La coexistencia de dos agriculturas en Argentina Una mirada a la vida de una granja familiar: ¿Cómo sobrevivir al lado de las grandes empresas?

Desde los primeros años del siglo XX, el desarrollo de Argentina como país estaba coincidió con el desarrollo de la industria agrícola. Hoy, Argentina es famosa por su papel en el mercado global como exportadora de bienes naturales. No solamente es un país con uno de los niveles más altos de alimentos transgénicos, sino que tiene el título del mayor exportador de producción orgánica en América Latina. Con los dos tipos de agricultura —exitosos pero contradictorios— con un enfoque hacia la exportación, quería entender como esta coexistencia está reflejada en el mercado interno para los bienes naturales. A través de investigaciones secundarias intensivas y completas, varias entrevistas con los actores en la industria y una estadía de una semana en una granja familiar orgánica, pronto descubrí que esta coexistencia no es está reflejada institucionalmente en el mercado interno. Por el neoliberalismo de los noventas y un esfuerzo fuerte de ser integrado en el mercado global, el modelo de agricultura actual está a favor de las grandes empresas que cultiven mono-producción masiva con el objetivo de la exportación. De hecho, la mayoría del mercado interno orgánico opera afuera del sistema de regulación y certificación, con poco apoyo del gobierno. Por lo tanto, el modelo actual para agricultura no apoya la producción orgánica de pequeña escala. Además, los dos tipos diferentes de agricultura comparten mucha de la misma terminología para referirse a sus objetivos y métodos de producción, reflejando incorrectamente el discurso político de la industria agrícola. Por una desconexión con el sistema regulado institucionalmente y una falta de conciencia de sus consumidores más allá de sus consumidores directos, el mercado interno ha formado sus propias dinámicas sociales y operacionales para sobrevivir, dependiendo en los métodos de producción sostenibles, las relaciones directas entre los productores y los consumidores, y una red de intercambios entre los productores orgánicos, revolucionando poco a poco el modelo de producción agrícola. Consecuentemente, entre los crecientes problemas globales sociales, políticos y ecológicos relacionados con el desarrollo, este modelo de producción orgánica local presenta una solución sostenible. Since the early 1900’s, Argentina’s development as a country has largely coincided with the development of its agriculture industry. Today, Argentina is well-known for its role in the global market as an exporter of natural goods. Not only is it a country with one of the highest levels of transgenic crops, but it also holds the title of the largest exporter of organic production in Latin America. With these two successful yet contradictory forms of agriculture largely geared toward exportation, I set out to understand how this coexistence is reflected in the internal market for natural goods. Through intensive, thorough secondary research, various interviews with different actors in the industry and a week -long stay on an organic family farm, I soon discovered that this coexistence is not institutionally reflected in the internal market. In light of the neoliberalism of the 90’s and a strong effort to be integrated into the global market, Argentina’s current agriculture model caters to large companies who cultivate mass mono-production largely for the purpose of exportation. In fact, the majority of internal organic market operates outside of the system of regulation and certification, with little government support. Therefore, the current model for agriculture doesn’t support small-scale organic production. Furthermore, these two different types of agriculture share much of the same terminology to refer to their production methods and objectives, poorly reflecting the political discourse of the agriculture industry. With a disconnect from the institutionally regulated system and a lack of customer awareness beyond their immediate consumers, the internal organic market has formed its own social and operational dynamics to survive, relying on sustainable methods of production, a direct consumer to producer relationship and an exchange network of producers, ultimately revolutionizing the model of agriculture production little by little. Consequently, in a context of growing social, political, and environmental global issues surrounding development, this model of local, organic production presents a sustainable solution

Food web characteristics of six intertidal habitat types of the Wadden Sea

Ecological network analysis (ENA) is a helpful tool to study complex ecosystem processes. The diverse species interactions are described as flows of energy providing a simplified representation of the natural system based on attributes and features. In the Wadden Sea, a unique ecosystem along the coastline of Denmark, Germany and the Netherlands, physical forces form the vast intertidal areas to diverse habitat types that differ in their species composition and abundance. Those habitats are important foraging areas for top predators such as birds. In the present study the food web of six habitats characteristic for the Wadden Sea (cockle field, razor clam field, mud flat, mussel bank, sand flat and seagrass meadow) were analyzed in a modelling approach. The functional and structural properties of the food webs were compared to assess differences and similarities in the system functioning. Although all systems revealed a good balance between their degree of organization and their robustness against external perturbations, they differed in their detailed features. The cockle field and the mussel bank both exhibited a strong dependence of their efficiency on external imports. The razor clam field, dominated by the introduced species Ensis directus, appeared to be a rather small and stressed system with low energy transfer. The mud flat system was characterized by a high use of microphytobenthos and appeared to be not fully developed yet. Bird predation was most pronounced in the sand flat and the seagrass meadow and led to an increase in energy transfer, parallel pathways and pathways lengths in these habitats. Each system shows characteristic features and plays a different role in the Wadden Sea ecosystem by contributing significantly to the whole system functioning

