Abstract In nitrogen-limited lakes, cyanobacterial nitrogen (N) fixation rates can be high. However, the effect of cyanobacterial N fixation on ecosystem N availability depends, in part, on the retention of fixed N. Here, we explore patterns of benthic and pelagic N fixation and fixed N retention in Lake Mývatn, Iceland. Our N budget, updated from previous assessments, showed that the annual rate of lake-scale N fixation needed to account for the deficit between external N supply and N loss varies greatly from year to year, primarily due to variation in the magnitude of N loss via outflow and midge emergences that transport and deposit N on the shore. Extrapolations from recent direct measurements of pelagic and benthic N fixation under scenarios of different benthic and pelagic N-fixer abundances showed that the capacity for N fixation is much higher in the pelagic than the benthic zone. We then explored the degree to which N fixed in the pelagic zone is retained and recycled within the lake using a dynamic N budget that leverages data on patterns of N loss via the outlet river Laxá. This revealed that approximately two-thirds of organic N in the pelagic zone must be incorporated into the benthos to explain patterns of N loss via outflow from the river Laxá. Together, these results suggest N fixation in pelagic cyanobacterial blooms may supply most of the N for benthic primary production in Mývatn.

Exometabolites released by benthic primary producers (BPP) are an integral part of the coral reef food web. Depending on their origin and composition these complex mixtures of dissolved organic compounds support a distinct microbial community. Which exudate components are preferentially used by microbes, how this preference differs between exudate types, and what molecular features drive the microbial community differentiation is still poorly understood. Here we use an untargeted metabolomics approach (liquid chromatography-tandem mass spectrometry (LC/MS-MS)) to assess the microbial uptake of exudates produced by BPP (mixed coral community, macroalgae, turf algae, and coral-macroalgae, coral-turf algae). We can show that that exudate compounds and especially those unique to a specific BPP or mixed community are the most favored substrate for microbes in the respective communities. Our data suggests that in each BPP treatment the unique combination of organic compounds is the main driver selecting for a specific microbial community composition rather than a specific single substance. This emphasizes the complexity of mechanisms and metabolisms that constitute and structure communities in ecosystems as intricate as coral reefs.

The MOSE (Experimental Electromechanical Module), consisting of rows of mobile gates can temporarily isolate the Venice lagoon from the Adriatic Sea during extreme high tides. To investigate how the lagoon ecosystem is affected by a prolonged segregation from the oxygenating seawater, we performed two enclosure experiments in July 2019 (48h) and October 2020 (28h) by artificially secluding small portions of the organic-enriched Palude di Cona area, using 18 mesocosms (~ 0.8 m 3 each). We followed the closure effects on planktonic and benthic communities at several trophic levels ( i.e. prokaryotes, microalgae, consumers). Our results suggest that the reduced hydrodynamics induced by the MOSE closure, leading to an enhanced deposition of the suspended material over time, affects the main biological processes and the pelagic-benthic coupling in the Venice lagoon. Over the summer experiment, the concentrations of N-NO 3 and N-NO 2 , and some phototrophic components and functions ( i.e. chl-a, Synechococcus , picoeukaryotes, primary production) in the water column were significantly reduced. The smallest phototrophs gradually settled towards the sediments, drastically diminishing their abundance, whereas the largest phytoplankton cells (dinoflagellates and diatoms) took advantage and increased their density during the experiment due to the significantly higher availability of N-NH 4 , deriving from the prompt degradation of organic matter. The higher Total Organic C content in surface sediments, deriving from the gradual sinking of suspended particulate organic matter, stimulated the microbial components and processes notably, both in the water column and in the sediments. In parallel, the higher availability of N-NH 4 stimulated the microphytobenthic abundance and benthic primary production. In the autumn experiment, most of the investigated variables displayed opposite patterns, likely ascribable to the different season and diverse meteorological conditions. Our holistic approach represents a reference to evaluate the impact of floodgates on coastal ecosystems, an increasingly frequent engineering solution around the world to rising sea levels.

