Journal articles: 'Aquatic consumers'

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Possamai, B., DJ Hoeinghaus, and AM Garcia. "Shifting baselines: Integrating ecological and isotopic time lags improves trophic position estimates in aquatic consumers." Marine Ecology Progress Series 666 (May 20, 2021): 19–30. http://dx.doi.org/10.3354/meps13682.

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Nitrogen stable isotope ratios (δ15N) are routinely used to estimate consumer trophic positions (TPs). This method is very sensitive to the chosen isotopic baseline, which should incorporate all temporal isotopic variability occurring in the base of the food web sustaining the consumers. However, there is still no consensus on the different methods to represent time intervals for isotopic assimilation. It is uncertain if researchers should compute a single baseline obtained by averaging δ15N source values across all time periods, multiple baselines based on δ15N source values collected concomitantly with consumers, or consider a time lag between sources and consumers. Aiming to provide empirical evidence to help select the best option, we designed 4 methods using different temporal lags between consumers and producers based on a 9 yr time series of carbon and nitrogen stable isotopes in an estuary. The 4 tested baseline methods considered the δ15N average of producers sampled in all years (Global); the same season as consumers (Concomitantly); the season before the collection of consumers (Delayed); and the previous season as well as the same season of consumer sampling (Interpolation). Comparison of results with an expected model (based on stomach content data) showed that the Delayed method is the most appropriate. We conclude that time lags in the incorporation of stable isotope values between sources and consumers must be considered in baseline δ15N calculations to improve TP estimates and provide more reliable modeling results. Additionally, we provide other recommendations to improve sampling designs when using stable isotopes in TP estimations.

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Zanden, M. Jake Vander, and Joseph B. Rasmussen. "PRIMARY CONSUMER δ13C AND δ15N AND THE TROPHIC POSITION OF AQUATIC CONSUMERS." Ecology 80, no. 4 (June 1999): 1395–404. http://dx.doi.org/10.1890/0012-9658(1999)080[1395:pccana]2.0.co;2.

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Budhathoki, Mausam, Danny Campbell, Ben Belton, Richard Newton, Saihong Li, Wenbo Zhang, and David Little. "Factors Influencing Consumption Behaviour towards Aquatic Food among Asian Consumers: A Systematic Scoping Review." Foods 11, no. 24 (December 14, 2022): 4043. http://dx.doi.org/10.3390/foods11244043.

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Asia accounts for over 70% of total global aquatic food consumption, but aquatic food consumption behaviours and attitudes among Asian consumers are poorly documented and understood. This paper synthesises literature on factors influencing aquatic food consumption behaviour in Asia and the potential to support transitions toward more sustainable food consumption patterns. We identified 113 studies for inclusion in a scoping review, and identified five clusters of publications: (1) product attributes, availability, and accessibility (24% of publications); (2) willingness to pay for aquatic foods (25%); (3) psychosocial factors (e.g., attitudes and subjective norms) (17%); (4) sociodemographic and lifestyle factors (21%); and (5) miscellaneous factors, including food safety and social status (13%). This study indicates that multiple interacting factors influence aquatic food consumption behaviours among Asian consumers, among which price is central. Knowledge of, and attitudes toward, the perceived quality and safety of aquatic foods were identified as important but were mediated by household characteristics. Sustainable production practices, country of origin, and ecolabels were found to be less influential on consumption behaviour. We found that improving consumers’ knowledge and attitudes about the quality and safety of aquatic foods might positively influence aquatic food consumption behaviour. Future multidisciplinary research is required to better understand interactions among the multiple factors that influence Asian consumers’ aquatic food consumption behaviour.

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McCaffery, Magnus, and Lisa Eby. "Beaver activity increases aquatic subsidies to terrestrial consumers." Freshwater Biology 61, no. 4 (February 1, 2016): 518–32. http://dx.doi.org/10.1111/fwb.12725.

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Garcia, Alexandre M., David J. Hoeinghaus, João P. Vieira, Kirk O. Winemiller, David M. L. Motta Marques, and Marlise A. Bemvenuti. "Preliminary examination of food web structure of Nicola Lake (Taim Hydrological System, south Brazil) using dual C and N stable isotope analyses." Neotropical Ichthyology 4, no. 2 (June 2006): 279–84. http://dx.doi.org/10.1590/s1679-62252006000200014.

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Taim Ecological Reserve is located within the Taim Hydrological System and was created to protect a heterogeneous and productive landscape harboring exceptional biological diversity in southern Brazil. Using stable isotope ratio analyses of carbon (delta13C) and nitrogen (delta15N), we provide a preliminary description of the food web structure, including estimates of production sources supporting fish populations and vertical trophic structure, within a representative lake of this system. A total of 21 organisms (5 macrophytes, 3 mollusks and 13 adult fishes) representing 16 species were collected for isotope analysis. Fishes had delta13C values ranging from -24.30º/oo to -28.31º/oo , showing concordance with the range of values observed for macrophytes (-25.49 to -27.10º/oo), and suggesting that these plants could be a major carbon source supporting these fishes. delta13C signatures of Corbicula (-30.81º/oo) and Pomacea (-24.26º/oo) indirectly suggest that phytoplankton and benthic algae could be alternative carbon sources for some consumers. Nitrogen isotope ratios indicated approximately three consumer trophic levels. The pearl cichlid Geophagus brasiliensis was a primary consumer. Two catfishes (Trachelyopterus lucenai and Loricariichthys anus) were secondary consumers. Two congeneric pike cichclids (Crenicichla lepidota and C. punctata), a catfish (Pimelodus maculatus) and the characids Astyanax fasciatus and Oligosarcus robustus were tertiary consumers. Further studies including additional primary producers and consumers and greater sample numbers should be conducted to provide a more complete and detailed description of food web structure and dynamics within the reserve.

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Vander Zanden, M. J., G. Cabana, and J. B. Rasmussen. "Comparing trophic position of freshwater fish calculated using stable nitrogen isotope ratios (δ15N) and literature dietary data." Canadian Journal of Fisheries and Aquatic Sciences 54, no. 5 (May 1, 1997): 1142–58. http://dx.doi.org/10.1139/f97-016.

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Stable nitrogen isotope ratios ( delta 15N) are commonly used to represent the trophic structure of aquatic systems, yet the ability of delta 15N to indicate the trophic position of aquatic consumers remains untested using traditional dietary methods. Interpreting the delta 15N of aquatic consumers relative to large, long-lived primary consumers such as unionid mussels provides a continuous measure of an organism's trophic position that adjusts for among-system variation in baseline delta 15N. We used this method to estimate the trophic position of eight littoral fish species from 36 lakes in Ontario and Quebec. We validated these delta 15N measures of trophic position by compiling literature dietary data from 342 populations of these same fish species and calculated a continuous measure of trophic position for each population. Mean dietary trophic position estimates corresponded closely to 15N estimates, with mean trophic position ranging from 3.3 for pumpkinseed (Lepomis gobbosus) to 4.4 for walleye (Stizostedion vitreum). Both methods indicated approximately one trophic level of variation among populations of a species. This study confirms the ability of baseline-adjusted delta 15N to represent the trophic position of aquatic consumers.

