Hydrobiology, Volume 2, Issue 1 (March 2023) – 18 articles

Most of the human population lives in cities, and understanding their impact on freshwater environments is essential. Streams in cities face many environmental challenges that have been described in the concept of Urban Stream Syndrome. This concept illustrates urban streams’ biological, hydrological, chemical, and physical stressors. In tropical streams, these stressors impact shrimp, fish, insects, and other macroinvertebrates that inhabit the freshwater ecosystems. Freshwater shrimp are vulnerable to urban activities, physical, chemical, and ecological impacts. For this reason, these organisms have been used as biological indicators of stream health in the tropics. The shredder shrimp Xiphocaris elongata plays a fundamental role in the organic matter process and decomposition. The objectives of this study were to characterize the population of X. elongata and to identify differences in the abundance of X. elongata between urban and forest streams. Our results showed that highly urbanized areas have a significantly lower abundance of the shredder shrimp X. elongata than medium or low urban reach in the urban and forested watersheds. This study also showed that physicochemical and geomorphological variables are important environmental factors that influence the abundance of X. elongata in Puerto Rican streams. Full article

The Odonata are not typically regarded as informative taxa for stream bioassessment in North America compared to other insects, particularly when monitoring the ecological impacts of organic pollution. However, we hypothesized that stream-dwelling odonates are useful bioindicators of riparian conditions because vegetation associated with streams is used for oviposition and establishing breeding territories and is likely a cue for a suitable nymphal habitat. We sampled odonates from multiple microhabitats and all macroinvertebrates from riffle habitat in 12 Ozark Highlands (USA) spring streams along a gradient of riparian conditions. We also measured a standard suite of physical and chemical variables in each stream. We compared various aspects of the odonate and riffle macroinvertebrate assemblages among sites to evaluate sensitivity to variables associated with riparian structure compared to the other physical and chemical variables measured. The odonates were strongly associated with riparian-specific variables, while riffle macroinvertebrates were associated with riparian variables to a lesser degree. The additional environmental variables explained minimal variation in either assemblage. Overall, our results suggest that Odonata alone could be useful for biomonitoring associated with riparian structure around Ozark spring streams. The sensitivity of odonates to riparian conditions in other Nearctic regions should be further studied to identify regional and species-specific differences. Full article

Aquatic beetle diversity was compared between three study sites in the state of Tlaxcala, central Mexico: Stream 1 (San Ambrosio), stream 2 (San Tadeo), and a lake (Acuitlapilco). Sampling took place bimonthly during an annual cycle. A total of 2968 specimens were obtained, which were grouped into twenty three species, fifteen genera, and six families (Elmidae, Dryopidae, Dytiscidae, Gyrinidae, Haliplidae, and Hydrophilidae). Stream 2 showed the highest values of abundance (1570 individuals), while stream 1 had the highest richness (18 species). Abundance values showed two peaks each in rainy and dry seasons. The proportion of rare and dominant species was similar in all study sites. Based on species accumulation curves, the maximum estimated number of species has not been achieved in either of the three sites. Regarding alpha diversity (effective number of species), stream 1 presented the highest zero-order diversity estimated with 18.5 species. Regarding beta diversity, lotic systems (streams 1 and 2) presented a similarity of 75%. Finally, regarding the trophic structure of the adult aquatic beetle community, herbivores, predators, and decomposers were most representative in this study. Based on our results, Tlaxcala probably holds a significant diversity of aquatic beetles. This appears to indicate that species composition in geographic areas, regardless of their relatively small size, is worth documenting and, of course, preserving. Full article

There are many important protected areas in the Western Balkan region, which are shared between Albania, Montenegro, Kosovo, North Macedonia, and Greece. These areas have special importance based on their species density (mosses and higher plants) per surface unit. These transboundary ecosystems, which include mountainous massifs, lakes, and rivers, are biodiversity hotspots for the whole of Europe. Species and habitat densities are high compared to other countries in Southeast Europe. However, political borders fragment properly across two or three countries, which often have different approaches and rules for nature protection and the use of resources. Hence, in this short opinion piece, we stress common and cooperative transboundary protection and management in these countries. Furthermore, the European Union’s policy towards the Western Balkan countries in the Stabilization and Association Process (SAP), with the goal of their eventual EU membership, is crucial. Therefore, our appeal is addressed not only to the respective local communities and national governments but also to the European Commission and related EU institutions. We stress the importance of these cross-border ecosystems in the integration process. Full article

