scholarly journals Benthic invaders control the phosphorus cycle in the world’s largest freshwater ecosystem

2021 ◽  
Vol 118 (6) ◽  
pp. e2008223118 ◽  
Author(s):  
Jiying Li ◽  
Vadym Ianaiev ◽  
Audrey Huff ◽  
John Zalusky ◽  
Ted Ozersky ◽  
...  
Keyword(s):  
Great Lakes ◽  
Aquatic Ecosystems ◽  
Water Quality Management ◽  
Single Species ◽  
Freshwater Ecosystem ◽  
P Availability ◽  
Phosphorus Cycle ◽  
Quagga Mussels ◽  
Balance Analysis ◽  
Open Question

The productivity of aquatic ecosystems depends on the supply of limiting nutrients. The invasion of the Laurentian Great Lakes, the world’s largest freshwater ecosystem, by dreissenid (zebra and quagga) mussels has dramatically altered the ecology of these lakes. A key open question is how dreissenids affect the cycling of phosphorus (P), the nutrient that limits productivity in the Great Lakes. We show that a single species, the quagga mussel, is now the primary regulator of P cycling in the lower four Great Lakes. By virtue of their enormous biomass, quagga mussels sequester large quantities of P in their tissues and dramatically intensify benthic P exchanges. Mass balance analysis reveals a previously unrecognized sensitivity of the Great Lakes ecosystem, where P availability is now regulated by the dynamics of mussel populations while the role of the external inputs of phosphorus is suppressed. Our results show that a single invasive species can have dramatic consequences for geochemical cycles even in the world’s largest aquatic ecosystems. The ongoing spread of dreissenids across a multitude of lakes in North America and Europe is likely to affect carbon and nutrient cycling in these systems for many decades, with important implications for water quality management.

scholarly journals Microplastics in the diet of nestling double-crested cormorants (Phalacrocorax auritus), an obligate piscivore in a freshwater ecosystem

2019 ◽  
Vol 76 (11) ◽  
pp. 2156-2163 ◽  
Author(s):  
Cole B. Brookson ◽  
Shane R. de Solla ◽  
Kim J. Fernie ◽  
Monina Cepeda ◽  
Chelsea M. Rochman
Keyword(s):  
Great Lakes ◽  
Aquatic Ecosystems ◽  
Natural Fibres ◽  
Laurentian Great Lakes ◽  
Freshwater Ecosystem ◽  
Phalacrocorax Auritus ◽  
Marine Systems ◽  
Freshwater Systems ◽  
Diving Bird

Anthropogenic debris, namely plastic, is a concern across aquatic ecosystems worldwide, with freshwater systems being understudied relative to marine systems. In this study, we quantified and characterized debris in the diet of double-crested cormorant chicks (Phalacrocorax auritus) from three sites in two of the Laurentian Great Lakes to (i) determine whether or not the diet of double-crested cormorants in the Laurentian Great Lakes includes anthropogenic debris, (ii) characterize the size, shape, and type of debris incorporated, and (iii) examine relationships between the amount of debris ingested and their proximity to industrial–urban centres. Overall, >86% of cormorants in our study had anthropogenic debris (mostly fibers) in their digestive tracts with no correlation between site and the amount of debris ingested. The ingested debris includes microplastics, natural fibres from textiles, and other anthropogenic materials (e.g., glass). To the best of our knowledge, this is one of the first studies to examine anthropogenic debris in a diving bird in the Laurentian Great Lakes and one of few studies investigating this in freshwater birds.

A storm water retrofit plan for the mimico creek watershed

1999 ◽  
Vol 39 (12) ◽  
pp. 133-140
Author(s):  
J. Y. Li ◽  
D. Banting
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Great Lakes ◽  
Management Practices ◽  
Water Quality Management ◽  
Storm Water ◽  
Planning Tool ◽  
Creek Watershed ◽  
Urbanized Areas ◽  
Goals And Objectives

Storm water quality management in urbanized areas remains a challenge to Canadian municipalities as the funding and planning mechanisms are not well defined. In order to provide assistance to urbanized municipalities in the Great Lakes areas, the Great Lakes 2000 Cleanup Fund and the Ontario Ministry of the Environment commissioned the authors to develop a Geographic Information System planning tool for storm water quality management in urbanized areas. The planning tool comprises five steps: (1) definition of storm water retrofit goals and objectives; (2) identification of appropriate retrofit storm water management practices; (3) formulation of storm water retrofit strategies; (4) evaluation of strategies with respect to retrofit goals and objectives; and (5) selection of storm water retrofit strategies. A case study of the fully urbanized Mimico Creek wateshed in the City of Toronto is used to demonstrate the application of the planning tool.

