of 58000 seabirds were tallied,i.e.a mean value of 510 per count.The most abundant species was short-tailed shearwater:43250 individuals representing 74%of the total.Fulmar and kittiwake represented 13%and 8%of the total.Important geographical differences were noted,concerning both the number of seabird species and their abundance.The following species were tallied mainly in the northern zone(North of 60°N):fulmar(light morphs),short-tailed shearwater,Vega(herring)gull and horned puffin.In the southern zone,including Commander(Komandorski)Islands,observed species included fulmar(dark morphs),pelagic cormorant,glaucous-winged gull,red-legged kittiwake and black guillemot.The vast majority of the 100 cetaceans and 40 pinnipeds were tallied in the southern area,mainly porpoises,killer whale and humpback whale,and Largha(spotted)seal.展开更多
Geochemical characteristics of a 107 cm long sediment profile,collected from Ganquan Island,South China Sea,were analyzed.Based on concentrations of bio-elements（Cu,Zn,Cd,Ba,As, Se,P）,^（210）Pb and AMS^（14）C dati...Geochemical characteristics of a 107 cm long sediment profile,collected from Ganquan Island,South China Sea,were analyzed.Based on concentrations of bio-elements（Cu,Zn,Cd,Ba,As, Se,P）,^（210）Pb and AMS^（14）C dating,we reconstructed seabird population of Ganquan Island over the past 2200 years.Seabirds inhabited this island more than 2200 years ago,and their population displayed remarkable fluctuations with two peaks around 2100-1850 yr BP and 900-300 yr BP,respectively.The seabird population change profile on Ganquan Island is similar to that on Dongdao Island over the past 1800 years.We examined the relationship between the seabird population and climate,and found it quite complicated.The seabird population did not reach the maximum during the Medical Warm Period（MWP）with relatively high average temperature;however,it remained near the peak value for about 600 years during the climatic transition period and the Little Ice Age（LIA）,indicating that a relatively cool climate is favorable for seabirds on Ganquan Island.展开更多
Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be loca...Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be located far from the colony, and return to the colony regularly. In this context, flexibility in movement behavior may be crucial for breeding success. During chick-rearing, Procellariformes species can alternate short trips lasting 1-4 days for chick provisioning with longer trips for self-provisioning in what has been called a dual-foraging strategy. We analyzed foraging trips from 136 Scopoli＇s shearwaters from three Mediterranean colonies tracked with GPS during 6 chick-rearing seasons to assess whether the adoption of a dual fo- raging strategy depends on the quality of habitat surrounding the colony. We found a marked dual-foraging strategy only in birds from the Linosa colony which was the largest colony in terms of breeding pairs and was characterized by having a lower marine habitat quality. Birds from this colony performed foraging trips that extended up to 369 km from the nest and lasted more than 10 days. In general, the decision to perform long lasting trips was triggered by lower values of primary production and higher offspring weight. Contrary to expectation, the decision to feed far from the colony was not related to the parents＇ weight. At the same time, despite the higher productivity offered by distant areas, the higher proportion of long trips performed by birds breeding in poor areas was not sufficient to maintain the same body mass as the ones breeding in richer areas [Current Zoology 60 （5）： 622-630, 2014].展开更多
The study of parental food provisioning is essential for understanding the breeding ecology of birds.We conducted the first study using accelerometry to detect food provisioning in birds,using Support Vector Machine(S...The study of parental food provisioning is essential for understanding the breeding ecology of birds.We conducted the first study using accelerometry to detect food provisioning in birds,using Support Vector Machine(SVM)models to identify when adults feed chicks of three different age classes.Accelerometers were attached to the head of adult female Imperial Shags(Leucocarbo atriceps),and various attributes derived from the acceleration signals were used to train SVM models for each chick age class.Model performance improved with chick age class,with SVM models achieving high overall accuracy(>88%)and highest sensitivity in older chick categories(>91%).However,precision values,especially for younger chicks,remained relatively low(between 26%and 45%).The application of a time filter based on the minimum duration of the observed food provisioning behaviours for each chick age category,improved model performance by reducing false provisioning behaviours,particularly in the model for older chicks,which showed the highest precision(72.4%).This study highlights the effectiveness of accelerometry and machine learning in studying parental food provisioning in birds,providing a rapid and accurate data collection method to complement traditional techniques.The described methodology can be applied to any bird species that exhibits distinctive movements while feeding its offspring and has suitable characteristics for attaching an accelerometer to the body part that best captures this movement.Finally,it is hoped that the results of this study will contribute to future research on key questions in parental investment theory and reproductive strategies in birds.展开更多
Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to...Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.展开更多