Global change is rapidly altering temperature and light regimes in marine environments, yet the physiological responses of benthic primary producers to these shifts remain poorly understood. Red (Phyllophora), brown (Cystoseira) and green (Flabellia) macroalgae dominate distinct assemblages in the Mediterranean Sea and act as ecosystem engineers that overgrow rocky substrates or seagrass meadows. Their taxon-specific physiological responses to changing temperature and light levels may have long-lasting consequences on algal community composition and overall ecosystem functioning, but remain poorly understood. Here, we experimentally test how water temperature and light availability affect photosynthesis and respiration in these macroalgae using specimens collected on Giglio Island, Italy. We exposed different macroalgae to a full-factorial combination of three temperatures (21, 26, and 30 °C) and light intensity levels (180, 320, and 760 µM photons m− 2 s− 1) and measured oxygen fluxes to determine net photosynthesis (Pn) and respiration (R). Temperature and light both significantly influenced net photosynthesis, with marked taxon-specific responses. In Cystoseira, photosynthesis nearly ceased in high light and high temperature conditions, also indicated by a critically low photosynthesis to respiration (P:R) ratio. Flabellia and Phyllophora maintained more stable photosynthetic rates under medium light and temperature conditions and showed a moderate decline in their P: R ratios. Flabellia sustained slightly higher photosynthesis rates in high light and temperature conditions than Phyllophora and both significantly outperformed Cystoseira under maximal light and temperature conditions. Our findings suggest that under increasing temperature and light regimes, Cystoseira may decline, Phyllophora may persist, and Flabellia may even thrive. This may in turn degrade habitat complexity and affect coastal community assembly, as Flabellia, unlike the architecturally complex and persistent Cystoseira, does not form stable, three-dimensional habitats for associated organisms.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-28235-8.

Abstract Upwelling of hypolimnetic water in lakes is important for littoral food webs as it enhances production through nutrient subsidies to surface waters. The aim of this study was to understand the role of hypolimnetic upwelling on littoral nutrient supply and diet of a freshwater unionid mussel, kākahi ( Echyridella menziesii) in an oligotrophic lake using stable isotopes (δ 15 N) as a tracer of hypolimnetic nitrogen. Upwelling events can be highly variable spatially and temporally, so to complement observations, this study used a three-dimensional hydrodynamic model (AEM3D) to simulate the transport of water from upwelling events and understand their potential impacts on kākahi. The study was conducted over an annual cycle in a large (area 620 km 2 , average depth ~ 94 m), monomictic, oligotrophic New Zealand lake. The hydrodynamic model simulations showed a strong spatial gradient. Upwelling was strongest along north-facing areas of the western shoreline owing to the prevailing south-westerly winds. The spatio-temporal distribution of nitrate-δ 15 N within the littoral zone was positively related to the rate of simulated upwelling, indicating inputs of 15 N-enriched hypolimnetic water. Kākahi δ 15 N values were positively related to upwelling averaged over an annual period, demonstrating that upwelling hotspots are ecologically meaningful. Interestingly, littoral particulate organic matter δ 15 N showed no pattern with upwelling but were homogeneous in distribution, consistent with rapid flushing with offshore water. These findings suggest that benthic littoral habitats act as hotspots for nutrient subsidies to surface waters, and that the signature of 15 N is retained over periods far longer than the duration of the upwelling by cycling within benthic primary producers and consumers.

Increased allochthonous dissolved organic carbon provides a competitive advantage for planktonic over benthic primary producers in shallow lakes

Abstract Intraspecific variation modifies ecological processes and ecosystem functioning. Still, we know relatively little of how the nature and strength of ecosystem effects caused by intraspecific variation may interact with climate change. We conducted a mesocosm experiment to test if, and to what extent, ocean warming modifies the ecological impacts of intraspecific variation in a predatory fish. The mesocosms consisted of a simplified coastal food web with threespine stickleback (Gasterosteus aculeatus) as the top predator, from a population where two stickleback phenotypes with either complete or incomplete lateral armour plating coexist and display differentiated predation behaviour: The completely plated phenotype often feeds more on invertebrate herbivores compared with the incompletely plated phenotype. Presence of stickleback reduced biomass of arthropod shredders (crustaceans, insect larvae). Warming (+4°C) strengthened this predation, releasing benthic primary producers (diatoms) from top‐down control, causing a trophic cascade. This trophic cascade was attributed to one of the plate phenotypes: the completely plated stickleback increased their predation on shredders under warming, while the incompletely plated stickleback instead decreased their predation. Diatom biomass responded accordingly: warming increased diatom biomass in the presence of completely plated stickleback but not when incompletely plated stickleback was present. Our results suggest that different plate phenotypes of threespine stickleback differentially affect lower trophic levels and that warming may exacerbate these cascading effects. These trait‐dependent effects on trophic cascades highlight the consequences of intraspecific variation on ecosystem functioning. Read the free Plain Language Summary for this article on the Journal blog.

