scholarly journals Variability in nitrogen-derived trophic levels of Arctic marine biota

Polar Biology ◽  
2020 ◽  
Author(s):  
Renske P. J. Hoondert ◽  
Nico W. van den Brink ◽  
Martine J. van den Heuvel-Greve ◽  
Ad M. J. Ragas ◽  
A. Jan Hendriks
Keyword(s):  
Stable Isotopes ◽  
Enrichment Factors ◽  
Trophic Levels ◽  
The Arctic ◽  
Marine Biota ◽  
Arctic Ecosystems ◽  
Arctic Species ◽  
Single Region ◽  
Benthic Food ◽  
Species Specific

AbstractStable isotopes are often used to provide an indication of the trophic level (TL) of species. TLs may be derived by using food-web-specific enrichment factors in combination with a representative baseline species. It is challenging to sample stable isotopes for all species, regions and seasons in Arctic ecosystems, e.g. because of practical constraints. Species-specific TLs derived from a single region may be used as a proxy for TLs for the Arctic as a whole. However, its suitability is hampered by incomplete knowledge on the variation in TLs. We quantified variation in TLs of Arctic species by collating data on stable isotopes across the Arctic, including corresponding fractionation factors and baseline species. These were used to generate TL distributions for species in both pelagic and benthic food webs for four Arctic areas, which were then used to determine intra-sample, intra-study, intra-region and inter-region variation in TLs. Considerable variation in TLs of species between areas was observed. This is likely due to differences in parameter choice in estimating TLs (e.g. choice of baseline species) and seasonal, temporal and spatial influences. TLs between regions were higher than the variance observed within regions, studies or samples. This implies that TLs derived within one region may not be suitable as a proxy for the Arctic as a whole. The TL distributions derived in this study may be useful in bioaccumulation and climate change studies, as these provide insight in the variability of trophic levels of Arctic species.

Impacts of riverine terrestrial organic matter on the lower trophic levels of an Arctic shelf ecosystem

2021 ◽  
Author(s):  
Michael Bedington ◽  
Ricardo Torres ◽  
Luca Polimene ◽  
Phillip Wallhead ◽  
Bennett Juhls ◽  
...  
Keyword(s):  
Organic Matter ◽  
Future Climate ◽  
Trophic Levels ◽  
The Arctic ◽  
Nutrient Concentrations ◽  
Climate Scenarios ◽  
Arctic Ecosystems ◽  
Terrestrial Organic Matter ◽  
Biogeochemical Models ◽  
Near Shore

<p>The Arctic ocean receives 11% of the entire global river discharge via several great Arctic rivers that drain vast catchments underlain with carbon-rich permafrost. Arctic marginal shelf seas are therefore heavily influenced by terrestrial dissolved organic matter (tDOM) supply, influencing coastal biogeochemical processes and food-webs, as well as physio-chemical properties (e.g. stratification or nutrient concentrations).</p><p>Whilst carbon and associated macronutrients supplied by tDOM may enhance the nutrient and carbon substrates for lower trophic levels (phytoplankton/zooplankton), promoting increased local and regional productivity, it can also have opposing effects through a series of indirect processes (e.g. increased light absorption limiting light penetration through the water column). Understanding the relative importance and timing of these processes, and how they vary spatially, is necessary to identify how land-ocean interfaces currently operate.</p><p>Future climate scenarios indicate increased quantities of riverine tDOM delivered to the near-shore, with increased freshwater runoff and greater terrestrial permafrost thaw and erosion. This is likely to be exacerbated by the disappearance of seasonal sea ice cover and increased coastal erosion rates. We can therefore expect changes in planktonic phenology and productivity, with concomitant changes in bacterial and higher trophic level success. Understanding how these factors interact and may change under future climate scenarios is therefore critical to predict the future impact on shelf sea Arctic ecosystems and the ecosystem services they provide.</p><p>In the Changing Arctic Carbon cycle in the cOastal Ocean Near-shore (CACOON) project (UK-Germany collaboration) we are using coupled hydrodynamic-biogeochemical models in the extensive shallow shelf of the Laptev sea to explore the relationship between these factors. The ecosystem model ERSEM has been adapted to explicitly include a tDOM component. This coupled model system allows us to investigate both the role of present day tDOM in an Arctic coastal ecosystem and to project the potential impacts of increased tDOM input in future.</p>