scholarly journals Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia

2018 ◽  
Vol 15 (1) ◽  
pp. 279-295 ◽  
Author(s):  
Corina Buendía ◽  
Axel Kleidon ◽  
Stefano Manzoni ◽  
Björn Reu ◽  
Amilcare Porporato
Keyword(s):  
Amazon Basin ◽  
P Availability ◽  
Phosphorus Cycle ◽  
Terra Firme ◽  
The Andes ◽  
P Content ◽  
Spatial Redistribution ◽  
Soil Age ◽  
Seasonally Flooded ◽  
Lowland Amazonia

Abstract. Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.

Modeling ships' ballast water as invasion threats to the Great Lakes

2002 ◽  
Vol 59 (7) ◽  
pp. 1245-1256 ◽  
Author(s):  
Hugh J MacIsaac ◽  
Thomas C Robbins ◽  
Mark A Lewis
Keyword(s):  
Great Lakes ◽  
Ballast Water ◽  
Aquatic Ecosystems ◽  
Propagule Pressure ◽  
Current Knowledge ◽  
Invasion Process ◽  
Long Distance ◽  
Invasion Models ◽  
Terrestrial Habitats ◽  
Shipping Traffic

The spread of nonindigenous species (NIS) in aquatic ecosystems provides an opportunity to develop new perspectives on the invasion process. In this paper we review existing invasion models, most of which were developed to describe invasions of terrestrial habitats, and propose an alternative that explores long-distance invasions mediated by discharge of contaminated ballast water by ships inbound to the Great Lakes. Based on current knowledge of shipping traffic to the Great Lakes, our model predicts that mid-ocean exchange of ballast water lowers propagule delivery by approximately three to four orders of magnitude relative to unexchanged ballast water. Propagule pressure of individual ships that enter the Great Lakes loaded with cargo and that declare "no ballast on board" (NOBOB) is typically one to two orders of magnitude higher than that of vessels that exchange ballast. Because NOBOB vessels dominate (~90%) inbound traffic into the Great Lakes, these vessels collectively appear to pose the greatest risk of new introductions, even though their individual risks are low.

Working in Freshwater: The Great Lakes Observing System Contributions to Regional and National Observations, Data Infrastructure, and Decision Support

2010 ◽  
Vol 44 (6) ◽  
pp. 84-98 ◽  
Author(s):  
Jennifer Read ◽  
Val Klump ◽  
Tom Johengen ◽  
David Schwab ◽  
Kelli Paige ◽  
...  
Keyword(s):  
Decision Support ◽  
Great Lakes ◽  
Information Needs ◽  
Water Security ◽  
Freshwater Ecosystem ◽  
Detroit River ◽  
Data Infrastructure ◽  
Multiple User ◽  
A Charge ◽  
Management Functions

AbstractThe Laurentian Great Lakes is the world’s largest freshwater ecosystem. A charge of the Great Lakes Observing System (GLOS) Regional Association is to help coordinate and integrate data and information relative to the needs of multiple user communities—decision makers with responsibility for coastal resources, maritime operations, human health and water security data, and issues associated with adapting to climate change and weather-related hazards. This article outlines the process GLOS has developed for determining regional data and information needs, how GLOS outreach activities inform data management functions and the development of decision support tools, and how the nearshore network of multiple observation platform types was conceived and is being implemented. The article finishes with a case study of this approach as it is being applied to source water protection, spill response, and search and rescue in the St. Clair River, Lake St. Clair, and Detroit River, the connecting channels that link Lake Huron to Lake Erie.

scholarly journals Litter inputs and phosphatase activity affect the temporal variability of organic phosphorus in a tropical forest soil in the Central Amazon

2021 ◽  
Author(s):  
Karst J. Schaap ◽  
Lucia Fuchslueger ◽  
Marcel R. Hoosbeek ◽  
Florian Hofhansl ◽  
Nathielly Pires Martins ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Phosphatase Activity ◽  
Litter Decomposition ◽  
Soil Phosphorus ◽  
Litter Production ◽  
P Availability ◽  
Organic P ◽  
Phosphorus Cycle ◽  
P Fractions ◽  
Soil P