Peoples can readily and affordably obtain small indigenous fish species (SIS), with a maximum length of 25 cm, that can be found in niches in small bodies of water (such as canals, ponds, wetlands, streams, etc.). SIS contribute valuable and significant macro- and micronutrients in Bangladesh. SIS are excellent suppliers of vitamins and minerals. The main micronutrients are copper, iodine, iron, selenium, chromium, and zinc, which can help prevent mineral deficiency and enzymatic response in the human body. SIS, such as the mola (Amblypharyngodon mola), cotio (Osteobrama cotio), darkina (Esomus danricus), etc., are easily digestible by the human gut. Nutrients of these fish are quickly accessible by the intestine. These fish are comparatively cheap and easy to capture and promote the presence of particular vitamins in SIS, including A, D, E, and K, as well as vitamin B components. This review paper focuses on the SIS nutritional contribution and their efficacy of preventing malnutrition in developing countries such as Bangladesh and the whole world. Full article

Stoneflies are a globally threatened aquatic insect order. In Arkansas, a diverse group of winter stonefly (Capniidae: Allocapnia) have not been surveyed since the 1980s, likely because species-level identification requires the rarely-collected adult form. Allocapnia mohri, a regional endemic, was previously commonly found in mountainous, intermittent streams from the Ouachita Mountains ecoregion north to the Ozark Highlands, but no species distributional models including land use or climate variables exist to our knowledge. We collected adults from 71 stream reaches from the historic Arkansas range from November to April 2020 and 2021. We modeled distributions using random forest (RF) models populated with landscape, climate, and both data to determine which were most predictive of species presence. Correlations between landscape or climate variables and presence were examined using multiple logistic regression. The landscape RF models performed better than the climate or landscape + climate RF models. A. mohri presence sites tended to have a greater elevation, a lower mean July temperature, and a greater percentage of very slow infiltration soils in the watershed, compared to absence sites. A. mohri was absent at the Ouachita Mountains sites and may be experiencing a range contraction or migration northward. Full article

Intensive and regular fishing occurs in the marine area of the natural park “Parque Natural do Sudoeste Alentejano e Costa Vicentina” (PNSACV; SW coast of continental Portugal). In 2011, this area became a marine park with different protection levels (total, partial, and complementary). We assessed in 2011 and 2012 if partial protection (PP) in Marine Protected Areas (MPAs) changed the taxa richness, abundance, size, and community composition of cryptic and non-cryptic fishes. We also determined if these effects were observed outside PP areas in adjacent control areas. Underwater visual censuses (UVC) of cryptic and non-cryptic fish species were conducted in rocky subtidal habitats (~10 m deep) with band transects (25 × 2 m and 25 × 4 m, respectively) to determine abundance and size classes. The northern half of the PNSACV was sampled at a scale of tens (site—two sites per area; 4–6 transects per site) and hundreds (area) of meters. Two PP and six control areas were sampled. The homogeneity and abundance of bottom habitat types were assessed at each site. Effects of protection were not detected in the community structure or univariate analyses (i.e., taxa richness and total abundance) of non-cryptic and cryptic fishes. The early phase of the MPAs may have driven the lack of significant protection effects. Replication in time within a monitoring program is recommended to assess these conservation measures’ ecological effects. Full article