Shifting precipitation patterns associated with global climate change are significantly impacting lotic ecosystems worldwide. To understand how these changes influence stream fish community assembly, we conducted a space-for-time study under a steep natural rainfall gradient in the coastal plain region of Texas (USA). Leveraging multi-year intra-annual fish surveys and environmental data from nine streams, we assessed the effects of precipitation regime on functional diversity and trait distributions, focusing on the relative importance of environmental filtering, interspecific interaction, and individual environmental drivers. Fish communities transitioned from functionally underdispersed to overdispersed with increasing precipitation rate, suggesting that filtering was a key assembly mechanism in more arid communities, while species interaction played a more important role under wetter climates. Deviations in functional dispersion across the rainfall gradient were best explained by changes in relative distributions of traits (functional evenness) as opposed to losses or additions of traits (functional richness) between sites, and the best predictors of these deviations were mean annual rainfall, low-flow frequency, and prevalence of hypoxic conditions. Proportional abundances of hypoxia-tolerant, herbivorous taxa within communities were associated mainly with the same predictors, illustrating the importance of these fishes’ increasing prevalence with increased aridity. Relationships between their abundances and benthic primary producer densities may also point to changes in grazing pressure, possibly stemming from top-down trophic processes. The shift from communities with low functional diversity dominated by hypoxia-tolerant, herbivorous taxa to more diverse assemblages as rainfall rates increased was non-linear, which may represent an important precipitation-driven threshold in community assembly. Our observations across this spatial rainfall gradient may translate to similar community-level changes in lotic ecosystems experiencing temporally shifting precipitation patterns, ultimately leading to increased understanding of relationships between functional trait distributions and climate, as well as providing valuable knowledge for predicting the impacts of changing precipitation regimes in freshwater ecosystems worldwide.

Rice fields are one of the most important agricultural environments in Northern Italy. These agroecosystems are characterized by high variations in water temperature, shading by rice plants, and sporadic droughts that affect the life of aquatic organisms. In the present study, we carried out an analysis within the limits of two rice fields and their water supply canal in the Lomellina (Lombardy; NW Italy). The aims of this study were (1) to quantify the main benthic primary producers colonizing the two rice fields and their feeding canal, focusing on diatoms, green algae, and cyanobacteria; and (2) to shed light on the taxonomic and functional composition of diatom communities living in these three environments. The study was conducted during the spring and summer 2023, corresponding to the growth phases of rice plants and the peak of diatom primary productivity. A total of 54 samples were collected from these three environments, by using artificial substrates. Diatoms dominated the canal channeling water to the rice fields, while diatoms and cyanobacteria were co-present in the two rice fields. Among the diatoms, low-profile and motile guilds were dominant in the water canal while, to the contrary, we observed a higher percentage of motile tolerant species in the rice fields, such as Navicula veneta, Nitzschia amphibia and Planothidiun incuriatum, a recently described species. The analysis of the microalgae communities can be useful to define the proper management of wetland-like environments and the conservation of their biodiversity.

Climate change is driving many species to shift their geographical ranges poleward to maintain their environmental niche. However, for endemic species with restricted ranges, like the Critically Endangered whitefin swellshark (Cephaloscyllium albipinnum), endemic to southeastern Australia, such dispersal may be limited. Nevertheless, there is a poor understanding of how C. albipinnum might spatially adjust its distribution in response to climate change or whether suitable refugia exist for this species in the future. Therefore, to address this gap, this study utilised maximum entropy (MaxEnt) modelling to determine the potential distribution of suitable habitat for C. albipinnum under present-day (2010-2020) climate conditions and for future conditions, under six shared socioeconomic pathways (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-6.0 and SSP5-8.5) for the middle (2040-2050) and end (2090-2100) of the century. Under present-day conditions (2010-2020), our model predicted a core distribution of potentially suitable habitat for C. albipinnum within the Great Australian Bight (GAB), with benthic primary productivity and surface ocean temperature identified as key distribution drivers. However, under all SSP scenarios, future projections indicated an expected range shift of at least 72 km, up to 1,087 km in an east-southeast direction towards Tasmania (TAS). In all future climate scenarios (except SSP1-1.9 by 2100), suitable habitat is expected to decline, especially in the high-emission scenario (SSP5-8.5), which anticipates a loss of over 70% of suitable habitat. Consequently, all future climate scenarios (except SSP1-1.9 by 2100) projected a decrease in suitable habitat within a currently designated marine protected area (MPA). These losses ranged from 0.6% under SSP1-1.9 by 2050 to a substantial 89.7% loss in coverage under SSP5-8.5 by 2100, leaving just 2.5% of suitable habitat remaining within MPAs. With C. albipinnum already facing a high risk of extinction, these findings underscore its vulnerability to future climate change. Our results highlight the urgency of implementing adaptive conservation measures and management strategies that consider the impacts of climate change on this species.