Longline fisheries for tunas and tuna-like species present an existential threat to many populations of albatrosses and petrels worldwide. To prevent this form of mortality we developed a new technology designed to de...Longline fisheries for tunas and tuna-like species present an existential threat to many populations of albatrosses and petrels worldwide. To prevent this form of mortality we developed a new technology designed to deploy baited hooks underwater beyond the dive depths of?seabirds (6 - 10 m for the species most commonly caught). The underwater bait setter is a stern-mounted, hydraulically-operated and computer-controlled?device that catapults?baited hooks underwater in a steel capsule?connected to hydraulic winches by Spectra®rope. Baits are flushed from the capsule by water pressure through a spring-loaded bait release door. The chief engineering challenges in the developmental stageswere ensuring:?1) bait delivery?to target depths with cycle times (time from release to recovery) that were practical for fishing operations;?2) bait retention in the capsule (no drop-outs) on the descent phase of the cycle;?3) baits, upon?release at target depth, were not drawn up the water column on the capsule recovery phase (from possible hook-ups and/or suction);and?4) the retention of baits?on?hooks post-release from the capsule was not affected by the mechanical release underwater. Operational trials with the final version of the capsule yielded?satisfactory cycle times to depths of 6 - 10 m. All baits were retained?in the capsule on the descent and?released as required?at target depths (n = 606 deployments). Bait retention on hooks post release from the capsule and retention on hooks hand-set at the surface (the conventional method) were statistically indistinguishable.?The underwater bait setter is modular in construction and can be fitted to all types of vessel sterns.展开更多
Botanical, soil chemistry and soil microbiology variables were tested as predictors of in situ soil respiration rate in the various terrestrial habitats on sub-Antarctic Marion Island (47oS, 38oE). Inorganic P and tot...Botanical, soil chemistry and soil microbiology variables were tested as predictors of in situ soil respiration rate in the various terrestrial habitats on sub-Antarctic Marion Island (47oS, 38oE). Inorganic P and total N concentration were the best predictors amongst the chemistry variables and bacteria plate count the best of the microbiology variables. However, while these chemistry and microbiology variables could accurately predict soil respiration rate for particular habitats, they proved inadequate predictors across the whole range of habitats. The best suite of predictors comprised only botanical variables (relative covers of five plant guilds) and accounted for 94% of the total across-habitat variation in soil respiration rate. Mean field soil respiration rates (2.1 - 15.5 mmol CO2 m-2 h-1) for habitats not influenced by seabirds or seals are similar to rates in comparable Northern Hemisphere tundra habitats. Seabird and seal manuring enhances soil respiration rates to values (up to 27.6 mmol CO2 m-2 h-1) higher than found at any tundra site. Glucose, N, P or N plus P were added to three habitats with contrasting soil types;a fellfield with mineral, nutrient-poor soil, a mire with organic, nutrient-poor soil and a shore-zone herbfield heavily manured by penguins and with organic, nutrient-rich soil. Glucose addition stimulated soil respiration in the fellfield and mire (especially the former) but not in the coastal herbfield soil. N and P, alone or together, did not stimulate respiration at any of the habitats, but adding glucose to fellfield soils that had previously been fortified with P or NP caused a similar increase in respiration rate, which was greater than the increase when adding glucose to soils fortified only with N. This suggests that fellfield soil respiration is limited by P rather than N, and that there is no synergism between the two nutrients. For the mire and coastal herbfield, adding glucose to soils previously fortified with N, P or NP did not enhance rates more than adding glucose to soils that had received no nutrient pre-treatment.展开更多
Through ingestion and subsequent egestion,Arctic seabirds can bioaccumulate microplastics at and around their colony breeding sites.While microplastics in Arctic seabirds have been well documented,it is not yet unders...Through ingestion and subsequent egestion,Arctic seabirds can bioaccumulate microplastics at and around their colony breeding sites.While microplastics in Arctic seabirds have been well documented,it is not yet understood to what extent these particles can act as transport vehicles for plastic-associated contaminants,including legacy persistent organic pollutants(POPs),trace metals,and organic additives.We investigated the occurrence and pattern of organic and inorganic co-contaminants of microplastics in two seabird species from the Canadian Arctic-northern fulmar(Fulmarus glacialis)and black-legged kittiwake(Rissa tridactyla).We found that fulmars had higher levels of plastic contamination and emerging organic compounds(known to be plastic additives)than kittiwakes,whereas higher concentrations of legacy POPs were found in kittiwakes than the fulmars.Furthermore,fulmars,the species with the much larger foraging range(~200 km),had higher plastic pollution and overall contaminant burdens,indicating that birds may be acting as long-range transport vectors for plasticassociated pollution.Our results suggest a potential connection between plastic additive contamination and plastic pollution burdens in the bird stomachs,highlighting the importance of treating plastic particles and plastic-associated organic additives as co-contaminants rather than separate pollution issues.展开更多