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Malik, Tariq H., and Jae Chul Choi. "Social Media Versus Personal Experience in the Consumer’s Apprehension on Imported Food Security and Safety Dilemma." SAGE Open 11, no. 2 (April 2021): 215824402110074. http://dx.doi.org/10.1177/21582440211007486.

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South Korea imports a large amount of agricultural and aquatic food products from China, which meets its food security. However, the import from China raises food safety questions, leading to food safety apprehension. We explored the source of the Korean consumer’s apprehension. Based on the apprehension reduction theory (ART) developed from interviews with Korean consumers in the first stage of the study, we conducted a survey to assess the social media as an indirect source of information and direct experience of the consumer in the second stage of the study. We received 504 responses, of which 1/3 of the respondents had visited China in the last year. Using FSS (Food Safety Satisfaction) as the dependent variable (1— low to 5— high), we link information from the social media vis-à-vis direct experience and made three discoveries. (a) The information quantity of social media increases the consumer’s apprehension, partially refuting the ART. (ii) FSS increased in response to information flow from the direct experience of the consumer with Chinese imported food. (c) The direct information from experience mediates the effects of indirect information (social media) on apprehension about agricultural and aquatic product imports. We made three inferences. First, information quantity and quality have separated roles in the ART. Second, social media increases the free-market style information flow, turning legitimate products to illegitimate and vice versa. Third, the collective irrationality from the information quantity needs institutional bricolage to legitimize the chaotic nature of the untamed information.

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Smith, Val H. "Competition between consumers." Limnology and Oceanography 36, no. 4 (June 1991): 820–23. http://dx.doi.org/10.4319/lo.1991.36.4.0820.

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9

Bennett, Abigail, Emma Rice, Park Muhonda, Emmanuel Kaunda, Sam Katengeza, Lenis Saweda O. Liverpool-Tasie, Ben Belton, et al. "Spatial analysis of aquatic food access can inform nutrition-sensitive policy." Nature Food 3, no. 12 (December 15, 2022): 1010–13. http://dx.doi.org/10.1038/s43016-022-00642-4.

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AbstractAquatic foods are critical for food and nutrition security in Malawi, but it is unclear which populations benefit from different aquatic foods and what factors shape food access. Spatial analysis of food flows across value chains from Lake Malawi to domestic consumers shows that usipa (Engraulicypris sardella) reaches more consumers than chambo (Oreochromis karongae) across all Malawi districts, particularly rural populations. Higher number of markets, nutrient content, and overall supply coupled with lower retail prices and volumes make usipa more accessible to consumers than chambo. Spatial analysis of food flows can guide policymakers towards supporting fisheries that reach vulnerable populations and designing interventions that enhance physical and economic access to fish.

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Ebm, Nadine, Fen Guo, Michael T. Brett, Stuart E. Bunn, and Martin J. Kainz. "Polyunsaturated fatty acids in fish tissues more closely resemble algal than terrestrial diet sources." Hydrobiologia 848, no. 2 (November 16, 2020): 371–83. http://dx.doi.org/10.1007/s10750-020-04445-1.

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AbstractThe River Continuum Concept implies that consumers in headwater streams have greater dietary access to terrestrial basal resources, but recent studies have highlighted the dietary importance of high-quality algae. Algae provide consumers with physiologically important omega-3 (n-3) polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA). However, terrestrial plants and most benthic stream algae lack the long-chain (LC) n-3 PUFA docosahexaenoic acid (DHA, 22:6n-3), which is essential for neural development in fish and other vertebrates. We sampled subalpine streams to investigate how the PUFA composition of neural (brain and eyes), muscle, and liver tissues of freshwater fish is related to their potential diets (macroinvertebrates, epilithon, fresh and conditioned terrestrial leaves). The PUFA composition of consumers was more similar to epilithon than to terrestrial leaves. Storage lipids of eyes most closely resembled dietary PUFA (aquatic invertebrates and algae). However, DHA and arachidonic acid (ARA, 20:4n-6) were not directly available in the diet but abundant in organs. This implies that algal PUFA were selectively retained or were produced internally via enzymatic PUFA conversion by aquatic consumers. This field study demonstrates the nutritional importance of algal PUFA for neural organs in aquatic consumers of headwater regions.

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Twining, Cornelia W., J. Thomas Brenna, Peter Lawrence, David W. Winkler, Alexander S. Flecker, and Nelson G. Hairston. "Aquatic and terrestrial resources are not nutritionally reciprocal for consumers." Functional Ecology 33, no. 10 (July 19, 2019): 2042–52. http://dx.doi.org/10.1111/1365-2435.13401.

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12

Frost, Paul C., Jonathan P. Benstead, Wyatt F. Cross, Helmut Hillebrand, James H. Larson, Marguerite A. Xenopoulos, and Takehito Yoshida. "Threshold elemental ratios of carbon and phosphorus in aquatic consumers." Ecology Letters 9, no. 7 (July 2006): 774–79. http://dx.doi.org/10.1111/j.1461-0248.2006.00919.x.

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13

Richardson, William B., and Stephen T. Threlkeld. "Complex Interactions of Multiple Aquatic Consumers: An Experimental Mesocosm Manipulation." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 1 (January 1, 1993): 29–42. http://dx.doi.org/10.1139/f93-004.

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In 7-m3 outdoor tanks filled with lake water, the presence/absence of omnivorous young-of-the-year Micropterus salmoides, zooplanktivorous Menidia beryllina, and herbivorous larval Hyla chrysocelis was experimentally manipulated. A cross-classified design was used to assess the interactive effects of these vertebrate consumers on the experimental food webs. Large zooplankters and large, actively swimming macroinvertebrates (Ceriodaphnia, Simocephalus, Corixidae, Notonectidae, and Dytiscidae) were particularly susceptible to depletion by both fish species. Micropterus tanks contained greater numbers of Keratella quadrata and Hebridae but fewer benthic cyclopoid copepods. Menidia tanks contained more Synedra and algal filaments. Hyla exerted only minor direct effects on the tank communities. When both fish species were in the same tank, both had elevated mortality. Micropterus, in tanks with Menidia and Hyla, were larger and in better condition than in tanks without Hyla. The primary effects of the experimental manipulations on food web components were two- and three-way interactions in which the effect of a given treatment was dependent on the presence of another treatment. Results suggest that the addition or removal of consumers may not cause linear, additive changes in food webs.