Seasonal Variation of Arctic Ecosystems Towards Oil Spill

2014 ◽  
Vol 2014 (1) ◽  
pp. 299801
Author(s):  
Marte Rusten ◽  
Odd Willy Brude ◽  
Øivin Aarnes ◽  
Børre Johan Paaske
Keyword(s):  
Oil Spill ◽  
Physical Environment ◽  
Seasonal Variability ◽  
Oil And Gas ◽  
Seasonal Migration ◽  
The Arctic ◽  
Risk Level ◽  
Identification System ◽  
Arctic Ecosystems ◽  
Arctic Species

Due to melting of sea ice and predicted richness of petroleum resources, there is an increasing interest and activity in Arctic regions both for shipping and the oil&gas industry. Operations in the Arctic represent specific challenges due to both physical and biological environmental factors. The lack of infrastructure and the extreme physical environment including ice, strong seasonal variability in temperatures and daylight, put specific requirements to ensure safety of personnel and equipment during normal operations and put restraints on search and rescue (SAR) and oil spill recovery operations in case of an accident (ship collision or blow-out). The seasonal variability and extreme physical environment have also resulted in the evolution of specific adaptations of Arctic species, like extensive seasonal migrations and aggregations in large numbers to feed, mate and nurture their young that make them particularly vulnerable in certain periods and areas. Due to the low temperatures, Arctic species are also particularly vulnerable to contamination to oil that will affect their insulating layers of feather or fur. In addition to pollution from discharges and emissions, physical disturbances from ships such as strikes of whales and other marine mammals are of concern in areas where shipping routes overlap with seasonal migration and areas of aggregation. All activities represent a certain risk. To sanction shipping and oil&gas activities in the Arctic will require acceptance of the associated risk level. Stakeholders need to understand what creates the risk level, and on which facts, assessments and assumptions it is made. In this project we have produced an interactive map on which key risk factors associated with oil and gas and shipping activities in the Arctic are identified and assessed. By combining pan Arctic distribution patterns of arctic species at vulnerable life stages with ship traffic obtained from Automatic Identification System (AIS) data, existing oil and gas activity, SAR and vessel action radius and statistics on data related to the physical environment (ice coverage and features, temperature, marine icing, visibility etc.) we have constructed a map based risk matrix in order to communicate to key stakeholders in a form that supports their most important decisions. The map illustrates that the Arctic is not a uniform environment and that the risk picture is continuously changing throughout the season.

scholarly journals Climate change and ocean acidification impacts on lower trophic levels and the export of organic carbon to the deep ocean

2013 ◽  
Vol 10 (9) ◽  
pp. 5831-5854 ◽  
Author(s):  
A. Yool ◽  
E. E. Popova ◽  
A. C. Coward ◽  
D. Bernie ◽  
T. R. Anderson
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Ocean Acidification ◽  
21St Century ◽  
Trophic Level ◽  
Large Scale ◽  
World Ocean ◽  
Trophic Levels ◽  
The Arctic ◽  
Marine Biota

Abstract. Most future projections forecast significant and ongoing climate change during the 21st century, but with the severity of impacts dependent on efforts to restrain or reorganise human activity to limit carbon dioxide (CO2) emissions. A major sink for atmospheric CO2, and a key source of biological resources, the World Ocean is widely anticipated to undergo profound physical and – via ocean acidification – chemical changes as direct and indirect results of these emissions. Given strong biophysical coupling, the marine biota is also expected to experience strong changes in response to this anthropogenic forcing. Here we examine the large-scale response of ocean biogeochemistry to climate and acidification impacts during the 21st century for Representative Concentration Pathways (RCPs) 2.6 and 8.5 using an intermediate complexity global ecosystem model, MEDUSA-2.0. The primary impact of future change lies in stratification-led declines in the availability of key nutrients in surface waters, which in turn leads to a global decrease (1990s vs. 2090s) in ocean productivity (−6.3%). This impact has knock-on consequences for the abundance of the low trophic level biogeochemical actors modelled by MEDUSA-2.0 (−5.8%), and these would be expected to similarly impact higher trophic level elements such as fisheries. Related impacts are found in the flux of organic material to seafloor communities (−40.7% at 1000 m), and in the volume of ocean suboxic zones (+12.5%). A sensitivity analysis removing an acidification feedback on calcification finds that change in this process significantly impacts benthic communities, suggesting that a~better understanding of the OA-sensitivity of calcifying organisms, and their role in ballasting sinking organic carbon, may significantly improve forecasting of these ecosystems. For all processes, there is geographical variability in change – for instance, productivity declines −21% in the Atlantic and increases +59% in the Arctic – and changes are much more pronounced under RCP 8.5 than the RCP 2.6 scenario.