Persistent organochlorine pollutants (POPs) are analyzed for the dropping-amended soils from the habitats of Antarctic seabirds and seals in Fildes Peninsula and Ardley Island. The concentration ranges are 0.21 to 3.8...Persistent organochlorine pollutants (POPs) are analyzed for the dropping-amended soils from the habitats of Antarctic seabirds and seals in Fildes Peninsula and Ardley Island. The concentration ranges are 0.21 to 3.85 ng/g for polychlorinated biphenyls (ΣPCBs),0.09 to 2.01 ng/g for organochlorine pesticides (ΣDDT),and 0.06 to 0.76 ng/g for hexachlorocyclohexanes (HCHs). Among these,hepata-chlorobiphenyls,hexachlorobiphenyls,p,p′-DDE and α-HCH compounds are dominant. The concentra-tion ranges of ΣPCB,DDT and HCH in the eggs of skuas were 91.9―515.5 ng/g,56.6―304.4 ng/g and 0.5―2.0 ng/g respectively; those in the eggs of penguins were 0.4―0.9 ng/g,2.4―10.3 ng/g and 0.1― 0.4 ng/g; and those in the eggs of giant petrel were 38.1―81.7 ng/g,12.7―53.7 ng/g and 0.5―1.5 ng/g respectively. The dominant POP compounds in the eggs are PCB180,PCB153,p,p′-DDE and hexa-chlorobenzene (HCB). The present study shows that the concentration of POPs in the sea-bird-inhabited-dropping-amended soil varies with the extent of predation and nest occupancy of dif-ferent seabird populations. Statistical analysis on the POP concentrations from the different seabird eggs implies that the difference in the bio-concentration levels of the birds depends on the bio-habits of the species,such as the range of activity,distance of immigration,feeding pattern,and nest occupation. Among these,the most important factor is the location of the seabirds in the food chain and their feeding pattern. This shows that POPs accumulated in the seabirds resulted from the bio-concentration through the food chain. In addtion,210Pb dating for the dropping-amended soils (AD1-a and AD2) was performed,which provided the POP accumulation rate and the historic record for the soil profile. It indicates that POP will continuously affect the Antarctic ecosystem for a long time.展开更多
Animal-attached technologies can be powerful means to quantify space use and behavior;however,there are also ethical implications associated with capturing and instrumenting animals.Furthermore,tagging approaches are ...Animal-attached technologies can be powerful means to quantify space use and behavior;however,there are also ethical implications associated with capturing and instrumenting animals.Furthermore,tagging approaches are not necessarily well-suited for examining the movements of multiple individuals within specific,local areas of interest.Here,we assess a method of quantifying animal space use based on a modified theodolite with an inbuilt laser rangefinder.Using a database of>4200 tracks of migrating birds,we show that detection distance in-creases with bird body mass(range 5 g to>10 kg).The maximum distance recorded to a bird was 5500 m and measurement error was≤5 m for targets within this distance range:a level comparable to methods such as GPS tagging.We go on to present a case study where this method was used to assess habitat selection in seabirds operating in dynamic coastal waters close to a tidal turbine.Combining positional data with outputs from a hydrographic model revealed that great cormorants(Phalacrocorax carbo)appeared to be highly selective of current characteristics in space and time,exploiting areas where mean current speeds were<0.8 m∙s^(−1) and diving at times when turbulent energy levels were low.These birds also oriented into tidal currents during dives.Taken together,this suggests that collision risks are low for cormorants at this site,as the 2 conditions avoided by cormorants(high mean current speeds and turbulence levels)are associated with operational tidal turbines.Over-all,we suggest that this modified theodolite system is well-suited to the quantification of movement in small areas associated with particular development strategies,including sustainable energy devices.展开更多
基金carried out with logistic and financial support from the Instituto Antártico Argentino
文摘The Scotia Sea is one of the most biologically rich regions of Antarctica, and it hosts a large community of upper trophic-level predators. Long-term at-sea monitoring provides valuable information on the Antarctic marine ecosystem and relationships among top predators. This paper presents the results of at-sea monitoring of seabirds and cetaceans over five consecutive summer seasons （2010--2014） in the Scotia Sea, Antarctica. A total of 11 656 flying birds belonging to 24 species were recorded in 884 ten-minute counts. Six Procellariiformes species were abundant： Black-browed Albatross, Cape Petrel, Southern Fulmar, Antarctic Prion, Wilson＇s Storm-petrel, and Black-bellied Storm-petrel. Only three of these species accounted for 82% of the total abundance： Antarctic Prion （40%）, Southern Fulmar （22%）, and Cape Petrel （20%）. A total of 678 baleen whales belonging to five species were recorded along a sampling effort of 2 351 nautical miles： Humpback, Sei, Southern Right, Fin, and Minke whales, which had different abundances during the study. The Fin Whale had the highest mean encounter rate for the 5 years （0.29 whales per nautical mile）, followed by the Humpback Whale （0.09 whales per nautical mile）. Annual dissimilarity in abundance of both seabirds and cetaceans occurred in conjunction with changes in the sea surface temperature and ice cover, showing the dependence of top predators on environmental changes. The largest aggregations of all top predators （seabirds and cetaceans） were recorded in two regions, west and south of the South Orkney Islands, suggesting important prey availability （especially krill） in those areas.
