This study investigated the diversity and distribution of dwarf crocodiles in eight bushmeat markets in Benin City, Edo State, Nigeria. The markets surveyed were New Benin, Oliha, Uselu, Oba Market, Ekiuwa, Ugbighokogho, Evbotubu, and Third Market between October 2022 and May 2023. A multi-method approach was employed, combining observation and measurement techniques. The Shannon-Wiener Index (H'), Simpson's Index (D), and Species Evenness (E) were calculated to determine the diversity and distribution of dwarf crocodiles. The results showed that Ekiuwa and Ugbighokogho markets had the highest Shannon-Wiener Index (H') values of 0.84 and 0.86, respectively, indicating higher species diversity. These markets also had the lowest Simpson's Index (D) values of 0.41 and 0.39, respectively, indicating lower species dominance. Additionally, Ekiuwa and Ugbighokogho markets had the highest Species Evenness (E) values of 0.92 and 0.94, respectively, indicating a more even distribution of individuals among species. However, when considering the monthly variation, Oliha, Ugbighokogho, and 3rd Market had the highest Shannon-Wiener Index (H') values of 1.05, 1.06, and 1.05, respectively, indicating higher species diversity. The results suggest that some markets have higher species diversity and evenness, indicating a more sustainable trade. The study recommends that conservation efforts focus on regulating the trade in dwarf crocodiles and promoting sustainable harvesting practices.
Since 1998, phytoplankton communities have been systematically studied at five stations in the northern and central parts of the Venice Lagoon (VL). The long-term maintenance of this phytoplankton data series, alongside similar datasets for other communities (e.g., zooplankton, macrozoobenthos, and macrophytes), has contributed to the inclusion of the VL as a site in the Italian Long-Term Ecological Research (LTER) network. In this paper, we synthesize key insights into the phytoplankton ecology of the VL’s LTER stations, based exclusively on published studies. Specifically, we provide an overview of phytoplankton taxonomic composition, morphological traits, seasonal succession, long-term trends and interactions with the other components of the planktonic communities.
The aim of this review is to reconstruct the scientific research on cyanobacteria and cyanotoxins carried out in the artificial lakes of Sardinia (Italy), the second largest island in the Mediterranean Sea, over a period of about 50 years, from the 1970s to the present. The information contained in scientific articles in Web of Science and Scopus databases was analysed using specific keywords. In addition, scientific articles not included in the above-mentioned databases were considered if they were published after a peer review process or if they were available on the website of public institutions. The analysis resulted in the identification of 60 scientific papers containing information on cyanobacteria and/or cyanotoxins, leading to a list of 77 taxa signalled and four groups of cyanotoxins ascertained (microcystins, anatoxin, cylindrospermopsin; β-N-Methylamino-L-Alanine, BMAA). In addition to these results, we point out the research we are carrying out and would like to continue in the future, a future in which it will be extremely important to be able to juggle the expected progressive affirmation of cyanobacteria and related issues. We highlight the difficulty of finding scientific articles published before the 2000s in the most widely used databases (Web of Science and Scopus), despite the fact that the production is rich and cutting-edge compared to the period in which the research was carried out. Finally, we signal the importance of close collaboration between institutions to obtain the results reported, the overcoming of disciplinary boundaries and the development of a collaborative rather than competitive environment between different research groups in dealing with such complex topics.
The nearshore region of a coastal ecosystem is an everchanging, dynamic, transitional zone between land and open sea. It is a highly productive area because of sufficient sunlight and nutrients. The main aim of this research is to study the diversity and abundance of zooplankton especially holoplankton and meroplankton in relation with physicochemical factors for one year with their seasonality. Along with the diversity indices, multivariate ordination indices like Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA) were applied to study the diversity and their relationship with physicochemical factors. PERMANOVA was also used to test whether the abundance and physicochemical factors differed significantly across sampling sites and seasons. The study showed that holoplankton diversity in the Fishing Harbour (FH) was highest during the pre-monsoon season and lowest during the post-monsoon season. The meroplankton diversity was the highest during the pre-monsoon season and lowest during the monsoon season which was also recorded from the FH. Principal Component Analysis (PCA) showed that Salinity, pH, dissolved oxygen and primary productivity as the significant physicochemical parameters affecting the Holoplankton and Meroplankton diversity. Canonical Correspondence Analysis (CCA) for holoplankton showed that salinity, pH, dissolved oxygen and primary productivity were positively related with copepods. While non-copepod species were positively related with salinity, pH and dissolved oxygen except primary productivity. Similarly, meroplankton groups showed positive correlation with temperature only.