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Galloway, Aaron W. E., and Suzanne M. Budge. "The critical importance of experimentation in biomarker-based trophic ecology." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1804 (June 15, 2020): 20190638. http://dx.doi.org/10.1098/rstb.2019.0638.

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Fatty acids are commonly used as biomarkers for making inferences about trophic relationships in aquatic and soil food webs. However, researchers are often unaware of the physiological constraints within organisms on the trophic transfer and modification of dietary biomarkers in consumers. Fatty acids are bioactive molecules, which have diverse structures and functions that both complicate and enhance their value as trophic tracers. For instance, consumers may synthesize confounding non-dietary sourced markers from precursor molecules, and environmental conditions also affect fatty acid composition. There is a vital need for more research on the uptake and transfer of trophic biomarkers in individual organisms in order to advance the field and make meaningful use of these tools at the scale of populations or ecosystems. This special issue is focused on controlled feeding experiments on a diverse taxonomic breadth of model consumers from freshwater, marine and soil ecosystems with a goal of creating a more integrated understanding of the connection between consumer physiology and trophic ecology. This article is part of the theme issue ‘The next horizons for lipids as ‘trophic biomarkers’: evidence and significance of consumer modification of dietary fatty acids'.

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Bishop, Bradley Wade, Carolyn F. Hank, and Joel T. Webster. "The Data Life Aquatic." International Journal of Digital Curation 16, no. 1 (January 5, 2022): 10. http://dx.doi.org/10.2218/ijdc.v16i1.635.

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This paper assesses data consumers’ perspectives on the interoperable and re-usable aspects of the FAIR Data Principles. Taking a domain-specific informatics approach, ten oceanographers were asked to think of a recent search for data and describe their process of discovery, evaluation, and use. The interview schedule, derived from the FAIR Data Principles, included questions about the interoperability and re-usability of data. Through this critical incident technique, findings on data interoperability and re-usability give data curators valuable insights into how real-world users access, evaluate, and use data. Results from this study show that oceanographers utilize tools that make re-use simple, with interoperability seamless within the systems used. The processes employed by oceanographers present a good baseline for other domains adopting the FAIR Data Principles.

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Da Silva, Vicente De Paulo Rodrigues, Kettrin Farias Bem Maracajá, Lincoln Eloi De Araújo, José Dantas Neto, Danilo De Oliveira Aleixo, and João Hugo Baracuy da Cunha Campos. "Water footprint of individuals with different diet patterns." Ambiente e Agua - An Interdisciplinary Journal of Applied Science 8, no. 1 (April 26, 2013): 250. http://dx.doi.org/10.4136/ambi-agua.967.

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The “water footprint” (WF) concept has been recently introduced as an important indicator of human water consumption. WF is defined as the total volume of water used during the production and consumption of goods and services as well as of direct water consumption by humans. The objective of this work was to use the WF concept to analyze vegetarian and non-vegetarian consumers with different levels of family income. A case study was conducted with residents of Caicó city (Brazil) in order to estimate total amount of water consumed or polluted while producing the goods and services utilized by these consumers. The results indicated that, on average, the WF of the vegetarian consumer represents 58% of non- vegetarian consumers. The WF of the non-vegetarian female consumer was 10-13% smaller than that of the male consumer while for vegetarian consumers the female’s WF was only 5.8% less than the male’s. The WF of the consumer increases linearly with the family income. A population’s water footprint increases as a function of family income and decreases according to eating habits.

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Huang, I.-Yu, Yao-Sung Lin, Chang-Po Chen, and Hwey-Lian Hsieh. "Food web structure of a subtropical headwater stream." Marine and Freshwater Research 58, no. 7 (2007): 596. http://dx.doi.org/10.1071/mf06127.

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The food web structure of a headwater stream (Hapen Creek) in subtropical northern Taiwan, which is subject to regular typhoon disturbances, was characterised using stable isotope techniques. δ13C and δ15N signatures were used to examine (i) the relative contributions of allochthonous versus. autochthonous sources to the web, and (ii) the trophic organisation of the community including the predominant feeding guilds and the most prevalent feeding mode. This study presents food web attributes for one of the very few food webs studied to date in a subtropical region. Consumers utilised allochthonous and autochthonous carbon sources differently depending on their trophic positions. The majority of consumers exploited more autochthonous carbon sources. Consumers at higher trophic positions in the food web had more direct and greater association with benthic algae. Higher-order consumers also consumed allochthonous carbon in an indirect manner by assimilating lower-order insects. The results reveal the importance of invertebrate consumer snails and aquatic insects in the transfer of organic matter. Omnivores predominated in the food web; this may reflect an opportunistic foraging strategy that enables them to adapt to hydrological disturbances and a fluctuating food supply.

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Anderson, Caroline, and Gilbert Cabana. "δ15N in riverine food webs: effects of N inputs from agricultural watersheds." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 2 (February 1, 2005): 333–40. http://dx.doi.org/10.1139/f04-191.

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We examined the use of the natural abundance of nitrogen stable isotopes (δ15N) as a tracer of anthropo genic perturbations of the nitrogen (N) cycle at the watershed scale in 82 river sites draining 13 watersheds in the St. Lawrence Lowlands in Quebec. Mean δ15N values of aquatic primary consumers varied greatly among sites (+2 to +15), most of this variation (88%) being attributable to site effects. Variation in δ15N values among functional feeding groups of primary consumers within sites was comparatively lower (<1). Within watersheds, δ15N values of primary consumers (and organisms of higher trophic levels) tracked longitudinal changes in the percentage of agricultural area. Overall, the percentage of total watershed area under agriculture explained up to 69% of the variation in mean primary consumer δ15N values. Similar positive correlations were observed for predatory invertebrates and non-piscivorous fish. In general, our results show that δ15N in riverine food webs reacts strongly to spatial patterns in the intensity of N inputs related to agricultural land use.

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Kang, Chang-Keun, Hyun-Woo Kim, Hyun Je Park, and Chung Il Lee. "Sharing Scientific Evidence of the Response of Aquatic Animals to Environmental Change." Fishes 8, no. 1 (January 5, 2023): 40. http://dx.doi.org/10.3390/fishes8010040.

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Aquatic animals, which are ecologically important consumers in aquatic ecosystems and widely distributed in rivers, lakes, and seas, which occupy 70% of the earth’s surface, respond in unique ways to environmental changes at various temporal and spatial scales, and have optimized strategies for survival [...]

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Herwig, Brian R., David H. Wahl, John M. Dettmers, and Daniel A. Soluk. "Spatial and temporal patterns in the food web structure of a large floodplain river assessed using stable isotopes." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 3 (March 1, 2007): 495–508. http://dx.doi.org/10.1139/f07-023.