文摘During the ARK-XXIII/3 expedition of icebreaking RV Polarstern in the high Arctic Ocean(partim north of 73°N)from 25 August to 10 October 2008,550 transect counts lasting 30 min were devoted to seabird and marine mammal counts from the bridge.In the whole area,the three most numerous species,kittiwake Rissa tridactyla,fulmar Fulmarus glacialis and Brünnich’s guillemot Uria lomvia represented 90%of the total of 12000 individuals registered,followed by ivory gull Pagophila eburnea,black guillemot Cepphus grylle and Ross’s gull Rodostethia rosea.Four geographical zones were recognized on the basis of number of species and density.Both were especially low in the deeper areas(mean depth of 3000 m),both ice-free and heavily ice-covered:0.3 birds per 30 min count belonging to three and four species respectively.The most numerous species was kittiwake with 0.25 per count(50 individuals)in the ice-covered area.Pinniped numbers were very low as well,the most numerous of the four species tallied being 20 harp seals Phoca groenlandica and 10 ringed seal Pusa hispida.Seven polar bears Ursus maritimus were encountered.These observations were basically confirmed during 12 helicopter flights lasting one hour each with very low numbers:50 kittiwakes and 13 harp seals,almost none in the ice-covered deep zone.A comparison between data obtained from ship and from helicopter seems however to reflect the importance of seabird followers including for long distances.The only cetaceans were two adult belugas Delphinapterus leucas tallied from helicopter.
基金financially supported by National Polar Special Program “Impact and Response of Antarctic Seas to Climate Change” (Grant nos. IRASCC2020-2022-05, IRASCC2020-2022-06)
文摘The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to January 2020,a survey of seabirds was carried out on the board icebreaker R/V Xuelong 2 in the Cosmonaut Sea and the Cooperation Sea.Twenty-three bird species were recorded.Antarctic petrel(Thalassoica antarctica),Antarctic prion(Pachyptila desolata),and Arctic tern(Sterna paradisaea)were the most abundant species.A total of about 37500 birds belonging to 23 species were recorded.Around 23%of the region had no record of birds.A large number of birds was recorded in 39°E-40°E,44°E-46°E and 59°E-60°E.Many areas,such as 33°E-35°E,39°E-41°E,44°E-46°E and 59°E-60°E show a great richness.More than two-thirds of seabirds(71%)were observed in the zone near the ocean front.The prediction of the distributions of the most dominant species Antarctic petrel also showed that the area near the ocean front region had an important ecological significance for seabirds.The results suggest that the distribution of seabirds in the Cosmonaut Sea is highly heterogenous.
文摘This article is part of our long-term study on the quantitative at-sea distribution of the marine "upper trophic levels"—seabirds and marine mammals—in polar ecosystems, aiming at quantifying the factors influencing their distribution as well as detecting possible spatial and temporal changes, with special attention to hydrography and to global climate changes. During an expedition of icebreaking RV Polarstern in February 2010, along the North–South transect between New Zealand and the Ross Gyre, off the Ross Sea, 3200 seabirds belonging to 22 identified pelagic species were recorded during 338 half-hour transect counts. Four major hotspots were identified. These were in Sub-tropical Water off New Zealand(up to 300 birds per count), and at the main Southern Ocean fronts: the Sub-Antarctic Front(up to 240 per count), the Antarctic Front(up to 150 per count) and the Polar Front(up to 200 per count), representing the vast majority of recorded seabirds. The most numerous species in the three frontal zones were: prions—mainly slender-billed Pachyptila belcheri—and Salvin’s albatross Thalassarche [cauta]salvini. The eight more abundant species represented 2650 birds, i.e. more than 80% of the total. A random forest clustering method identified four groups of seabird species occupying similar oceanographic niches.
文摘There is now abundant evidence that contemporary climatic change has indirectly affected a wide-range of species by changing trophic interactions,competition,epidemiology and habitat.However,direct physiological impacts of changing climates are rarely reported for endothermic species,despite being commonly reported for ectotherms.We review the evidence for changing physiological constraints on endothermic vertebrates at high temperatures,integrating theoretical and empirical perspectives on the morphology,physiology and behavior of marine birds.Potential for increasing heat stress exposure depends on changes in multiple environmental variables,not just air temperature,as well as organism-specific morphology,physiology and behavior.Endotherms breeding at high latitudes are vulnerable to the forecast,extensive temperature changes because of the adaptations they possess to minimize heat loss.Low-latitude species will also be challenged as they currently live close to their thermal limits and will likely suffer future water shortages.Small,highly-active species,particularly aerial foragers,are acutely vulnerable as they are least able to dissipate heat at high temperatures.Overall,direct physiological impacts of climatic change appear underrepresented in the published literature,but available data suggest they have much potential to shape behavior,morphology and distribution of endothermic species.Coincidence between future heat stress events and other energetic constraints on endotherms remains largely unexplored but will be key in determining the physiological impacts of climatic change.Multi-scale,biophysical modeling,informed by experiments that quantify thermoregulatory responses of endotherms to heat stress,is an essential precursor to urgently-needed analyses at the population or species level.