Relationship between morphometrics and trophic levels in deep-sea fishes

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Deep Sea ◽  
Strong Relationship ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Fish Size ◽  
Wide Range ◽  
Gape Size ◽  
Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

Routine identification of four sympatric species of calanoid copepods Pseudocalanus spp. in the Atlantic Arctic using a species-specific polymerase chain reaction

2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova
Keyword(s):  
Polymerase Chain Reaction ◽  
Life Cycles ◽  
The Arctic ◽  
Relative Distribution ◽  
Chain Reaction ◽  
Specific Polymerase Chain Reaction ◽  
Routine Identification ◽  
Polymerase Chain ◽  
Species Specific ◽  
Plankton Communities

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.

scholarly journals Societal implications of a changing Arctic Ocean

AMBIO ◽  
2021 ◽  
Author(s):  
Henry P. Huntington ◽  
Andrey Zagorsky ◽  
Bjørn P. Kaltenborn ◽  
Hyoung Chul Shin ◽  
Jackie Dawson ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Indigenous Peoples ◽  
Global Climate ◽  
Rapid Change ◽  
The Arctic ◽  
Cultural Continuity ◽  
Societal Implications ◽  
Arctic Ecosystems ◽  
The Many

AbstractThe Arctic Ocean is undergoing rapid change: sea ice is being lost, waters are warming, coastlines are eroding, species are moving into new areas, and more. This paper explores the many ways that a changing Arctic Ocean affects societies in the Arctic and around the world. In the Arctic, Indigenous Peoples are again seeing their food security threatened and cultural continuity in danger of disruption. Resource development is increasing as is interest in tourism and possibilities for trans-Arctic maritime trade, creating new opportunities and also new stresses. Beyond the Arctic, changes in sea ice affect mid-latitude weather, and Arctic economic opportunities may re-shape commodities and transportation markets. Rising interest in the Arctic is also raising geopolitical tensions about the region. What happens next depends in large part on the choices made within and beyond the Arctic concerning global climate change and industrial policies and Arctic ecosystems and cultures.

scholarly journals Investigation of mercury concentrations in fur of phocid seals using stable isotopes as tracers of trophic levels and geographical regions

Polar Biology ◽  
2011 ◽  
Vol 34 (9) ◽  
pp. 1411-1420 ◽  
Author(s):  
Aurore Aubail ◽  
Jonas Teilmann ◽  
Rune Dietz ◽  
Frank Rigét ◽  
Tero Harkonen ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Trophic Levels ◽  
Geographical Regions ◽  
Phocid Seals

scholarly journals Observed and predicted effects of climate change on Arctic caribou and reindeer

2018 ◽  
Vol 26 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Conor D. Mallory ◽  
Mark S. Boyce
Keyword(s):  
Climate Change ◽  
Rangifer Tarandus ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Global Trends ◽  
Warming Climate ◽  
The Many ◽  
Rapid Environmental Change ◽  
Full Consideration ◽  
Strong Concern

The ability of many species to adapt to the shifting environmental conditions associated with climate change will be a key determinant of their persistence in the coming decades. This is a challenge already faced by species in the Arctic, where rapid environmental change is well underway. Caribou and reindeer (Rangifer tarandus) play a key role in Arctic ecosystems and provide irreplaceable socioeconomic value to many northern peoples. Recent decades have seen declines in many Rangifer populations, and there is strong concern that climate change is threatening the viability of this iconic Arctic species. We examine the literature to provide a thorough and full consideration of the many environmental factors that limit caribou and reindeer populations, and how these might be affected by a warming climate. Our review suggests that the response of Rangifer populations to climate change is, and will continue to be, varied in large part to their broad circumpolar distribution. While caribou and reindeer could have some resilience to climate change, current global trends in abundance undermine all but the most precautionary outlooks. Ultimately, the conservation of Rangifer populations will require careful management that considers the local and regional manifestations of climate change.