The aim of this review paper is to identify the production trends of shrimp and rice farming systems and associated hydrobiological parameters such as salinity in the coastal districts of Bangladesh. An intensive literature review has been conducted to explore salt stress-driven land use change, crop production, and changing ecosystem hydrobiology to adapt climate change impact from 2012–2022. The results indicate that a gradual extension of salt-driven land use and land cover (LULC) change has stressed agricultural production to a greater extent from 1973 to 2022 due to the high level of salinity. The unplanned expansion of shrimp culture is creating adverse consequences for the coastal ecosystem. Some suggestions have been proposed by analysing the mechanisms of crops’ response to salt stress, including several physiological, biochemical, and molecular bases to mitigate the adverse effects of salinity on agricultural production. Alternatively, prawn, shrimp, and crab have similar or slightly higher economic outputs, except for the crop-based agricultural system, which is highly affected by salinity rise. However, due to low input costs, low maintenance, and less environmental impact, farmers are shifting towards crab fattening and thus changing the hydrobiology of coastal land use and land cover. Full article

Two Streptomyces strains, named N11-26 and DC10-5, were isolated from deep-sea and non-photosynthetic stony coral, respectively. Strain N11-26 produces lobophorin C and divergolides, which are antimicrobial substances. This study aimed to classify these strains and reveal their cryptic potential to synthesize other secondary metabolites, such as polyketides and nonribosomal peptides. Strains N11-26 and DC10-5 showed 16S rRNA gene sequence similarities of 100% and 99.9% to Streptomyces olivaceus NRRL B-3009^T, respectively. By digital DNA–DNA hybridization using whole-genome sequences, these strains were classified as Streptomyces olivaceus. Strain N11-26 was closer to the type strain of S. olivaceus than strain DC10-5 and possessed 17 clusters of polyketide synthase (PKS) and/or nonribosomal peptide synthetases (NRPS) genes, whereas strain DC10-5 harbored 19 clusters. Putative products by these gene clusters were predicted by bioinformatic analyses. Although 15 clusters were conserved between the two strains, two and four clusters were specific in strains N11-26 and DC10-5, respectively. This represents a diversity of potential polyketide and nonribosomal peptide compounds between strains of S. olivaceus. To the best of our knowledge, this is the first report annotating all the PKS and NRPS gene clusters in S. olivaceus strains with their putative products to provide useful information for genome mining. Full article

The main goal of this research was to evaluate how well existing and emerging land management practices may be used to manage landscapes for various ecosystem services. By employing a mixed methods approach and conducting a case study in the Prespa Lakes watershed in southeast Europe, this goal was achieved. The necessary information was initially gathered using a semi-stratified survey. Following that, the primary ecosystem services and land management practices present in Prespa Lakes watershed were determined via a workshop and a Delphi survey. The identified ecosystem services were ranked using the multi-criteria analytical hierarchy process method. The most important ecosystem service topics included tourism and recreation, maintenance of healthy water bodies, wildlife habitats, healthy food production, natural and heritage values, and biodiversity. Finally, a set of primary priority land management practices for meeting production and ecosystem service goals in the current conditions of the Prespa Lakes watershed was produced utilizing a ranking framework. The very high priority land management practices include livestock breeding to meet both production and conservation objectives, organic farming, diversified crop rotation, crop and tree diversity, restored wetlands, and planning at landscape level. This study provides an important tool for assessing changes in ecosystem service provision under alternative land management practices. Full article

The contemporary distribution of crenobiontic endemics in central Texas is enigmatic because only some springs are occupied by crenobionts despite other unoccupied springs having seemingly suitable habitats. In the absence of complete paleo-records, a cohesive and widely accepted explanation for this biogeography has eluded researchers for many years. We suggest that data on contemporary species with obligate coevolution, such as parasites with multiple obligate hosts in their life cycles, can help to fill intervening gaps in the paleo-record because the contemporary distribution of such a parasite indicates that its hosts cohabitated without interruption since the arrival of the parasite. To test this conjecture, we studied one such parasite endemic to a select few central Texas springs, Huffmanela huffmani. By studying the distribution of the intermediate host, geologic and paleo-climatic records, performing lab experiments with live animals, and examining archived museum specimens of the definitive hosts from the 1950s, we were able to test multiple predictions about how the distribution of H. huffmani became what it is today. Our results corroborate a narrative suggesting that several severe droughts since the Wisconsin glaciations are responsible for having sculpted the present-day distribution of central Texas crenobionts. Full article