文摘Along China’s 18,000-kilometer mainland coastline and across its 4.73 million square kilometers of territorial waters,scenes of crystal-clear waves lapping against pristine shores with flocks of seabirds soaring overhead are becoming increasingly common.The concept of“harmony between humanity and the sea”has been widely embraced by Chinese people,and numerous bays have become showcases for ecological beauty.
基金financial and logistic support for fieldwork campaigns,GPS tracking devices and laboratory analysis from the project LIFE Ilhas Barreira project(LIFE18 NAT/PT/000927)funding provided by Foundation for Science and Technology,I.P.(FCT)to MARE(UIDB/MAR/04292/2020,https://doi.org/10.54499/UIDB/04292/2020 and UIDP/04292/2020,https://doi.org/10.54499/UIDP/04292/2020)+1 种基金the Associate Laboratory ARNET(LA/P/0069/2020,https://doi.org/10.54499/LA/P/0069/2020)supported by FCT doctoral fellowships(10.54499/2020.07495.BD,SFRH/BD/145827/2019)。
文摘Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecology of this species and interactions with human stressors to establish management measures.We collected regurgitates(n=182)and blood samples(n=48)to study Little Terns’diet,health condition and isotopic niche,and individually tracked breeding adults(n=9,during 2021 and 2022)at 2 sandy beaches 21 km apart and located within Ria Formosa Natural Park,Algarve,Portugal.Although both areas are adjacent to foraging coastal marine areas and an estuarine lagoon system with saltpans,they differ in human disturbance.We also compared breeding success and adult health measures between these 2 colonies.The main prey for both populations were Sand Smelts Atherina spp.and Gobies Pomatoschistus spp.,and no differences in δ^(13)C and δ^(15)N stable isotopic values between colonies were found.Tracking data revealed that individuals foraged in the surroundings of their breeding colonies.Entrance Channels and Ocean were the most frequently used habitats for foraging by individuals from the less disturbed colony.Adults from the more disturbed colony foraged mostly in Entrance Channels.Overall,all individuals tended to forage during daytime.There were no differences in health measures of individuals between colonies,though breeding success at the most disturbed colony was comparably lower.It is important to protect both breeding areas and adjacent foraging habitats for Little Terns,particularly given the expected increasing pressure from human activities on coastal areas worldwide.
文摘We investigated the role of hydrological features, such as water masses, fronts, eddies, and sea ice, in affecting the distribution of upper trophic level species in the Scotia Sea region during autumn. On board RV Polarstern, we performed 365 30-min strip transects recording seabirds and marine mammals along the North Scotia Ridge and the South Sandwich Trench in March--April 2013. Among the 7 identified cetacean species recorded, the humpback whale Megaptera novaeangliae was the most abundant baleen whale （40 individuals）, and noteworthy were sightings of six southern right whales Eubalaena australis. Pinnipeds （3 species, 1650 individuals） were dominated by Antarctic fur seal Arctocephalus gazella （99%）, and seabirds （36 species, 18900 individuals） by Antarctic prion Pachyptila desolata （-50%）. The distribution of these top predators was highly patchy with the majority of observations concentrated in a few counts. This heterogeneity is likely a result of prey availability, and we discuss how hydrological features may have caused the patchiness.
基金supported by project INACH T 1809project FONDECYT 1140466project INACH RG 09-14
文摘In recent decades, polar regions of the planet have witnessed an increase in human presence. Antarctica is considered one of the most pristine regions of the world, but it could be affected by pollution owing to anthropogenic activities, particularly in the Antarctic Peninsula. Human presence can increase the levels of some trace metals in Antarctic environments, an issue that needs to be evaluated. To acquire data of trace metal contamination in the Antarctic Peninsula region, concentrations （dry weight） of Cd, Pb, As, Cu, Hg and Zn in fresh excrement of Ad61ie penguins were determined by atomic absorption spectrophotometry. During the 2012/2013 austral summer, samples were collected from four important nesting sites on the Antarctic Peninsula： Arctowski Base, Kopaitic Island （both sites in the northern Antarctic Peninsula）, Yalour Island and Avian Island （both sites in the southern Antarctic Peninsula）. Data showed that Ad61ie penguin excreta had significantly higher levels （mg.kg~） of As, Cd, Hg, Pb and Cu at Arctowski Base and Kopaitic Island, both sites that have major anthropogenic activities that probably contributed to increased metal levels. The levels of trace metals in Ad61ie penguins were similar to those reported in excreta of Antarctic species in previous studies, and lower than those in excreta of other Antarctic animals. Data suggest that metals ingested by these penguin species that feed in the sea, end up in terrestrial ecosystems.