Abstract Purpose The tropical phosphorus cycle and its relation to soil phosphorus (P) availability are a major uncertainty in projections of forest productivity. In highly weathered soils with low P concentrations, plant and microbial communities depend on abiotic and biotic processes to acquire P. We explored the seasonality and relative importance of drivers controlling the fluctuation of common P pools via processes such as litter production and decomposition, and soil phosphatase activity. Methods We analyzed intra-annual variation of tropical soil phosphorus pools using a modified Hedley sequential fractionation scheme. In addition, we measured litterfall, the mobilization of P from litter and soil extracellular phosphatase enzyme activity and tested their relation to fluctuations in P- fractions. Results Our results showed clear patterns of seasonal variability of soil P fractions during the year. We found that modeled P released during litter decomposition was positively related to change in organic P fractions, while net change in organic P fractions was negatively related to phosphatase activities in the top 5 cm. Conclusion We conclude that input of P by litter decomposition and potential soil extracellular phosphatase activity are the two main factors related to seasonal soil P fluctuations, and therefore the P economy in P impoverished soils. Organic soil P followed a clear seasonal pattern, indicating tight cycling of the nutrient, while reinforcing the importance of studying soil P as an integrated dynamic system in a tropical forest context.

scholarly journals A Single Species, Micromonas pusilla (Prasinophyceae), Dominates the Eukaryotic Picoplankton in the Western English Channel

2004 ◽  
Vol 70 (7) ◽  
pp. 4064-4072 ◽  
Author(s):  
Fabrice Not ◽  
Mikel Latasa ◽  
Dominique Marie ◽  
Thierry Cariou ◽  
Daniel Vaulot ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Fluorescent In Situ Hybridization ◽  
Algal Species ◽  
Sampling Period ◽  
Single Species ◽  
English Channel ◽  
Green Algal ◽  
Micromonas Pusilla ◽  
Green Algal Species

ABSTRACT The class Prasinophyceae (Chlorophyta) contains several photosynthetic picoeukaryotic species described from cultured isolates. The ecology of these organisms and their contributions to the picoeukaryotic community in aquatic ecosystems have received little consideration. We have designed and tested eight new 18S ribosomal DNA oligonucleotide probes specific for different Prasinophyceae clades, genera, and species. Using fluorescent in situ hybridization associated with tyramide signal amplification, these probes, along with more general probes, have been applied to samples from a marine coastal site off Roscoff (France) collected every 2 weeks between July 2000 and September 2001. The abundance of eukaryotic picoplankton remained high (>103 cells ml−1) during the sampling period, with maxima in summer (up to 2 × 104 cells ml−1), and a single green algal species, Micromonas pusilla (Prasinophyceae), dominated the community all year round. Members of the order Prasinococcales and the species Bathycoccus prasinos (Mamiellales) displayed sporadic occurrences, while the abundances of all other Prasinophyceae groups targeted remained negligible.

Establishing an energy balance for crop-based digestion

2009 ◽  
Vol 59 (6) ◽  
pp. 1053-1060 ◽  
Author(s):  
A. Salter ◽  
C. J. Banks
Keyword(s):  
Energy Balance ◽  
Crop Production ◽  
Single Species ◽  
Energy Conversion Efficiency ◽  
Production Cycle ◽  
Energy Yield ◽  
Crop Species ◽  
Energy Inputs ◽  
Balance Analysis ◽  
Energy Balance Analysis

The paper examines methods for calculating energy surpluses through anaerobic digestion and gives some examples of the practical application of these in crop-based systems. The surplus energy is the balance between that produced as a usable energy source and that used in crop production, conversion of the biomass into biogas, and conversion of biogas into a usable form: these are the direct energy inputs. The energy balance also takes into account the embedded energy used in the construction of machinery and buildings and for their repair and maintenance: the indirect energy inputs. The area of land available for fuel production is finite and therefore the energy yield is best considered on a per hectare basis. This allows comparison of energy conversion efficiency where the biomass yield for that area may vary depending on a range of inputs, e.g. rate of fertiliser application or irrigation requirements. It also allows direct comparison between different crop species or varieties within a single species. For an accurate energy balance analysis direct and indirect energy requirements have to be established for all the stages in the crop-based energy production cycle.

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