Little-known arctic species Montacuta spitzbergensis (Bivalvia: Montacutidae) from the north-western Pacific with notes on Montacuta substriata and Tellimya ferruginosa

2008 ◽  
Vol 88 (2) ◽  
pp. 347-356 ◽  
Author(s):  
Gennady M. Kamenev
Keyword(s):  
Sea Of Okhotsk ◽  
First Record ◽  
Western Pacific ◽  
The Arctic ◽  
Arctic Species ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
North Western ◽  
North Western Pacific

An expanded description of a little-known arctic species Montacuta spitzbergensis from the Sea of Okhotsk with new data on its morphology, ecology and geographical distribution is given. This is the first record of M. spitzbergensis from the north-western Pacific. It differs from other species of Montacuta in its large (to 8.4 mm), elongate–ovate, thick shell with wide, slightly curved hinge plate, wide, short, and shallow resilifer, and weakly developed external ligament. This species occurs in the Arctic Ocean (Spitsbergen, Barents, Kara, Laptev and Chukchi Seas) and the Pacific Ocean (Sea of Okhotsk) at depths from 9 to 232 m at a bottom temperature from −1.62°C to +2.50°C. The hinge structure of the type species of the genera Montacuta and Tellimya is also discussed.

scholarly journals ‘Taking Fishers’ Knowledge to the Lab’: An Interdisciplinary Approach to Understand Fish Trophic Relationships in the Brazilian Amazon

2021 ◽  
Vol 9 ◽  
Author(s):  
Paula Evelyn Rubira Pereyra ◽  
Gustavo Hallwass ◽  
Mark Poesch ◽  
Renato Azevedo Matias Silvano
Keyword(s):  
Stable Isotopes ◽  
Food Webs ◽  
Fish Species ◽  
Trophic Interactions ◽  
Brazilian Amazon ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Ecological Knowledge ◽  
Data Limitations ◽  
Combining Data

Trophic levels can be applied to describe the ecological role of organisms in food webs and assess changes in ecosystems. Stable isotopes analysis can assist in the understanding of trophic interactions and use of food resources by aquatic organisms. The local ecological knowledge (LEK) of fishers can be an alternative to advance understanding about fish trophic interactions and to construct aquatic food webs, especially in regions lacking research capacity. The objectives of this study are: to calculate the trophic levels of six fish species important to fishing by combining data from stable isotopes analysis and fishers’ LEK in two clear water rivers (Tapajós and Tocantins) in the Brazilian Amazon; to compare the trophic levels of these fish between the two methods (stable isotopes analysis and LEK) and the two rivers; and to develop diagrams representing the trophic webs of the main fish prey and predators based on fisher’s LEK. The fish species studied were Pescada (Plagioscion squamosissimus), Tucunaré (Cichla pinima), Piranha (Serrasalmus rhombeus), Aracu (Leporinus fasciatus), Charuto (Hemiodus unimaculatus), and Jaraqui (Semaprochilodus spp.). A total of 98 interviews and 63 samples for stable isotopes analysis were carried out in both rivers. The average fish trophic levels did not differ between the stable isotopes analysis and the LEK in the Tapajós, nor in the Tocantins Rivers. The overall trophic level of the studied fish species obtained through the LEK did not differ from data obtained through the stable isotopes analysis in both rivers, except for the Aracu in the Tapajós River. The main food items consumed by the fish according to fishers’ LEK did agree with fish diets as described in the biological literature. Fishers provided useful information on fish predators and feeding habits of endangered species, such as river dolphin and river otter. Collaboration with fishers through LEK studies can be a viable approach to produce reliable data on fish trophic ecology to improve fisheries management and species conservation in tropical freshwater environments and other regions with data limitations.

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