This paper introduces and summarises a selection of contributions that were presented during a workshop on cyanobacterial blooms held at S. Michele all’Adige (Trento) in December 2023. The meeting originated with an increasing interest in a reciprocal exchange of knowledge and experiences between government bodies and research institutions following the widespread cyanobacterial blooms detected in the southern Alpine area and other Italian regions. The papers have been collected in the special issue “Potentially toxic cyanobacteria blooms in the southern Alps and the Italian peninsula”.
In recent years, there has been a rise in cyanobacterial blooms, and climate warming is believed to be a key driver sustaining these changes. Climate change may affect the geographic distribution of potentially toxigenic species and cyanobacteria, leading to the appearance of new threats in previously unexposed areas. Recently, the potentially toxic cyanobacterium Raphidiopsis (Cylindrospermopsis) raciborskii, known for forming blooms, has increased its presence, particularly in temperate regions. In this work, we expanded the knowledge about the distribution of R. raciborskii in Northern Italy. Specifically, we reported new observations recorded during the last decade based on investigations carried out in the framework of scientific and government monitoring and large biogeographical surveys carried out on the whole Alpine Space area. The detection of R. raciborskii in Northern Italy highlights the importance of closely monitoring freshwater quality and implementing measures to prevent the spread of harmful organisms.
Water is essential for health, and climate change can compromise its quality. The Local Brianza Health Protection Agency (ATS) has initiated a biennial monitoring project of water supply sources to ensure safe and clean water access, in line with the United Nations (UN) Agenda 2030. The project has identified vulnerabilities in the water supply chain, finding the presence of cyanobacteria in 19.7% of samples. Risk assessment results show that climatic conditions could influence the vulnerability of sources.
In this paper, we briefly describe episodes of cyanobacterial blooms that have occurred in lakes of northern Italy since 2000. In addition to listing the species involved in these blooms, we provide information on the trophic and ecological status of the water bodies and the presence of algal toxins. Furthermore, we report an example of a risk assessment effort aimed at developing a quality control system for water intended for human consumption. The use of high-frequency monitoring techniques, integrated with predictive modelling, remote sensing, and molecular analysis for species identification, is becoming increasingly important in the context of the effects of ongoing climate change.
Cylindrospermopsis raciborskii is a toxic cyanobacterium that can form blooms potentially harmful to humans and animals. The proliferation of this species is difficult to predict, and its blooms are hard to detect as they cause just a moderate change in water colour. Global warming might increase the incidence of its proliferation worldwide. This trend was observed also by ARPAE that detected a growth in the presence of this alga in Emilia Romagna lakes and reservoirs in the last three years. This note describes the monitoring activities conducted by ARPAE during these algal blooms and the risk management actions implemented.
This short note illustrates some algal blooms caused by potentially toxic cyanobacteria in water bodies in the NE Alps, focusing in particular on the last ten years. The data illustrated come from monitoring activities, bathing health assessments, and analyses carried out on citizen reports. The most important blooms were caused by Planktothrix rubescens, Dolichospermum spp., and Microcystis aeruginosa, and affected Lakes Ledro, Caldonazzo, and Serraia. Experience in the Trentino region has highlighted the importance of effective and timely communication between the monitoring institutions and the users of the lake, to minimize any negative health effects and to increase the knowledge of the population.
Since the beginning of the 1990s, Lake Garda has been affected by the development of surface blooms caused by the cyanobacterium Dolichospermum lemmermannii. Moreover, several other potentially toxigenic cyanobacteria were identified in the water samples collected during the monitoring activities, including the microcystins producer Planktothrix rubescens and a new species able to synthesize anatoxins (Tychonema bourrellyi). A plan has been activated by ARPAV (Regional Agency for Environmental Prevention of Veneto) to monitor algal communities and assess any risk of cyanobacterial proliferation that could affect the lake ecosystem and the bathing areas. In this work, we will briefly describe and critically comment on the main results obtained from the monitoring activities.
In 2015, the World Health Organization (WHO) declared Antimicrobial Resistance (AMR) as one of the most critical health issues. It proposed, with the Food and Agriculture Organization (FAO) and OIE (World Organization for Animal Health), to address this by a One Health approach, recognizing the connection between humans, animals, and environmental health. Currently, a hypothesis is developing that cyanobacteria and cyanotoxins may contribute to AMR in water. Recent research appears to suggest: i) an impact of cyanotoxins on antibiotic-resistance gene transfer between bacteria; ii) a role of cyanobacteria as a reservoir of AMR. Finally, cyanotoxin production appears to be stimulated by cyanobacteria exposure to antibiotics. These findings strengthen the importance of considering the environment in its complexity.
Surface water can exhibit a range of colours beyond the expected blue or green. These anomalous colourations can be triggered by different factors, both natural and anthropogenic, and not always are signs of pollution. This note explores the phenomenon of water discolouration, focusing on natural causes and analysing how factors such as algal and bacterial blooms influence water colour. The study provides examples of specific events that occurred in the Emilia-Romagna region and documented by ARPAE and highlights the importance of monitoring these colouration events in order to provide valuable insights into the health of water bodies and the surrounding environment.