The ecosystem services can be divided using two major classification systems, the Millennium Ecosystem Assessment (MEA) and the Common International Classification of Ecosystem Services (CICES). In the MEA system, the ecosystem services are divided into four major service clusters: supporting, provisioning, regulating, and cultural. On the other hand, the CICES system regards the “MEA supporting services” as organism natural function (and not an ecosystem service). Thus, this function is the basis for all the three CICES ecosystem services (provisioning, regulating, and cultural) provided by one organism. These ecosystem services can be analyzed for the type of habitat, fauna or flora. Seaweeds, or marine macroalgae, are one of the key organisms in estuarine and seawater habitats ecosystems, which currently is of extreme importance due to the climate changes and the blue–green economy. Seaweeds and humankind have been interlinked from the beginning, mainly as a food source, fibers, biochemicals, natural medicine, ornamental resources, art inspiration, and esthetic values in several coastal communities. Moreover, currently they are being studied as green carbon, carbon sequestration, and as a possible source for the biomedical and pharmaceutical areas. This review is a concise review of all ecological services provided by seaweeds and their impact in the human life and maintenance of the ecosystem status quo. The future of seaweeds use is also approached, regarding the promotion of seaweed ecological services and its dangers in the future. Full article

Few studies have explored the relative strength of ecogeographic versus lineage-specific effects on a global scale, particularly for poikilotherms, those organisms whose internal temperature varies with their environment. Here, we compile a global dataset of life history traits in Daphnia, at the species-and population-level, and use those data to parse the relative influences of lineage-specific effects and climate. We also compare the thermal response (plasticity) of life history traits and their dependence on climate, temperature, precipitation, and latitude. We found that the mode of evolution for life history traits varies but that the thermal response of life history traits most often follows a random walk model of evolution. We conclude that life history trait evolution in Daphnia is not strongly species-specific but is ecogeographically distinct, suggesting that life history evolution should be understood at the population level for Daphnia and possibly for other poikilotherms. Full article

At the landscape level, freshwater ecosystems are linked at various spatial and temporal scales by movements of different fauna components adapted to life in water. We review the literature on the state of landscape connectivity and related aquatic species that connect different types of freshwater habitats, focusing on linkages from streams, large rivers and standing water bodies. Based on existing evidence, it is clear that biotic linkages throughout current mosaic have important consequences for biological integrity and biodiversity. The recent developments with regard to urbanization, expansion of urban centers, infrastructure development, and hydropower plant construction in Albania are in line with global destruction and fragmentation of habitats resulting in the parceling up of landscapes that, in this very case, have been caused by human population growth and development activities. The primary aim of this article is to address the landscape connectivity in a wider northeastern part of Albania considering various protected areas. The landscape connectivity is a pillar component of connectivity conservation that has emerged as a response approach to a range of threats to biodiversity, which include habitat degradation and destruction, fragmentation and climate changes. The approach analyses of landscape connectivity were defined from a human perspective in a linkage among different protected areas, including National Park Albanian Alps, Nature Park Korrab-Koritnik, National Park ShebenikJabllanica, Pogradec Landscape Protected Areas and National Park Prespa. The basis of this analysis lies in the Network of Protected Areas (NPAs) of Albania. Cumulatively, the protected areas connectivity, aquatic ecosystem linkage and individual movements connect populations within and among landscape mosaics and contribute to national and regional diversity and resilience to disturbance. This study highlights the importance of considering both terrestrial and aquatic ecosystems connectivity in conservation planning and management. Full article