IntroductionNon-native species are widely recognized as threats to biodiversity, ecosystems, and the services they provide to humans. The Mediterranean Sea has a high biodiversity of endemic species and is a hot spot of biological invasions. One of the most recent threats to Mediterranean ecosystems is the invasion of the Atlantic blue crab Callinectes sapidus.MethodsThe occurrences of the crab throughout the Mediterranean coastline were indexed from citizen science through the Global Biodiversity Information Facility. Using spatial analysis and linear mixed models, we investigated geomorphology (i.e., water depth and coastal wetlands extension), water physical variables (i.e., salinity and winter and summer water temperature), water quality variables (i.e., chlorophyll-a, nitrate and orthophosphate) and anthropogenic factors (i.e., ship density and population size) potentially affecting the blue crab occurrence along the coast.ResultsOur results showed that nitrate, as an indicator of riverine nutrient loading, and water depth, as an indicator of slope of the bottom, were the most influential variables in explaining the occurrences of blue crabs. Water temperature and salinity had lesser impacts; anthropogenic factors, such as the density of commercial marine traffic and human population size had no effect on blue crab occurrence.DiscussionThese results sug gest that benthic primary production and shallow water drive blue crab occurrences along the Mediterranean coasts. Even considering data limitations and gaps, our large-scale findings contribute to a broader understanding of the factors that drive blue crab invasion success which, in turn, can inform management actions and outline research needs.

ABSTRACTKelp forests are dynamic coastal habitats that generate large amounts of carbon‐rich detritus. The fate of this detritus is largely unknown and considered a missing link in global carbon budgets. Kelp detritus can serve as food for benthic invertebrates and pelagic invertebrate larvae, but we know close to nothing about the role of kelp detritus as food for other zooplankton. We conducted feeding experiments to test if the highly abundant pelagic copepod Calanus finmarchicus can feed on fragments of two dominant kelp species, Saccharina latissima and Laminaria hyperborea. A series of experiments including particle ingestion, fecal pellet production, and DNA tracing tended to support the hypothesis that C. finmarchicus can feed on kelp particles of both species, but at a reduced rate relative to when on a regular phytoplankton diet. Moreover, the results provide initial evidence that L. hyperborea contains substances that are toxic to copepods, an observation that warrants further research. Pelagic copepods consuming kelp detritus would constitute a largely undescribed pathway of carbon from benthic primary producers to the pelagic food web, and a trajectory for deep‐sea carbon sequestration. We hope these preliminary results will inspire future studies on the role of pelagic filter feeders in carbon transport and turnover from macroalgae habitats.

The West Antarctic Peninsula (WAP) is a hotspot of climate warming, evidencing glacier retreat and a decrease in the fast-ice duration. This study provides a>30-y time-series (1987-2022) on annual and seasonal air temperatures in Potter Cove (Isla 25 de Mayo/King George Island). It investigates the interaction between warming, glacial melt, fast-ice and the underwater conditions (light, salinity, temperature, turbidity) over a period of 10years along the fjord axis (2010-2019), and for the first time provides a unique continuous underwater irradiance time series over 5years (2014-2018). The effects on the annual light budget in the water column were studied along the fjord axis in three areas, a low glacier influence area (LGI), an intermediate glacier influence area (IGI), and a high glacier influence area (HGI). To determine the possible impact of light limitation on the viability of benthic primary producers, the minimum annual light requirements and the daily metabolic carbon balance of two key macroalgal Antarctic species, Himantothallus grandifolius and Palmaria decipiens, were estimated. The mean annual, autumn, winter and spring air temperature has risen during the last three decades, but summer temperatures kept rather stable. Turbidity caused by glacial melt mostly governs the underwater light climate while fast-ice duration is currently of minor importance for the annual light budget. Glacier melting differentially affected the fjord system along its axis. The three areas showed quantitative differences in turbidity and underwater irradiance varying across seasons and years. Water clarity significantly decreased within the last few years, with key macroalgal species probably not reaching their minimum annual light requirements during warmer years. This may have considerable effects on the primary productivity of the ecosystem.