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We assessed naturally occurring stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) for available food resources and consumers in the mainstream channel of the Mississippi River. Isotopic ratios were assessed for organic sources and organisms at two different sites during a fall, spring, and two summer seasons. Terrestrial C4 plants did not appear to be an important carbon source for consumers in the mainstream channel. A mixing model, IsoSource, indicated that terrestrial C3 vegetation, suspended algae, and epixylon were at times important food resources for large river consumers. Many consumer signatures fell outside the mixing polygon defined by these sources, indicating that there was a 13C-depleted food resource for which we did not account. We could not distinguish precisely whether downstream allochthonous and autochthonous carbon, or in situ production, was the dominant food resource supporting consumers in these systems. However, our data suggest that in situ organic matter sources can be important. Consumer δ13C and δ15N signatures intermediate between several sources indicated widespread omnivory in the river reaches that we studied. To fully understand food web structure and energy sources in complex large river ecosystems, an integrative approach that combines related empirical data sets is needed.

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Shen, Xin, Xun Cao, Sonia Sadeghian Esfahani, and Tayyaba Saleem. "Factors Influencing Consumers’ Purchase Intention on Cold Chain Aquatic Products under COVID-19: An Investigation in China." International Journal of Environmental Research and Public Health 19, no. 8 (April 18, 2022): 4903. http://dx.doi.org/10.3390/ijerph19084903.

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Following the detection of COVID-19 in cold chain aquatic products (CCAP) at Xinfadi Produce Wholesale Market in Beijing, China, in June 2020, novel coronavirus positive tests of CCAP have been reported in such markets of Dalian, Xi’an, Qingdao, Taiyuan, and other places, which has aroused the concern of Chinese consumers. The CCAP outbreak puts tremendous pressure on public health management and threatens customer well-being. This article uses the theoretical model of planned behavior (TPB) to investigate Chinese consumers’ purchasing intentions of CCAP under this circumstance. A total of 783 questionnaires were administered in China with empirical analysis through a structural equation model. The results show that attitudes (ATT) towards the safety of CCAP and subjective norms (SN) have significant positive effects on customers’ purchasing behavior intention (BI); the emotional response to the health concern (EM) of CCAP has a significant positive impact on SN, ATT, and BI; and BI of CCAP is significantly affected by individual characteristics. The BI of CCAP for those married consumers living in cities and towns with a low monthly consumption frequency is more likely to be affected by the new coronavirus epidemic events. This paper is one of the first studies that contribute to the literature by exploring the influencing factors of the consumption behavior intention over the COVID-19 pandemic in China from a public health perspective. The findings provide significant implications for cold chain operators, market managers, and policymakers to develop guidelines and offer a framework to initiate and support the produce market and boost consumer health confidence in CCAP at the practitioner level.

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Soo, Chen Lin, Shahirah Sabana, Cheng Ann Chen, and Yii Siang Hii. "Understanding microplastics in aquatic ecosystems – A mini review." Borneo Journal of Marine Science and Aquaculture (BJoMSA) 5, no. 2 (December 31, 2021): 63–69. http://dx.doi.org/10.51200/bjomsa.v5i2.3386.

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Microplastic is defined as plastic debris with a size less than 5mm. It is characterized based on colour, shape, and polymer type. Microplastics have been discovered in a variety of aquatic environments, including freshwater, estuarine, and marine waters. The presence of microplastic in aquatic systems poses a threat not only to aquatic organisms, but to human consumers of food harvested from these environments. This paper reviews the key characteristics of microplastics, how they contaminate aquatic ecosystems, and their effects on aquatic organisms. Efforts have been made to highlight the knowledge gaps in these areas and measures that deserve attention for addressing the problem.

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Lepori, Fabio, Dirk Gaul, Daniel Palm, and Björn Malmqvist. "Food-web responses to restoration of channel heterogeneity in boreal streams." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 11 (November 1, 2006): 2478–86. http://dx.doi.org/10.1139/f06-142.

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We assessed the biomass and stable-isotope composition (δ13C and δ15N) of consumers (aquatic insects and fish (Cottus gobio)) and potential food sources (detritus, biofilm, seston, algae, and mosses) in channelized and restored streams in Sweden, assessing the hypotheses that restoration enhances detritus storage and detritus-based secondary production. Restored sites stored more detritus than channelized sites, with differences (+5.4% on average) prominent in margins, i.e., the channel area within 1.4 m from the banks. The biomass of other resources was similar between restored and channelized sites. Most common aquatic insects, including several putative detritivores, showed δ13C values indicating reliance on aquatic (probably algal) carbon sources. The insectivorous fish Cottus gobio, on the contrary, appeared to be more dependent on terrestrial (detrital) carbon sources. The biomass and mean δ13C values of the consumers were similar between restored and channelized sites, suggesting that restoration did not increase net secondary production or the fraction of secondary production based on detritus. We concluded that the increase in detritus storage at restored sites was either insufficient to enhance detritus-based production or the consumers were not limited by the availability of detritus.

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Petrescu, Dacinia, Ruxandra Petrescu-Mag, Dorin Manciula, Ioan Nistor, and Veronica Ilieș. "Wastewater Reflections in Consumer Mind: Evidence from Sewage Services Consumer Behaviour." Sustainability 11, no. 1 (December 27, 2018): 123. http://dx.doi.org/10.3390/su11010123.

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Environmental concerns have become an important decision-making determinant for consumers. Hundreds of emerging pollutants and their metabolites are listed as present in European aquatic environments and human settlements are blamed as major sources of water pollution. It was assumed that as long as water treatment is not totally effective and it requires a high amount of energy and resources, household’s contribution through correct behaviour in relation to the load of waste they discharge in the sewage system can reduce efforts towards wastewater treatment. Consequently, the main objective of this study was to investigate households’ perception and behaviour related to wastewater treatment services. Results are based on a random survey with a sample of 125 Romanian consumers of water supply and sewage services. A key finding is that investigated wastewater services consumers perceive the effect of discharging untreated wastewater in the environment as highly negative both on human health and on the environment, thus pointing out the importance associated by them to water treatment. This research argues that understanding wastewater services consumer behaviour enlarges the way toward reducing environmental disturbances.

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Ingram, Travis, Blake Matthews, Chris Harrod, Tom Stephens, Jonathan Grey, Russell Markel, and Asit Mazumder. "Lipid extraction has little effect on the δ15N of aquatic consumers." Limnology and Oceanography: Methods 5, no. 10 (October 2007): 338–42. http://dx.doi.org/10.4319/lom.2007.5.338.

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Rubbo, Michael J., Lisa K. Belden, and Joseph M. Kiesecker. "Differential responses of aquatic consumers to variations in leaf-litter inputs." Hydrobiologia 605, no. 1 (February 1, 2008): 37–44. http://dx.doi.org/10.1007/s10750-008-9298-z.

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Sotelo, Carmen G., María Blanco, Patricia Ramos, José A. Vázquez, and Ricardo I. Perez-Martin. "Sustainable Sources from Aquatic Organisms for Cosmeceuticals Ingredients." Cosmetics 8, no. 2 (June 9, 2021): 48. http://dx.doi.org/10.3390/cosmetics8020048.