Cyanobacteria, often referred to as blue-green algae, are a diverse group of photosynthetic bacteria that play a crucial role in various ecosystems. However, their proliferation and toxin production pose significant challenges to environmental, animal, and human health. In recent years, the interplay between cyanobacteria, climate change, and the production of cyanotoxins has garnered increased attention. This short note aims to delve into the intricate relationship between cyanobacteria and the production of cyanotoxins, the toxicological risks associated with exposure, and strategies for risk assessment and management.
This study aims to describe the response of two persistent chlorophyll-a maxima to physical processes that affect the po- sition of the thermocline/nitracline in the Eastern Tropical North Pacific (ETNP). We focused on Long Rossby Waves (LRWs) due to their relevance to the ETNP circulation and their potential role in introducing nutrients into the euphotic zone. We found that the shallower chlorophyll-a maximum in oxygenated waters became more intense when denser waters (containing more nu- trients) moved toward the surface. This suggests that changes in isopycnals and nitracline displacements modify nutrient supply in the euphotic zone, leading to changes in phytoplankton growth. The suboxic and deeper chlorophyll-a maximum showed a strong association with the 26 kg m-3 isopycnal, which was only mechanically displaced, and its chlorophyll-a content did not seem to covary with irradiance or nutrients. The decor- related responses of the chlorophyll-a maxima could be ex- plained if different phytoplankton groups are associated with them. LRWs can affect the position of the thermocline/nitracline and isopycnals in an annual cycle, but it seems to be a “back- ground” signal modulated by higher frequency processes such as mesoscale eddies and other Rossby waves. The co-occurrence of processes can control the nitracline depth, and thus the input of nutrients into the euphotic zone, leading to sporadic enhance- ments in chlorophyll-a concentration in one maximum.
Lake Toba is one of the largest lakes in North Sumatra Province, Indonesia. Its waters are used for multiple purposes, constituting an important natural and economic resource. Most of the waters of Lake Toba come from the overflow of disposal of agriculture, livestock, fisheries, tourism, households, and other activities. The present study identified water quality based on total nitrogen, total phosphorus, chlorophyll-a and other water quality parameters carried out at 60 sampling sites grouped into 6 observation stations, i.e., control areas (located in the middle and far from direct activities), community floating net cages, company floating net cages, settlement, hospitality, and river mouths. The main water quality components were very dynamic at the monitoring stations in three seasons (rainy, transition, and dry). Total nitrogen concentration tended to be higher in the rainy season than in the transition and dry seasons. However, all stations tended to be classified as mesotrophic or higher in all seasons, with total nitrogen concentrations greater than 12.5 mg L–1. Total phosphorus at the six stations was highly dynamic in all seasons and tended to decrease in the dry season. The concentration of total phosphorus was higher at the settlement and hospitality stations than at the other stations. The total phosphorus of the settlement and hospitality stations reached 0.18 mg L–1 and 0.17 mg L–1, respectively, in the rainy season. In general, total phosphorus concentrations in the waters of Lake Toba were above 0.1 mg L–1, which allowed the lake to be classified as above mesotrophic status.
We report the measurement of the Fluxes of Dissolved Compounds at the Sediment-Water Interface (DFSWIs), obtained by analyzing data collected in the Italian Exclusive Economic Zone (EEZ) of the Northern and Central Adriatic Sea from 1982. We also describe the methods, honed by Italy’s Consiglio Nazionale delle Ricerche (CNR), employed to measure and calculate DFSWIs, including benthic chambers and landers, sediment-water interface micro-profiling, on-board incubation, and pore water modeling. Data analysis demonstrated that in situ measurements are the most reliable approaches, but that on-board collected data also supply interesting results. The DFSWI data allowed to divide the Adriatic seafloor into areas with similar DFSWI types and intensities and to define the role of sediments as sources or sinks of chemicals such as nutrients, Dissolved Inorganic Carbon (DIC), and metals. DFSWIs mainly depend on dissolved and solid river inputs, Marine Organic Matter (mOM) production, and sediment reworking. They show a seasonal temperature-related trend, which in summer induces increased chemical reaction kinetics and microbial activity. DFSWIs decline from the Po River mouths southward, along the Holocene mud wedge. North of the Po River Delta, the DFSWIs are weaker and confined to the areas in front of the major river mouths, due to poor Organic Matter (OM) inputs and strong reworking of bottom sediments. The area south of the Po Delta cusp is characterized by strong DFSWIs, due to the high deposition of solid inputs from the Po River, strong primary production, and protection from the Western Adriatic Current and Bora storms; in summer, higher temperatures, and calm hydrodynamic conditions generate near-bottom hypoxic to anoxic environments in this area. In Northern and Central Adriatic offshore areas, negative DIC and phosphate fluxes are due to poorly reactive OM reaching this area and to the mainly carbonate composition and oxic environment of local bottom sediments. DFSWI data analysis highlighted the important contribution of sediments to marine carbon and nutrient cycles. This is particularly important for carbon, which plays a major role in seawater acidification and global climate change. The study also provides average DFSWI data for each diagenetic area, which allow calculating the carbon and nutrient budgets in the Adriatic Sea.