基金executed as part of the Innovative Mitigation Tools for Avian Conflicts with wind Turbines(INTACT)projectfinanced by a consortium consisting of the Research Council of Norway(Grant 226241)Vattenfall,Statkraft,Statoil,Energy Norway,Tronder Energi Kraft,Norwegian Water Resources and Energy Directorate and NINA
文摘Background: Concerns for bird collisions with wind turbines affect the deployment of onshore and offshore windpower plants.To avoid delays in consenting processes and to streamline the construction and operation phase,functional mitigation measures are required which efficiently reduces bird mortality.Vision is the primary sensory system in birds,which for a number of species also includes the ultraviolet spectrum.Many bird species that are known to collide with offshore wind turbines are sensitive in the violet or ultraviolet spectrum.For species that are mainly active at lower ambient light levels,lighting may deter birds from the lit area.Utilizing(ultra)violet lights may in addition not disturb humans.However,we do not know whether UV-sensitive birds in flight actually respond behaviourally to UV lights.Methods: We therefore tested the efficacy of two types of lights within the violet(400 nm) and ultraviolet(365 nm) spectrum to deter birds from the lit area.These lights were placed vertically and monitored continuously between dusk and dawn using an avian radar system.Results: Relative to control nights,bird flight activity(abundance) was 27% lower when the ultraviolet light was on.Violet light resulted in a 12% decrease in overall abundance,and in addition,a vertical displacement was seen,increasing the average flight altitude by 7 m.Although temporal changes occurred,this effect persisted over the season below 40 m above sea level.Conclusions: Although the results from this pilot study are promising,we argue there still is a long way to go before a potentially functional design to mitigate collisions that has proven to be effective in situ may be in place.
文摘Seabird and marine mammal at-sea distribution in the western Bering Sea and along the eastern Kamtchatka(Kamtsjatka)Peninsula was determined during 114 transect counts,lasting 30 min each,in September 2018.A total of 58000 seabirds were tallied,i.e.a mean value of 510 per count.The most abundant species was short-tailed shearwater:43250 individuals representing 74%of the total.Fulmar and kittiwake represented 13%and 8%of the total.Important geographical differences were noted,concerning both the number of seabird species and their abundance.The following species were tallied mainly in the northern zone(North of 60°N):fulmar(light morphs),short-tailed shearwater,Vega(herring)gull and horned puffin.In the southern zone,including Commander(Komandorski)Islands,observed species included fulmar(dark morphs),pelagic cormorant,glaucous-winged gull,red-legged kittiwake and black guillemot.The vast majority of the 100 cetaceans and 40 pinnipeds were tallied in the southern area,mainly porpoises,killer whale and humpback whale,and Largha(spotted)seal.
基金funded by National Natural Science Foundation of China(No.40730107)the National Basic Research Program of China(973 Program,No. 2010CB428902)+2 种基金Knowledge Innovation Program of CAS (KZCX2-EW-QN50)Ph.D.Programs Foundation of the Ministry of Education of China for new teachers (20093402120004)the Fundamental Research Funds for the Central Universities(WK2060190007)
文摘Geochemical characteristics of a 107 cm long sediment profile,collected from Ganquan Island,South China Sea,were analyzed.Based on concentrations of bio-elements（Cu,Zn,Cd,Ba,As, Se,P）,^（210）Pb and AMS^（14）C dating,we reconstructed seabird population of Ganquan Island over the past 2200 years.Seabirds inhabited this island more than 2200 years ago,and their population displayed remarkable fluctuations with two peaks around 2100-1850 yr BP and 900-300 yr BP,respectively.The seabird population change profile on Ganquan Island is similar to that on Dongdao Island over the past 1800 years.We examined the relationship between the seabird population and climate,and found it quite complicated.The seabird population did not reach the maximum during the Medical Warm Period（MWP）with relatively high average temperature;however,it remained near the peak value for about 600 years during the climatic transition period and the Little Ice Age（LIA）,indicating that a relatively cool climate is favorable for seabirds on Ganquan Island.
文摘Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be located far from the colony, and return to the colony regularly. In this context, flexibility in movement behavior may be crucial for breeding success. During chick-rearing, Procellariformes species can alternate short trips lasting 1-4 days for chick provisioning with longer trips for self-provisioning in what has been called a dual-foraging strategy. We analyzed foraging trips from 136 Scopoli＇s shearwaters from three Mediterranean colonies tracked with GPS during 6 chick-rearing seasons to assess whether the adoption of a dual fo- raging strategy depends on the quality of habitat surrounding the colony. We found a marked dual-foraging strategy only in birds from the Linosa colony which was the largest colony in terms of breeding pairs and was characterized by having a lower marine habitat quality. Birds from this colony performed foraging trips that extended up to 369 km from the nest and lasted more than 10 days. In general, the decision to perform long lasting trips was triggered by lower values of primary production and higher offspring weight. Contrary to expectation, the decision to feed far from the colony was not related to the parents＇ weight. At the same time, despite the higher productivity offered by distant areas, the higher proportion of long trips performed by birds breeding in poor areas was not sufficient to maintain the same body mass as the ones breeding in richer areas [Current Zoology 60 （5）： 622-630, 2014].