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Long life expectancy of populations in the developing world together with some cultural and social issues has driven the need to pay special attention to health and physical appearance. Cosmeceuticals are gaining interest in the cosmetic industry as their uses fulfills a double purpose: the requirements of a cosmetic (clean, perfume, protect, change the appearance of the external parts of the body or keeping them in good condition) with a particular bioactivity function. The cosmetics industry, producing both cosmetics and cosmeceuticals, is currently facing numerous challenges to satisfy different attitudes of consumers (vegetarianism, veganism, cultural or religious concerns, health or safety reasons, eco-friendly process, etc.). A currently growing trend in the market is the interest in products of low environmental impact. Marine origin ingredients are increasingly being incorporated into cosmeceutical preparations because they are able to address several consumer requirements and also due to the wide range of bioactivities they present (antioxidant, whitening, anti-aging, etc.). Many companies claim “Marine” as a distinctive marketing signal; however, only a few indicate whether they use sustainable ingredient sources. Sustainable marine ingredients might be obtained using wild marine biomass through a sustainable extractive fishing activity; by adopting valorization strategies including the use of fish discards and fish by-products; and by sustainably farming and culturing marine organisms.

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Herwig, Brian R., Daniel A. Soluk, John M. Dettmers, and David H. Wahl. "Trophic structure and energy flow in backwater lakes of two large floodplain rivers assessed using stable isotopes." Canadian Journal of Fisheries and Aquatic Sciences 61, no. 1 (January 1, 2004): 12–22. http://dx.doi.org/10.1139/f03-139.

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Carbon and nitrogen stable isotopes (δ13C and δ15N, respectively) were measured for locally abundant primary producers, detritus, aquatic invertebrates, and fish in backwater lakes of two large floodplain rivers in an effort to understand patterns of energy dependence and trophic structure within these habitats. We observed trophic enrichment values for 15N that were within the ranges observed for other aquatic systems but were often considerably lower than the 3.4 typically assumed in stable isotope studies. Production based on benthic and terrestrial material, combined with planktonic production for larval fish, appears to be an important energy source supporting consumers in backwater lakes of large floodplain rivers. Our isotopic data challenge the conventional wisdom that macrophytes are centrally involved in supplying carbon to aquatic consumers in shallow lakes and that food webs in most lakes are sustained almost exclusively by carbon fixed by phytoplankton.

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Kreutzweiser, David, David Nisbet, Paul Sibley, and Taylor Scarr. "Loss of ash trees in riparian forests from emerald ash borer infestations has implications for aquatic invertebrate leaf-litter consumers." Canadian Journal of Forest Research 49, no. 2 (February 2019): 134–44. http://dx.doi.org/10.1139/cjfr-2018-0283.

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Rapid loss of ash (Fraxinus spp.) trees in riparian forests from an invasive insect, the emerald ash borer (EAB; Agrilus planipennis Fairmaire, 1888), could pose risk of altering organic matter inputs to water bodies that underpin many aquatic ecosystem processes. We measured the composition of riparian forests and their leaf-litter contributions to headwater streams and determined the relative palatability of ash leaves and leaves of three other common riparian trees to aquatic invertebrate leaf-litter consumers (the stonefly (Pteronarcys sp.) and the cranefly (Tipula sp.)) in laboratory microcosms and whole invertebrate communities in forest streams. Ash trees contributed, on average, 24% to riparian tree density and 20% to total litterfall. Among the four common streamside trees accounting for 65% of total litterfall, ash was the first or second most preferred food source for consumers. Leaf packs without ash decomposed at slower rates than packs containing 25%–100% ash leaves. Preferential feeding on ash leaves infers a high-quality food source selected by consumers, and this concurred with comparatively high N content and low C–N ratio of ash leaves. Aquatic invertebrate communities on leaf packs in streams differed among leaf mixtures with or without ash, although community dissimilarity was low. The loss of ash in riparian forests represents an EAB-induced reduction in a high-quality resource subsidy to organic matter consumers in streams. We discuss how this has implications for risk predictions and management response strategies.

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Pereira, Renato Crespo, Nathália Nocchi, Tatiana U. P. Konno, and Angelica R. Soares. "Diverse traits of aquatic plants cannot individually explain their consumption by the generalist gastropod Biomphalairia glabrata." PeerJ 9 (September 20, 2021): e12031. http://dx.doi.org/10.7717/peerj.12031.

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Several experimental studies on aquatic plants have reported the prevalence of chemical defense mechanism against herbivory, as opposed to structural, life-forms or other traits. Here, our laboratory feeding experiments and integrative analysis explored the relationship among palatability (fresh or reconstituted plants used as artificial diet) and various chemical/nutritional traits (i.e., contents of dry mass, ash, nitrogen, protein, and phenols) of diverse aquatic plants and their susceptibility to consumption by the generalist gastropod Biomphalaria glabrata. Biomphalaria glabrata consumed all of the assayed aquatic plants in a hierarchical yet generalized way, with the consumption of fresh plants, their reconstituted forms and defensive properties of lipophilic extracts not being significantly correlated with plant physical or chemical traits to determine the feeding preference of the gastropod. Our results do not reveal a prevalence for a specific plant attribute contributing to herbivory. Instead, they indicate that the susceptibility of aquatic plants to generalist consumers is probably related to a combination of their chemical and physical properties, resulting in moderate grazing rates by generalist consumers.

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Li, Yongtao, and Changbiao Zhong. "Factors driving consumption behavior for green aquatic products." British Food Journal 119, no. 7 (July 3, 2017): 1442–58. http://dx.doi.org/10.1108/bfj-10-2016-0456.

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Purpose The purpose of this paper is to investigate the factors that influence consumers’ consumption behavior with regard to green aquatic products from a social cognitive theory perspective. Design/methodology/approach A web survey was used to collect the data. The survey subjects were citizens of Ningbo City in Zhejiang Province. A total of 403 subjects were obtained through the sampling service, and 337 subjects were retained after strict examination. The data were used to construct a partial least squares structural equation model. Findings The cognition of green aquatic products significantly positively affects outcome expectancy, self-efficacy, perception of others’ behavior, and socio-structural conditions. Self-efficacy and outcome expectancy significantly positively influence consumption intention. Self-efficacy, perception of others’ behavior, and consumption intention significantly positively affect consumption behavior. Practical implications The concept, connotations and benefits of green aquatic products should be widely publicized through diversified channels to increase people’s knowledge of these products and to encourage people to distinguish them from regular aquatic products and to believe in their benefits. In addition, measures should be taken to guarantee that only genuine green aquatic products can enter the market because the false claims of some products have damaged consumers’ belief in these products. Originality/value To test the effect of the cognition of green aquatic products, the construct “the cognition of green aquatic products” was added to the model based on social cognitive theory. This paper contributes to the existing literature by further exploring how cognitive aspects affect consumption behavior with regard to green food.

