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Wpływ globalnego ocieplenia na hydrodynamikę i biologię Wielkich Jezior Mazurskich (WJM) - homotermia wiosenna i jej skutki

Siuda Waldemar, Kiersztyn Bartosz, Grabowska-Gruca Karolina

Technologia Wody

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2024

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Nr 1 (83)

10-19

PL

Ekosystemy wodne są czułymi detektorami globalnego ocieplenia oraz towarzyszących mu zmian klimatycznych. Wzrost temperatury wpływa bezpośrednio zarówno na hydrodynamikę zbiorników wodnych jak i na bytujące w nich mikrobiocenozy, powodując kompleksowe i wielopłaszczyznowe zmiany w ich strukturze gatunkowej, aktywności fizjologicznej i wzajemnych relacjach. Prowadzi to do zmian i zaburzeń w funkcjonowaniu ogniw, łańcuchów i sieci troficznych, a w konsekwencji w przepływie materii i energii przez ekosystemy wodne. Okres wiosennego mieszania się wód (homotermii wiosennej) jest szczególnie istotny dla jezior dimiktycznych. Warunkuje on bowiem ich funkcjonowanie w okresie letnim. W artykule wykazano, że w latach 2000 - 2022 w głębokich jeziorach centralnej i południowej części Systemu Wielkich Jezior Mazurskich okres ten ulegał systematycznemu wydłużaniu. W położonym na północnym krańcu Systemu Jeż. Przystań tendencja ta była widoczna lecz słabiej zaznaczona. Jako, że w stosunkowo krótkich odcinkach czasowych efekty długookresowych zmian klimatycznych są skutecznie „maskowane" przez czynniki pogodowe określenie ich wpływu na fizyko-chemię. i biologię WJM jest trudne. Pomimo to w artykule przedyskutowano również potencjalne konsekwencje tego zjawiska: jego wpływ na hydrodynamikę wód jeziornych, parametry fizyko-chemiczne wody, mikroplankton jeziorny oraz łańcuchy i sieci troficzne. Jeziora Systemu WJM stanowią około 18% zasobów wód powierzchniowych Polski. Dlatego też choć tezy sformułowane przez autorów, skonfrontowane ze skutkami opisywanymi w dostępnej literaturze mogą skłaniać do polemiki to zainicjowanie dyskusji dotyczącej tego tematu wydaje się autorom ważne. Płynące z niej wnioski pozwolą bowiem na przygotowanie się na nadchodzące zmiany, zminimalizowanie ich niekorzystnego wpływu na System WJM a być może również na opracowanie sposobów wykorzystania ich skutków pozytywnych w biotechnologiach środowiskowych stosowanych dla rekultywacji i rewitalizacji głębokich zbiorników wodnych.

EN

Aquatic ecosystems are sensitive detectors of global warming and accompanying effects of climate change. Increasing temperatures directly affect both the hydrodynamics of water bodies and the microbiocenoses that reside in them, causing complex and multifaceted changes in their species structure, physiological activity and interspecies interactions. This leads to changes and disturbances In the functioning of food links, chains and webs, and consequently the flow of matter and energy through aquatic ecosystems. The period of spring mixing of waters (spring homothermy) is particularly important for dimictic lakes. This is because it determines their functioning during summer period. The article shows that in the years 2000-2022 in the deep lake sof the central and southern part of the Great Masurian Lakes System, period of water mixing was systematically extended. In Lake Przystań, located at the northern edge of the System, this trend was also evident but much less pronounced. As the effects of long-term climate change are effectively "masked" by weather factors over relatively short time scales, deter-mining their impact on the physico-chemistry and biology of the WJM is difficult. Despite this, the article also discusses the potential consequences of this phenomenon: its impact on lake water hydrodynamics, water physico-chemical parameters, lake microplankton as well as on food chains and webs . The lakes of the WJM System account for about 18% of Poland's surface water resources. Therefore, although the theses formulated by the authors, confronted with ones described in the available literature, may be debatable, it seems important for the authors to initiate a discussion on this topic. This is because the conclusions drawn from it will allow to prepare for the coming changes, minimize their adverse effects on the WJM System and perhaps develop ways to use their positive effects in environmental biotechnologies applied to the reclamation and revitalization of deep water reservoirs.