基金supported by a grant from the National Agency for the Promotion of Science and Technology of Argentina(grant PICT,2017-1996 to AGL)by two awards,one from the Association of Field Ornithologists and the other from Aves Argentinas to MDC。
文摘The study of parental food provisioning is essential for understanding the breeding ecology of birds.We conducted the first study using accelerometry to detect food provisioning in birds,using Support Vector Machine(SVM)models to identify when adults feed chicks of three different age classes.Accelerometers were attached to the head of adult female Imperial Shags(Leucocarbo atriceps),and various attributes derived from the acceleration signals were used to train SVM models for each chick age class.Model performance improved with chick age class,with SVM models achieving high overall accuracy(>88%)and highest sensitivity in older chick categories(>91%).However,precision values,especially for younger chicks,remained relatively low(between 26%and 45%).The application of a time filter based on the minimum duration of the observed food provisioning behaviours for each chick age category,improved model performance by reducing false provisioning behaviours,particularly in the model for older chicks,which showed the highest precision(72.4%).This study highlights the effectiveness of accelerometry and machine learning in studying parental food provisioning in birds,providing a rapid and accurate data collection method to complement traditional techniques.The described methodology can be applied to any bird species that exhibits distinctive movements while feeding its offspring and has suitable characteristics for attaching an accelerometer to the body part that best captures this movement.Finally,it is hoped that the results of this study will contribute to future research on key questions in parental investment theory and reproductive strategies in birds.
基金supported by the National Natural Science Foundation of China(T2350005 to YL)。
文摘Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.
文摘Longline fisheries for tunas and tuna-like species present an existential threat to many populations of albatrosses and petrels worldwide. To prevent this form of mortality we developed a new technology designed to deploy baited hooks underwater beyond the dive depths of?seabirds (6 - 10 m for the species most commonly caught). The underwater bait setter is a stern-mounted, hydraulically-operated and computer-controlled?device that catapults?baited hooks underwater in a steel capsule?connected to hydraulic winches by Spectra®rope. Baits are flushed from the capsule by water pressure through a spring-loaded bait release door. The chief engineering challenges in the developmental stageswere ensuring:?1) bait delivery?to target depths with cycle times (time from release to recovery) that were practical for fishing operations;?2) bait retention in the capsule (no drop-outs) on the descent phase of the cycle;?3) baits, upon?release at target depth, were not drawn up the water column on the capsule recovery phase (from possible hook-ups and/or suction);and?4) the retention of baits?on?hooks post-release from the capsule was not affected by the mechanical release underwater. Operational trials with the final version of the capsule yielded?satisfactory cycle times to depths of 6 - 10 m. All baits were retained?in the capsule on the descent and?released as required?at target depths (n = 606 deployments). Bait retention on hooks post release from the capsule and retention on hooks hand-set at the surface (the conventional method) were statistically indistinguishable.?The underwater bait setter is modular in construction and can be fitted to all types of vessel sterns.
文摘Botanical, soil chemistry and soil microbiology variables were tested as predictors of in situ soil respiration rate in the various terrestrial habitats on sub-Antarctic Marion Island (47oS, 38oE). Inorganic P and total N concentration were the best predictors amongst the chemistry variables and bacteria plate count the best of the microbiology variables. However, while these chemistry and microbiology variables could accurately predict soil respiration rate for particular habitats, they proved inadequate predictors across the whole range of habitats. The best suite of predictors comprised only botanical variables (relative covers of five plant guilds) and accounted for 94% of the total across-habitat variation in soil respiration rate. Mean field soil respiration rates (2.1 - 15.5 mmol CO2 m-2 h-1) for habitats not influenced by seabirds or seals are similar to rates in comparable Northern Hemisphere tundra habitats. Seabird and seal manuring enhances soil respiration rates to values (up to 27.6 mmol CO2 m-2 h-1) higher than found at any tundra site. Glucose, N, P or N plus P were added to three habitats with contrasting soil types;a fellfield with mineral, nutrient-poor soil, a mire with organic, nutrient-poor soil and a shore-zone herbfield heavily manured by penguins and with organic, nutrient-rich soil. Glucose addition stimulated soil respiration in the fellfield and mire (especially the former) but not in the coastal herbfield soil. N and P, alone or together, did not stimulate respiration at any of the habitats, but adding glucose to fellfield soils that had previously been fortified with P or NP caused a similar increase in respiration rate, which was greater than the increase when adding glucose to soils fortified only with N. This suggests that fellfield soil respiration is limited by P rather than N, and that there is no synergism between the two nutrients. For the mire and coastal herbfield, adding glucose to soils previously fortified with N, P or NP did not enhance rates more than adding glucose to soils that had received no nutrient pre-treatment.