The influence of birds on the structure and functioning of coastal food webs

The Wadden Sea is one of the most important stop-over sites for migrating and breeding birds. About 10-12 million birds per year use the area for foraging and consume about 25 to 45% of the standing stock of macrozoobenthos. But little is known about the influence of birds on the entire ecosystem. We conducted Ecological Network Analysis (ENA) in an important breeding and resting site in the north-eastern German Wadden Sea to determine the influence of birds on the food web. The model was based on the yearly average of empirical data taken in the study site. In its current condition, the system appears to be in a well-balanced status, with a relative Ascendency of 32.3% and a robustness of 36.5%. The diversity of flows was high showed by a Flow Diversity of 5.1 and numerous parallel pathways represented by an Effective Link-Density of 3.3. A large variety of different bird species uses the area for foraging. As top predators, these bird species are included directly or indirectly in most of the pathways. Birds induce a huge negative impact on their prey items with a less pronounced positive feedback reaction to the competitors and food resources of those organisms. There is also a strong negative impact among the bird compartments probably due to competition between the bird species on the intertidal flats. Changes in the biomass of the birds revealed alterations in the food web structure. With a decline in the avian biomass the system showed a decrease in connectivity and diversity of flows but an increase in recycling. Birds therefore appear to be an important factor for the food web structure. Changes in the bird population could affect the complexity and functioning of the entire ecosystem. Thus, it is recommended to include birds in coastal food web studies which has rarely been done before. The use of such holistic approaches would facilitate undertaking management measures

Biomarkers in ringed seals reveal recent onset of borealization in the high- compared to the mid-latitude Canadian Arctic

This work resulted from the ARISE project (NE/P006035/1), part of the Changing Arctic Ocean program, funded by the UKRI Natural Environment Research Council (NERC).Warming of the Arctic has resulted in environmental and ecological changes, termed borealization, leading to the northward shift of temperate species. Borealization has occurred across all trophic levels, altering the structure of the food web. The onset and rate of borealization likely varies with latitude, depending on local warming and advection of warmer water into the Arctic. In order to assess latitudinal trends in food web structure in the Arctic, we analyzed stable nitrogen isotopes of specific amino acids alongside bulk stable carbon isotopes in ringed seal muscle tissue from the Canadian Arctic Archipelago (high-Arctic) and Southern Baffin Bay (mid-Arctic) from 1990 to 2016. Our results indicate a shift in food web structure in the high-Arctic that has occurred more recently when compared with the mid-Arctic. Specifically, over the past 25 years, the trophic position of ringed seals from the mid-Arctic was largely constant, whereas the trophic position of ringed seals decreased in the high-Arctic, reaching similar values observed in the mid-Arctic in 2015-2016. This suggests a potential shortening of the food chain length in the high-Arctic, possibly driven by changes in zooplankton communities feeding complexity in association with sea ice decline. This study identifies a temporal offset in the timing of borealization in the Canadian Arctic, resulting in different response of food webs to ecological changes, depending on latitude.Publisher PDFPeer reviewe

Compound specific isotope analyses of harp seal teeth : tools for trophic ecology reconstruction

This work resulted from the ARISE project (NE/P006035/1 awarded to CM and RJ, and NE/P00623X/1 awarded to SS), part of the Changing Arctic Ocean programme, funded by the UKRI Natural Environment Research Council (NERC).As sentinels of ecosystem health, high trophic level predators integrate information through all levels of the food web. Their tissues can be used to investigate spatiotemporal variability in foraging behaviour, and with the appropriate analytical methods and tools, archived samples can be used to reconstruct past trophic interactions. Harp seal (Pagophilus groenlandicus) teeth collected in the 1990s from the Northwest Atlantic were analysed for bulk stable carbon and nitrogen isotopes (δ13Cbulk and δ15Nbulk), and compound specific stable nitrogen isotopes of amino acids (δ15NAA) for the first time. We developed a fine-scale, annual growth layer group (GLG) dentine sub-sampling method corresponding to their second and third year of life. In accordance with previous diet studies, while there was individual variability in δ15Nbulk, δ13Cbulk, and δ15NAA measurements, we did not detect significant differences in isotopic niche widths between males and females, or between GLGs. Relative trophic position was calculated as the baseline corrected δ15NAA values using trophic (glutamic acid) and source (phenylalanine and glycine) amino acids. Variability was measured between individuals in their relative trophic position, but within individual variability was low, suggesting that they fed at the same trophic level over these 2 years of life. These novel δ15NAA data may therefore suggest individual, specialist harp seal foraging behaviour in sub-adults. Our findings show that compound specific stable isotope signatures of archived, inert predator tissues can be used as tools for the retrospective reconstruction of trophic interactions on broad spatiotemporal scales.PostprintPeer reviewe

Do birds influence the structure and functioning of coastal food webs?