Large freshwater mussels (Unionida) are long-lived, have large bodies, and produce thousands to millions of larvae (glochidia) that usually must attach to host fish tissue to complete their life cycle. This is an obligate parasitic stage of mussel larvae. However, less than one in onemillion find a suitable host and survive. The degree of host specificity varies among unionid species, from specialists that can successfully parasitize only one or a few closely related fish species to generalists that can complete development on a taxonomically broad range of fish species. In addition, freshwater mussels are among the most threatened groups of animals. This is due to habitat destruction, the introduction of non-native species, and the loss of host fish on which their larvae (glochidia) are obligate parasites. Glochidiosis harms fish by affecting their growth; on the other hand, freshwater mussels play an important role in freshwaters by improving water quality and ridding the water of bacteria, algae, and pollutants, they are an indicator species of water quality. During our parasitological survey of fish from the Macedonian part of Lake Prespa in April 2022, many glochidia were found on the gills, skin, and fins of two endemic fishes, Prespa roach (Rutilus prespensis) and Prespa nase (Chondrostoma prespense), in the range of tens to thousands on one host. We thus recorded these two endemic species as new hosts of A. cygnea. Full article

The present study was conducted to understand the changes in gonads and hematological parameters in climbing perch (Anabas testudineus) exposed to synthetic estrogen and progestogen [mixture of ethinylestradiol (EE2) and desogestrel (DES)]. Climbing perch were exposed to four different concentrations of EE2/DES mixtures, viz. 0 ng of EE2 and DES/L (T0), 3 ng EE2 and 15 ng DES/L (T3), 30 ng EE2 and 150 ng DES/L (T30), and 300 ng EE2 and 1500 ng DES/L (T300) for 60 days. On days 45 and 60, samples were taken to assess changes in somatic indexes, gonad histology, and hematological parameters. The gonadosomatic index (GSI) increased in both females and males with increasing concentrations of estrogen mixtures except for T30 females, which was the lowest among all\four treatments. The hepatosomatic index (HSI) was observed to be increased in males as estrogen content increased. However, compared to fish at T0, HSI in female individuals did not vary in T30 fish, where the value was the highest among all the treatments. On day 45, histological observations showed no feminization or intersexuality but several germ-cell deformities in the ovary (adhesion, degenerated oocyte wall, degenerated granulose layer, increased interfollicular space, atretic follicle, and cytoplasmic clumping) and testes (increased interstitial area, focal loss of spermatocyte, dilation of the lumen, breakage of tubular epithelium, and elongated seminiferous tubule) were observed in fish exposed to EE2 and DES. Fish reared at T30 had lower RBC count, hemoglobin (Hb), glucose, and hematocrit levels. On day 60, fish reared at T30 had the highest Hb content compared to fish raised in other treatment conditions. WBC was progressively higher with increasing EE2/DES concentrations. Significant erythrocyte cytoplasmic abnormalities and erythrocyte nuclear abnormalities were observed in fish exposed to higher EE2/DES concentrations. The present study provides insights into the adverse impacts of synthetic estrogens sourced from human contraceptive pills on fish physiology. Full article

Floodplains are critically important ecosystems that provide a whole suite of ecosystem services, including nutrient and carbon sequestration, flood mitigation, water storage, and critical wildlife habitat. However, human modification of rivers and floodplains through channelization, artificial levee construction, reductions in the active floodplain area, and water management can significantly reduce the ecosystem function of river–floodplain systems. In this study, we evaluated the changes in the nutrient loading of the Kissimmee River floodplain during the restoration of the river–floodplain system. In addition to time-series loading analysis, we also evaluated soil nutrient concentrations across the lower portion of the Kissimmee River floodplain. During the 44-year nutrient loading time-series, the floodplain remained a nutrient exporter with changes in nutrient loading generally corresponding to both water quality (i.e., point source reductions) and hydrologic restoration activities in the watershed and Kissimmee River floodplain. During the study period, inputs of total phosphorus and total nitrogen loads from upstream either significantly increased or remained the same. In addition to external sources of nutrients, internal sources of nutrients from floodplain soils can also contribute to the total nutrient export from the system. These internal sources could be organic via the decomposition of organic matter or geologic from the original excavation of the canal and/or restoration backfilling. Soil nutrient concentrations vary between vegetative communities and landscape position and could be a significant source of phosphorus to the downstream system, which is plagued by eutrophic conditions. Therefore, as floodplain function in the Kissimmee River continues to be restored and managed, additional effort may be needed to address nutrient inputs and internal legacy nutrients. Full article