基金supported by Environment and Climate Change Canada,the Nunavut Wildlife Management Board,the Northern Contaminants Program(M-08 and M-74)the Crown-Indigenous Relations and Northern Affairs Department,and Acadia University.
文摘Through ingestion and subsequent egestion,Arctic seabirds can bioaccumulate microplastics at and around their colony breeding sites.While microplastics in Arctic seabirds have been well documented,it is not yet understood to what extent these particles can act as transport vehicles for plastic-associated contaminants,including legacy persistent organic pollutants(POPs),trace metals,and organic additives.We investigated the occurrence and pattern of organic and inorganic co-contaminants of microplastics in two seabird species from the Canadian Arctic-northern fulmar(Fulmarus glacialis)and black-legged kittiwake(Rissa tridactyla).We found that fulmars had higher levels of plastic contamination and emerging organic compounds(known to be plastic additives)than kittiwakes,whereas higher concentrations of legacy POPs were found in kittiwakes than the fulmars.Furthermore,fulmars,the species with the much larger foraging range(~200 km),had higher plastic pollution and overall contaminant burdens,indicating that birds may be acting as long-range transport vectors for plasticassociated pollution.Our results suggest a potential connection between plastic additive contamination and plastic pollution burdens in the bird stomachs,highlighting the importance of treating plastic particles and plastic-associated organic additives as co-contaminants rather than separate pollution issues.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40576003 and 40276037)
文摘Persistent organochlorine pollutants (POPs) are analyzed for the dropping-amended soils from the habitats of Antarctic seabirds and seals in Fildes Peninsula and Ardley Island. The concentration ranges are 0.21 to 3.85 ng/g for polychlorinated biphenyls (ΣPCBs),0.09 to 2.01 ng/g for organochlorine pesticides (ΣDDT),and 0.06 to 0.76 ng/g for hexachlorocyclohexanes (HCHs). Among these,hepata-chlorobiphenyls,hexachlorobiphenyls,p,p′-DDE and α-HCH compounds are dominant. The concentra-tion ranges of ΣPCB,DDT and HCH in the eggs of skuas were 91.9―515.5 ng/g,56.6―304.4 ng/g and 0.5―2.0 ng/g respectively; those in the eggs of penguins were 0.4―0.9 ng/g,2.4―10.3 ng/g and 0.1― 0.4 ng/g; and those in the eggs of giant petrel were 38.1―81.7 ng/g,12.7―53.7 ng/g and 0.5―1.5 ng/g respectively. The dominant POP compounds in the eggs are PCB180,PCB153,p,p′-DDE and hexa-chlorobenzene (HCB). The present study shows that the concentration of POPs in the sea-bird-inhabited-dropping-amended soil varies with the extent of predation and nest occupancy of dif-ferent seabird populations. Statistical analysis on the POP concentrations from the different seabird eggs implies that the difference in the bio-concentration levels of the birds depends on the bio-habits of the species,such as the range of activity,distance of immigration,feeding pattern,and nest occupation. Among these,the most important factor is the location of the seabirds in the food chain and their feeding pattern. This shows that POPs accumulated in the seabirds resulted from the bio-concentration through the food chain. In addtion,210Pb dating for the dropping-amended soils (AD1-a and AD2) was performed,which provided the POP accumulation rate and the historic record for the soil profile. It indicates that POP will continuously affect the Antarctic ecosystem for a long time.
文摘Animal-attached technologies can be powerful means to quantify space use and behavior;however,there are also ethical implications associated with capturing and instrumenting animals.Furthermore,tagging approaches are not necessarily well-suited for examining the movements of multiple individuals within specific,local areas of interest.Here,we assess a method of quantifying animal space use based on a modified theodolite with an inbuilt laser rangefinder.Using a database of>4200 tracks of migrating birds,we show that detection distance in-creases with bird body mass(range 5 g to>10 kg).The maximum distance recorded to a bird was 5500 m and measurement error was≤5 m for targets within this distance range:a level comparable to methods such as GPS tagging.We go on to present a case study where this method was used to assess habitat selection in seabirds operating in dynamic coastal waters close to a tidal turbine.Combining positional data with outputs from a hydrographic model revealed that great cormorants(Phalacrocorax carbo)appeared to be highly selective of current characteristics in space and time,exploiting areas where mean current speeds were<0.8 m∙s^(−1) and diving at times when turbulent energy levels were low.These birds also oriented into tidal currents during dives.Taken together,this suggests that collision risks are low for cormorants at this site,as the 2 conditions avoided by cormorants(high mean current speeds and turbulence levels)are associated with operational tidal turbines.Over-all,we suggest that this modified theodolite system is well-suited to the quantification of movement in small areas associated with particular development strategies,including sustainable energy devices.