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Richardson, John S., and Mark S. Wipfli. "Getting quantitative about consequences of cross-ecosystem resource subsidies on recipient consumers." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 11 (November 2016): 1609–15. http://dx.doi.org/10.1139/cjfas-2016-0242.

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Most studies of cross-ecosystem resource subsidies have demonstrated positive effects on recipient consumer populations, often with very large effect sizes. However, it is important to move beyond these initial addition–exclusion experiments to consider the quantitative consequences for populations across gradients in the rates and quality of resource inputs. In our introduction to this special issue, we describe at least four potential models that describe functional relationships between subsidy input rates and consumer responses, most of them asymptotic. Here we aim to advance our quantitative understanding of how subsidy inputs influence recipient consumers and their communities. In the papers following, fish were either the recipient consumers or the subsidy as carcasses of anadromous species. Advancing general, predictive models will enable us to further consider what other factors are potentially co-limiting (e.g., nutrients, other population interactions, physical habitat, etc.) and better integrate resource subsidies into consumer–resource, biophysical dynamics models.

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Ayal, Yoram, and Elli Groner. "Primary Consumer Body Size and Food-Chain Length in Terrestrial Communities." Israel Journal of Ecology and Evolution 55, no. 4 (May 6, 2009): 329–43. http://dx.doi.org/10.1560/ijee.55.4.329.

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Using 21 community food webs, we tested Elton's two hypotheses regarding the main factors limiting food-chain length in terrestrial communities, namely, energy (energy limitation hypothesis—ELH) and body size (size limitation hypothesis—SLH). As predators tend to be larger than their prey, food-chains are size-structured: animal size increases with trophic position. We found a negative correlation between the size of the primary consumer and the length of the chain. Food-chains based on small primary consumers are longer than those based on large primary consumers, and size rather than energetic efficiency is the main contributing factor. We found no correlation between habitat productivity and mean food-chain length. All these findings support the SLH over the ELH. Our results suggest that, as in aquatic communities, a single factor—a predator/prey size-ratio greater than 1—governs the structure of terrestrial communities.

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Jardine, Timothy D., Aaron W. E. Galloway, and Martin J. Kainz. "Unlocking the power of fatty acids as dietary tracers and metabolic signals in fishes and aquatic invertebrates." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1804 (June 15, 2020): 20190639. http://dx.doi.org/10.1098/rstb.2019.0639.

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Determining the transfer and transformation of organic matter in food webs is a fundamental challenge that has implications for sustainable management of ecosystems. Fatty acids (FA) offer a potential approach for resolving complex diet mixtures of organisms because they provide a suite of molecular tracers. Yet, uncertainties in the degree of their biochemical modification by consumers, due to selective retention or metabolism, have limited their application. Here, we consolidated 316 controlled feeding studies of aquatic ectotherms (fishes and invertebrates) involving 1404 species–diet combinations to assess the degree of trophic modification of FA in muscle tissue. We found a high degree of variability within and among taxa in the %FA in consumer muscle tissue versus %FA in diet regression equations. Most saturated FA had weak relationships with the diet ( r 2 < 0.30) and shallow slopes ( m < 0.30), suggesting a lack of retention in muscle when fed in increasing amounts. Contrarily, several essential FA, including linoleic (18:2n-6) and α-linolenic acid (18:3n-3), exhibited significant relationships with the diet ( m > 0.35, r 2 > 0.50), suggesting supply limitations and selective retention in muscle by consumers. For all FA, relationships strengthened with increasing taxonomic specificity. We also demonstrated the utility of new correction equations by calculating the potential contributions of approximately 20 prey items to the diet of selected species of generalist fishes using a FA mixing model. Our analyses further reveal how a broad range of fishes and invertebrates convert or store these compounds in muscle tissue to meet physiological needs and point to their power in resolving complex diets in aquatic food webs. This article is part of the theme issue ‘The next horizons for lipids as ‘trophic biomarkers’: evidence and significance of consumer modification of dietary fatty acids’.

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Silva, Márcio J. da, Bruno R. S. Figueiredo, Robson T. C. Ramos, and Elvio S. F. Medeiros. "Food resources used by three species of fish in the semi-arid region of Brazil." Neotropical Ichthyology 8, no. 4 (October 15, 2010): 819–25. http://dx.doi.org/10.1590/s1679-62252010005000010.

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Temporary and semi-permanent aquatic habitats in semi-arid Brazil have been reported as important sites supporting a diverse fish fauna. As such, they must be able to trophically sustain fish species that feed at different trophic levels. This study aims to describe the diets of Astyanax aff. bimaculatus, Hoplias malabaricus and Prochilodus brevis in aquatic systems in semi-arid Brazil, providing evidence of the importance of these habitats as supporters of large consumers like fish. The diet of the three species studied was diverse, feeding on a range of food items, from microalgae to fish. Despite that, a few items were more important to each of the study species. These results and the relatively high rates of stomach fullness indicate that a diverse and abundant food range is available in the study sites, but species seem to select some food resources. The present study provides evidence that despite being highly variable, intermittent and semi-permanent aquatic systems in semi-arid Brazil are able to trophically sustain large consumers.

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Pettit, N. E., D. M. Warfe, P. G. Close, B. J. Pusey, R. Dobbs, C. Davies, D. Valdez, and P. M. Davies. "Carbon sources for aquatic food webs of riverine and lacustrine tropical waterholes with variable groundwater influence." Marine and Freshwater Research 68, no. 3 (2017): 442. http://dx.doi.org/10.1071/mf15365.

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Food web studies integrate ecological information and provide understanding of ecosystem function. Aquatic ecosystems of the Kimberley region (north-western Australia) have high conservation significance as hotspots for maintaining local and regional biodiversity. This study investigated the influence of waterhole type and persistence on the strength of consumer reliance on local energy resources for aquatic food webs. Changes in water isotopic composition indicated groundwater inputs were enough to overcome evaporative losses in some waterholes. Other waterholes had varying levels of isotope enrichment suggesting insufficient groundwater input to ‘compensate’ for evaporative loss. C and N isotope analysis indicated considerable overlap among energy sources in waterholes between macrophytes and periphyton but gradient analysis indicated that periphyton is a major carbon source for aquatic consumers. Groundwater-fed waterholes appeared to have higher quality food sources (indicated by lower C:N ratios), but there was minimal evidence that direct groundwater contributions were related to food web processes. Nonetheless, in a region where groundwater is influential in maintaining aquatic habitats, future development of groundwater reserves will likely affect the ecological and cultural value of freshwater wetlands by either reducing their permanence or size or indirectly through possible alteration to the role of periphyton in supporting the food web.