Mediterranean coastal systems, particularly those characterized by river mouths, have played an important role in the history of human civilization, thanks to unique species assemblages, a high biodiversity, and complex ecological interactions. The overlapping of multiple cross-scale effects, triggered by the ongoing climate change, makes these systems particularly important sites for ecological studies. Here, we have investigated the phytoplankton community structure in the terminal stretch of the Sele River (Tyrrhenian Sea) under two different hydrological regimes: i) with river mouth occluded by sediments preventing water exchange with the sea; ii) with river mouth completely opened, which allowed the maximum water mass exchanges between the river and the sea. The strong variations in physical-chemical properties of the water column, the point-distribution of total phytoplankton biomass, and the dominance of cryptophytes and cyanophytes under occluded and opened river mouth, respectively, indicate the presence of strong allogenic pressures acting on the system. Our data suggest that the monitoring of phytoplankton communities in the terminal stretch of micro-tidal estuaries, could be a useful tool for studying the extent of climate change underway in Mediterranean coastal marine areas.
Species distribution is a combination of ecological, historical, stochastic, and evolutionary mechanisms, and is a process that has been severely impacted by anthropogenic activities. Freshwater zooplankton is adequate to assess that combination because it groups cosmopolitan and endemic species. We hypothesized that the spatial distribution of Diaphanosoma species is defined by a complex interaction between factors such as spatial limitation, limitation of environmental conditions, and ecological conditions. We georeferenced the occurrence of Diaphanosoma in Brazil to study the potential distribution of the species, preference of ecoregions, environmental features associated with Diaphanosoma, and their co-occurring patterns. Five species of Diaphanosoma are widely distributed in Brazil. D. spinulosum and D. birgei were widely distributed while D. fluviatile and D. polyspina had a more restricted distribution. The occurrences of Diaphanosoma species were shown to have an association with factors such as the total concentrations of nitrogen and phosphorus, pH and, temperature, except in the case of the D. brevireme. Our results show that geographic, environmental, and biotic filters can drive the spatial distribution of species of the genus Diaphanosoma. Therefore, the distribution and spatial occurrence of these species depend on dispersal capacity and spatial restrictions, suitability of the abiotic environment, and ecological interactions.
The classic paradigm, not always unequivocal though, that seagrass macrobenthic abundance and diversity are greater than those in adjacent unvegetated areas, was tested in a Mediterranean lagoon for which evidence is lacking. We compared the community structure and species composition of macrobenthic assemblages in three distinct areas of the Mistras Lagoon (Sardinia, Italy) dominated by i) the seagrass Cymodocea nodosa (Cym), ii) mixed-macrophyte/detritus (Mix), and iii) unvegetated sediments (Unv). Samplings were conducted in each area twice in spring (April and May) and twice in autumn (October and November) 2010. Multivariate analyses showed significant differences among the three areas and a marked separation between the two vegetated (Cym and Mix) and the unvegetated (Unv) areas. The top discriminating species, indicated by SIMPER analysis, were characterized by direct development lacking free living larvae. They included marine species, e.g. Cerithium lividulum, Microdeutopus gryllotalpa, Loripes orbiculatus and Gammarus aequicauda, at Cym vs Mix, whereas the pair discrimination of the areas Cym vs Unv and Mix vs Unv mostly depended on the marine Abra tenuis, the opportunistic Chironomidae and Capitella capitata, and the brackish Hydrobia acuta. Both vegetated areas showed a higher species number than the unvegetated area. Differently, abundance was higher in Unv than in Cym and Mix in all sampling dates, most notably in spring likely because of reproductive events, due to both opportunistic (C. capitata, chironomids) and halolimnobic (H. acuta, Cerastoderma glaucum) species. Overall, the present study demonstrated the importance of biological factors in structuring the macrobenthic assemblages of the Mistras Lagoon. Habitatforming phanerogams hosted species-rich assemblages, species-specific reproductive cycles and adaptive strategies contributed to drive species colonization and abundance distribution. Both vegetated and unvegetated patches were found to contribute greatly to the local-scale heterogeneity of the habitat, highlighting the importance of coastal lagoons as hotspots for benthic biodiversity. For these reasons, lagoons must be considered major targets for conservation measures.