2

Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China

Ning Jiajia, Du Feiyan, Wang Xuehui, Wang Lianggen, Li Yafang

Oceanologia

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2019

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No. 61 (2)

208--217

EN

Trophic interactions are common worldwide, both within and between ecosystems. This study elucidated the trophic connectivity between intertidal and offshore zone, in Mirs Bay, China. The contributions of offshore suspended particulate organic matter (SPOM), intertidal macroalgae and epiphytes to consumer biomass were assessed, and the trophic pathways were identified through the use of stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) of basal sources and consumers. Mean δ13C values of basal sources had a wide range (-19.6‰ to -11.8‰) and were generally well separated in Mirs Bay. The average δ13C of consumers in Mirs Bay ranged from -19.2‰ to -11.8‰, reflecting a carbon source integrated from different primary producer signals. IsoSource model solutions indicated consumers assimilated organic carbon from a mixture of basal sources. Offshore SPOM carbon was the primary carbon source supporting most consumers in both intertidal and offshore zones. Intertidal macroalgae and epiphytes also accounted for a large fraction for some consumers. δ15N data indicated 5 trophic levels in Mirs Bay. Intertidal consumers, except for Capitulum mitella, had a TP (trophic position) between 2 and 3, and mainly included filter-feeders and grazers. In contrast, almost all offshore consumers had a TP of between 3 and 4 except for filter-feeders (zooplankton), planktivores (Clupanodon punctatus and Sardinella aurita) and piscivores (Gymnura japonica). The basal sources fueled consumer through two trophic pathways, each of which involved organisms of both intertidal and offshore zones, implying trophic connectivity between them in the Mirs Bay ecosystem.

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The use of stable isotope analyses in freshwater ecology: Current awareness

Grey Jonathan

Polish Journal of Ecology

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2006

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Vol. 54, nr 4

563-584

EN

Ecological research using stable isotopes has progressed rapidly during the last 20 years and although more studies are including the addition of isotopically labelled compounds at tracer levels, the overwhelming majority rely on measurements of natural abundance ratios. Access to isotope ratio mass spectrometry has increased, spurred on by awareness of the techniques and increasing demand, and consequently cost of sample analysis has dropped. Today stable isotopes of carbon ([13]C/[12]C), nitrogen ([15]N/[14]N), sulphur ([34]S/[32]S), oxygen ([18]O/[16]O), and hydrogen ([2]H/[1]H) can be determined routinely. Perhaps one of the most appealing attributes of isotopic signatures is their potential use to find patterns and determine mechanisms across a range of scales from the molecular level through to characterizing whole food webs, reconstructing palaeoenvironments, tracing nutrient fluxes between ecosystems and identifying subsidies, or migrations of organisms. Ecologists from every discipline who are unlikely to have been trained as isotope chemists have added stable isotope analysis (SIA) to their "toolbox", but often increasing use leads to increasing abuse. The usefulness of SIA arises from predictable physical and enzymatic-based discrimination between biological and non-biological materials leading to different isotopic compositions. Without some ecological understanding of these, interpretation of isotope-derived data can often be flawed. Here, I explore how SIA recently has been used for research in aquatic ecology, reviewing how some of these techniques have allowed elucidation of key processes in aquatic systems such as the contribution of allochthony to lake food webs, and discuss the "state of the art". Included are some thoughts on where our knowledge in aquatic ecology remains deficient and how continued development and future application of SIA and interdisciplinary methodologies may be applied.

4

Daphnia: model herbivore, predator and prey

Lampert Winfried

Polish Journal of Ecology

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2006

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Vol. 54, nr 4

607-620

EN

In the past 30 years, Daphnia has become a model organism in aquatic ecology. I review the changing concepts and paradigms in plankton ecology as reflected in the work on Daphnia. The availability of radiotracers favoured a new physiological approach that resulted in better energetic models and more reliable estimates of filtering rates. This led to deeper insights into the role of herbivore grazing on phytoplankton and microbial communities, and nutrient recycling. It provided a conceptual basis for general hypotheses on predictable seasonal successions (e.g. the PEG model). On the other hand, increasing knowledge about selective predation on zooplankton triggered population dynamic models and gave explanations for changing community structures. The Size-Efficiency-Hypothesis generated a framework for studies on trade-offs between competitive ability and susceptibility to predation. Daphnia was now in the centre of interaction-based concepts, being predator and prey at the same time. It was the backbone of practical applications of the theory in food-web manipulations. When ultimate factors came into the focus, Daphnia played an important role in explaining striking phenomena like diel vertical migration and cyclomorphosis. Its central position in food-webs, the unique propagation mode, easy cultivation and accessibility by molecular genetic methods made it a favourite object for studies in evolutionary ecology, concerning local adaptation, evolution of defences and life histories, induced phenotypic change, and genetic diversity. The large advantage of Daphnia over other biological model organisms is that its importance in pelagic freshwater systems is undoubtedly known. Hence there is a direct way of applying the results to ecological systems.