The Wadden Sea is one of the most important stop-over sites for 10 to 12 Million migrating birds per year. But little is known about the influence of birds on the entire ecosystem. We conducted Ecological Network Analysis (ENA) in an important resting site in the Wadden Sea to determine the influence of birds on the food web. A large variety of different bird species uses the area for foraging and is included directly or indirectly in most of the pathways. Birds induce a negative impact on their prey items with a positive feedback reaction to the preys’ competitors and food sources. There is also a strong negative impact among the bird compartments probably due to competition between the birds. Changes in the biomass of the birds revealed alterations in the food web structure. With a decline in the avian biomass the system showed a decrease in connectivity and diversity of flows but an increase in recycling. Changes in the bird population could affect the complexity and functioning of the entire ecosystem. Thus, the use of such holistic approaches would facilitate undertaking management measures

Multi-decadal environmental change in the Barents Sea recorded by seal teeth

This work resulted from the ARISE project (NE/P006035/1, NE/P006000/1), part of the Changing Arctic Ocean programme, jointly funded by the UKRI Natural Environment Research Council (NERC). We thank Jim Ball for his help in the isotopic lab in Liverpool University. This work resulted from the ARISE project, part of the Changing Arctic Ocean programme.Multiple environmental forcings, such as warming and changes in ocean circulation and nutrient supply, are affecting the base of Arctic marine ecosystems, with cascading effects on the entire food web through bottom-up control. Stable nitrogen isotopes (δ15N) can be used to detect and unravel the impact of these forcings on this unique ecosystem, if the many processes that affect the δ15N values are constrained. Combining unique 60-year records from compound specific δ15N biomarkers on harp seal teeth alongside state-of-the-art ocean modelling, we observed a significant decline in the δ15N values at the base of the Barents Sea food web from 1951 to 2012. This strong and persistent decadal trend emerges due to the combination of anthropogenic atmospheric nitrogen deposition in the Atlantic, increased northward transport of Atlantic water through Arctic gateways and local feedbacks from increasing Arctic primary production. Our results suggest that the Arctic ecosystem has been responding to anthropogenically induced local and remote drivers, linked to changing ocean biology, chemistry and physics, for at least 60 years. Accounting for these trends in δ15N values at the base of the food web is essential to accurately detect ecosystem restructuring in this rapidly changing environment.Publisher PDFPeer reviewe

Interactions between environmental contaminants and gastrointestinal parasites: novel insights from an integrative approach in a marine predator

Environmental contaminants and parasites are ubiquitous stressors that can affect animal physiology and derive from similar dietary sources (co-exposure). To unravel their interactions in wildlife, it is thus essential to quantify their concurring drivers. Here, the relationship between blood contaminant residues (11 trace elements and 17 perfluoroalkyl substances) and nonlethally quantified gastrointestinal parasite loads was tested while accounting for intrinsic (sex, age, and mass) and extrinsic factors (trophic ecology inferred from stable isotope analyses and biologging) in European shags Phalacrocorax aristotelis. Shags had high mercury (range 0.65–3.21 μg g–1 wet weight, ww) and extremely high perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) residues (3.46–53 and 4.48–44 ng g–1 ww, respectively). Males had higher concentrations of arsenic, mercury, PFOA, and PFNA than females, while the opposite was true for selenium, perfluorododecanoic acid (PFDoA), and perfluooctane sulfonic acid (PFOS). Individual parasite loads (Contracaecum rudolphii) were higher in males than in females. Females targeted pelagic-feeding prey, while males relied on both pelagic- and benthic-feeding organisms. Parasite loads were not related to trophic ecology in either sex, suggesting no substantial dietary co-exposure with contaminants. In females, parasite loads increased strongly with decreasing selenium:mercury molar ratios. Females may be more susceptible to the interactive effects of contaminants and parasites on physiology, with potential fitness consequences

Trophic redundancy in benthic fish food webs increases with scarcity of prey items, in the Southern Baltic Sea

Bottom trawling is one of the main pressures on benthic ecosystems, directly impacting the targeted species and physically disturbing the seabed and the benthic invertebrate communities, in turn indirectly impacting benthivorous fish and the entire benthic food web structure and functioning. To predict the cascading effect of bottom trawling on benthic and demersal fish communities, it is crucial to understand the trophic interactions between benthic and demersal fish and benthic invertebrates. Here, we assessed the diet of benthic and demersal fish and the structure and functioning of the benthic food web in two areas in the German Baltic Sea, the Fehmarnbelt and the Odra Bank. The Fehmarnbelt benthic invertebrate community is characterized by a high number of species and biomass, contrary to the one on the Odra Bank which is species poor with high individual abundance but low biomass. We used mixing models based on stable isotopes of carbon and nitrogen combined with stomach content analyses to estimate the fish diet at both sites, and we used community-wide trophic indices, derived from stable isotopes to compare the structure and functioning of the fish benthic food webs. We show that fish in the Fehmarnbelt can chose preferential prey items, resulting in higher trophic diversity, contrary to fish on the Odra Bank, which feed on all available prey species, resulting in higher trophic redundancy. We found that the generalist behavior of fish on the Odra Bank is likely the result of scarcity in prey items, the benthic invertebrate community being species poor with high abundance of small individuals. We demonstrate that the differences in structure and functioning of the benthic fish food web between the two sites was mainly driven by differences in the characteristics of the benthic prey communities