Dissolved organic matter (DOM) released by benthic primary producers fuels coral reef food webs. Anthropogenic stressors cause shifts from coral to algae dominance on many reefs, and resulting alterations in the DOM pool can promote opportunistic microbes and potential coral pathogens in reef water. To better understand these DOM-induced effects on bacterioplankton communities, we compared the carbohydrate composition of coral- and macroalgae-DOM and analyzed the response of bacterioplankton from an algae-dominated reef to these DOM types. In line with the proposed microbialization of reefs, coral-DOM was efficiently utilized, promoting energy transfer to higher trophic levels, whereas macroalgae-DOM likely stimulated microbial respiration over biomass production. Contrary to earlier findings, coral- and not algal-DOM selected for opportunistic microbial taxa, indicating that a change in the prevalent DOM composition, and not DOM type, may promote the rise of opportunistic microbes. Presented results may also apply to other coastal marine ecosystems undergoing benthic community shifts.

Coastal darkening is expected to have pervasive impacts on benthic primary producers. However, the effects of nitrogen enrichment, an often-co-occurring stressor, on benthic primary producers and their functions is less clear. This study investigates the interactive effects of coastal darkening and nitrogenous eutrophication, including nitrogen source (NH4+ vs. NO3−), on the function of the kelp Ecklonia radiata. First, an in-situ experiment was used to assess the differential impacts of NH4+ and NO3− pulse enrichment on the photosynthetic performance and pH modulation capacity of E. radiata. Second, a laboratory experiment was used to assess the longer-term impacts of nitrogen enrichment under low-light conditions mimicking coastal darkening on service provisioning, including photosynthetic performance, pH modulation, nutrient uptake and growth. While pulse nitrogen enrichment had no impacts on the photosynthetic performance of E. radiata in-situ, persistent exposure to either NH4+ or NO3− acted as a stressor to sporophytes as indicated by elevated rates of dark respiration and lamina erosion and reduced photosynthetic efficiency and growth rates. Furthermore, low-light conditions elicited reduced photosynthetic capacity at saturating irradiance, which extended to a reduction in the extent of pH modulation, and significantly increased lamina erosion. While the two stressors appeared to act on distinct parameters, ultimately, both darkening and eutrophication directly reduced net primary production, especially when in combination. These results demonstrate the negative interactive effects of coastal darkening and eutrophication on E. radiata function, while suggesting a vulnerability of E. radiata to even moderate levels of persistent nitrogen enrichment. This vulnerability highlights the need to consider environmental conditions during kelp conservation and restoration, and when attempting to valorise kelp ecophysiology for nature-based solutions.

The Yellow Sea is one of the most thoroughly studied shelf seas in the northwestern Pacific. However, many aspects of the northern Yellow Sea sediments remain poorly understood. Sedimentary chloropigments and total organic carbon (TOC) are crucial components that indicate benthic primary productivity and ecosystem functioning in the marginal sea system. The present study investigated the temporal and spatial variations of sediment chloroplastic pigments (Chl-a and Pha-a) and TOC contents in relation to seasons and the northern Yellow Sea Cold Water Mass (NYSCWM). Decadal trends were also examined using linear regression on time-series data from 12 cruises conducted over a nine-year period (2006–2014). The correlations between sedimentary Chorophy-a (Chl-a), Pheophorbide-a (Pha-a), TOC, and their ratios with other abiotic and biotic factors were analyzed to detect any effects of the NYSCWM on the spatiotemporal distribution of sediment Chl-a, Pha-a, TOC contents, as well as the ecological relevance of their ratios as indicators of food quality (freshness) in the benthic system. The NYSCWM substantially influences the spatial and seasonal distribution of sedimentary Chl-a, Pha-a, and TOC contents. High values of Pha-a, TOC, and the ratios of Pha-a/(Chl-a + Pha-a) and TOC/Chl-a were often observed in the central region of the NYSCWM, where Chl-a showed clear seasonal fluctuations while Pha-a and TOC remained relatively constant. While sedimentary TOC appears to negatively mirror the spatial pattern of primary productivity in the water column, the spatial pattern of sedimentary Chl-a in relation to NYSCWM is less evident. However, the contents of Pha-a and TOC in the central NYSCWM sediments were higher than those at surrounding NYSCWM stations. Surface sediment Pha-a/(Chl-a + Pha-a) ratio was negatively correlated with meiofauna abundance and biomass and positively correlated with nematode/copepod ratio. This finding indicates that the quality of sediment organic matter is important to meiofauna. Conversely, the lower organic degradation rate at the lower bottom temperature of the NYSCWM may explain the observed higher Pha-a and TOC contents in its central area. Time-series data collected over nine years at the NYSCWM stations showed a decreasing trend for Chl-a, while TOC and the ratio of Pha-a/(Chl-a + Pha-a) exhibited increasing tendencies. This trend may imply a reduced quality of food supply to the benthic food web in the shelf sea system, along with degraded ecosystem functioning and service under the impacts of global change and anthropogenic disturbances.