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Galloway, Aaron W. E., Michael T. Brett, Gordon W. Holtgrieve, Eric J. Ward, Ashley P. Ballantyne, Carolyn W. Burns, Martin J. Kainz, et al. "A Fatty Acid Based Bayesian Approach for Inferring Diet in Aquatic Consumers." PLOS ONE 10, no. 6 (June 26, 2015): e0129723. http://dx.doi.org/10.1371/journal.pone.0129723.

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Mendoza-Carranza, Manuel, David J. Hoeinghaus, Alexandre M. Garcia, and Ángel Romero-Rodriguez. "Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico." Neotropical Ichthyology 8, no. 1 (March 2010): 171–78. http://dx.doi.org/10.1590/s1679-62252010000100020.

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Mangrove and seagrass habitats are important components of tropical coastal zones worldwide, and are conspicuous habitats of Centla Wetland Biosphere Reserve (CWBR) in Tabasco, Mexico. In this study, we examine food webs in mangrove- and seagrass-dominated habitats of CWBR using stable isotope ratios of carbon and nitrogen. Our objective was to identify the importance of carbon derived from mangroves and seagrasses to secondary production of aquatic consumers in this poorly studied conservation area. Carbon and nitrogen isotope ratios of basal sources and aquatic consumers indicated that the species-rich food webs of both habitats are dependent on riparian production sources. The abundant Red mangrove Rhizophora mangle appears to be a primary source of carbon for the mangrove creek food web. Even though dense seagrass beds were ubiquitous, most consumers in the lagoon food web appeared to rely on carbon derived from riparian vegetation (e.g. Phragmites australis). The introduced Amazon sailfin catfish Pterygoplichthys pardalis had isotope signatures overlapping with native species (including high-value fisheries species), suggesting potential competition for resources. Future research should examine the role played by terrestrial insects in linking riparian and aquatic food webs, and impacts of the expanding P. pardalis population on ecosystem function and fisheries in CWBR. Our findings can be used as a baseline to reinforce the conservation and management of this important reserve in the face of diverse external and internal human impacts.

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Zhartybaeva, Meruert, Symbat Tulegenova, Nurlan Muntaev, and Zhanar Oralbekova. "Water quality of aquatic ecosystems of Akmola region." Bulletin of the Karaganda University. “Biology, medicine, geography Series” 108, no. 4 (December 30, 2022): 34–48. http://dx.doi.org/10.31489/2022bmg4/34-38.

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Currently, the issue of protecting natural resources from polluting and preventing pollution requires worldwide attention. In general, water resources are becoming an invaluable resource that explains the sustainable development of any state. Rational use and protection of water sources is becoming one of the most pressing issues in our country. Pollution of water sources, in turn, affects the deterioration of water quality, living organisms that live in water sources (algae, fish, etc.), and the health of consumers. Since water is the most important resource in the world, it is a task to protect and prevent environmental risk. Therefore, to monitor the aquatic ecosystems of Akmola region, the research team conducted research in laboratory conditions, taking water samples from water bodies (Nura, Ishim Riversand Taldykol, Maybalyk, and Zhaltyrkol Lakes) from a practical trip organized by the research group. Research studies on water samples taken from water bodies showed that the water was polluted, and in some indicators the maximum rural concentration was exceeded. It is clear that pollutants affect water biota, although in most cases they are not the cause. According to water samples, the level of pollution of water sources was assessed. Protection of Water Resources in general from pollutants is one of the strategic tasks of the country.

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Duffy, D. C., W. R. Siegfried, and S. Jackson. "Seabirds as consumers in the southern Benguela region." South African Journal of Marine Science 5, no. 1 (June 1, 1987): 771–90. http://dx.doi.org/10.2989/025776187784522676.

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Meunier, Cédric L., Emily M. Herstoff, Carla Geisen, and Maarten Boersma. "A matter of time and proportion: the availability of phosphorus-rich phytoplankton influences growth and behavior of copepod nauplii." Journal of Plankton Research 42, no. 5 (August 27, 2020): 530–38. http://dx.doi.org/10.1093/plankt/fbaa037.

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Abstract Although consumers may use selective feeding to cope with suboptimal resource quality, little work has examined the mechanisms that underlie selective feeding, the efficiency of this behavior or its influence on consumer growth rate. Furthermore, a consumer’s exposure to suboptimal resources may also influence the consumer’s behavior and life history, including growth rate. Here, we studied how the availability of P-rich and P-poor phytoplankton influences the growth and behavior of copepod nauplii. We observed that copepod nauplii preferentially feed on P-rich prey. We also found that even relatively short exposure to P-rich phytoplankton yielded higher nauplii growth rates, whereas the presence of P-poor phytoplankton in a mixture impaired growth. Overall, we observed that swimming speed decreased with increasing phytoplankton P-content, which is a behavioral adjustment that may improve utilization of heterogeneously distributed high-quality food in the field. Based on our results, we propose that the optimal prey C: P ratio for copepod nauplii is very narrow, and that deviations from this optimum have severe negative consequences for growth.

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Hogsden, Kristy L., and Rolf D. Vinebrooke. "Environmental predictors of benthic consumers and autotrophic communities along a recovery gradient." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 10 (October 1, 2005): 2226–39. http://dx.doi.org/10.1139/f05-138.

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Ecological theory predicts that biological factors replace abiotic regulation of community structure during recovery from ecosystem stress. We examined relationships between benthic autotroph (epilithic periphyton) and consumer communities, and environmental variables, along a gradient of six recovering acidified lakes to identify the best explanatory variables of community structure. Dissolved organic carbon, pH, and total dissolved phosphorus were important predictors of autotrophic biomass, while total dissolved phosphorus was the only significant factor explaining variation in consumer biomass. Abiotic factors (e.g., dissolved organic carbon, pH) were also significant predictors of autotrophic and consumer community composition. Autotrophic biomass was significantly greater in recovering lakes owing to an increased abundance of attached filamentous green algae. However, consumer biomass did not differ significantly between severely stressed and recovering lakes because of a compensatory shift from numerous small tolerant omnivores to fewer large-bodied sensitive grazers. Lack of a significant relationship between autotrophic and consumer biomass along with stable isotopic evidence of few primary consumers suggested that grazing pressure was weak, especially in the stressed lakes. The persistent importance of abiotic factors to autotrophic and consumer communities suggested that ecosystem recovery remained incomplete in these lakes.

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Hoeinghaus, D. J., J. P. Vieira, C. S. Costa, C. E. Bemvenuti, K. O. Winemiller, and A. M. Garcia. "Estuary hydrogeomorphology affects carbon sources supporting aquatic consumers within and among ecological guilds." Hydrobiologia 673, no. 1 (May 26, 2011): 79–92. http://dx.doi.org/10.1007/s10750-011-0751-z.

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Martinez del Rio, Carlos, and Scott R. McWilliams. "How essential fats affect bird performance and link aquatic ecosystems and terrestrial consumers." Proceedings of the National Academy of Sciences 113, no. 43 (October 6, 2016): 11988–90. http://dx.doi.org/10.1073/pnas.1614106113.

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Stenroth, Karolina, Lina E. Polvi, Emma Fältström, and Micael Jonsson. "Land-use effects on terrestrial consumers through changed size structure of aquatic insects." Freshwater Biology 60, no. 1 (October 8, 2014): 136–49. http://dx.doi.org/10.1111/fwb.12476.

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Smits, Adrianne P., Daniel E. Schindler, Jonathan B. Armstrong, Michael T. Brett, Jackie L. Carter, and Bianca S. Santos. "Thermal constraints on stream consumer responses to a marine resource subsidy." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 11 (November 2016): 1661–71. http://dx.doi.org/10.1139/cjfas-2015-0420.

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Spawning migrations of Pacific salmon (Oncorhynchus spp.) to coastal watersheds provide a rich resource subsidy to freshwater consumers. However, variation in thermal regimes and spawning activity across the landscape constrain the ability of poikilothermic consumers to assimilate eggs and carcasses. We investigated how sockeye salmon (Oncorhynchus nerka) spawning density and stream temperature affect the growth, body condition, and fatty acid composition of juvenile coho salmon (Oncorhynchus kisutch), a known egg predator, in seven tributaries of the Wood River in Southwest Alaska. We compared mean body size of juvenile coho salmon in late summer among 3–7 years per stream and found that the largest mean size occurred in warm streams in which sockeye salmon spawned, although overall subsidy magnitude (spawner density) had no effect on consumer body size. Individuals that consumed more salmon eggs (estimated from δ15N) were larger and had altered fatty acid composition but did not have higher relative body condition. These results indicate that effects of marine subsidies on freshwater consumers depend both on local habitat conditions and on individual variation in energy allocation.

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Page, Henry M., Scott D. Cooper, Sheila W. Wiseman, Danuta Bennett, Kristie Klose, Steven Sadro, Craig Nelson, and Thomas Even. "Comparisons of stable isotope (C, H, N) signatures for revealing organic matter sources and trophic relationships in headwater streams." Canadian Journal of Fisheries and Aquatic Sciences 74, no. 12 (December 2017): 2110–21. http://dx.doi.org/10.1139/cjfas-2016-0322.

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We compared the efficacy of stable carbon, hydrogen, and nitrogen isotope ratios in identifying the resources used by insect consumers in headwater streams of southern California. We also compared gut contents with consumer stable isotope ratios and mixing model estimates of resource contributions to predator diet. Stable hydrogen isotope ratios (as δ2H) of algivores were well separated from ratios for detritivores, whereas relationships between stable carbon (as δ13C) and nitrogen (as δ15N) ratios of consumers and their expected diets were weaker and more ambiguous. δ2H values of primary consumers more strongly reflected the proportions of their gut contents consisting of algae than δ13C values. Τhe proportions of algivorous prey in predator gut contents increased with mixing model estimates of algivore contributions to predator diet using δ2H but not δ13C values. Our findings support the use of hydrogen isotope ratios in food web studies of streams in southern California and their potential use in assessing the effects of anthropogenic and natural disturbance on basal resource contributions to food webs that might not otherwise be identified using carbon isotope ratios.

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Uddin, Md Taj, Mehedi Hasan Rasel, Aurup Ratan Dhar, Mr Badiuzzaman, and Md Sazedul Hoque. "Factors Determining Consumer Preferences for Pangas and Tilapia Fish in Bangladesh: Consumers’ Perception and Consumption Habit Perspective." Journal of Aquatic Food Product Technology 28, no. 4 (April 4, 2019): 438–49. http://dx.doi.org/10.1080/10498850.2019.1597004.

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Jæger, Bjørn, and Alok Mishra. "IoT Platform for Seafood Farmers and Consumers." Sensors 20, no. 15 (July 29, 2020): 4230. http://dx.doi.org/10.3390/s20154230.

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There has been a strong growth in aquatic products supported by the global seafood industry. Consumers demand information transparency to support informed decisions and to verify nutrition, food safety, and sustainable operations. Supporting these needs rests on the existence of interoperable Internet of Things (IoT) platforms for traceability that goes beyond the minimum “one up, one down” scheme required by regulators. Seafood farmers, being the source of both food and food-information, are critical to achieving the needed transparency. Traditionally, seafood farmers carry the costs of providing information, while downstream actors reap the benefits, causing limited provision of information. Now, global standards for labelling, data from IoT devices, and the reciprocity of utility from collecting data while sharing them represent great potential for farmers to generate value from traceability systems. To enable this, farmers need an IoT platform integrated with other IoT platforms in the value network. This paper presents a case study of an enterprise-level IoT platform for seafood farmers that satisfies consumers’ end-to-end traceability needs while extracting data from requests for information from downstream actors.

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Kılıç, Emel, Meral Soylu, and Mustafa Selcuk Uzmanoglu. "Ardahan İli Su Ürünleri Tüketim Alışkanlıklarının Belirlenmesi." Turkish Journal of Agriculture - Food Science and Technology 7, no. 7 (July 19, 2019): 1028. http://dx.doi.org/10.24925/turjaf.v7i7.1028-1039.2536.

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The aim of this study is to determine the consumption habits of aquatic products in Ardahan province and its districts. The study carried out between 2014 and 2015 was prepared face to face with the consumers by using a questionnaire prepared to measure the consumption habits of aquatic products. The research material consisted of data collected from 302 people by face to face survey method. When the demographic data were analysed according to the results of the study; 73.84% of the respondents were native to Ardahan and 26.15% were immigrants, 38.08% were female, 61.92% were male, the average age was 32.50 and the average monthly income was 1862.80 TL. According to the findings of the study, per capita annual fish consumption is 39 kg and per capita monthly fish consumption is 3.25 kg. The most preferred species of freshwater fish was trout (75.22%), while anchovy was found in marine fish (48.57%). While 21.98% of the participants consume fish, 18.73% chicken, 17.62% veal, 13.52% goose, 13.34% sheep, 6.67% goat meat and 4.19% turkey meat, only 1.71% prefer aquatic species such as mussels and shrimps. The important reason why fish is preferred is being healthy with 45.03%. The other most consumed aquatic products is mussel with 11.92%. It was determined that 76.49% of the consumers did not consume aquatic products other than fish. As a result, it is determined that although there is no coastline of Ardahan and the socio-economic level of the people is not high, the consumption of fish is high. The people of the region who deal with cattle as a source of livelihood prefer to consume aquatic products. In this respect, Ardahan is at the level that can be an example to Turkey.

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Journal articles on the topic 'Aquatic consumers'

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