The carbon acquisition strategies of aquatic photosynthetic organisms play a key role in the growth and survival of a species. There is much research indicating that the predicted changes (e.g., the balance between carbonate species: CO2, HCO3-, and CO32-) in the seawater carbonate chemistry, due to ocean acidification, could affect benthic primary producers and their communities. However, considerably less is known about brackish water (e.g., the Baltic Sea), and even less about the possible effects of acidification on freshwater biota. This study aimed to compare the carbon uptake strategies of two dominant charophyte species: Chara aspera and Chara tomentosa growing in freshwater lakes of Estonia and in the brackish NE Baltic Sea. This could indicate how they might respond to the predicted increasing CO2 concentration linked to climate change scenrios. Carbon use strategies in charophytes were determined by analysing natural carbon isotope signatures (δ13C), pH drift experiments and photosynthesis vs. dissolved inorganic carbon curves. The study showed that freshwater and brackish water C. aspera and C. tomentosa likely use different carbon uptake mechanisms. Our results indicated that freshwater charophytes preferentially use CO2 and brackish water charophytes HCO3-, likely due to their local acclimatization to different growth environments. Also, C. tomentosa and C. aspera from the studied lakes are likely carbon saturated (photosynthetic processes are operating at their maximum efficiency due to the availability of dissolved inorganic carbon in their environment) and probably will not gain photosynthetic advantages from acidification. However, the predicted increase in CO2 concentration may positively affect the growth of the charophytes in the brackish Baltic Sea.

Progressive enrichment of benthic primary producer and dreissenid δ15N with depth in Lakes Erie and Ontario

In a global context of invasive alien species (IAS), native predators are often eradicated by functionally different IAS, which may induce complex cascading consequences on ecosystem functioning because of the key role predators play in structuring communities and stabilizing food webs. In permanent ponds, the most abundant freshwater systems on Earth, global human-mediated introductions of alien omnivores such as the pet trade goldfish are driving broad-scale patterns of native predators' exclusion, but cascading consequences on food web structure and functioning are critically understudied. We compared food webs of naturally fishless ponds versus ponds where dominant native predators (newts) had been extirpated by invasive goldfish within the last decade. Integrating community-wide isotopic, taxonomic and functional traits approaches, our study reveals that pond food webs collapsed in both vertical and horizontal dimensions following goldfish introduction and the associated exclusion of native predators. Consumer taxonomic diversity was drastically reduced, essentially deprived of amphibians as well as predatory and mobile macroinvertebrates to the profit of burrowing, lower trophic level consumers (detritivores). Changes in community structure and function underlined a regime shift from a macrophyte-dominated system mainly characterized by benthic primary production (periphyton), to a macrophyte-depleted state of ponds hosting communities mainly associated with phytoplankton primary production and detritus accumulation, with higher tolerance to eutrophication and low dissolved oxygen concentration. Results underline major impacts of widely introduced omnivores such as the goldfish on the functioning of pond ecosystems with potentially dramatic consequences on the key ecosystem services they deliver, such as global biodiversity support or water quality improvement. They also shed light on the key role of submerged aquatic vegetation in supporting diverse communities and complex food webs in shallow lentic systems and call for urgent consideration of threats posed by IAS on ponds' ecosystems by managers and policymakers.

Abstract Benthic primary producers (BPP) in inland waters, including aquatic macrophytes and periphyton, are foundational habitats that are highly sensitive to multiple human drivers of environmental change. However, long‐term seasonal monitoring of BPP is limited, leaving us with little information on the cause, directionality, and consequences of the potential shifts in timing of BPP life cycle events. Here, we review the literature on the phenological changes of BPP and show that BPP respond primarily to temperature, but also to other interactive drivers related to climate change and eutrophication. In addition, we present four rare case studies where BPP display strong and earlier shifts in event timing associated with increasing temperature and discuss potential impacts of these changes on ecosystem functioning. Given the responsive nature of BPP to multiple human drivers, we provide suggestions on how to improve basic monitoring to better understand the future impact of phenological changes of this critical habitat.